CA1141407A - Seal and seal assembly - Google Patents
Seal and seal assemblyInfo
- Publication number
- CA1141407A CA1141407A CA000335582A CA335582A CA1141407A CA 1141407 A CA1141407 A CA 1141407A CA 000335582 A CA000335582 A CA 000335582A CA 335582 A CA335582 A CA 335582A CA 1141407 A CA1141407 A CA 1141407A
- Authority
- CA
- Canada
- Prior art keywords
- seal
- leg
- set forth
- end portion
- sides
- 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
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- Sealing Of Bearings (AREA)
Abstract
Seal and Seal Assembly Abstract A seal has a body, a leg and first and second sealing areas. The seal is used in a seal assembly having first and second members such as, for example, a frame portion and steering knuckle of a work vehicle.
Apparatus such as a bearing supports the knuckle in rotation relative to a king pin of the frame portion.
Foreign matter can enter between the frame portion and steering knuckle and interfere with vehicle steering.
In the assembly, the sealing surfaces contact substan-tially perpendicular surfaces of the frame portion to block passage of foreign matter to the bearing. A
second end portion of the seal leg can be controllably deflectable in order to permit overfill of lubricant to pass from the bearing cavity between the frame portion and steering knuckle.
Apparatus such as a bearing supports the knuckle in rotation relative to a king pin of the frame portion.
Foreign matter can enter between the frame portion and steering knuckle and interfere with vehicle steering.
In the assembly, the sealing surfaces contact substan-tially perpendicular surfaces of the frame portion to block passage of foreign matter to the bearing. A
second end portion of the seal leg can be controllably deflectable in order to permit overfill of lubricant to pass from the bearing cavity between the frame portion and steering knuckle.
Description
Description Seal and Seal Assembly Technical Fie_ The invention relates to a seal and seal assembly. More particularly, the invention relates to a leg of a seal which is controllably deflectable and has first and second sealing areas in slidable contact with substantially perpendicular surfaces in the seal assembly.
Ba~round Art In the use of a seal and seal assembly, it is desirable to block passage of foreign matter in one direction but to permit deflection of the seal in another direction to, for example, allow overfilling a bearing wi-th lubricant to clean the bearing.
U.S. Patent 4,043,620 which issued to Otto on August 23, 1977, discloses configurations of bearing seals used to seal openings between a housing and a rotatable shaft.
U.S. Patent 3,687,464 which issued to Jackson et al on August 29, 1972, discloses a seal which has a U-shaped cross-section and is used to seal against a shaft and a housing perpendicularly oriented to the shaft. U.S. Patent 3,841,723 which issued on October 25, 15, 1974, to Kelso shows a seal having a dust lip and a spring biased seal lip.
For example, a steering assembly for a work vehicle commonly includes an axle or frame mounted king pin about which a steering knuckle is rotatable.
Rotation of the steering knuckle provides corresponding rotation of a spindle to controllably turn a wheel of the vehicle attached thereto. The steering knuckle is
Ba~round Art In the use of a seal and seal assembly, it is desirable to block passage of foreign matter in one direction but to permit deflection of the seal in another direction to, for example, allow overfilling a bearing wi-th lubricant to clean the bearing.
U.S. Patent 4,043,620 which issued to Otto on August 23, 1977, discloses configurations of bearing seals used to seal openings between a housing and a rotatable shaft.
U.S. Patent 3,687,464 which issued to Jackson et al on August 29, 1972, discloses a seal which has a U-shaped cross-section and is used to seal against a shaft and a housing perpendicularly oriented to the shaft. U.S. Patent 3,841,723 which issued on October 25, 15, 1974, to Kelso shows a seal having a dust lip and a spring biased seal lip.
For example, a steering assembly for a work vehicle commonly includes an axle or frame mounted king pin about which a steering knuckle is rotatable.
Rotation of the steering knuckle provides corresponding rotation of a spindle to controllably turn a wheel of the vehicle attached thereto. The steering knuckle is
-2-supported about the king pin by a bearing which must be protected and periodically lubricated to assure proper performance of the steering assembly.
The bearing is exposed to the environment of the work vehicle through an opening loca~ed between the steering knuckle and axle owing to the relative rota-tion of the two components. Heretofore, a seal having two lips or legs and being connected to the steering knuckle has been used. The two lips contact or seal against a surface on the frame or axle to block passage of foreign matter to the bearing. However, when lubri-cant is subsequently injected into the bearing said seal also blocks passage of the lubricant out of the bearing. In situations where the bearing is over-filled, such as to drive old lubricant from thebearing, this can cause damage to the seal or improper performance of the steering assembly. The result is a waste of time and labor owing to the reduced perfor-mance of the steering assembly or downtime in replacing the seal.
Therefore, it is desirable to provide a seal which blocks passage of foreign matter in one direc-tion, such as to the bearing, and controllably deflects in another direction to permit lubricant overfill of the bearing to relieve for substantially preventing damage to the seal as a result of the overfill.
Disclosure of Invention In one aspect of the present invention, a seal comprises a body; a leg having first, second and third sides, a middle portion and first and second end por-tions and being connec-ted at the first end portion to the body, the first side being in cross-section straight along its full length and generally opposed to the second side, the second side having in cross-- section a straight portion intersecting the third side '~,
The bearing is exposed to the environment of the work vehicle through an opening loca~ed between the steering knuckle and axle owing to the relative rota-tion of the two components. Heretofore, a seal having two lips or legs and being connected to the steering knuckle has been used. The two lips contact or seal against a surface on the frame or axle to block passage of foreign matter to the bearing. However, when lubri-cant is subsequently injected into the bearing said seal also blocks passage of the lubricant out of the bearing. In situations where the bearing is over-filled, such as to drive old lubricant from thebearing, this can cause damage to the seal or improper performance of the steering assembly. The result is a waste of time and labor owing to the reduced perfor-mance of the steering assembly or downtime in replacing the seal.
Therefore, it is desirable to provide a seal which blocks passage of foreign matter in one direc-tion, such as to the bearing, and controllably deflects in another direction to permit lubricant overfill of the bearing to relieve for substantially preventing damage to the seal as a result of the overfill.
Disclosure of Invention In one aspect of the present invention, a seal comprises a body; a leg having first, second and third sides, a middle portion and first and second end por-tions and being connec-ted at the first end portion to the body, the first side being in cross-section straight along its full length and generally opposed to the second side, the second side having in cross-- section a straight portion intersecting the third side '~,
-3 and oriented to extend parallel to the first side along the full length of the first side and an arcuate por-tion defining an arcuate surface extending curviline-arly inwardly in a direction generally toward the first side and defining a reduced cross-sectional area of the leg at the middle portion relative to the second end portion, the third side being in cross~section straight along its full length and intersecting the first and second sides at the second end portion~ the second end portion being controllably deflectable relative to the first end portion in response to a force exerted on at least one of the first and third sides; and first and second sealing areas positioned on the leg adjacent the intersection of the first and third sides, and the 15 intersection of the second and third sides, ::
respectively.
Brief Description of Drawings FIG. 1 is a diagrammatic view showing one embodiment of the seal assembly of the present inven-tion associated with a steering mechanism;
FIG. 2 is a diagrammatic partial view of FIG.
1 showing the invention in greater detail;
FIG. 3 is a aiagrammatic cross-sectional view showing one embodiment of the seal of the present invention; and FIG. 4 is a diagrammatic view showing another embodiment of the seal and seal assembly of the present invention associated with the steering mechanism.
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Best Mode for Carrying Out the Inven-tion Referring to FIG. 1, a seal assembly 10 includes first and second members 12,14 ro-tatable one relative to the other and a seal 16. The first member '2 is, for example, a frame portion 20 of a work vehicle 21. Said frame portion 20 includes an axle 22, king pin 24 and a spacer 26. The second member 14 is, for example, a s-teering knuckle 27 of the work vehicle which is positioned adjacent said frame portion 20. The steering knuckle 27 is rotatable about the fixed frame portion 20 in response to input forces exerted in steering the work vehicle 21. Means 28, shown as a bearing 30, is provided for supporting said ~rame portion 20 and the steering knuckle 27 in rotation one relative to the other. Such wheel steering construction is well known in the vehicle art.
The frame portion 20 has first and second surfaces 32,34 oriented substantially perpendicular one relative to the other and defined by the spacer 26 and axle 22, respectively. The frame portion 20 and steer-ing knuckle 27 define an annular opening 36 between said steering knuckle 27 and sald first and second surfaces 32,34. The seal 16 in the seal assembly 10 is annular in configuration and is positioned at a location sufficient for controllably sealing the passage of material through said annular opening 36 as will be hereinafter described.
Referring particularly to FIG. 3~ the seal 16 includes a body 38, a leg 40 and first and second 30 sealing areas 42,44. The leg 40 has first, second and third sides 46,48,50, first and second end portions 52,~4 and a middle portion 56. Said leg 40 is connected at the first end portion 52 to the body 38 and extends outwardly from said body 38. The first and second sides 46,48 are substantially linear, and generally ~B~4~
opposed one to the other. The third side 50 intersects the first and second sides 46,48 at the second end portion 54 preferably at respective angles ~1,A2 o~
about 90~. Said seal 16 preferably has only a single leg 40 as shown.
The first and second sealing areas 42,44 are each positioned on the leg 40 adjacent the intersection of the first and third s~des 46,50 and the intersection of the second and third sides 48,50, respectively. Said sealing arèas 42,44 are preferably located at or formed by the intersection of the first and thixd sides 46,50 and the second and third sides 48,50 respectively.
The second end portion 54 of the leg 40 is of a construction suffic~ent for being controllably deflectable relative to the first end portion 52 in response to a force exerted on at least one oE the first and third sides 46,50 of the leg 40. In the embodiment shown, the second side 48 of the leg 40, which is generally opposed to the first side 46, is of a configuration sufficient for defi~ing a reduced cross-sectional area of said leg 40 at the middle portion 56 relative to said second end portion 54. The reduction in cross-sectional area, as further defined below by the configuration of said second side 48, provides controllable deflection of the second end portion 54 for the purposes hereinafter discussed.
The second side 48 of the leg 40 has an arcuate surface 58 extending curvilinearly inwardly on said leg 40 from the second end portion 54 toward the middle portion 56 in a direction generally toward the first side 46. The leg 40 has a width at Wl defined by the distance between the first and second sides 46,48 and the arcuate surface 58 extends inwardly at the middle portion 56 about one-half of said width (shown at W2). In other words, the second side 48 extends curvilinearly inwardly and progressively reduces the ' .
cross-sectional area of the second leg 40 from the second end portion 54 toward the middle portion 56.
Thus, the cross-sectional area adjacent W2 is less than the cross-sectional area adjacent Wl. It is also desirable that said arcuate surface 58 further extend curvilinearly outwardly from the middle portion 56 toward the first end portion 52 of the leg 40 in a direction from the ~irst side 46 and intersect the body 38 at a location 60 at which the leg 40 connects at the second side 48 to the body 38.
The second side 48 has an arcuate portion 62 defining the arcuate surface 58 of said second side 48 and a substantially linear portion 64 intersecting the third side 50 of the leg 40 and which is preferably substantially parallel to the first side 46 of said leg 40. Said linear portion 64 has a length (~1) about one-third the length L2 of the first side 46 in order to maintain sufficient width at the second end portion 54 of the leg 40 for adequate rigidity of the seal 16 in position in the seal assembly 10 against the first and second surfaces 32,34 of the frame portion 20.
Further, the first sealing area 42 is positioned on the leg 40 at a location immediately adjacent a point 66 on . the second side 48 from which the arcuate surface 58 extends inwardly toward the first side 46.
Referring to the embodiment of FIG. 4, means 63 is provided for biasing the second end portion 54 of the leg 40 relative to the first end portion 52 of said leg 40 in a direction Dl from the second side 48 toward the first side 46 of the leg 40. Said biasing means 63 is shown as a spring 65, such as a helica1 spring, positioned on the second side 48 of the leg 40 and retained in a groove 67 formed in the arcuate portion 62 of said second side 48. In an annular configuration of the seal 16, which is the preferred embodiment, the spring 65 tends to bias outwardly against and about . : ' ' ' , `" 7 said second side 48 to urge said first and second sealing areas 42,44 into contact with the first and second surfaces 32,34 when the seal 16 is posi~i~ned in the seal assembly 10. Said biasing means 63 can also be, for example, a ring or similar element which tends to expand outwardly against the second side 48.
q'he body 38, leg 40 and first and second sealing areas 42,44 are preferably o~ unitary, elasto-meric construction. The seal 16 also has a carrier element 68 connected or molded to the body 38 o~ at least first and second sides 70,72 of said body 40.
The carrier element 68 is of metallic construction as is known in the art. The first and second sides 46,50 of the leg 40 intersect third and fourth sides 74,76 of the body 38 and define the orientation of the leg 40 relative to the body 38 as shown. It should be under-stood that the seal 16 can be of other conflgurations as is known in the art without departing from the invention.
In the installed position of the seal 16 in the seal assembly 10, the seal body 38 is connected to the steering knuckle 27 and positioned adjacent and extending about the annular opening 36. In the embodi-ment shown, said seal 16 is press fit into a substan-tially circular bore 77 defined by the steering knuckle 27 owing to the oversize configuration of the metallic carrier element 68. The first sealing area 42 is positioned in sealing, slidable contact with the first surface 32 of the frame portion 20. The second sealing surface 44 is positioned in sealing slidable contact with the second surface 34 of the frame portion 20. It is desirable that the second end portion 54 of the leg 40 be controllably deflectable as above described with respect to the individual seal 16. ~he first and second sealing areas 42/44 are thus removable from contact with the first and second surfaces 32,34, respectively, in response to controllably deflectiny the second end portion 54.
A line 78 passing between the first and second sealing areas 42,44 intersec~s the first surface 32 of the frame portion 20 at an angle A5 in a range of about 45 to about 90. The third side 50 extends be-tween said sealing areas 42,44 and defines said line 78. The angle A~ in the preferred embodiment is about 45. In other words, said line 78 passing between the sealing areas 42,44 defines a chord 80 of a circle 82 having a radial line 84. The radial line 84 substan-tially bisects the chord 80 and passes immediately adjacent the intersection 86 of first and second planes 32',34' defined bv the first and second surfaces 32,34 of the frame portion 20. As is also shown, the first side 42 of the leg 40 intersects the Eirst surface 32 of the frame portion 20 at an angle A6 of about 60.
The linear portion 64 of the second side 44 intersects the second surface 34 of the frame portion 20 at an angle ~7 of about 60.
It is desirable that the first and second sealing areas 42,44 urge against the first and second surfaces 32,34 of the frame portion 20, respectively, in order to maintain a positive "seal" against said surfaces 32,34. The biasing means 65 or spring 67 in the embodiment of FIG. 4 biases the second end portion 54 of the leg 40 relative to the first end portion 52 of the leg 40 in a direction D2 toward the first surface 32 of the frame portion 20 to assure the positive 3a "seal". Said direction D2 is shown substantially the same as the direction Dl. The positive "seal" can also be assured by preloading the leg 40. In o-ther words, the orientation of the first side 46 of the leg 40, as represented by angle A3~ (FIG. 3) can be provided in the seal 16 such that said first side 46 is displaced ~rom said angle A3 to an installation angle A4 (FIG. 2) when the seal 16 is in the installed position. Thus, angle A3 is provided less than angle A4 to establish t~e preloaded condition.
On the sealed assembly 10, the leg 40 forms an annular chamber 88 with the frame portion 20. The annular chamber 88 is defined by the first and second surfaces 32,34 of said frame portion 20 and the third side 50 of the leg 40. The leg 40 also forms ~irst and second channels 90,92 with said frame portion 20. Said first and second channels 90,92 are defined by the first side 42 of the leg 40 and the first surface of the frame portion 20 and the second side 44 of the leg 40 and the second surface 34 o the frame portion 20, respectively. Said channels 90,92 are of a construc-tion suficient for being positionable in communication one with the other in response to removing the first and second sealing areas 42,44 from contac-t with the first and second surfaces 32,34 respectively.
It is desirable that in the seal assembly 10 the second end portion 54 of the leg 40 be controllably deflectable relative to the first end portion 52 of the leg 40, as was explained previously with respect to the seal 16. Also, the configuration of said seal 16 is preferably also as above explained with respect to the seal 16. The first and second sealing areas 42,44 are removable from contact with the first and second surfaces 32,34 of the frame portion 20, respectively, in response to controllably deflecting said second end portion 54, as is shown by way of example in FIG. 1. The channels 90,92 are in fluid con~unication one with the other in response to exerting a force on at least one of the first and third sides 46,50 of the leg 40 for deflecting said second end portion 54.
It should be understood that the seal 16 and seal assembly 10 can be of other configurations as is known in the art without departing from the invention.
Industrial Applicabilit~v In the use of -the seal 16 in the seal assembly 10, the first and second sealing areas 42,44 slidably contact the first and second surfaces 32,3~ of the frame portion 20 to block passage of foreign matter through the annular opening 36 and to the bearing 30.
Overfill of lubricant in the bearing 30 controllably deflects the second end portion 54 of the leg 40 to relieve lubricant through the annular opening 36 to clean the bearing 30.
For example, input forces on the steering knuckle 27 through a steering arm 93 cause said knuckle 27 to rotate relative to the frame portion 20. In rotation the first and second sealing surfaces 42,44 wipe or slide along the frame portion 20 to prevent passage of di~t, water o~ the like through the annular opening 36 to the bearing 30. Thus, the bearing 30 is substantially protected from the effects of the environ-ment of the work vehicle 21. Said sealing surfaces 42,44 remain seated on the surfaces 32,34 of the frame portion 20 and the second end portion 54 of the ley 40 resists deflection from forces exerted on the seal 16 by dirt or the li~e owing to the substantially linear configuration of the first side 46 of the leg 40 and its orientation relative to the frame portion 20.
After a period of use of the steering of the vehicle, it may be desirable to relubricate said bear-ing 30. The bearing 30 is commonly overfilled to permit flushiny of the old lubricant from the bearing 30. As the lubricant passes through the bearing 30, it will urge initially against the first side 46 of the leg 40 and exert a force on said first side 46. Where the force is sufficient, the second end portion 54 of the leg 40 will deflect about the point of intersection of the first side 46 of the leg 40 and the body 38 owing to the curvilinear configuration of the second --ll--side 48 of the leg 40 and the corresponding reduction in cross-sectional area. Deflection of the second end portion 54 removes the sealing surfaces 42,44 from contact with the frame portion 20. The lubricant then flows from the first channel 90 through the annular chamber 88 and out the second channel 92. This action is represented by flow lines 94 in FIG. 1.
Force is also exerted on the third side 50 of the leg 40 during overfill. This tends to promote relief or escape of the lubrlcant from the bearing 30.
Where the first and second seallng surfaces 32,34 urge against the frame portion 20, the relief of saicl lubricant tends to slow owing to the greater force required to overcome, for example, the spring 65 or preload o the leg 40. Following overfill some lubri-cant will be trapped in the annular chamber 88 and will act as an additional barrier to foreign matter.
It should be understood that a force exerted on only the third side 50 of the leg 40 will also deflect the seal 16.
The first and second sealing areas 42,44 preferably are represented by points of contact such as are formed by the intersections of the first and third sides 46,50 and second and third sides 48,50 of the legs 40, respectively, to reduce friction between the seal 16 and frame portion 20. The first sealing area 42 will, however, tend to wear a groove into the first surface 32 during operation of the vehicle steering.
The wearing action on the first sealing area 42 results in movement of the second sealing surface 34 toward the first surface 32, but does not interfere substantially with the performance of the seal 16.
The preferred orientation and configuration of the seal 16 is shown in the drawings The third side 50 intersects the first surface 32 at the angle A5 which is about 45. The first side 46 and linear portion 64 of the second side 48 intersect the first and second surfaces 32,34, respectively, at angles A6,A7 of about 60, It will be evident from a study of the drawings that other orientations or configura-tions of the seal 16 will to sorne degree lessen or increase the effect of the deflection and sealing capabilities of the seal 16. For example, a greater angle A5 tends to reduce the capabilities of seal 16 to relieve the lubricant flowing through -the bearlng 30 owing to a reduction in the size of the relief pathway available to said lubricant.
Other aspects, objects and advantages will become apparent from a study of -the specification, drawings and appended claims.
respectively.
Brief Description of Drawings FIG. 1 is a diagrammatic view showing one embodiment of the seal assembly of the present inven-tion associated with a steering mechanism;
FIG. 2 is a diagrammatic partial view of FIG.
1 showing the invention in greater detail;
FIG. 3 is a aiagrammatic cross-sectional view showing one embodiment of the seal of the present invention; and FIG. 4 is a diagrammatic view showing another embodiment of the seal and seal assembly of the present invention associated with the steering mechanism.
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Best Mode for Carrying Out the Inven-tion Referring to FIG. 1, a seal assembly 10 includes first and second members 12,14 ro-tatable one relative to the other and a seal 16. The first member '2 is, for example, a frame portion 20 of a work vehicle 21. Said frame portion 20 includes an axle 22, king pin 24 and a spacer 26. The second member 14 is, for example, a s-teering knuckle 27 of the work vehicle which is positioned adjacent said frame portion 20. The steering knuckle 27 is rotatable about the fixed frame portion 20 in response to input forces exerted in steering the work vehicle 21. Means 28, shown as a bearing 30, is provided for supporting said ~rame portion 20 and the steering knuckle 27 in rotation one relative to the other. Such wheel steering construction is well known in the vehicle art.
The frame portion 20 has first and second surfaces 32,34 oriented substantially perpendicular one relative to the other and defined by the spacer 26 and axle 22, respectively. The frame portion 20 and steer-ing knuckle 27 define an annular opening 36 between said steering knuckle 27 and sald first and second surfaces 32,34. The seal 16 in the seal assembly 10 is annular in configuration and is positioned at a location sufficient for controllably sealing the passage of material through said annular opening 36 as will be hereinafter described.
Referring particularly to FIG. 3~ the seal 16 includes a body 38, a leg 40 and first and second 30 sealing areas 42,44. The leg 40 has first, second and third sides 46,48,50, first and second end portions 52,~4 and a middle portion 56. Said leg 40 is connected at the first end portion 52 to the body 38 and extends outwardly from said body 38. The first and second sides 46,48 are substantially linear, and generally ~B~4~
opposed one to the other. The third side 50 intersects the first and second sides 46,48 at the second end portion 54 preferably at respective angles ~1,A2 o~
about 90~. Said seal 16 preferably has only a single leg 40 as shown.
The first and second sealing areas 42,44 are each positioned on the leg 40 adjacent the intersection of the first and third s~des 46,50 and the intersection of the second and third sides 48,50, respectively. Said sealing arèas 42,44 are preferably located at or formed by the intersection of the first and thixd sides 46,50 and the second and third sides 48,50 respectively.
The second end portion 54 of the leg 40 is of a construction suffic~ent for being controllably deflectable relative to the first end portion 52 in response to a force exerted on at least one oE the first and third sides 46,50 of the leg 40. In the embodiment shown, the second side 48 of the leg 40, which is generally opposed to the first side 46, is of a configuration sufficient for defi~ing a reduced cross-sectional area of said leg 40 at the middle portion 56 relative to said second end portion 54. The reduction in cross-sectional area, as further defined below by the configuration of said second side 48, provides controllable deflection of the second end portion 54 for the purposes hereinafter discussed.
The second side 48 of the leg 40 has an arcuate surface 58 extending curvilinearly inwardly on said leg 40 from the second end portion 54 toward the middle portion 56 in a direction generally toward the first side 46. The leg 40 has a width at Wl defined by the distance between the first and second sides 46,48 and the arcuate surface 58 extends inwardly at the middle portion 56 about one-half of said width (shown at W2). In other words, the second side 48 extends curvilinearly inwardly and progressively reduces the ' .
cross-sectional area of the second leg 40 from the second end portion 54 toward the middle portion 56.
Thus, the cross-sectional area adjacent W2 is less than the cross-sectional area adjacent Wl. It is also desirable that said arcuate surface 58 further extend curvilinearly outwardly from the middle portion 56 toward the first end portion 52 of the leg 40 in a direction from the ~irst side 46 and intersect the body 38 at a location 60 at which the leg 40 connects at the second side 48 to the body 38.
The second side 48 has an arcuate portion 62 defining the arcuate surface 58 of said second side 48 and a substantially linear portion 64 intersecting the third side 50 of the leg 40 and which is preferably substantially parallel to the first side 46 of said leg 40. Said linear portion 64 has a length (~1) about one-third the length L2 of the first side 46 in order to maintain sufficient width at the second end portion 54 of the leg 40 for adequate rigidity of the seal 16 in position in the seal assembly 10 against the first and second surfaces 32,34 of the frame portion 20.
Further, the first sealing area 42 is positioned on the leg 40 at a location immediately adjacent a point 66 on . the second side 48 from which the arcuate surface 58 extends inwardly toward the first side 46.
Referring to the embodiment of FIG. 4, means 63 is provided for biasing the second end portion 54 of the leg 40 relative to the first end portion 52 of said leg 40 in a direction Dl from the second side 48 toward the first side 46 of the leg 40. Said biasing means 63 is shown as a spring 65, such as a helica1 spring, positioned on the second side 48 of the leg 40 and retained in a groove 67 formed in the arcuate portion 62 of said second side 48. In an annular configuration of the seal 16, which is the preferred embodiment, the spring 65 tends to bias outwardly against and about . : ' ' ' , `" 7 said second side 48 to urge said first and second sealing areas 42,44 into contact with the first and second surfaces 32,34 when the seal 16 is posi~i~ned in the seal assembly 10. Said biasing means 63 can also be, for example, a ring or similar element which tends to expand outwardly against the second side 48.
q'he body 38, leg 40 and first and second sealing areas 42,44 are preferably o~ unitary, elasto-meric construction. The seal 16 also has a carrier element 68 connected or molded to the body 38 o~ at least first and second sides 70,72 of said body 40.
The carrier element 68 is of metallic construction as is known in the art. The first and second sides 46,50 of the leg 40 intersect third and fourth sides 74,76 of the body 38 and define the orientation of the leg 40 relative to the body 38 as shown. It should be under-stood that the seal 16 can be of other conflgurations as is known in the art without departing from the invention.
In the installed position of the seal 16 in the seal assembly 10, the seal body 38 is connected to the steering knuckle 27 and positioned adjacent and extending about the annular opening 36. In the embodi-ment shown, said seal 16 is press fit into a substan-tially circular bore 77 defined by the steering knuckle 27 owing to the oversize configuration of the metallic carrier element 68. The first sealing area 42 is positioned in sealing, slidable contact with the first surface 32 of the frame portion 20. The second sealing surface 44 is positioned in sealing slidable contact with the second surface 34 of the frame portion 20. It is desirable that the second end portion 54 of the leg 40 be controllably deflectable as above described with respect to the individual seal 16. ~he first and second sealing areas 42/44 are thus removable from contact with the first and second surfaces 32,34, respectively, in response to controllably deflectiny the second end portion 54.
A line 78 passing between the first and second sealing areas 42,44 intersec~s the first surface 32 of the frame portion 20 at an angle A5 in a range of about 45 to about 90. The third side 50 extends be-tween said sealing areas 42,44 and defines said line 78. The angle A~ in the preferred embodiment is about 45. In other words, said line 78 passing between the sealing areas 42,44 defines a chord 80 of a circle 82 having a radial line 84. The radial line 84 substan-tially bisects the chord 80 and passes immediately adjacent the intersection 86 of first and second planes 32',34' defined bv the first and second surfaces 32,34 of the frame portion 20. As is also shown, the first side 42 of the leg 40 intersects the Eirst surface 32 of the frame portion 20 at an angle A6 of about 60.
The linear portion 64 of the second side 44 intersects the second surface 34 of the frame portion 20 at an angle ~7 of about 60.
It is desirable that the first and second sealing areas 42,44 urge against the first and second surfaces 32,34 of the frame portion 20, respectively, in order to maintain a positive "seal" against said surfaces 32,34. The biasing means 65 or spring 67 in the embodiment of FIG. 4 biases the second end portion 54 of the leg 40 relative to the first end portion 52 of the leg 40 in a direction D2 toward the first surface 32 of the frame portion 20 to assure the positive 3a "seal". Said direction D2 is shown substantially the same as the direction Dl. The positive "seal" can also be assured by preloading the leg 40. In o-ther words, the orientation of the first side 46 of the leg 40, as represented by angle A3~ (FIG. 3) can be provided in the seal 16 such that said first side 46 is displaced ~rom said angle A3 to an installation angle A4 (FIG. 2) when the seal 16 is in the installed position. Thus, angle A3 is provided less than angle A4 to establish t~e preloaded condition.
On the sealed assembly 10, the leg 40 forms an annular chamber 88 with the frame portion 20. The annular chamber 88 is defined by the first and second surfaces 32,34 of said frame portion 20 and the third side 50 of the leg 40. The leg 40 also forms ~irst and second channels 90,92 with said frame portion 20. Said first and second channels 90,92 are defined by the first side 42 of the leg 40 and the first surface of the frame portion 20 and the second side 44 of the leg 40 and the second surface 34 o the frame portion 20, respectively. Said channels 90,92 are of a construc-tion suficient for being positionable in communication one with the other in response to removing the first and second sealing areas 42,44 from contac-t with the first and second surfaces 32,34 respectively.
It is desirable that in the seal assembly 10 the second end portion 54 of the leg 40 be controllably deflectable relative to the first end portion 52 of the leg 40, as was explained previously with respect to the seal 16. Also, the configuration of said seal 16 is preferably also as above explained with respect to the seal 16. The first and second sealing areas 42,44 are removable from contact with the first and second surfaces 32,34 of the frame portion 20, respectively, in response to controllably deflecting said second end portion 54, as is shown by way of example in FIG. 1. The channels 90,92 are in fluid con~unication one with the other in response to exerting a force on at least one of the first and third sides 46,50 of the leg 40 for deflecting said second end portion 54.
It should be understood that the seal 16 and seal assembly 10 can be of other configurations as is known in the art without departing from the invention.
Industrial Applicabilit~v In the use of -the seal 16 in the seal assembly 10, the first and second sealing areas 42,44 slidably contact the first and second surfaces 32,3~ of the frame portion 20 to block passage of foreign matter through the annular opening 36 and to the bearing 30.
Overfill of lubricant in the bearing 30 controllably deflects the second end portion 54 of the leg 40 to relieve lubricant through the annular opening 36 to clean the bearing 30.
For example, input forces on the steering knuckle 27 through a steering arm 93 cause said knuckle 27 to rotate relative to the frame portion 20. In rotation the first and second sealing surfaces 42,44 wipe or slide along the frame portion 20 to prevent passage of di~t, water o~ the like through the annular opening 36 to the bearing 30. Thus, the bearing 30 is substantially protected from the effects of the environ-ment of the work vehicle 21. Said sealing surfaces 42,44 remain seated on the surfaces 32,34 of the frame portion 20 and the second end portion 54 of the ley 40 resists deflection from forces exerted on the seal 16 by dirt or the li~e owing to the substantially linear configuration of the first side 46 of the leg 40 and its orientation relative to the frame portion 20.
After a period of use of the steering of the vehicle, it may be desirable to relubricate said bear-ing 30. The bearing 30 is commonly overfilled to permit flushiny of the old lubricant from the bearing 30. As the lubricant passes through the bearing 30, it will urge initially against the first side 46 of the leg 40 and exert a force on said first side 46. Where the force is sufficient, the second end portion 54 of the leg 40 will deflect about the point of intersection of the first side 46 of the leg 40 and the body 38 owing to the curvilinear configuration of the second --ll--side 48 of the leg 40 and the corresponding reduction in cross-sectional area. Deflection of the second end portion 54 removes the sealing surfaces 42,44 from contact with the frame portion 20. The lubricant then flows from the first channel 90 through the annular chamber 88 and out the second channel 92. This action is represented by flow lines 94 in FIG. 1.
Force is also exerted on the third side 50 of the leg 40 during overfill. This tends to promote relief or escape of the lubrlcant from the bearing 30.
Where the first and second seallng surfaces 32,34 urge against the frame portion 20, the relief of saicl lubricant tends to slow owing to the greater force required to overcome, for example, the spring 65 or preload o the leg 40. Following overfill some lubri-cant will be trapped in the annular chamber 88 and will act as an additional barrier to foreign matter.
It should be understood that a force exerted on only the third side 50 of the leg 40 will also deflect the seal 16.
The first and second sealing areas 42,44 preferably are represented by points of contact such as are formed by the intersections of the first and third sides 46,50 and second and third sides 48,50 of the legs 40, respectively, to reduce friction between the seal 16 and frame portion 20. The first sealing area 42 will, however, tend to wear a groove into the first surface 32 during operation of the vehicle steering.
The wearing action on the first sealing area 42 results in movement of the second sealing surface 34 toward the first surface 32, but does not interfere substantially with the performance of the seal 16.
The preferred orientation and configuration of the seal 16 is shown in the drawings The third side 50 intersects the first surface 32 at the angle A5 which is about 45. The first side 46 and linear portion 64 of the second side 48 intersect the first and second surfaces 32,34, respectively, at angles A6,A7 of about 60, It will be evident from a study of the drawings that other orientations or configura-tions of the seal 16 will to sorne degree lessen or increase the effect of the deflection and sealing capabilities of the seal 16. For example, a greater angle A5 tends to reduce the capabilities of seal 16 to relieve the lubricant flowing through -the bearlng 30 owing to a reduction in the size of the relief pathway available to said lubricant.
Other aspects, objects and advantages will become apparent from a study of -the specification, drawings and appended claims.
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A seal comprising:
a body;
a leg having first, second and third sides, a middle portion and first and second end portions and being connected at the first end portion to the body, said first side being in cross-section straight along its full length and generally opposed to said second side, said second side having in cross-section a straight portion intersecting the third side and oriented to extend parallel to the first side along the full length of said first side and an arcuate portion defining an arcuate surface extending curvilinearly inwardly in a direction generally toward the first side and defining a reduced cross-sectional area of said leg at the middle portion relative to the second end por-tion, said third side being in cross-section straight along its full length and intersecting said first and second sides at the second end portion, said second end portion being controllably deflectable relative to said first end portion in response to a force exerted on at least one of the first and third sides; and first and second sealing areas positioned on said leg adjacent the intersection of the first and third sides, and the intersection of the second and third sides, respectively.
a body;
a leg having first, second and third sides, a middle portion and first and second end portions and being connected at the first end portion to the body, said first side being in cross-section straight along its full length and generally opposed to said second side, said second side having in cross-section a straight portion intersecting the third side and oriented to extend parallel to the first side along the full length of said first side and an arcuate portion defining an arcuate surface extending curvilinearly inwardly in a direction generally toward the first side and defining a reduced cross-sectional area of said leg at the middle portion relative to the second end por-tion, said third side being in cross-section straight along its full length and intersecting said first and second sides at the second end portion, said second end portion being controllably deflectable relative to said first end portion in response to a force exerted on at least one of the first and third sides; and first and second sealing areas positioned on said leg adjacent the intersection of the first and third sides, and the intersection of the second and third sides, respectively.
2. The seal, as set forth in claim 1, wherein said first and second sealing areas are located at the intersection of the first and third sides and the intersection of the second and third sides respectively.
3. The seal, as set forth in claim 1 wherein said seal has only a single leg.
4. The seal, as set forth in claim 1, wherein said third side intersects the first side at an angle of about 90°.
5. The seal, as set forth in claim 1, wherein said third side intersects the second side at an angle of about 90°.
6. The seal, as set forth in claim 1, wherein said leg has a width defined by the distance between the first and second sides and the arcuate surface of said second side extends inwardly about one-half of said width.
7. The seal, as set forth in claim 1, wherein said arcuate surface extends curvilinearly out-wardly from the middle portion toward the first end portion in a direction from the first side and inter-sects the body.
8. The seal, as set forth in claim 1, wherein the length of the straight portion of the second side is about one-third the length of the first side.
9. The seal, as set forth in claim 1, wherein said body, leg and first and second sealing areas are of unitary, elastomeric construction.
10. The seal, as set forth in claim 1, wherein said seal is of an annular configuration.
11 The seal, as set forth in claim 1, including means for biasing said second end portion of the leg relative to said first end portion of the leg in a direction from the second toward the first side of the leg.
12. The seal, as set forth in claim 11, wherein said biasing means is a spring positioned on the second side of the leg.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000403351A CA1142197A (en) | 1978-12-26 | 1982-05-19 | Seal and seal assembly |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/004,791 US4210339A (en) | 1978-12-26 | 1978-12-26 | Seal and seal assembly |
| US4,791 | 1978-12-26 | ||
| USPCT78/00243 | 1978-12-26 | ||
| PCT/US1978/000243 WO1980001405A1 (en) | 1978-12-26 | 1978-12-26 | Seal and seal assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1141407A true CA1141407A (en) | 1983-02-15 |
Family
ID=26673476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000335582A Expired CA1141407A (en) | 1978-12-26 | 1979-09-13 | Seal and seal assembly |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1141407A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109114202A (en) * | 2018-10-22 | 2019-01-01 | 北京因时机器人科技有限公司 | Planetary reduction box and its sealing ring |
-
1979
- 1979-09-13 CA CA000335582A patent/CA1141407A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109114202A (en) * | 2018-10-22 | 2019-01-01 | 北京因时机器人科技有限公司 | Planetary reduction box and its sealing ring |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |