CA1138678A - Automotive transmission with continuously variable speed mechanism - Google Patents
Automotive transmission with continuously variable speed mechanismInfo
- Publication number
- CA1138678A CA1138678A CA000359235A CA359235A CA1138678A CA 1138678 A CA1138678 A CA 1138678A CA 000359235 A CA000359235 A CA 000359235A CA 359235 A CA359235 A CA 359235A CA 1138678 A CA1138678 A CA 1138678A
- Authority
- CA
- Canada
- Prior art keywords
- gear
- shaft
- clutch
- pulley
- transmission
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired
Links
- 230000005540 biological transmission Effects 0.000 title claims abstract description 35
- 230000007246 mechanism Effects 0.000 title claims abstract description 18
- 239000012530 fluid Substances 0.000 claims abstract description 25
- 230000008878 coupling Effects 0.000 claims abstract description 11
- 238000010168 coupling process Methods 0.000 claims abstract description 11
- 238000005859 coupling reaction Methods 0.000 claims abstract description 11
- 238000006073 displacement reaction Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000002844 continuous effect Effects 0.000 description 1
- 238000013270 controlled release Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
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
- F16H—GEARING
- F16H47/00—Combinations of mechanical gearing with fluid clutches or fluid gearing
- F16H47/06—Combinations of mechanical gearing with fluid clutches or fluid gearing the fluid gearing being of the hydrokinetic type
- F16H47/08—Combinations of mechanical gearing with fluid clutches or fluid gearing the fluid gearing being of the hydrokinetic type the mechanical gearing being of the type with members having orbital motion
-
- 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
- F16H—GEARING
- F16H37/00—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00
- F16H37/02—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings
- F16H37/021—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings toothed gearing combined with continuous variable friction gearing
- F16H37/022—Combinations of mechanical gearings, not provided for in groups F16H1/00 - F16H35/00 comprising essentially only toothed or friction gearings toothed gearing combined with continuous variable friction gearing the toothed gearing having orbital motion
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transmission Devices (AREA)
Abstract
AUTOMOTIVE TRANSMISSION WITH CONTINUOUSLY
VARIABLE SPEED MECHANISM
Abstract:
The disclosed transmission arrangement includes a fluid coupling (14) with impeller and turbine elements, and a lock-up (22) clutch for locking these elements together. A first shaft (20) is connected to the turbine element and the input pulley (48) of a continuously variable speed mechanism, which mechanism also has an output pulley (56) and a belt coupling the second pulley to the first.
A planetary forward-reverse gear set (24), with a clutch and a brake, determine the direction of rotation of the input pulley for a given rotation of the first shaft.
A second shaft (64), on a second axis, is connected to the output pulley (56) and also supports a first gear (66). A third shaft (70), on a third axis, includes a second gear (68) meshing with the first, and a third gear (72). A differential mechanism (74) includes a ring gear meshing with the third gear, and a pair of output connections for driving two axle shafts (86,88) on a fourth axis. This four axis arrangement provides effective use of a continuously variable speed mechanism with only a small transverse distance occupied in the engine compartment.
VARIABLE SPEED MECHANISM
Abstract:
The disclosed transmission arrangement includes a fluid coupling (14) with impeller and turbine elements, and a lock-up (22) clutch for locking these elements together. A first shaft (20) is connected to the turbine element and the input pulley (48) of a continuously variable speed mechanism, which mechanism also has an output pulley (56) and a belt coupling the second pulley to the first.
A planetary forward-reverse gear set (24), with a clutch and a brake, determine the direction of rotation of the input pulley for a given rotation of the first shaft.
A second shaft (64), on a second axis, is connected to the output pulley (56) and also supports a first gear (66). A third shaft (70), on a third axis, includes a second gear (68) meshing with the first, and a third gear (72). A differential mechanism (74) includes a ring gear meshing with the third gear, and a pair of output connections for driving two axle shafts (86,88) on a fourth axis. This four axis arrangement provides effective use of a continuously variable speed mechanism with only a small transverse distance occupied in the engine compartment.
Description
7ig AUTO~OTIVE TRANSMISSION WITH CONTINUOUSLY
VARIABL~ SPEED MECHANIS~
Description The present invention relates to a power transmission 5 which incorporates a continuously variable speed mechanism.
In general, automotive vehicles have used manual or automatic transmissions for changing the drive ratio between the engine output shaft and the drive wheels. The transmission is "shifted" or changed in finite steps from start-up, 10 when a high-torque, low-speed drive is provided, up to highway speeds, where a high-speed, low-to que drive is provided. Shifting is accomplished by the driver dicplacing a shift lever to change the ratio in a manual transmission, or in an automatic transmission by the controlled release and engagement of friction elements. Because such shifting is in step functions, the most efficient operation (fuel consumption, engine efficiency, and so forth) can only be approximated with a transmission which changes gears in discrete steps. It is thus desirable to provide a con-tinuously variable transmission (CVT) where the gearratio is varied in a regular, continuous manner, as the vehicle is started and accelerated to driving speeds.
The use of such a CVT employing variable-pitch pulleys in machine tools and similar variable speed systems has been known for some time. Recently considerable work has been directed to the improvement of such a continuously variable trans~ission to provide a practical component for an auto-motive drive train. One example of such a CVT is described and shown in U. S. Patent No. 4,0g4,203 -- Van Deursen et al.
T~is arrangement empioys a steel belt to transfer drive between the relativeiy movable sheaves of a primary and secondary pulley. By controlling tne sheave displacement --.. :
: -:
and thus the effective diameter -- of each pulley, a con-siderable range of speed variation is attained in a con-tinuous manner, without the step function change previously noted in connection with manual and automatic transmissions.
Even with recent advances, such CVT transmissions for auto-motive use have still been difficult to manufacture, and imposed weight and volume requirements not unlike those of other transmissions.
According to the present invention there is provided a transmission adapted to be driven by a prime mover, the transmission including a first shaft, a hydro-dynamic device including a fluid coupling having turbine and impeller elements with a torsional damper coupling the turbine element to the first shaft. The impeller is adapted for connection to the prime mover, and a lock-up clutch is engageable to drivingly connect the impeller and turbine elements for rotation together. A gear pump is connected to be driven when the first shaft is driven and to provide fluid under pressure for operating the lock-up clutch. A
continuously variable speed mechanism is provided which has an input pulley mounted for rotation on the first shaft, an output pulley and a belt intercoupling the pulleys. Each of the pulleys includes a pair of sheaves, one sheave of each pair being fixed with respect to lateral movement and the other sheave in the same pair being movable laterally relative to the one sheave. A planetary forward-reverse gear set is connected to the first shaft, and a clutch and brake is operatively associated with the planetary gear set to regulate the direction of rota-tion of the input pulley.
VARIABL~ SPEED MECHANIS~
Description The present invention relates to a power transmission 5 which incorporates a continuously variable speed mechanism.
In general, automotive vehicles have used manual or automatic transmissions for changing the drive ratio between the engine output shaft and the drive wheels. The transmission is "shifted" or changed in finite steps from start-up, 10 when a high-torque, low-speed drive is provided, up to highway speeds, where a high-speed, low-to que drive is provided. Shifting is accomplished by the driver dicplacing a shift lever to change the ratio in a manual transmission, or in an automatic transmission by the controlled release and engagement of friction elements. Because such shifting is in step functions, the most efficient operation (fuel consumption, engine efficiency, and so forth) can only be approximated with a transmission which changes gears in discrete steps. It is thus desirable to provide a con-tinuously variable transmission (CVT) where the gearratio is varied in a regular, continuous manner, as the vehicle is started and accelerated to driving speeds.
The use of such a CVT employing variable-pitch pulleys in machine tools and similar variable speed systems has been known for some time. Recently considerable work has been directed to the improvement of such a continuously variable trans~ission to provide a practical component for an auto-motive drive train. One example of such a CVT is described and shown in U. S. Patent No. 4,0g4,203 -- Van Deursen et al.
T~is arrangement empioys a steel belt to transfer drive between the relativeiy movable sheaves of a primary and secondary pulley. By controlling tne sheave displacement --.. :
: -:
and thus the effective diameter -- of each pulley, a con-siderable range of speed variation is attained in a con-tinuous manner, without the step function change previously noted in connection with manual and automatic transmissions.
Even with recent advances, such CVT transmissions for auto-motive use have still been difficult to manufacture, and imposed weight and volume requirements not unlike those of other transmissions.
According to the present invention there is provided a transmission adapted to be driven by a prime mover, the transmission including a first shaft, a hydro-dynamic device including a fluid coupling having turbine and impeller elements with a torsional damper coupling the turbine element to the first shaft. The impeller is adapted for connection to the prime mover, and a lock-up clutch is engageable to drivingly connect the impeller and turbine elements for rotation together. A gear pump is connected to be driven when the first shaft is driven and to provide fluid under pressure for operating the lock-up clutch. A
continuously variable speed mechanism is provided which has an input pulley mounted for rotation on the first shaft, an output pulley and a belt intercoupling the pulleys. Each of the pulleys includes a pair of sheaves, one sheave of each pair being fixed with respect to lateral movement and the other sheave in the same pair being movable laterally relative to the one sheave. A planetary forward-reverse gear set is connected to the first shaft, and a clutch and brake is operatively associated with the planetary gear set to regulate the direction of rota-tion of the input pulley.
- 2 -sb/
' ' ` ' ~ ' 1~313678 A second shaft is connec-ted to the output pulley with a first gear supported on the second shaft, a third shaft spaced from the second shaft, a second gear mounted on the third shaft in meshing engagement with the first gear, and a third gear mounted on the third shaft for rotation therewith. A differential mechanism is provided which includes an input ring gear connected to be driven by the third gear and adapted to drive a pair of axle shafts so that the axle shafts are driven through a four-axis drive train by the prime mover.
The invention allows the provision oE a continuously variable transmission suitable for automotive use which is simple to manufacture, of a practical size, and with a correspondingly reduced weight, while all the drive and control components are mounted on four axes, to reduce total width and allow installation in a small volume.
sb/ 2a -' -~3?C~'7~
079063-BL -3~
The invention will be more clearly understood from the following description which is given by way of example only with reference to the accompanying drawings, in which:
Figure 1 is a simplified diagram of a continuously variable transmission constructed in accordance with this invention;
Figures 2 and 3 together represent a cross-section of the transmission shown more generally in Figure l; and Figure 4 is a representation of the displacements between the axes of the transmission components shown in Figures 1, 2 and 3.
Figure 1 depicts in simplified form the transmission 10 of this invention. The transmission 10 includes a hydrodynamic device 14, a forward reverse planetary mechanism 24, a belt and pulley mechanism 53, a reduction gear section 63, and a differential mechanism 74.
A vehicle engine, for example, drives input or drive shaft 11. Drive shaft 11 is connected to an impeller 12 of a hydrodynamic device 14, shown as a fluid coupling which also has a turbine 16. The turbine is coupled through a torsional damper 18 to a first shaft 20, aligned along a first axis referenced A. A lock-up clutch 22 is positioned to lock the impeller to the turbine and shaft 20 with minimal losses when this clutch is actuated.
A forward-reverse planetary gear set 24 includes a sun gear 26, a pair of planet gears 28,30 and a ring gear 32. The planet or pinion gears 28,30 mesh with each other, with the ~irst pinion 28 also meshing with sun gear 26, and the outer pinion 30 in the mesh with ring gear 32. The pinion gears are supported on the carrier arms 34,36, of a carrier output element 38. A clutch 40 is connected between sun gear 26 and ring gear 32. A band brake mechanism 42 is coupled between ring gear 32 and ground. It is thus apparent that engagement of clutch 40 effectively locks up the sun gear to the ring gear, and provides a 1:1 ratio t;~3 , drive between shaft 20 and the output member 38 which is tied to another shaft 44. Release of clutch 40 and en-gagement of the band brake 42 grounds ring gear 32, to effect a reverse rotation of the shaft 44 with respect to the input angular displacement of shaft 20.
Belt-and-pulley mechanism 53 includes a shaft 44 connected to a movable sheave of an input or first pulley assembly 48, which also includes a movable sheave 50.
It will become apparent from the subsequent explanation 10 that the sheaves 46,50 of the first pulley assembly 48 are mounted for common rotation about axis A, but in a lateral sense, sheave 46 is fixed with respect to lateral movement whereas sheave 50 is movable along the direction of axis A. Hence the terms "fixed" and "movable" as applied to the sheave portions of each pulley assembly described herein, and in the appended claims, refer to lateral movement along an axis such as axis A and not to rotational or other conventional displacement. A fluid chamber 52 is defined behind movable sheave 50 as shown in a general manner, so that the admission of fluid under pressure into this chamber will displace movable sheave 50 to the right as shown in the drawing, and removal of fluid from the chamber will allow the sheave to be displaced to the left.
A belt 54 provides a driving connection between first pulley 48 and a second or output pulley 56, which includes a fixed sheave 58 and a movable sheave 60. A fluid chamber 52 is defined adjacent movable sheave 60 to afford dis-placement of this sheave to the left and right along axis B.
Thus the controlled displacement of adjustable sheave 50 in the first pulley 48, and a concomitant displacement in an opposite sense of the other movable sheave 60 in the output pulley 56, effects a change in the drive ratio be-tween shaft 20 and shaft 64, coupled to fixed sheave 58, in a well known manner. A more complete disclosure of .
`
such an arrangement is described in U. S. Patent No.
4,143,558 which issued March 13, 1979, and thus an ex-tensive showing and description of the movable pulley arrangements in such a drive system will not be given herein.
Reduction gear section 63 includes a first gear 66 affixed to one end of shaft 64, which is aligned along axis B. A second gear 68 is in mesh with gear 66 and is connected to a third shaft 70, aligned on third axis designated C. A third gear 72 is also connected to third shaft 70.
Differential mechanism 74 includes a ring gear 76 meshing with third gear 72 on shaft 70. The differential also includes pinion gears 80 mounted on a center pin 79, in turn mounted in a case on carrier 78, and a pair of output or side gears 82,84 meshing with gears 80 and connected respectively to individual axle shafts 86 and 88, aligned on a fourth axis designated D. Thus when input energy from any suitable prime mover is applied over input shaft 11, the output or axle shafts 86,88 are driven in a manner apparent from this brief explanation. A more detailed explanation of this structure and its operation will now be set out.
Considering now the more detailed showing of Figure ~, pilot 11 is welded or otherwise connected to cover 90, which in its turn is connected to impeller ]2 of fluid coupling 14. Those skilled in the art will appreciate that other hydrodynamic devices, such as a torque converter, could be substituted for fluid coupling 14. ~ driveplate assembly 92 incorporating a driveplate 96 is connected by fastening means, shown as bolts 94, to the prime mover, and fastened by additional nuts, studs or screws 98 to cover 30.
6~78 Lock-up clutch 22 includes a plurality of friction plates 100, certain of which are affixed to member 102 of the torsional damper 18. The other clutch plates are affixed to an extension of clutch cylinder 104, which in turn is welded to cover 90 for rotation as input drive plate 96 is driven. A fluid chamber 106 is coupled by a conduit 108 to another conduit 110, in the center of hollow shaft 112. A gear pump 114 is mounted on and driven by shaft 112, to provide the fluid under pressure for operating lock-up clutch 22 and the other fluid-actuated components of the arrangement shown in Figures 2 and 3.
Turbine element 16 is coupled by plate 116 to the damper 18, and the output side of damper 18 is connected 15 to member 118, which in turn is splined to first shaft 20 on axis A.
Shaft 20 is also splined to sun gear 26 of the planetary gear set 24, and is likewise splined to a forward clutch cylinder 120 which carries certain of the 20 friction discs 122 in forward clutch 40. The other clutch plates are affixed to forward clutch hub member 124, which in turn is welded to a ring gear support 126, one end of which is fastened to ring gear 32 of the forward-reverse gear set.
The carrier pin 36 is received in carrier output element 38, which is connected by a plurality of screws 128 (only one of which is shown) to laterally fixed sheave 46 of first or input pulley 48. Sheave 46 is journalled about axis A, and a bearing 130 is positioned between 30 sheave 46 and the adjacent portion 132 of the trans-mission housing. Sheave 50, is connected to fixed sheave 46/133 via a ball spline (not shown) which permits lateral movement only. In a rotational sense sheave 50 is, in effect, splined to sheave 46 for drive transmiss~on 35 puposes. These sheaves 45 and 50 of input pulley 4 rotate as an entity. The provision of fluid in the :
1'1 3~
chamber 52 is effective to displace movable sheave 50 to the right as shown in the drawing, from its maximum left position as illustrated, to increase the effective diameter of the pulley arrangement as seen by the belt.
The annular wall member 134 forms the rear wall of the fluid chamber, and a portion of this member also provides a stop for the extremity of adjustable sheave 50.
A seal member 136 is provided between wall member 134 and a cylinder 138 to retain the fluid within charnber 52 as the movable sheave is displaced to the right and then again to the left. Details of the metal belt itself and the more precise details of the sheave construction and arrangement are not shown in Figures 2 and 3, in that such arrangements are now known in this art. For example, see United States Patent No.
4,143,558 - Van Deursen et al, entitled "Variable-V-Belt Transmission", which issued March 13, 1979.
Second shaft 64 is mounted on the second axis, referenced B, at the juncture of Figures 2 and 3.
Shaft 64 is journalled between a bearing 142 at the left end, and another bearing assembly 144 at the right end. Fixed sheave 58 is integral with shaft 64 for rotation therewith about axis B when the output pulley assembly 56 receives angular drive over the belt (as represented iII ~igure 1) from the input pulley arrangement 48. In Figures 2 and 3, movable sheave 60 is connected to fixed pulley 58 by a ball spline (not shown), as explained above in connection with sheaves 50,46 of the first pulley. A first annular member 148 has one end portion affixed in shaft 64 for rotation therewith, and an additional outer annular member 150 is affixed to the movable pulley sheave 60 for cooperation with member 148 and the side wall of the pulley to define f]uid chamber 62. An orifice 1~2 in member 148 provides metered flow of fluid from - 1~3~7~
chamber 62 into the adjacent chamber portion 154 when chamber 62 is pressurized.
Fluid under pressure is supplied through a passage 162 in a member 146, through a passage 156 in the center of shaft 140, a radial passage 158 and a channel 160 within movable sheave 60 to complete the path for fluid transfer into chamber 62. In general the construction of the movable sheave 60 is similar to that shown above in connection with sheave 50 and depicted in greater detail in the patent referenced above.
Reduction gear section 63 includes gear 66 affixed to the left end of shaft 64, meshing with adjacent gear 68 to provide a first reduction through the transmission.
Gear 68 is splined to third shaft 70, journalled about a central axis C, the third axis of this arrangement.
Bearings 170,172 support shaft 70 in the position in-dicated. Also affixed to third shaft 70 is another gear 72, meshing with ring gear 76 of differential 74 which rotates about the fourth axis, D, of this system.
Ring gear 76 is secured to a differential carrier 78, which thus rotates with ring gear 76 and drives center pin 79 of differential 74. Pin 79 has rotatably mounted thereon pinion gears 80 of the differential, and the pinion gears in turn mesh with side gears 82,84 which are connected to drive axle shafts 86,88.
In operation, drive is supplied from the prime mover through driveplate 96 to cover 90, which drives impeller 12. This provides drive to turbine 16, which through torsional damper 18 drives shaft 20. Cover 90, via the cover hub, imparts drive to shaft 112 and thus to pump 114. The pump provides fluid under pressure through channel 110 in shaft 112, and other channels, for energizing the various components previously described.
When the turbine approaches the speed of the impeller, lock-up clutch 22 will be actuated in a well known manner by admitting fluid through the channel 108,106 to engage .
., ~3~78 07~063-BL -~-the clutch discs and in e~fect lock cover 90 to the torsional damper 18, to eliminate any losses in the fluid coupling. Accordingly, at this time shaft 20 is being driven from cover 90, but there is no drive over pulley system 53 until either clutch 40 or brake 42 is engaged.
Assuming it is desired to drive the vehicle in which the transmission is mounted in the forward direction, fluid is admitted into the chamber adjacent clutch plates 122 of forward clutch 40, in effect locking sun gear 26 to ring gear 32, and drive is taken from planet carrier 38 to drive fixed sheave 46 of first pulley assembly 48.
Pulley assemblies 48,56 are depicted in their start-up positions, to provide a low-speed, high-torque power transfer between the components on first axis A and those on second axis B. As the second pulley assembly 56 is driven, first gear 66 on shaft 64 is also driven, and this in turn drives gear 68, which meshes with gear 66. Gear 68, mounted on third shaft 70 on axis C, imparts drive to this shaft which in turn rotates gear 72 which meshes with ring gear 76. This in turn drives differential 74 to drive axle shafts 86,88.
If it is desired to reverse the direction of power flow from the prime mover to the axle shafts 86,88, forward clutch 40 is released, unlocking sun gear 26 from ring gear 32. Band brake 42 is then engaged, locking ring gear 32 to the transmission housing. Drive is then taken from sun gear 26 through planet carrier 38, to drive fixed sheave 46 in the opposite direction than that obtained when clutch 40 was engaged. The remainder of the system operates in the same manner as previously described to provide opposite rotation of axle shafts 86,88.
Figure 4 shows the spatial relationship between the four separate axes of the system shown in Figures 1-3, .~3~3~7~
viewed from the left hand side of a vehicle in which the transmission of the invention is mounted. Tbe center-line of the engine is shown along the vertical axis and axis A is on the centerline. The distances between axis A and the second, third and fourth axes B, C and D are indicated in millimeters on the illustration. At the right of the drawing, the vertical distances between axes A and B, and between axes A and D, are also shown.
It is thus apparent by mounting the several assemblies shown in Figures 1-3 in the manner shown, a system is provided for incorporating a continuously variable trans-mission on a multiple axis arrangement, with the minimum transverse distance required for effective driving of the output axle shafts when input rotational energy is received from a suitable prime mover~
' ' ` ' ~ ' 1~313678 A second shaft is connec-ted to the output pulley with a first gear supported on the second shaft, a third shaft spaced from the second shaft, a second gear mounted on the third shaft in meshing engagement with the first gear, and a third gear mounted on the third shaft for rotation therewith. A differential mechanism is provided which includes an input ring gear connected to be driven by the third gear and adapted to drive a pair of axle shafts so that the axle shafts are driven through a four-axis drive train by the prime mover.
The invention allows the provision oE a continuously variable transmission suitable for automotive use which is simple to manufacture, of a practical size, and with a correspondingly reduced weight, while all the drive and control components are mounted on four axes, to reduce total width and allow installation in a small volume.
sb/ 2a -' -~3?C~'7~
079063-BL -3~
The invention will be more clearly understood from the following description which is given by way of example only with reference to the accompanying drawings, in which:
Figure 1 is a simplified diagram of a continuously variable transmission constructed in accordance with this invention;
Figures 2 and 3 together represent a cross-section of the transmission shown more generally in Figure l; and Figure 4 is a representation of the displacements between the axes of the transmission components shown in Figures 1, 2 and 3.
Figure 1 depicts in simplified form the transmission 10 of this invention. The transmission 10 includes a hydrodynamic device 14, a forward reverse planetary mechanism 24, a belt and pulley mechanism 53, a reduction gear section 63, and a differential mechanism 74.
A vehicle engine, for example, drives input or drive shaft 11. Drive shaft 11 is connected to an impeller 12 of a hydrodynamic device 14, shown as a fluid coupling which also has a turbine 16. The turbine is coupled through a torsional damper 18 to a first shaft 20, aligned along a first axis referenced A. A lock-up clutch 22 is positioned to lock the impeller to the turbine and shaft 20 with minimal losses when this clutch is actuated.
A forward-reverse planetary gear set 24 includes a sun gear 26, a pair of planet gears 28,30 and a ring gear 32. The planet or pinion gears 28,30 mesh with each other, with the ~irst pinion 28 also meshing with sun gear 26, and the outer pinion 30 in the mesh with ring gear 32. The pinion gears are supported on the carrier arms 34,36, of a carrier output element 38. A clutch 40 is connected between sun gear 26 and ring gear 32. A band brake mechanism 42 is coupled between ring gear 32 and ground. It is thus apparent that engagement of clutch 40 effectively locks up the sun gear to the ring gear, and provides a 1:1 ratio t;~3 , drive between shaft 20 and the output member 38 which is tied to another shaft 44. Release of clutch 40 and en-gagement of the band brake 42 grounds ring gear 32, to effect a reverse rotation of the shaft 44 with respect to the input angular displacement of shaft 20.
Belt-and-pulley mechanism 53 includes a shaft 44 connected to a movable sheave of an input or first pulley assembly 48, which also includes a movable sheave 50.
It will become apparent from the subsequent explanation 10 that the sheaves 46,50 of the first pulley assembly 48 are mounted for common rotation about axis A, but in a lateral sense, sheave 46 is fixed with respect to lateral movement whereas sheave 50 is movable along the direction of axis A. Hence the terms "fixed" and "movable" as applied to the sheave portions of each pulley assembly described herein, and in the appended claims, refer to lateral movement along an axis such as axis A and not to rotational or other conventional displacement. A fluid chamber 52 is defined behind movable sheave 50 as shown in a general manner, so that the admission of fluid under pressure into this chamber will displace movable sheave 50 to the right as shown in the drawing, and removal of fluid from the chamber will allow the sheave to be displaced to the left.
A belt 54 provides a driving connection between first pulley 48 and a second or output pulley 56, which includes a fixed sheave 58 and a movable sheave 60. A fluid chamber 52 is defined adjacent movable sheave 60 to afford dis-placement of this sheave to the left and right along axis B.
Thus the controlled displacement of adjustable sheave 50 in the first pulley 48, and a concomitant displacement in an opposite sense of the other movable sheave 60 in the output pulley 56, effects a change in the drive ratio be-tween shaft 20 and shaft 64, coupled to fixed sheave 58, in a well known manner. A more complete disclosure of .
`
such an arrangement is described in U. S. Patent No.
4,143,558 which issued March 13, 1979, and thus an ex-tensive showing and description of the movable pulley arrangements in such a drive system will not be given herein.
Reduction gear section 63 includes a first gear 66 affixed to one end of shaft 64, which is aligned along axis B. A second gear 68 is in mesh with gear 66 and is connected to a third shaft 70, aligned on third axis designated C. A third gear 72 is also connected to third shaft 70.
Differential mechanism 74 includes a ring gear 76 meshing with third gear 72 on shaft 70. The differential also includes pinion gears 80 mounted on a center pin 79, in turn mounted in a case on carrier 78, and a pair of output or side gears 82,84 meshing with gears 80 and connected respectively to individual axle shafts 86 and 88, aligned on a fourth axis designated D. Thus when input energy from any suitable prime mover is applied over input shaft 11, the output or axle shafts 86,88 are driven in a manner apparent from this brief explanation. A more detailed explanation of this structure and its operation will now be set out.
Considering now the more detailed showing of Figure ~, pilot 11 is welded or otherwise connected to cover 90, which in its turn is connected to impeller ]2 of fluid coupling 14. Those skilled in the art will appreciate that other hydrodynamic devices, such as a torque converter, could be substituted for fluid coupling 14. ~ driveplate assembly 92 incorporating a driveplate 96 is connected by fastening means, shown as bolts 94, to the prime mover, and fastened by additional nuts, studs or screws 98 to cover 30.
6~78 Lock-up clutch 22 includes a plurality of friction plates 100, certain of which are affixed to member 102 of the torsional damper 18. The other clutch plates are affixed to an extension of clutch cylinder 104, which in turn is welded to cover 90 for rotation as input drive plate 96 is driven. A fluid chamber 106 is coupled by a conduit 108 to another conduit 110, in the center of hollow shaft 112. A gear pump 114 is mounted on and driven by shaft 112, to provide the fluid under pressure for operating lock-up clutch 22 and the other fluid-actuated components of the arrangement shown in Figures 2 and 3.
Turbine element 16 is coupled by plate 116 to the damper 18, and the output side of damper 18 is connected 15 to member 118, which in turn is splined to first shaft 20 on axis A.
Shaft 20 is also splined to sun gear 26 of the planetary gear set 24, and is likewise splined to a forward clutch cylinder 120 which carries certain of the 20 friction discs 122 in forward clutch 40. The other clutch plates are affixed to forward clutch hub member 124, which in turn is welded to a ring gear support 126, one end of which is fastened to ring gear 32 of the forward-reverse gear set.
The carrier pin 36 is received in carrier output element 38, which is connected by a plurality of screws 128 (only one of which is shown) to laterally fixed sheave 46 of first or input pulley 48. Sheave 46 is journalled about axis A, and a bearing 130 is positioned between 30 sheave 46 and the adjacent portion 132 of the trans-mission housing. Sheave 50, is connected to fixed sheave 46/133 via a ball spline (not shown) which permits lateral movement only. In a rotational sense sheave 50 is, in effect, splined to sheave 46 for drive transmiss~on 35 puposes. These sheaves 45 and 50 of input pulley 4 rotate as an entity. The provision of fluid in the :
1'1 3~
chamber 52 is effective to displace movable sheave 50 to the right as shown in the drawing, from its maximum left position as illustrated, to increase the effective diameter of the pulley arrangement as seen by the belt.
The annular wall member 134 forms the rear wall of the fluid chamber, and a portion of this member also provides a stop for the extremity of adjustable sheave 50.
A seal member 136 is provided between wall member 134 and a cylinder 138 to retain the fluid within charnber 52 as the movable sheave is displaced to the right and then again to the left. Details of the metal belt itself and the more precise details of the sheave construction and arrangement are not shown in Figures 2 and 3, in that such arrangements are now known in this art. For example, see United States Patent No.
4,143,558 - Van Deursen et al, entitled "Variable-V-Belt Transmission", which issued March 13, 1979.
Second shaft 64 is mounted on the second axis, referenced B, at the juncture of Figures 2 and 3.
Shaft 64 is journalled between a bearing 142 at the left end, and another bearing assembly 144 at the right end. Fixed sheave 58 is integral with shaft 64 for rotation therewith about axis B when the output pulley assembly 56 receives angular drive over the belt (as represented iII ~igure 1) from the input pulley arrangement 48. In Figures 2 and 3, movable sheave 60 is connected to fixed pulley 58 by a ball spline (not shown), as explained above in connection with sheaves 50,46 of the first pulley. A first annular member 148 has one end portion affixed in shaft 64 for rotation therewith, and an additional outer annular member 150 is affixed to the movable pulley sheave 60 for cooperation with member 148 and the side wall of the pulley to define f]uid chamber 62. An orifice 1~2 in member 148 provides metered flow of fluid from - 1~3~7~
chamber 62 into the adjacent chamber portion 154 when chamber 62 is pressurized.
Fluid under pressure is supplied through a passage 162 in a member 146, through a passage 156 in the center of shaft 140, a radial passage 158 and a channel 160 within movable sheave 60 to complete the path for fluid transfer into chamber 62. In general the construction of the movable sheave 60 is similar to that shown above in connection with sheave 50 and depicted in greater detail in the patent referenced above.
Reduction gear section 63 includes gear 66 affixed to the left end of shaft 64, meshing with adjacent gear 68 to provide a first reduction through the transmission.
Gear 68 is splined to third shaft 70, journalled about a central axis C, the third axis of this arrangement.
Bearings 170,172 support shaft 70 in the position in-dicated. Also affixed to third shaft 70 is another gear 72, meshing with ring gear 76 of differential 74 which rotates about the fourth axis, D, of this system.
Ring gear 76 is secured to a differential carrier 78, which thus rotates with ring gear 76 and drives center pin 79 of differential 74. Pin 79 has rotatably mounted thereon pinion gears 80 of the differential, and the pinion gears in turn mesh with side gears 82,84 which are connected to drive axle shafts 86,88.
In operation, drive is supplied from the prime mover through driveplate 96 to cover 90, which drives impeller 12. This provides drive to turbine 16, which through torsional damper 18 drives shaft 20. Cover 90, via the cover hub, imparts drive to shaft 112 and thus to pump 114. The pump provides fluid under pressure through channel 110 in shaft 112, and other channels, for energizing the various components previously described.
When the turbine approaches the speed of the impeller, lock-up clutch 22 will be actuated in a well known manner by admitting fluid through the channel 108,106 to engage .
., ~3~78 07~063-BL -~-the clutch discs and in e~fect lock cover 90 to the torsional damper 18, to eliminate any losses in the fluid coupling. Accordingly, at this time shaft 20 is being driven from cover 90, but there is no drive over pulley system 53 until either clutch 40 or brake 42 is engaged.
Assuming it is desired to drive the vehicle in which the transmission is mounted in the forward direction, fluid is admitted into the chamber adjacent clutch plates 122 of forward clutch 40, in effect locking sun gear 26 to ring gear 32, and drive is taken from planet carrier 38 to drive fixed sheave 46 of first pulley assembly 48.
Pulley assemblies 48,56 are depicted in their start-up positions, to provide a low-speed, high-torque power transfer between the components on first axis A and those on second axis B. As the second pulley assembly 56 is driven, first gear 66 on shaft 64 is also driven, and this in turn drives gear 68, which meshes with gear 66. Gear 68, mounted on third shaft 70 on axis C, imparts drive to this shaft which in turn rotates gear 72 which meshes with ring gear 76. This in turn drives differential 74 to drive axle shafts 86,88.
If it is desired to reverse the direction of power flow from the prime mover to the axle shafts 86,88, forward clutch 40 is released, unlocking sun gear 26 from ring gear 32. Band brake 42 is then engaged, locking ring gear 32 to the transmission housing. Drive is then taken from sun gear 26 through planet carrier 38, to drive fixed sheave 46 in the opposite direction than that obtained when clutch 40 was engaged. The remainder of the system operates in the same manner as previously described to provide opposite rotation of axle shafts 86,88.
Figure 4 shows the spatial relationship between the four separate axes of the system shown in Figures 1-3, .~3~3~7~
viewed from the left hand side of a vehicle in which the transmission of the invention is mounted. Tbe center-line of the engine is shown along the vertical axis and axis A is on the centerline. The distances between axis A and the second, third and fourth axes B, C and D are indicated in millimeters on the illustration. At the right of the drawing, the vertical distances between axes A and B, and between axes A and D, are also shown.
It is thus apparent by mounting the several assemblies shown in Figures 1-3 in the manner shown, a system is provided for incorporating a continuously variable trans-mission on a multiple axis arrangement, with the minimum transverse distance required for effective driving of the output axle shafts when input rotational energy is received from a suitable prime mover~
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A transmission adapted to be driven by a prime mover, which transmission comprises a first shaft, a hydro-dynamic device comprising a fluid coupling having turbine and impeller elements, a torsional damper coupling said turbine element to said first shaft and said impeller adapted for connection to the prime mover, a lock-up clutch engageable to drivingly connect said impeller and turbine elements for rotation together, a gear pump connected to be driven when said first shaft is driven and to provide fluid under pressure for operating the lock-up clutch, a continuously variable speed mechanism having an input pulley mounted for rotation on said first shaft, an output pulley, and a belt intercoupling said pulleys, each of said pulleys including a pair of sheaves, one sheave of each pair being fixed with respect to lateral movement and the other sheave in that same pair being movable laterally relative to said one sheave, a planetary forward-reverse gear set connected to said first shaft, a clutch and a brake operatively associated with said planetary gear set to regulate the direction of rotation of said input pulley, a second shaft connected to said output pulley, a first gear supported on said second shaft, a third shaft spaced from said second shaft, a second gear mounted on said third shaft in meshing engagement with said first gear, a third gear mounted on said third shaft for rotation therewith, and a differential mechanism including an input ring gear connected to be driven by said third gear and adapted to drive a pair of axle shafts, whereby the axle shafts are driven through a four-axis drive train by the prime mover.
2. A transmission as claimed in Claim 1, wherein said hydrodynamic device is a fluid coupling.
3. A transmission as in Claim 1, wherein said third gear is formed integrally with said third shaft and said second gear is assembled to said third shaft separately and drivingly connected thereto by splines.
4. A transmission as in Claim 3, wherein said third gear is smaller in diameter than said second gear, whereby the axis of rotation of said second and third shafts and said axle shafts are located at minimum distances with respect to one another.
5. A transmission as in Claim 1, wherein said planetary forward-reverse gear set includes a sun gear connected to said first shaft, a planetary carrier connected to said input pulley, a ring gear being operatively associated with said brake mechanism, and said carrier including a plurality of pinion gears certain of which mesh with the ring gear and certain of which mesh with said sun gear;
said clutch being connected between said ring gear and said sun gear, whereby when said clutch is engaged a 1:1 drive is provided through said gear set in the forward direction, and when said brake is engaged said ring gear will be held stationary and the carrier and input pulley will be driven in the reverse direction.
said clutch being connected between said ring gear and said sun gear, whereby when said clutch is engaged a 1:1 drive is provided through said gear set in the forward direction, and when said brake is engaged said ring gear will be held stationary and the carrier and input pulley will be driven in the reverse direction.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7931189A GB2058251B (en) | 1979-09-07 | 1979-09-07 | Automotive transmission with continuously variable speed mechanism |
| GB79/31189 | 1979-09-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1138678A true CA1138678A (en) | 1983-01-04 |
Family
ID=10507694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000359235A Expired CA1138678A (en) | 1979-09-07 | 1980-08-28 | Automotive transmission with continuously variable speed mechanism |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS5646146A (en) |
| AU (1) | AU533794B2 (en) |
| CA (1) | CA1138678A (en) |
| DE (1) | DE3032121A1 (en) |
| FR (1) | FR2465130A1 (en) |
| GB (1) | GB2058251B (en) |
| IT (1) | IT1132689B (en) |
| SE (1) | SE443627B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1172232B (en) * | 1981-08-11 | 1987-06-18 | Fiat Auto Spa | DEVICE FOR THE TRANSMISSION OF THE MOTORCYCLE FROM THE CRANKSHAFT TO THE HALF-AXLES OF THE TWO DRIVE WHEELS OF A CAR VEHICLE THROUGH A CONTINUOUS SPEED VARIATOR WITH EXPANDABLE PULLEYS |
| JPS5842855A (en) * | 1981-09-08 | 1983-03-12 | Nippon Denso Co Ltd | Power transmission device for vehicle |
| NL190767C (en) * | 1982-09-16 | 1994-08-01 | Doornes Transmissie Bv | Transmission, especially for a motor vehicle. |
| JPS5980553A (en) * | 1982-10-30 | 1984-05-10 | Aisin Warner Ltd | Planetary gear transmission for forward/backward selection in automatic stepless speed change gear for vehicle |
| JPS5980554A (en) * | 1982-10-30 | 1984-05-10 | Aisin Warner Ltd | Planetary gear transmission in automatic speed change gear for vehicle |
| WO1984004144A1 (en) * | 1983-04-13 | 1984-10-25 | Zahnradfabrik Friedrichshafen | Continuously variable combined transmission |
| JPS59190563A (en) * | 1983-04-14 | 1984-10-29 | バン・ド−ルネズ・トランズミツシ−・ビ−・ブイ・ | Gearing for automobile |
| ATE33295T1 (en) * | 1984-04-06 | 1988-04-15 | Doornes Transmissie Bv | AUTOMOTIVE TRANSMISSION. |
| US4592457A (en) * | 1984-05-16 | 1986-06-03 | Van Doorne's Transmissie B.V. | Infinitely variable V-belt transmission for a motor vehicle |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB508750A (en) * | 1937-10-13 | 1939-07-05 | Porsche Ferdinand A | Improvements in transmission systems for automobiles |
| GB873451A (en) * | 1957-07-08 | 1961-07-26 | Renault | Improvements relating to the control of change-speed transmissions for automotive vehicles |
| GB1477747A (en) * | 1974-12-21 | 1977-06-22 | Gkn Transmissions Ltd | Variable speed transmission means |
| JPS5219861A (en) * | 1975-08-08 | 1977-02-15 | Toyota Motor Corp | Driving device for autocar |
| NL162183C (en) * | 1976-02-09 | 1980-04-15 | Doornes Transmissie Bv | INFLATABLE VARIABLE DRIVE. |
-
1979
- 1979-09-07 GB GB7931189A patent/GB2058251B/en not_active Expired
-
1980
- 1980-08-15 AU AU61509/80A patent/AU533794B2/en not_active Ceased
- 1980-08-15 SE SE8005776A patent/SE443627B/en not_active IP Right Cessation
- 1980-08-26 DE DE19803032121 patent/DE3032121A1/en not_active Withdrawn
- 1980-08-28 CA CA000359235A patent/CA1138678A/en not_active Expired
- 1980-09-03 FR FR8019021A patent/FR2465130A1/en active Granted
- 1980-09-05 JP JP12339480A patent/JPS5646146A/en active Pending
- 1980-09-05 IT IT24514/80A patent/IT1132689B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| FR2465130A1 (en) | 1981-03-20 |
| SE8005776L (en) | 1981-03-08 |
| JPS5646146A (en) | 1981-04-27 |
| GB2058251A (en) | 1981-04-08 |
| IT8024514A0 (en) | 1980-09-05 |
| FR2465130B1 (en) | 1983-12-09 |
| GB2058251B (en) | 1983-07-06 |
| DE3032121A1 (en) | 1981-03-19 |
| AU533794B2 (en) | 1983-12-08 |
| IT1132689B (en) | 1986-07-02 |
| AU6150980A (en) | 1981-03-12 |
| SE443627B (en) | 1986-03-03 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |