WO2016027146A1 - Chain belt - Google Patents

Chain belt Download PDF

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Publication number
WO2016027146A1
WO2016027146A1 PCT/IB2015/001378 IB2015001378W WO2016027146A1 WO 2016027146 A1 WO2016027146 A1 WO 2016027146A1 IB 2015001378 W IB2015001378 W IB 2015001378W WO 2016027146 A1 WO2016027146 A1 WO 2016027146A1
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WO
WIPO (PCT)
Prior art keywords
pin
section
chain belt
cross
hollow section
Prior art date
Application number
PCT/IB2015/001378
Other languages
French (fr)
Inventor
Naoyuki SHIBATA
Motoki Tabuchi
Original Assignee
Toyota Jidosha Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Jidosha Kabushiki Kaisha filed Critical Toyota Jidosha Kabushiki Kaisha
Publication of WO2016027146A1 publication Critical patent/WO2016027146A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
    • F16G5/00—V-belts, i.e. belts of tapered cross-section
    • F16G5/16—V-belts, i.e. belts of tapered cross-section consisting of several parts
    • F16G5/18—V-belts, i.e. belts of tapered cross-section consisting of several parts in the form of links

Definitions

  • the invention relates to a chain belt used in a belt transmission apparatus.
  • JP 2013-117306 A An invention related to a continuously variable transmission that uses a chain belt is described in Japanese Patent Application Publication No. 2013-117306 (JP 2013-117306 A).
  • the chain belt described in this JP 2013-117306 A is formed by coupling a chain element, which is constructed of links and pins, in an annular shape.
  • the pins of the chain belt are held between two opposing conical surfaces of a pulley.
  • the chain belt described in this JP 2013-117306 A is configured that a deformation rate of the pin in a length direction becomes a specified value or higher in the case where the pin is held and supported by the pulley.
  • the pin of the chain belt described in this JP 2013-117306 A is configured to be easily deformed by a bending load that acts on the pin.
  • JP 2008-215496 A describes an invention related to a continuously variable transmission of a chain belt type that has a purpose of preventing wear or damage of the pulley and the pin and reducing noise or vibration by preventing abutment of an edge of the pin.
  • JP 2012-247022 JP 2012-247022 A describes an invention related to a continuously variable transmission of a chain belt type that is configured to suppress the noise or the vibration by reducing a cross section of a link plate and reducing rigidity of the chain belt.
  • the pin of the chain belt described in JP 2013-117306 A is likely to be deformed by the bending load that acts on the pin. In other words, bending rigidity of the pin is lowered.
  • a force to deform the pin in a radial direction of the pulley acts on the pin. Since the pin is likely to be deformed by such a force, an impact experienced when the pin comes in contact with the pulley can be alleviated. Thus, the vibration or the noise caused by the impact can be reduced.
  • a tensile force that attempts to stretch the chain belt in a circumferential length direction acts on the chain belt during the power transmission. Accordingly, in addition to the force to deform the pin in the radial direction of the pulley as described above, a force to deform the pin in a tangential direction of the pulley, which is generated by the tensile force acting on the chain belt, acts on the pin of the chain belt.
  • a force to deform the pin in a tangential direction of the pulley which is generated by the tensile force acting on the chain belt, acts on the pin of the chain belt.
  • the pin is likely to be deformed by reducing the bending rigidity as described above, the noise or the vibration can be reduced.
  • a degree of the deformation by the tensile force is also increased. As a result, durability of the pin, and eventually, durability of the chain belt are possibly degraded.
  • the invention has been made in view of the above technical problems and provides a chain belt that can reduce noise or vibration and has favorable durability.
  • a chain belt that is wound around two pulleys to transmit power between the two pulleys.
  • the chain belt includes a link and a pin.
  • the link is a plate-shaped member provided with a coupling hole.
  • the pin is fitted to the coupling hole so as to couple the links in an annular shape, the pin having both end surfaces in an axial direction such that the both end surfaces respectively contact the pulleys and serve as power transmission surfaces.
  • the pin has a hollow section extending in the axial direction, and the hollow section is configured to lower bending rigidity of the pin.
  • the hollow section has a shape that, in a cross section that is perpendicular to the axial direction of the pin, a net length of the hollow section in a radial direction of the pulleys is longer than a net length of the hollow section in a tangential direction of the pulleys.
  • the hollow section may have a shape that a lowered amount in the radial direction is larger than a lowered amount in the tangential direction.
  • the lowered amount in the radial direction is a lowered amount with respect to average bending rigidity of the pin in a state that the link is wound around the pulleys in a case where the hollow section of the pin with the average bending rigidity in the radial direction of the pulleys is not provided.
  • the lowered amount in the tangential direction is a lowered amount with respect to the average bending rigidity of the pin in the case where the hollow section of the pin with the average bending rigidity in the tangential direction of the pulleys is not provided.
  • an area of a cross section of a center section of the pin may be larger than an area of a cross section of each end of the pin.
  • the cross section of the center section is perpendicular to the axial direction.
  • the cross section of the each end is perpendicular to the axial direction.
  • the pin may have a shape that an area of the cross section of the pin is increased toward the center section from the each end, and the cross section of the pin is perpendicular to the axial direction.
  • a shape of a cross section of the hollow section of the pin may be uniform in the axial direction and the cross section of the hollow section is perpendicular to the axial direction.
  • an area of a cross section of the center section of the pin may be smaller than an area of a cross section of each end of the pin.
  • the cross section of the center section is perpendicular to the axial direction.
  • the cross section of the each end is perpendicular to the axial direction.
  • the hollow section of the pin does not penetrate in the axial direction, and an area of a cross section of a center section of the pin is the maximum in the axial direction.
  • a cross section in the axial direction of the hollow section of the pin may have an oval shape and the cross section of the hollow section is perpendicular to the axial direction.
  • the hollow section of the pin may have a rectangular cross section with a long side in the radial direction of the pin and a short side in the tangential direction of the pin.
  • the hollow section of the pin may have a rhombic cross section in which a length of a diagonal line in the radial direction of the pin is longer than a length of a diagonal line in the tangential direction of the pin.
  • the hollow section of the pin may have plural hollow sections, and the plural hollow sections may be longitudinally aligned in the radial direction of the pin.
  • the pin in the chain belt, may have two of a first pin and a second pin as one pair and may be fitted to the coupling hole.
  • the first pin may be arranged on a forward traveling side in an advancing direction in the case where the pulleys rotate in a specified rotational direction
  • the second pin may be arranged on a rearward traveling side of the first pin in the advancing direction.
  • both of the first pin and the second pin may have the hollow section.
  • the pin in the chain belt, may have two of the first pin and the second pin as the one pair and may be fitted to the coupling hole.
  • the first pin may be arranged on the forward traveling side in the advancing direction in a case where the pulleys rotate in the specified rotational direction, and may have the hollow section.
  • the second pin may be arranged on the rearward traveling side of the first pin in the advancing direction and may not have the hollow section.
  • the pin may have two of the first pin and the second pin as the one pair and may be fitted to the coupling hole.
  • the first pin may be arranged on the forward traveling side in the advancing direction in the case where the pulleys rotate in the specified rotational direction, and may not have the hollow section.
  • the second pin may be arranged on the rearward traveling side of the first pin in the advancing direction and may have the hollow section.
  • the hollow section is provided in the pin of the chain belt. Since the hollow section is provided in the pin, the bending rigidity of the pin is lowered, and the pin is likely to be warped with respect to a bending load that acts on the pin. When the bending rigidity of the pin is lowered to facilitate warping of the pin, an impact force that is generated when the pin comes in contact with the pulleys during the power transmission can be alleviated. Accordingly, vibration or noise caused by the impact force can be reduced. In addition, since the hollow section is provided in the pin, it is possible to reduce a weight of the pin.
  • the impact force that is generated when the pin comes in contact with the pulleys during the power transmission can be reduced.
  • the vibration or the noise caused by the impact force can be reduced.
  • the hollow section is provided in the pin, a surface area of the pin is increased, and thus a heat radiation property of the pin can be improved. As a result, a heat load on the pin and the pulleys that contact the pin can be reduced.
  • the hollow section is provided in the pin, lubricating oil is caused to enter the hollow section, and thus a lubricating oil retaining property of the chain belt can be improved. As a result, it is possible to reduce friction between the pin or a movable portion of the chain belt and the pulleys.
  • the length in the each direction is set such that the net length in the radial direction of the pulleys is longer than the net length in the tangential direction of the pulleys.
  • the net length in the tangential direction of the pulleys is an integrated value of the length, to which lengths of overlapping portions in the tangential direction of the pulleys are not added.
  • the net length in the radial direction of the pulleys is an integrated value of the length, to which overlapping portions in the radial direction of the pulleys are not added.
  • the pin is configured as described above. Accordingly, while degradation of strength of the pin with respect to the bending load that acts in the tangential direction of the pulleys is suppressed, the pin can be provided to be easily warped with respect to the bending load that acts on the radial direction of the pulleys. Therefore, it is possible to provide the chain belt that can improve a silence property with respect to the vibration or the noise and has favorable durability.
  • the shape of the hollow section is determined such that the lowered amount of the bending rigidity of the pin due to the formation of the hollow section is larger in the radial direction of the pulleys than the tangential direction of the pulleys.
  • the lowering of the bending rigidity of the pin in the tangential direction of the pulleys is suppressed as much as possible.
  • the pin can be provided to be warped as easily as possible with respect to the bending load that acts in the radial direction of the pulleys. Therefore, it is possible to provide the chain belt that can improve the silence property with respect to the vibration or the noise and has the favorable durability.
  • the pin is provided such that the area of the cross section of the center section in the axial direction of the pin that is perpendicular to the axial direction of the pin is larger than the area of the cross section of the each end in the axial direction of the pin that is perpendicular to the axial direction.
  • the areas of the cross section are uniform, bending moment of the pin becomes the maximum in the center section in the axial direction.
  • the pin is provided to increase the area of the cross section of the center section as described above, difference between the bending moment that is generated in the center section in the axial direction of the pin and the bending moment that is generated at the each end in the axial direction of the pin can be reduced. Therefore, while degraded durability caused by the formation of the hollow section in the pin is suppressed, the bending rigidity can effectively be lowered.
  • the pin is provided such that the area of the cross section of the cross section thereof that is perpendicular to the axial direction of the pin is increased toward the center section from the each end in the axial direction of the pin.
  • the bending moment becomes the maximum in the center section in the axial direction of the pin.
  • the pin is provided such that the area of the cross section of the center section is gradually increased as described above, the bending moment that is generated in the pin can be equalized in the axial direction of the pin. Therefore, while the degraded durability caused by the formation of the hollow section in the pin is suppressed, the bending rigidity can effectively be lowered.
  • the hollow section is provided in both of the first pin and the second pin or only in the first pin.
  • the first pin is the pin that is arranged on a front side in the advancing direction of the chain belt when the pulleys rotate in the specified rotational direction (for example, a forward traveling direction).
  • the second pin is the pin that is arranged on a rear side in the advancing direction of the chain belt.
  • the larger bending load acts on the pin on the rear side in the advancing direction of the chain belt, that is, on the second pin than on the first pin.
  • the hollow section is at least provided in the first pin.
  • FIG. 1 is a view for illustrating one example of a belt transmission apparatus, to which a chain belt of an embodiment of the invention is applied;
  • FIG. 2 is a view for illustrating one example of a configuration of the chain belt of the embodiment and a configuration of a pin in the chain belt;
  • FIG. 3 is a view for illustrating one example of a configuration of a pin of a first example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through an axis of the pin and is perpendicular to a tangential direction of a pulley;
  • FIG. 4 is a view for illustrating deforming directions of the pin (a radial direction of the pulley and the tangential direction of the pulley) in the chain belt of the embodiment;
  • FIG. 5 is a view for illustrating a configuration example of a pin of a second example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through the axis of the pin and is perpendicular to the tangential direction of the pulley;
  • FIG. 6 is a view for illustrating a configuration example of a pin of a third example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through the axis of the pin and is perpendicular to the tangential direction of the pulley;
  • FIG. 7 is a view for illustrating a configuration example of a pin of a fourth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through the axis of the pin and is perpendicular to the tangential direction of the pulley;
  • FIG. 8 is a view for illustrating a configuration example of a pin of a fifth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to an axial direction of the pin
  • FIG. 9 is a view for illustrating a configuration example of a pin of a sixth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to the axial direction of the pin;
  • FIG. 10 is a view for illustrating a configuration example of a pin of a seventh example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to the axial direction of the pin;
  • FIG. 11 is a view for illustrating a configuration example of a pin of an eighth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to the axial direction of the pin;
  • FIG. 12 is a side view of the chain belt of the embodiment that is seen from the axial direction of the pin.
  • FIG. 13 is a view for illustrating a different configuration example of the chain belt of the invention from a configuration thereof shown in FIG. 12, and is a side view of the chain belt that is seen from the axial direction of the pin.
  • FIG. 1 shows a schematic configuration of a belt-type continuously variable transmission (CVT) 1 as one example of a belt transmission apparatus, to which a chain belt of the invention can be applied.
  • the CVT 1 shown in this FIG. 1 has a similar configuration to that of an existing general CVT. The configuration thereof is briefly described.
  • the CVT 1 includes a primary pulley 2, to which torque is transmitted from a power source (not shown), and a secondary pulley 3 for transmitting the torque to an output member (not shown).
  • the primary pulley 2 is configured by arranging a fixed sheave 2a and a movable sheave 2b, each of which has a tapered surface, to face each other. Since the fixed sheave 2a and the movable sheave 2b face each other, a belt winding groove 2c is formed therebetween. Then, it is configured to change a width of the belt winding groove 2c by moving the movable sheave 2b to approach or separate from the fixed sheave 2a by using an actuator (not shown).
  • the secondary pulley 3 is configured by arranging a fixed sheave 3 a and a movable sheave 3b, each of which has the tapered surface, to face each other. Since the fixed sheave 3 a and the movable sheave 3b face each other, a belt winding groove 3 c is formed therebetween. Then, it is configured to change a width of the belt winding groove 3 c by moving the movable sheave 3b to approach or separate from the fixed sheave 3a by using the actuator (not shown).
  • a chain belt 4 is wound around the belt winding groove 2c in the primary pulley 2 and the belt winding groove 3 c in the secondary pulley 3 described above.
  • the chain belt 4 is a transmission belt for transmitting the torque between the primary pulley 2 and the secondary pulley 3.
  • the chain belt 4 is configured by coupling plural links 5, each of which is referred to as a link, a plate, and the like, in an annular shape by pins 6.
  • the link 5 is, for example, formed of a metallic plate member.
  • the link 5 is formed with a coupling hole 5a, in which the pin 6 is inserted.
  • the coupling hole 5a is formed at two positions on both end sides in an axial direction of the link 5.
  • All of the links 5 can be configured to have the same shape. Alternatively, for example, as described in above-described JP 2013-117306 A and Japanese Patent No. 4372551, plural types of links with different shapes and dimensions can be combined to be used.
  • the pin 6 is, for example, formed of a metallic rod member. As described above, the pin 6 is fitted to the coupling hole 5a of the link 5 so as to couple the two links 5 and supports the link 5 in a manner to allow relative rotation of the specified two links 5 to each other.
  • the pin 6 is configured by including a first pin 6a and a second pin 6b that are arranged in parallel. These two of the first pin 6a and the second pin 6b are paired and fitted to the coupling hole 5a. Then, as shown in FIG. 3, the pin 6 is configured that both end surfaces 6c in an axial direction A of the pin 6 (a right and left direction in FIG. 3) respectively contact the tapered surfaces of each of the belt winding grooves 2c, 3c to serve as power transmission surfaces in a state that the chain belt 4 is wound around the pulleys 2, 3.
  • pins in the same shape are used as the first pin 6a and the second pin 6b in the example shown in FIG. 2. Then, these first pin 6a and second pin 6b are arranged to be symmetrical when seen in the axial direction A. Meanwhile, like a "first pin 3" and a "second pin 4" that are described in Japanese Patent Application Publication No. 2006-77890 (JP 2006-77890 A), for example, two pins with different shapes from each other can also be paired to be used as the pin 6 in the invention.
  • the pin 6 When the chain belt 4, which is used as the transmission belt of the belt-type continuously variable transmission 1 as described above, runs between the pulleys 2, 3 to transmit the power, the pin 6 is deformed by a bending load acting on the pin 6.
  • Directions in which the pin 6 is deformed in this case can mainly divided into two directions that are orthogonal to each other. More specifically, as shown in FIG. 4, the two directions are a radial direction R of the pulleys 2, 3 and a tangential direction T of the pulleys 2, 3 in a state that the chain belt 4 is wound around the pulleys 2, 3.
  • both of the end surfaces 6c of the pin 6 respectively contact the tapered surfaces of each of the belt winding grooves 2c, 3 c.
  • an impact force and a clamping force from each of the pulleys 2, 3 act on both of the end surfaces 6c of the pin 6.
  • the pin 6 is deformed such that a center section 6d is displaced in the radial direction R with both of the end surfaces 6c being fulcrums.
  • a tensile force that attempts to stretch the chain belt 4 in a circumferential length direction acts on the chain belt 4.
  • the circumferential length direction in this case corresponds to the tangential direction T when the chain belt 4 is in a state of being wound around the pulleys 2, 3.
  • the pin 6 is deformed by such a tensile force such that the center section 6d is displaced in the tangential direction T with contact portions thereof with the link 5 in the vicinity of both of the end surfaces 6c being the fulcrums.
  • bending rigidity of the pin 6 is lowered to facilitate warping of the pin 6 in the radial direction R. In this way, it is possible to reduce the impact force, which is generated when both of the end surfaces 6c of the pin 6 respectively contact the tapered surfaces of each of the pulleys 2, 3. As a result, vibration or noise caused by the impact force can be reduced.
  • the bending rigidity of the pin 6 is lowered, the pin 6 is also likely to be warped in the tangential direction T.
  • the pin 6 is required to have the specified bending rigidity for facilitating the deformation thereof in the radial direction R and securing the durability in the tangential direction T.
  • the pin 6 in the invention is formed with a hollow section 7 that is formed in the axial direction A. Compared to a case where the hollow section 7 is not formed, the bending rigidity of the pin 6 is lowered by forming the hollow section 7 in the pin 6.
  • a shape, dimensions, and a formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity as described above is larger than the lowered amount ⁇ of the bending rigidity, and the hollow section 7 is thereby formed in the pin 6.
  • the hollow section 7 is formed in the pin 6 such that the lowered amount (AEIR) of the bending rigidity (EI RI) of the pin 6 in the radial direction R with respect to the bending rigidity (EI R 0 ) of the pin 6 in the case where the hollow section 7 is not formed is larger than the lowered amount ( ⁇ ) of the bending rigidity (EI ⁇ ) of the pin 6 in the tangential direction T with respect to the bending rigidity (EI TO) of the pin 6 in the case where the hollow section 7 is not formed.
  • the pin 6 is formed with the hollow section 7 with an oval cross section that is perpendicular to the axial direction A.
  • the hollow section 7 in this example shown in FIG. 2 is formed in a center portion of the cross section that is perpendicular to the axial direction A such that a long axis of the oval shape in the cross section is set in the radial direction R and a short axis of the oval shape in the cross section is set in the tangential direction T.
  • the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ⁇ of the bending rigidity of the pin 6 in the tangential direction T by forming the hollow section 7 as described above.
  • the pin 6 in this chain belt 4 is formed to be easily warped with respect to a load acting in the radial direction R and to have the specified the bending rigidity with respect to a load acting in the tangential direction T.
  • the bending rigidity of the pin 6 in the radial direction R is lowered while the durability of the chain belt is secured. Therefore, it is possible to alleviate impact experienced when the pin 6 comes in contact with the pulleys 2, 3. As a result, the noise or the vibration caused by the impact can be reduced, and a silence property of the chain belt 4 with respect to the noise or the vibration can be improved.
  • the hollow section 7 of the pin 6 can be formed such that the shape of the cross section thereof that is perpendicular to the axial direction A is uniform in the axial direction.
  • the pin 6 can be formed such that areas of the cross section of cross sections thereof that are perpendicular to the axial direction A are the same in the axial direction A.
  • the hollow section 7 can easily be formed in the pin 6.
  • the pin 6 can be formed such that the areas of the cross section of the cross section of the center section 6d in the axial direction A that is perpendicular to the axial direction A is larger than an area of a cross section of each end 6e in the axial direction A that is perpendicular to the axial direction A.
  • the area of the cross section of the pin 6 is uniform in the axial direction A as in the example shown in FIG. 3, bending moment of the pin 6 becomes the maximum in the center section 6d in the axial direction A.
  • the pin 6 can be formed such that the cross sectional area of the cross section of the center section 6d in the axial direction A that is perpendicular to the axial direction A is smaller than the area of the cross section of each of the ends 6e in the axial direction A that is perpendicular to the axial direction.
  • the desired durability of the pin 6 is secured, and then the area of the center section 6d in the axial direction A is reduced, so as to lower the bending rigidity as in this example shown in FIG. 6. Accordingly, a further enhanced improvement effect of the silence property can be obtained.
  • the pin 6 can be formed such that the hollow section 7 does not penetrate in the axial direction A and the area of the center section 6d in the axial direction A that is perpendicular to the axial direction A is thereby maintained in a maximum state.
  • the bending rigidity thereof can effectively be lowered, so as to improve the silence property of the chain belt 4.
  • the cross section of the hollow section 7 formed in the pin 6 that is perpendicular to the axial direction A is formed in the oval shape.
  • the hollow section 7 can be formed to have an elliptical cross sectional shape in which a central portion in the radial direction R is flattened or dented.
  • the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy c > d when the length dimension in the radial direction R is set as c and the length dimension in the tangential direction T is set as d.
  • the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ⁇ of the bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7.
  • the hollow section 7 can be formed to have a rectangular cross sectional shape with a long side in the radial direction R and a short side in the tangential direction T.
  • the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy e > f when a length dimension of the side in the radial direction R is set as e and a length dimension of the side in the tangential direction T is set as f.
  • the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ⁇ of the bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7.
  • the hollow section 7 can be formed to have a rhombic cross sectional shape in which a diagonal line in the radial direction R is longer than a diagonal line in the tangential direction T.
  • the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy g > h when a length dimension of the diagonal line in the radial direction R is set as g and a length dimension of the diagonal line in the tangential direction T is set as h.
  • the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ⁇ of the bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7.
  • the hollow section 7 can be formed to be divided into plural hollow sections.
  • hollow sections 7a, 7b, 7c are formed to be vertically aligned in the radial direction R, and each of the hollow sections 7a, 7b, 7c has a circular cross section that is perpendicular to the axial direction A.
  • shapes, dimensions, and the number of the plural hollow sections are set such that a net length dimension i in the radial direction R is longer than a length dimension j in the tangential direction T.
  • the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy I > j.
  • the shape, the dimensions, the number, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the average bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ⁇ of the average bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7.
  • the average bending rigidity of the pin 6 in the tangential direction T or the radial direction R refers to the bending rigidity that is computed by integrating the plural hollow sections into a whole in such a case that the hollow section 7 is divided into the plural sections, for example, like this example shown in FIG. 11.
  • a surface area of the pin 6 can be increased, and a heat radiation property of the pin 6 is improved by the increase of the surface area of the pin 6.
  • a heat load on the pin 6 and the pulleys 2, 3, which contact the pin 6, can be reduced.
  • the pin 6 of this chain belt 4 can be configured by including two of the first pin 6a and the second pin 6b as the pair. More specifically, as shown in FIG. 12, in the case where the pulleys 2, 3 rotate in a specified rotational direction (a forward traveling direction here), the first pin 6a is arranged on a front side in the advancing direction of the chain belt 4 and the second pin 6b is arranged on a rear side in the advancing direction of the chain belt 4. In this example shown in FIG. 12, the hollow section 7 is formed in both of the first pin 6a and the second pin 6b.
  • the pin 6 is configured by including two of the first pin 6a and the second pin 6b as the pair, just as described, the hollow section 7 is formed in both of the first pin 6a and the second pin 6b.
  • the hollow section 7 is formed in both of the first pin 6a and the second pin 6b.
  • the hollow section 7 can only be formed in the first pin 6a.
  • the larger bending load acts on the second pin 6b, which is arranged on the rear side in the advancing direction of the chain belt 4, than on the first pin 6a.
  • the hollow section 7 is only formed in the first pin 6a, on which the larger bending load acts.
  • the hollow section 7 is not formed in the first pin 6a, on which the larger bending load acts, but can only be formed in the second pin 6b, on which the relatively small bending load acts. In this case, since the hollow section 7 is only formed in the second pin 6b, on which the small bending load acts, the degraded durability, which is caused by the formation of the hollow section 7 in the pin 6, can effectively be suppressed.

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Abstract

In a chain belt (4) that is wound around two pulleys (2, 3) to transmit power and includes: plural plate-shaped links (5); and a pin (6) fitted to a coupling hole (5a) provided in the link (5) so as to couple the links (5) in an annular shape and having both end surfaces (6c) in an axial direction (A) that respectively contact the pulleys (2, 3) and serve as power transmission surfaces, the pin (6) is formed with a hollow section (7) that is formed in the axial direction (A) and lowers bending rigidity of the pin (6), and the hollow section (7) is formed such that a net length (a) thereof in a radial direction R of the pulleys (2, 3) is longer than a net length (b) thereof in a tangential direction (T) of the pulleys (2, 3) in a cross section that is perpendicular to the axial direction (A) of the pin (6).

Description

CHAIN BELT
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates to a chain belt used in a belt transmission apparatus.
2. Description of Related Art
[0002] An invention related to a continuously variable transmission that uses a chain belt is described in Japanese Patent Application Publication No. 2013-117306 (JP 2013-117306 A). The chain belt described in this JP 2013-117306 A is formed by coupling a chain element, which is constructed of links and pins, in an annular shape. The pins of the chain belt are held between two opposing conical surfaces of a pulley. Then, in order to reduce high-frequency noise that is generated when the chain belt is wound around the pulley, the chain belt described in this JP 2013-117306 A is configured that a deformation rate of the pin in a length direction becomes a specified value or higher in the case where the pin is held and supported by the pulley. In other words, the pin of the chain belt described in this JP 2013-117306 A is configured to be easily deformed by a bending load that acts on the pin.
[0003] It should be noted that Japanese Patent Application Publication No. 2008-215496 (JP 2008-215496 A) describes an invention related to a continuously variable transmission of a chain belt type that has a purpose of preventing wear or damage of the pulley and the pin and reducing noise or vibration by preventing abutment of an edge of the pin. In consideration of a fact that a center portion of the pin is deformed in an arch shape in a manner to be pulled back to the rear with respect to an advancing direction of the chain belt during power transmission and the abutment of the edge thereby becomes significant on a rear side of both of end surfaces of the pin, the chain belt described in this JP 2008-215496 A is formed in such a shape that both of the end surfaces of the pin can suppress the abutment of the edge as described above. [0004] In addition, Japanese Patent Application Publication No. 2012-247022 (JP 2012-247022 A) describes an invention related to a continuously variable transmission of a chain belt type that is configured to suppress the noise or the vibration by reducing a cross section of a link plate and reducing rigidity of the chain belt.
[0005] As described above, the pin of the chain belt described in JP 2013-117306 A is likely to be deformed by the bending load that acts on the pin. In other words, bending rigidity of the pin is lowered. When the chain belt is wound around the pulley and the pin of the chain belt comes in contact with the pulley, a force to deform the pin in a radial direction of the pulley acts on the pin. Since the pin is likely to be deformed by such a force, an impact experienced when the pin comes in contact with the pulley can be alleviated. Thus, the vibration or the noise caused by the impact can be reduced.
[0006] Meanwhile, a tensile force that attempts to stretch the chain belt in a circumferential length direction acts on the chain belt during the power transmission. Accordingly, in addition to the force to deform the pin in the radial direction of the pulley as described above, a force to deform the pin in a tangential direction of the pulley, which is generated by the tensile force acting on the chain belt, acts on the pin of the chain belt. Thus, if the pin is likely to be deformed by reducing the bending rigidity as described above, the noise or the vibration can be reduced. However, a degree of the deformation by the tensile force is also increased. As a result, durability of the pin, and eventually, durability of the chain belt are possibly degraded.
SUMMARY OF THE INVENTION
[0007] The invention has been made in view of the above technical problems and provides a chain belt that can reduce noise or vibration and has favorable durability.
[0008] According to one aspect of the invention, a chain belt that is wound around two pulleys to transmit power between the two pulleys is provided. The chain belt includes a link and a pin. The link is a plate-shaped member provided with a coupling hole. The pin is fitted to the coupling hole so as to couple the links in an annular shape, the pin having both end surfaces in an axial direction such that the both end surfaces respectively contact the pulleys and serve as power transmission surfaces. Then, the pin has a hollow section extending in the axial direction, and the hollow section is configured to lower bending rigidity of the pin. Here, the hollow section has a shape that, in a cross section that is perpendicular to the axial direction of the pin, a net length of the hollow section in a radial direction of the pulleys is longer than a net length of the hollow section in a tangential direction of the pulleys.
[0009] In addition, in the chain belt, the hollow section may have a shape that a lowered amount in the radial direction is larger than a lowered amount in the tangential direction. Here, the lowered amount in the radial direction is a lowered amount with respect to average bending rigidity of the pin in a state that the link is wound around the pulleys in a case where the hollow section of the pin with the average bending rigidity in the radial direction of the pulleys is not provided. The lowered amount in the tangential direction is a lowered amount with respect to the average bending rigidity of the pin in the case where the hollow section of the pin with the average bending rigidity in the tangential direction of the pulleys is not provided.
[0010] In addition, in the chain belt, an area of a cross section of a center section of the pin may be larger than an area of a cross section of each end of the pin. Here, the cross section of the center section is perpendicular to the axial direction. The cross section of the each end is perpendicular to the axial direction.
[0011] In addition, in the chain belt, the pin may have a shape that an area of the cross section of the pin is increased toward the center section from the each end, and the cross section of the pin is perpendicular to the axial direction.
[0012] In addition, in the chain belt, a shape of a cross section of the hollow section of the pin may be uniform in the axial direction and the cross section of the hollow section is perpendicular to the axial direction.
[0013] In addition, in the chain belt, an area of a cross section of the center section of the pin may be smaller than an area of a cross section of each end of the pin. Here, the cross section of the center section is perpendicular to the axial direction. The cross section of the each end is perpendicular to the axial direction.
[0014] In addition, in the chain belt, the hollow section of the pin does not penetrate in the axial direction, and an area of a cross section of a center section of the pin is the maximum in the axial direction.
[0015] In addition, in the chain belt, a cross section in the axial direction of the hollow section of the pin may have an oval shape and the cross section of the hollow section is perpendicular to the axial direction.
[0016] In addition, in the chain belt, the hollow section of the pin may have a rectangular cross section with a long side in the radial direction of the pin and a short side in the tangential direction of the pin.
[0017] In addition, in the chain belt, the hollow section of the pin may have a rhombic cross section in which a length of a diagonal line in the radial direction of the pin is longer than a length of a diagonal line in the tangential direction of the pin.
[0018] In addition, in the chain belt, the hollow section of the pin may have plural hollow sections, and the plural hollow sections may be longitudinally aligned in the radial direction of the pin.
[0019] Then, in the chain belt, the pin may have two of a first pin and a second pin as one pair and may be fitted to the coupling hole. The first pin may be arranged on a forward traveling side in an advancing direction in the case where the pulleys rotate in a specified rotational direction, and the second pin may be arranged on a rearward traveling side of the first pin in the advancing direction. In addition, both of the first pin and the second pin may have the hollow section.
[0020] In addition, in the chain belt, the pin may have two of the first pin and the second pin as the one pair and may be fitted to the coupling hole. The first pin may be arranged on the forward traveling side in the advancing direction in a case where the pulleys rotate in the specified rotational direction, and may have the hollow section. Then, the second pin may be arranged on the rearward traveling side of the first pin in the advancing direction and may not have the hollow section. [0021] Furthermore, in the chain belt, the pin may have two of the first pin and the second pin as the one pair and may be fitted to the coupling hole. The first pin may be arranged on the forward traveling side in the advancing direction in the case where the pulleys rotate in the specified rotational direction, and may not have the hollow section. Then, the second pin may be arranged on the rearward traveling side of the first pin in the advancing direction and may have the hollow section.
[0022] According to the chain belt as described above, the hollow section is provided in the pin of the chain belt. Since the hollow section is provided in the pin, the bending rigidity of the pin is lowered, and the pin is likely to be warped with respect to a bending load that acts on the pin. When the bending rigidity of the pin is lowered to facilitate warping of the pin, an impact force that is generated when the pin comes in contact with the pulleys during the power transmission can be alleviated. Accordingly, vibration or noise caused by the impact force can be reduced. In addition, since the hollow section is provided in the pin, it is possible to reduce a weight of the pin. When the weight of the pin is reduced, the impact force that is generated when the pin comes in contact with the pulleys during the power transmission can be reduced. Thus, the vibration or the noise caused by the impact force can be reduced. In addition, since the hollow section is provided in the pin, a surface area of the pin is increased, and thus a heat radiation property of the pin can be improved. As a result, a heat load on the pin and the pulleys that contact the pin can be reduced. In addition, since the hollow section is provided in the pin, lubricating oil is caused to enter the hollow section, and thus a lubricating oil retaining property of the chain belt can be improved. As a result, it is possible to reduce friction between the pin or a movable portion of the chain belt and the pulleys. Thus, since the hollow section is provided in the pin, durability of the pin, and thus the chain belt, and durability of the pulleys, around which the chain belt is wound, can be improved. Furthermore, according to the invention of this claim 1 , in the shape of the hollow section of the pin in the cross section that is perpendicular to the axial direction of the pin, the length in the each direction is set such that the net length in the radial direction of the pulleys is longer than the net length in the tangential direction of the pulleys. The net length in the tangential direction of the pulleys is an integrated value of the length, to which lengths of overlapping portions in the tangential direction of the pulleys are not added. The net length in the radial direction of the pulleys is an integrated value of the length, to which overlapping portions in the radial direction of the pulleys are not added. The pin is configured as described above. Accordingly, while degradation of strength of the pin with respect to the bending load that acts in the tangential direction of the pulleys is suppressed, the pin can be provided to be easily warped with respect to the bending load that acts on the radial direction of the pulleys. Therefore, it is possible to provide the chain belt that can improve a silence property with respect to the vibration or the noise and has favorable durability.
[0023] In addition, according to the chain belt as described above, the shape of the hollow section is determined such that the lowered amount of the bending rigidity of the pin due to the formation of the hollow section is larger in the radial direction of the pulleys than the tangential direction of the pulleys. Thus, the lowering of the bending rigidity of the pin in the tangential direction of the pulleys is suppressed as much as possible. At the same time, the pin can be provided to be warped as easily as possible with respect to the bending load that acts in the radial direction of the pulleys. Therefore, it is possible to provide the chain belt that can improve the silence property with respect to the vibration or the noise and has the favorable durability.
[0024] Furthermore, according to the chain belt as described above, the pin is provided such that the area of the cross section of the center section in the axial direction of the pin that is perpendicular to the axial direction of the pin is larger than the area of the cross section of the each end in the axial direction of the pin that is perpendicular to the axial direction. When the areas of the cross section are uniform, bending moment of the pin becomes the maximum in the center section in the axial direction. Meanwhile, since the pin is provided to increase the area of the cross section of the center section as described above, difference between the bending moment that is generated in the center section in the axial direction of the pin and the bending moment that is generated at the each end in the axial direction of the pin can be reduced. Therefore, while degraded durability caused by the formation of the hollow section in the pin is suppressed, the bending rigidity can effectively be lowered.
[0025] Furthermore, according to the chain belt as described above, the pin is provided such that the area of the cross section of the cross section thereof that is perpendicular to the axial direction of the pin is increased toward the center section from the each end in the axial direction of the pin. When the area of the cross section is uniform, the bending moment becomes the maximum in the center section in the axial direction of the pin. On the other hand, since the pin is provided such that the area of the cross section of the center section is gradually increased as described above, the bending moment that is generated in the pin can be equalized in the axial direction of the pin. Therefore, while the degraded durability caused by the formation of the hollow section in the pin is suppressed, the bending rigidity can effectively be lowered.
[0026] Furthermore, according to the chain belt as described above, in the case where two of the first pin and the second pin are paired and aligned in a circumferential direction of the chain belt to couple the links and where the hollow section as described above is at least provided in the first pin, the hollow section is provided in both of the first pin and the second pin or only in the first pin. The first pin is the pin that is arranged on a front side in the advancing direction of the chain belt when the pulleys rotate in the specified rotational direction (for example, a forward traveling direction). The second pin is the pin that is arranged on a rear side in the advancing direction of the chain belt. In a portion of the chain belt, to which a tensile force is applied when the chain belt transmits the power between the two pulleys, the larger bending load acts on the pin on the rear side in the advancing direction of the chain belt, that is, on the second pin than on the first pin. On the other hand, the hollow section is at least provided in the first pin. Thus, while the degraded durability caused by the formation of the hollow section in the pin is suppressed, the bending rigidity can effectively be lowered. Here, in the case where the hollow section is not provided in the first pin, on which the larger bending load acts, but the second pin, on which the relatively small bending load acts, has the hollow section, the degraded durability can effectively be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:
FIG. 1 is a view for illustrating one example of a belt transmission apparatus, to which a chain belt of an embodiment of the invention is applied;
FIG. 2 is a view for illustrating one example of a configuration of the chain belt of the embodiment and a configuration of a pin in the chain belt;
FIG. 3 is a view for illustrating one example of a configuration of a pin of a first example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through an axis of the pin and is perpendicular to a tangential direction of a pulley;
FIG. 4 is a view for illustrating deforming directions of the pin (a radial direction of the pulley and the tangential direction of the pulley) in the chain belt of the embodiment;
FIG. 5 is a view for illustrating a configuration example of a pin of a second example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through the axis of the pin and is perpendicular to the tangential direction of the pulley;
FIG. 6 is a view for illustrating a configuration example of a pin of a third example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through the axis of the pin and is perpendicular to the tangential direction of the pulley;
FIG. 7 is a view for illustrating a configuration example of a pin of a fourth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that passes through the axis of the pin and is perpendicular to the tangential direction of the pulley;
FIG. 8 is a view for illustrating a configuration example of a pin of a fifth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to an axial direction of the pin; FIG. 9 is a view for illustrating a configuration example of a pin of a sixth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to the axial direction of the pin;
FIG. 10 is a view for illustrating a configuration example of a pin of a seventh example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to the axial direction of the pin;
FIG. 11 is a view for illustrating a configuration example of a pin of an eighth example in the chain belt of the embodiment, and is a cross-sectional view of the pin that is perpendicular to the axial direction of the pin;
FIG. 12 is a side view of the chain belt of the embodiment that is seen from the axial direction of the pin; and
FIG. 13 is a view for illustrating a different configuration example of the chain belt of the invention from a configuration thereof shown in FIG. 12, and is a side view of the chain belt that is seen from the axial direction of the pin.
DETAILED DESCRIPTION OF EMBODIMENT
[0028] Next, the invention will be described specifically with reference to the drawings. FIG. 1 shows a schematic configuration of a belt-type continuously variable transmission (CVT) 1 as one example of a belt transmission apparatus, to which a chain belt of the invention can be applied. The CVT 1 shown in this FIG. 1 has a similar configuration to that of an existing general CVT. The configuration thereof is briefly described. The CVT 1 includes a primary pulley 2, to which torque is transmitted from a power source (not shown), and a secondary pulley 3 for transmitting the torque to an output member (not shown).
[0029] The primary pulley 2 is configured by arranging a fixed sheave 2a and a movable sheave 2b, each of which has a tapered surface, to face each other. Since the fixed sheave 2a and the movable sheave 2b face each other, a belt winding groove 2c is formed therebetween. Then, it is configured to change a width of the belt winding groove 2c by moving the movable sheave 2b to approach or separate from the fixed sheave 2a by using an actuator (not shown).
[0030] Similarly, the secondary pulley 3 is configured by arranging a fixed sheave 3 a and a movable sheave 3b, each of which has the tapered surface, to face each other. Since the fixed sheave 3 a and the movable sheave 3b face each other, a belt winding groove 3 c is formed therebetween. Then, it is configured to change a width of the belt winding groove 3 c by moving the movable sheave 3b to approach or separate from the fixed sheave 3a by using the actuator (not shown).
[0031] A chain belt 4 is wound around the belt winding groove 2c in the primary pulley 2 and the belt winding groove 3 c in the secondary pulley 3 described above. The chain belt 4 is a transmission belt for transmitting the torque between the primary pulley 2 and the secondary pulley 3. As shown in FIG. 2 and FIG. 3, the chain belt 4 is configured by coupling plural links 5, each of which is referred to as a link, a plate, and the like, in an annular shape by pins 6.
[0032] The link 5 is, for example, formed of a metallic plate member. The link 5 is formed with a coupling hole 5a, in which the pin 6 is inserted. In an example shown in FIG. 2, the coupling hole 5a is formed at two positions on both end sides in an axial direction of the link 5. All of the links 5 can be configured to have the same shape. Alternatively, for example, as described in above-described JP 2013-117306 A and Japanese Patent No. 4372551, plural types of links with different shapes and dimensions can be combined to be used.
[0033] The pin 6 is, for example, formed of a metallic rod member. As described above, the pin 6 is fitted to the coupling hole 5a of the link 5 so as to couple the two links 5 and supports the link 5 in a manner to allow relative rotation of the specified two links 5 to each other. In the example shown in FIG. 2, the pin 6 is configured by including a first pin 6a and a second pin 6b that are arranged in parallel. These two of the first pin 6a and the second pin 6b are paired and fitted to the coupling hole 5a. Then, as shown in FIG. 3, the pin 6 is configured that both end surfaces 6c in an axial direction A of the pin 6 (a right and left direction in FIG. 3) respectively contact the tapered surfaces of each of the belt winding grooves 2c, 3c to serve as power transmission surfaces in a state that the chain belt 4 is wound around the pulleys 2, 3.
[0034] It should be noted that pins in the same shape are used as the first pin 6a and the second pin 6b in the example shown in FIG. 2. Then, these first pin 6a and second pin 6b are arranged to be symmetrical when seen in the axial direction A. Meanwhile, like a "first pin 3" and a "second pin 4" that are described in Japanese Patent Application Publication No. 2006-77890 (JP 2006-77890 A), for example, two pins with different shapes from each other can also be paired to be used as the pin 6 in the invention.
[0035] When the chain belt 4, which is used as the transmission belt of the belt-type continuously variable transmission 1 as described above, runs between the pulleys 2, 3 to transmit the power, the pin 6 is deformed by a bending load acting on the pin 6. Directions in which the pin 6 is deformed in this case can mainly divided into two directions that are orthogonal to each other. More specifically, as shown in FIG. 4, the two directions are a radial direction R of the pulleys 2, 3 and a tangential direction T of the pulleys 2, 3 in a state that the chain belt 4 is wound around the pulleys 2, 3.
[0036] More specifically, when the chain belt 4 is wound around the pulleys 2, 3, both of the end surfaces 6c of the pin 6 respectively contact the tapered surfaces of each of the belt winding grooves 2c, 3 c. In this way, an impact force and a clamping force from each of the pulleys 2, 3 act on both of the end surfaces 6c of the pin 6. By these forces, the pin 6 is deformed such that a center section 6d is displaced in the radial direction R with both of the end surfaces 6c being fulcrums. In addition, in a state that the chain belt 4 is wound around the pulleys 2, 3 and transmits the power between the pulleys 2, 3, a tensile force that attempts to stretch the chain belt 4 in a circumferential length direction acts on the chain belt 4. The circumferential length direction in this case corresponds to the tangential direction T when the chain belt 4 is in a state of being wound around the pulleys 2, 3. The pin 6 is deformed by such a tensile force such that the center section 6d is displaced in the tangential direction T with contact portions thereof with the link 5 in the vicinity of both of the end surfaces 6c being the fulcrums. [0037] As described above, bending rigidity of the pin 6 is lowered to facilitate warping of the pin 6 in the radial direction R. In this way, it is possible to reduce the impact force, which is generated when both of the end surfaces 6c of the pin 6 respectively contact the tapered surfaces of each of the pulleys 2, 3. As a result, vibration or noise caused by the impact force can be reduced. On the other hand, since the bending rigidity of the pin 6 is lowered, the pin 6 is also likely to be warped in the tangential direction T. When the pin 6 is likely to be warped in the tangential direction T, that is, an amount of the deformation of the pin 6 in the tangential direction T is increased, durability of the pin 6 is possibly degraded. Thus, the pin 6 is required to have the specified bending rigidity for facilitating the deformation thereof in the radial direction R and securing the durability in the tangential direction T.
[0038] In order to satisfy contradictory requirements as described above, the pin 6 in the invention is formed with a hollow section 7 that is formed in the axial direction A. Compared to a case where the hollow section 7 is not formed, the bending rigidity of the pin 6 is lowered by forming the hollow section 7 in the pin 6. When the bending rigidity of the pin 6 in the radial direction R in the case where the hollow section 7 is not formed is set as EIRO, and the bending rigidity of the pin 6 in the radial direction R in the case where the hollow section 7 is formed is set as EIRJ, a lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R, which is caused by the formation of the hollow section 7, is AEIR = EIR0 - EIRJ. Similarly, when the bending rigidity of the pin 6 in the tangential direction T in the case where the hollow section 7 is not formed is set as Eljo, and the bending rigidity of the pin 6 in the tangential direction T in the case where the hollow section 7 is formed is set as Eln, a lowered amount ΔΕΙχ of the bending rigidity of the pin 6 in the tangential direction T, which is caused by the formation of the hollow section 7, is ΔΕΙχ = ΕΙχο - ΕΓπ.
[0039] Then, a shape, dimensions, and a formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity as described above is larger than the lowered amount ΔΕΙχ of the bending rigidity, and the hollow section 7 is thereby formed in the pin 6. In other words, the hollow section 7 is formed in the pin 6 such that the lowered amount (AEIR) of the bending rigidity (EI RI) of the pin 6 in the radial direction R with respect to the bending rigidity (EI R0) of the pin 6 in the case where the hollow section 7 is not formed is larger than the lowered amount (ΔΕΙχ) of the bending rigidity (EI τι) of the pin 6 in the tangential direction T with respect to the bending rigidity (EI TO) of the pin 6 in the case where the hollow section 7 is not formed.
[0040] In the example shown in FIG. 2, the pin 6 is formed with the hollow section 7 with an oval cross section that is perpendicular to the axial direction A. The hollow section 7 in this example shown in FIG. 2 is formed in a center portion of the cross section that is perpendicular to the axial direction A such that a long axis of the oval shape in the cross section is set in the radial direction R and a short axis of the oval shape in the cross section is set in the tangential direction T. In other words, the hollow section 7 in this example shown in FIG. 2 is formed such that dimensions and a shape of each portion thereof are set to satisfy a > b when a length dimension in the radial direction R (a length of the long axis) is set as a and a length dimension in the tangential direction T (a length of the short axis) is set as b. Then, the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ΔΕΙτ of the bending rigidity of the pin 6 in the tangential direction T by forming the hollow section 7 as described above. Accordingly, the pin 6 in this chain belt 4 is formed to be easily warped with respect to a load acting in the radial direction R and to have the specified the bending rigidity with respect to a load acting in the tangential direction T. Thus, the bending rigidity of the pin 6 in the radial direction R is lowered while the durability of the chain belt is secured. Therefore, it is possible to alleviate impact experienced when the pin 6 comes in contact with the pulleys 2, 3. As a result, the noise or the vibration caused by the impact can be reduced, and a silence property of the chain belt 4 with respect to the noise or the vibration can be improved.
[0041] Like the pin in a first example shown in FIG. 3, the hollow section 7 of the pin 6 can be formed such that the shape of the cross section thereof that is perpendicular to the axial direction A is uniform in the axial direction. In other words, the pin 6 can be formed such that areas of the cross section of cross sections thereof that are perpendicular to the axial direction A are the same in the axial direction A. In this case, the hollow section 7 can easily be formed in the pin 6.
[0042] Other than the above, for example, like a pin of a second example shown in FIG. 5, the pin 6 can be formed such that the areas of the cross section of the cross section of the center section 6d in the axial direction A that is perpendicular to the axial direction A is larger than an area of a cross section of each end 6e in the axial direction A that is perpendicular to the axial direction A. In the case where the area of the cross section of the pin 6 is uniform in the axial direction A as in the example shown in FIG. 3, bending moment of the pin 6 becomes the maximum in the center section 6d in the axial direction A. On the contrary, as in this example shown in FIG. 5, since the pin 6 is formed to increase the area of the cross section of the center section 6d in the axial direction A, the bending moment generated in the pin 6 can be equalized in the axial direction A. Thus, while the degraded durability of the chain belt 4, which is caused by the formation of the hollow section 7 in the pin 6, is suppressed, the bending rigidity thereof can effectively be lowered, so as to improve the silence property of the chain belt 4.
[0043] In addition, for example, like a pin of a third example shown in FIG. 6, the pin 6 can be formed such that the cross sectional area of the cross section of the center section 6d in the axial direction A that is perpendicular to the axial direction A is smaller than the area of the cross section of each of the ends 6e in the axial direction A that is perpendicular to the axial direction. The desired durability of the pin 6 is secured, and then the area of the center section 6d in the axial direction A is reduced, so as to lower the bending rigidity as in this example shown in FIG. 6. Accordingly, a further enhanced improvement effect of the silence property can be obtained.
[0044] In addition, for example, like a pin of a fourth example shown in FIG. 7, the pin 6 can be formed such that the hollow section 7 does not penetrate in the axial direction A and the area of the center section 6d in the axial direction A that is perpendicular to the axial direction A is thereby maintained in a maximum state. In this case, similar to the above example shown in FIG. 5, while the degraded durability of the chain belt 4, which is caused by the formation of the hollow section 7 in the pin 6, is suppressed, the bending rigidity thereof can effectively be lowered, so as to improve the silence property of the chain belt 4.
[0045] In the example shown in FIG. 2, the cross section of the hollow section 7 formed in the pin 6 that is perpendicular to the axial direction A is formed in the oval shape. Other than the above, for example, like a pin of a fifth example shown in FIG. 8, the hollow section 7 can be formed to have an elliptical cross sectional shape in which a central portion in the radial direction R is flattened or dented. In this case, the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy c > d when the length dimension in the radial direction R is set as c and the length dimension in the tangential direction T is set as d. Then, the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ΔΕΙγ of the bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7.
[0046] In addition, for example, like a pin of a sixth example shown in FIG. 9, the hollow section 7 can be formed to have a rectangular cross sectional shape with a long side in the radial direction R and a short side in the tangential direction T. In this case, the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy e > f when a length dimension of the side in the radial direction R is set as e and a length dimension of the side in the tangential direction T is set as f. Then, the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ΔΕΙχ of the bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7.
[0047] In addition, for example, like a pin of a seventh example shown in FIG. 10, the hollow section 7 can be formed to have a rhombic cross sectional shape in which a diagonal line in the radial direction R is longer than a diagonal line in the tangential direction T. In this case, the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy g > h when a length dimension of the diagonal line in the radial direction R is set as g and a length dimension of the diagonal line in the tangential direction T is set as h. Then, the shape, the dimensions, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ΔΕΙχ of the bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7.
[0048] Furthermore, for example, like a pin of an eighth example shown in FIG. 1 1 , the hollow section 7 can be formed to be divided into plural hollow sections. In this example shown in FIG. 1 1 , hollow sections 7a, 7b, 7c are formed to be vertically aligned in the radial direction R, and each of the hollow sections 7a, 7b, 7c has a circular cross section that is perpendicular to the axial direction A. In this case, shapes, dimensions, and the number of the plural hollow sections are set such that a net length dimension i in the radial direction R is longer than a length dimension j in the tangential direction T. It should be noted that the net length dimension I in the radial direction R is an integrated value of a length dimension of the hollow section 7 in the radial direction R, to which length dimensions of overlapping portions thereof are not added. That is, in this example shown in FIG. 1 1, the net length dimension I is I = i\ + i2 + i3. In this case, the hollow section 7 is formed such that the dimensions and the shape of the each portion thereof are set to satisfy I > j. Then, the shape, the dimensions, the number, and the formed position of the hollow section 7 are set such that the lowered amount AEIR of the average bending rigidity of the pin 6 in the radial direction R is larger than the lowered amount ΔΕΙχ of the average bending rigidity of the pin 6 in the tangential direction T by forming such a hollow section 7. It should be noted that the average bending rigidity of the pin 6 in the tangential direction T or the radial direction R refers to the bending rigidity that is computed by integrating the plural hollow sections into a whole in such a case that the hollow section 7 is divided into the plural sections, for example, like this example shown in FIG. 11. When the hollow section 7 is formed to be divided into the plural sections as in this example shown in FIG. 11 , a surface area of the pin 6 can be increased, and a heat radiation property of the pin 6 is improved by the increase of the surface area of the pin 6. Thus, a heat load on the pin 6 and the pulleys 2, 3, which contact the pin 6, can be reduced.
[0049] As described above, the pin 6 of this chain belt 4 can be configured by including two of the first pin 6a and the second pin 6b as the pair. More specifically, as shown in FIG. 12, in the case where the pulleys 2, 3 rotate in a specified rotational direction (a forward traveling direction here), the first pin 6a is arranged on a front side in the advancing direction of the chain belt 4 and the second pin 6b is arranged on a rear side in the advancing direction of the chain belt 4. In this example shown in FIG. 12, the hollow section 7 is formed in both of the first pin 6a and the second pin 6b. When the pin 6 is configured by including two of the first pin 6a and the second pin 6b as the pair, just as described, the hollow section 7 is formed in both of the first pin 6a and the second pin 6b. Thus, an effect in suppressing the vibration and the noise that is achieved by reducing the bending rigidity of the pin 6 and an effect in maintaining the durability of the pin 6 can well balanced.
[0050] In the above example shown in FIG. 12, the hollow section 7 is formed in both of the first pin 6a and the second pin 6b. On the contrary, as shown in FIG. 13, the hollow section 7 can only be formed in the first pin 6a. In a portion of the chain belt 4, to which the tensile force is applied when the chain belt 4 transmits the power between the two pulleys 2, 3, the larger bending load acts on the second pin 6b, which is arranged on the rear side in the advancing direction of the chain belt 4, than on the first pin 6a. In consideration of such an event, the hollow section 7 is only formed in the first pin 6a, on which the larger bending load acts. In this way, while the degraded durability, which is caused by the formation of the hollow section 7 in the pin 6, is suppressed, the bending rigidity of the pin 6 is effectively lowered. Therefore, the effect in suppressing the vibration and the noise, which is achieved by lowering the bending rigidity of the pin 6, can be obtained. [0051] It should be noted that, on the contrary to the above example shown in FIG. 13, the hollow section 7 is not formed in the first pin 6a, on which the larger bending load acts, but can only be formed in the second pin 6b, on which the relatively small bending load acts. In this case, since the hollow section 7 is only formed in the second pin 6b, on which the small bending load acts, the degraded durability, which is caused by the formation of the hollow section 7 in the pin 6, can effectively be suppressed.

Claims

CLAIMS:
1. A chain belt for being wound around two pulleys to transmit power between the two pulleys, the chain belt comprising:
a link that is a plate member provided with a coupling hole; and
a pin fitted to the coupling hole to couple the links in an annular shape, the pin having both end surfaces in an axial direction such that the both end surfaces respectively contact the pulleys and serve as power transmission surfaces, the pin having a hollow section extending in the axial direction, and the hollow section being configured to lower bending rigidity of the pin, wherein
the hollow section has a shape that, in a cross section that is perpendicular to the axial direction of the pin, a net length of the hollow section in a radial direction of the pulleys is longer than a net length of the hollow section in a tangential direction of the pulleys.
2. The chain belt according to claim 1, wherein the hollow section has a shape that a lowered amount in the radial direction is larger than a lowered amount in the tangential direction, the lowered amount in the radial direction is a lowered amount with respect to average bending rigidity of the pin in a state that the link is wound around the pulleys in a case where the hollow section of the pin with the average bending rigidity in the radial direction of the pulleys is not provided, and the lowered amount in the tangential direction is a lowered amount with respect to the average bending rigidity of the pin in the case where the hollow section of the pin with the average bending rigidity in the tangential direction of the pulleys is not provided.
3. The chain belt according to claim 1 or 2, wherein
an area of a cross section of a center section of the pin is larger than an area of a cross section of each end of the pin, the cross section of the center section is perpendicular to the axial direction, and the cross section of the each end is perpendicular to the axial direction.
4. The chain belt according to claim 3, wherein
the pin has a shape that an area of the cross section of the pin is increased toward the center section from the each end, and
the cross section of the pin is perpendicular to the axial direction.
5. The chain belt according to claim 1 or 2, wherein
a shape of the cross section of the hollow section of the pin is uniform in the axial direction and the cross section of the hollow section is perpendicular to the axial direction.
6. The chain belt according to claim 1 or 2, wherein
an area of a cross section of a center section of the pin is smaller than an area of a cross section of each end of the pin, the cross section of the center section is perpendicular to the axial direction, and the cross section of the each end is perpendicular to the axial direction.
7. The chain belt according to claim 1 or 2, wherein
the hollow section of the pin does not penetrate in the axial direction, and an area of a cross section of a center section of the pin is the maximum in the axial direction.
8. The chain belt according to claim 1 or 2, wherein
the cross section of the hollow section of the pin in the axial direction has an oval shape and the cross section of the hollow section is perpendicular to the axial direction.
9. The chain belt according to claim 1 or 2, wherein
the hollow section of the pin has a rectangular cross section with a long side in the radial direction of the pin and a short side in the tangential direction of the pin.
10. The chain belt according to claim 1 or 2, wherein
the hollow section of the pin has a rhombic cross section, in which a length of a diagonal line in the radial direction of the pin is longer than a length of a diagonal line in the tangential direction of the pin.
11. The chain belt according to claim 1 or 2, wherein
the hollow section of the pin has the plural hollow sections, and the plural hollow sections are longitudinally arranged in the radial direction of the pin.
12. The chain belt according to any one of claims 1 through 11, wherein
the pin has two of a first pin and a second pin as one pair, the pin is fitted to the coupling hole, the first pin is arranged on a forward traveling side in an advancing direction in a case where the pulleys rotate in a specified rotational direction, the second pin is arranged on a rearward traveling side of the first pin in the advancing direction, and both of the first pin and the second pin have the hollow section.
13. The chain belt according to any one of claims 1 through 11, wherein
the pin has two of a first pin and a second pin as one pair, the pin is fitted to the coupling hole, the first pin is arranged on a forward traveling side in an advancing direction in a case where the pulleys rotate in a specified rotational direction, and the first pin has the hollow section, and the second pin is arranged on a rearward traveling side of the first pin in the advancing direction and does not have the hollow section.
14. The chain belt according to any one of claims 1 through 11, wherein
the pin has two of a first pin and a second pin as one pair, the pin is fitted to the coupling hole, the first pin is arranged on a forward traveling side in an advancing direction in the case where the pulleys rotate in a specified rotational direction, and the first pin does not have the hollow section, and the second pin is arranged on a rearward traveling side of the first pin in the advancing direction and has the hollow section.
PCT/IB2015/001378 2014-08-21 2015-08-17 Chain belt WO2016027146A1 (en)

Applications Claiming Priority (2)

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JP2014-168512 2014-08-21
JP2014168512A JP2016044726A (en) 2014-08-21 2014-08-21 Chain belt

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Publication number Priority date Publication date Assignee Title
JP6990092B2 (en) * 2017-11-14 2022-01-12 株式会社Subaru Chain belt

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB974507A (en) * 1960-03-14 1964-11-04 Werner Reimers Rocker joint for link chain
DE10222973A1 (en) * 2002-05-23 2003-12-04 Univ Karlsruhe Belt system for continuous variable transmission comprises plastic, metal or ceramic coatings on pulley surfaces or on surfaces of belt which contact it to increase friction
JP2006077890A (en) 2004-09-09 2006-03-23 Jtekt Corp Power transmission chain and power transmission device equipped therewith
JP2008215496A (en) 2007-03-05 2008-09-18 Jtekt Corp Power transmission chain and power transmission device
JP4372551B2 (en) 2001-12-14 2009-11-25 ルーク ラメレン ウント クツプルングスバウ ベタイリグングス コマンディートゲゼルシャフト In particular, a transmission device with winding means for force transmission between two conical pulley pairs of the transmission device
JP2012247022A (en) 2011-05-30 2012-12-13 Nissan Motor Co Ltd Chain-type variable-speed transmission mechanism
JP2013117306A (en) 2011-10-31 2013-06-13 Toyota Central R&D Labs Inc Chain-type continuously variable transmission
JP2014202251A (en) * 2013-04-03 2014-10-27 株式会社ジェイテクト Pin for power transmission chain, and power transmission chain

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB974507A (en) * 1960-03-14 1964-11-04 Werner Reimers Rocker joint for link chain
JP4372551B2 (en) 2001-12-14 2009-11-25 ルーク ラメレン ウント クツプルングスバウ ベタイリグングス コマンディートゲゼルシャフト In particular, a transmission device with winding means for force transmission between two conical pulley pairs of the transmission device
DE10222973A1 (en) * 2002-05-23 2003-12-04 Univ Karlsruhe Belt system for continuous variable transmission comprises plastic, metal or ceramic coatings on pulley surfaces or on surfaces of belt which contact it to increase friction
JP2006077890A (en) 2004-09-09 2006-03-23 Jtekt Corp Power transmission chain and power transmission device equipped therewith
JP2008215496A (en) 2007-03-05 2008-09-18 Jtekt Corp Power transmission chain and power transmission device
JP2012247022A (en) 2011-05-30 2012-12-13 Nissan Motor Co Ltd Chain-type variable-speed transmission mechanism
JP2013117306A (en) 2011-10-31 2013-06-13 Toyota Central R&D Labs Inc Chain-type continuously variable transmission
JP2014202251A (en) * 2013-04-03 2014-10-27 株式会社ジェイテクト Pin for power transmission chain, and power transmission chain

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