The present invention relates to a lock for a bearing adjuster for a differential bearing and an input bearing.
The current practice to adjust differential bearings is to provide a shim pack, selective spacer or threaded adjuster to set the bearing preload. Spacers and shims have the disadvantage that they are difficult to install, provide only a set increment of adjustment and are costly. Threaded adjusters are easy to assemble, but require some type of locking mechanism to ensure that the adjuster does not rotate in service. Typical lock mechanisms are cumbersome due to the necessity to align a keeper (lock plate, cotter pin or cap screw) in a slot. Alternately, a thin ductile member such as a stamped lock plate or nut flared extension can be staked into a keyway. This staking has the advantage that it is infinitely adjustable, but is highly dependent on the integrity of the stake operation. The stake depth is a variable that can affect the bearing adjuster retention in service.
Other bearing adjuster lock mechanisms attempt to pinch the adjuster threads axially to take all the clearance out of the threads. These pinch systems are infinitely adjustable, but they rely on friction which is highly variable, as opposed to a mechanical lock, which is much more positive.
In light of the disadvantages of the prior art it would be advantageous to have a mechanical lock for a threaded adjuster that is infinitely adjustable and which is not dependent on the integrity of the installation technique.
One embodiment of the present invention is directed toward a bearing adjuster lock having a bearing adjuster, a locking device and a combined differential carrier and bearing cap. The locking device can extend through a channel in the bearing cap to the bearing adjuster. The locking device deforms the threads of the bearing adjuster to lock the bearing adjuster with the combined differential carrier and bearing cap.
Another embodiment of the present invention includes providing the channel in the bearing adjuster and locating the locking device through the channel so that it deforms the shared threads of the combined differential carrier and bearing cap to lock the combined differential carrier and bearing cap with the bearing adjuster. The present invention may also be used with an input bearing system.
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which:
It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless the claims expressly state otherwise.
Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views,
The power transmission shaft may drive a drop gear set 14 and a power divider (not shown), such as used in a forward differential of a tandem axle system. While a forward differential is depicted, it should be appreciated that the present invention can work equally well with a single drive axle system.
Carrier 12 houses, provides supports for, and maintains the relative position of, the other components of differential 10. Carrier 12 may be made from conventional metals and metal alloys such as steel, iron or aluminum and is conventional in the art. Carrier 12 may include several members coupled together using conventional fasteners (not shown). These members may include, but are not limited to, forward member 40 and bearing caps 42, 44. Structures 40, 42, 44 of carrier 12 together define a pair of openings 46, 48 disposed about an axis 50 of rotation for axle half shafts 32, 34 and through which shafts 32, 34 extend.
One embodiment of a bearing cap 44 is depicted in
Power transmission shaft transfers torque from a drive shaft (not shown) through a power divider (not shown) to pinion gear 16 and is conventional in the art. Pinion gear 16 is disposed about an axis 52 of rotation that extends generally perpendicular to axis 50. Power transmission shaft is supported for rotation within member 40 of carrier 12 by bearing assemblies (not shown).
Pinion gear 16 transfers torque from power transmission shaft to ring gear 18. Pinion gear 16 may be made from conventional metals and metal alloys and may comprise a hypoid gear.
Ring gear 18 is provided to transfer torque from pinion gear 16 to case 20 and is conventional in the art. Ring gear 18 may also be made from conventional metals and metal alloys and may also comprise a hypoid gear. Gear 18 is affixed to case 20 or may be integral therewith and is disposed about axis 56.
Case 20 is provided to house spider 22 and bevel gears 24, 26, 28, 30 and to transfer torque to bevel gears 24, 26, 28, 30. Case 20 is conventional in the art and may be made from conventional metals and metal alloys. Case 20 includes first and second members 57, 58 that are coupled together using fasteners such as bolts or in other ways customary in the art. Case 20 is disposed within carrier 12 and, in particular, within openings 46, 48 of carrier 12. Case 20 is also disposed about axis 50 and is supported for rotation about axis 50 relative to carrier 12 by bearing assemblies 36, 38.
Spider 22 provides a mounting arrangement for bevel gears 26, 28 and is conventional in the art. Spider 22 is coupled to case 20 for rotation therewith and supports at least two bevel gears 26, 28 that rotate with spider 22.
Bevel gears 24, 26, 28, 30 are provided to divide and transfer torque to axle half shafts 32, 34. Gears 24, 26, 28, 30 are conventional in the art and may be made from conventional metals and metal alloys. Gears 26, 28 are mounted on spider 22 for rotation with spider 22. Gears 24, 30 are mounted on axle half shafts 32, 34 for rotation with shafts 32, 34 and rotate in response to rotation of gears 26, 28.
Axle half shafts 32, 34 transfer torque to wheels (not shown) disposed on either side of differential 10. Shafts 32, 34 are conventional in the art and extend outwardly from differential case 20 and carrier 12 through openings 46, 48 Bearing assemblies 36, 38 enable rotation of differential case 20 within carrier 12. Assemblies 36, 38 are disposed within openings 46, 48 of carrier 12 between case 20 and carrier 12 and are disposed about axis 56. Each of the assemblies 36, 38 may include an inner bearing race 60, 62, a bearing 64, 66, and an outer bearing race 68, 70.
The inner bearing races 60, 62 are supported on a radially outer surface of case 20 and abut shoulders 72, 74, respectively, formed in case 20. Bearing 64, 66 are disposed between the inner bearing races 60, 62 and the outer bearing races 68, 70, respectively. Bearings 64, 66 may be any friction reducing devices known to those skilled in the art such as ball bearings, tapered bearings or a combination of tapered and ball bearings. Preferably, bearings 64, 66 are tapered roller bearings. It is also within the scope of the present invention to mount bearings 64, 66 with stationary inner races, as seen in U.S. Pat. No. 4,733,578, which is incorporated by reference in its entirety herein, without departing from the scope of the present invention.
Referring now to
The bearing adjuster 76 can be threaded into the threads 84 so that the race surface 82 abuts the outer race 70 of the bearing 66. The preload on the bearing 66 can thus be adjusted by threading the bearing adjuster 76 into or out of the shared threads 86 while the race surface 82 abuts the outer race 70 of the bearing 66. It can be appreciated that the preload on the bearing 66 is infinitely adjustable within the range of the threads 84, 86 of the bearing adjuster 76 and the combined differential carrier 12 and bearing cap 44.
The bearing adjuster 76 may be made of cast, ductile iron, or it may be made of stamped, cast or forged steel.
As seen in both
A locking device 94, comprised of a shaft 96 and a thread deforming structure 98 on the end of the shaft 96, is located within the channel 90. Preferably, the shaft 96 is threaded and the channel 90 is threaded so that the shaft 96 can be selectively advanced within the channel 90.
The thread deforming structure 98 may be such as a tapered point, as best seen in
Preferably, the shaft 96, or at least the thread deforming structure 98, is made of a material that is harder than the material of the bearing adjuster 76. For example, the shaft 96, or at least the thread deforming structure 98, can be made of heat-treated, hardened carbon steel.
While a single channel 90 is depicted in the bearing cap 44, it must be appreciated that more than one channel 90 can be located in the bearing cap 44. For example, as seen in
The present invention also comprises locating one or more channels 90, and the locking devices 94, in the differential carrier 12 itself. These channels can be separated from, or in addition to, the channel, or channels, in the bearing cap 44.
Another embodiment of the present invention is depicted in
In this embodiment, a bearing adjuster 102 has a channel 104 extending from an inner circumferential surface 106 to an outer circumferential surface 108. Preferably, the channel 104 is threaded for receiving a locking device 110, comprised of a shaft 112 and a thread deforming structure 114 on the end of the shaft 112. The shaft 112 has threads that are complimentary with the threads of the channel 104. The complimentary threads permit the shaft 112 to be selectively advanced within the channel 104 from the inner circumferential surface 106.
The thread deforming structure 114 may be such as a tapered point. The tapered point may be located along a centerline 116 of the shaft 112. The locking device 110 may also comprise a thread deforming structure that is a frusto-conical shape. It can be appreciated that this shape has a larger surface area for contacting the bearing adjuster 102, as compared to the point. Both of these embodiments can be appreciated based on a review of
Preferably, the shaft 112, or at least the thread deforming structure 114, is made of a material that is harder than the material of the differential carrier 12. For example, the shaft 112, or at least the thread deforming structure 114, can be made of heat-treated, hardened carbon steel.
While
The present invention may also be used with an input bearing system of a vehicle, as described below and depicted in
The carrier 120 has an outer surface 130 and an inner surface 132. The carrier 120 also defines an opening 134. Adjacent the opening 134, the inner surface 132 of the carrier 120 is provided with a set of threads 136. An input bearing adjuster 138, having a complimentary set of threads 140 on an exterior surface 142, engages with the threads 136 of the differential carrier 120.
The input bearing adjuster 138 has a groove 144 for receiving an outer race 146 associated with an input bearing 148. The groove 144 is substantially L-shaped, defining a horizontal portion 150 and a vertical leg 152 connected to the horizontal portion 150. An outer peripheral portion 154 of the outer race 146 abuts the horizontal portion 150 of the groove 144 and a front portion 156 of the outer race 156 is partially contacted by the vertical leg 152.
The input bearing 148, which may be a tapered bearing, is located radially inward from the outer race 146. An inner race 158 is located between the input shaft 122 and the input bearing 148. The input bearing 148, outer race 156 and inner race 158 define an input bearing system 160. It can be appreciated that the input bearing system 160 permits rotation of the input shaft 122 within the differential case 120.
A thread deforming structure 162 is located on an end of a shaft 164 of a locking device 166. The shaft 164 extends through a channel 168 in the differential carrier 120. Preferably, the channel 168 extends substantially perpendicularly through the differential carrier 120 with respect to the inner and outer surfaces 130, 132. In a preferred embodiment, the channel 168 is threaded to receive complimentary threads on the shaft 164. The thread deforming structure 162 may comprise a point on the end of the shaft 164 or it can be a frusto-conical surface, as shown in
It should be appreciated that the input bearing adjuster 138 can be used with differential bearing adjusters 76 and/or 102 and their locking devices without departing from the scope of the present invention.
A preferred method of using the invention depicted in
When the desired amount of preload has been applied to the bearing 66, by virtue of the bearing adjuster 76 being threaded into the differential carrier 12 and bearing cap 44, it is preferred to secure the bearing adjuster 76 so that the preload is constantly maintained. As depicted in the figures, the shaft 96 of the locking device 94 is inserted from the outer surface 92 of the bearing cap 44 into the channel 90. The shaft 96 is inserted until the thread deforming structure 98 contacts the threads 84 on the outer circumferential surface 78 of the bearing adjuster 76. The thread deforming structure 98 is advanced into the threads 84 of the outer circumferential surface 78 to deform the threads 84. The amount of thread deformation is controlled by applying a predetermined amount of torque to the shaft 96. The deformation of the threads 84 by the thread deforming structure 98 locks the bearing adjuster 76 in place in the differential carrier 12 and bearing cap 44. An adhesive 170 can be applied to the shaft 96 where it enters the bearing cap 44 to prevent the shaft 96 from moving.
It is a discovery of the present invention that the threads 84 of the bearing adjuster 76 can be deformed in a variety of different locations as the desired amount of preload is established without diminishing the performance of the threads 84. Additionally, the thread deforming structure 98 and shaft 96 can be repeatedly removed from the channel 90 and reused.
It should be appreciated that the locking device 94 can be located through the differential carrier 12 to contact the bearing adjuster 76 and lock it in place in a similar method.
A preferred method of using the invention depicted in
When the desired amount of preload has been applied to the bearing 66 by virtue of the bearing adjuster 102 being threaded into the differential carrier 12 and bearing cap 44, it is preferred to secure the bearing adjuster 102 so that the preload is constantly maintained. The shaft 112 is threaded into the channel 104 from the inner circumferential surface 106. The shaft 112 is inserted until the thread deforming structure 114 contacts the threads 86 on the differential carrier 12. The thread deforming structure 114 is advanced into the threads 86 of the differential carrier 12 to deform the threads 86. The amount of thread deformation is controlled by applying a predetermined amount of torque to the shaft 112. The deformation of the threads 86 by the thread deforming structure 114 locks the bearing adjuster 102 in place in the differential carrier 12. An adhesive 170 can be applied to the shaft 112 where it enters the bearing adjuster 102 to prevent the shaft 112 from moving.
It is a discovery of the present invention that the threads 86 of the differential carrier 12 can be deformed in a variety of different locations as the desired amount of preload is established without diminishing the performance of the threads 86. Additionally, the thread deforming structure 114 and shaft 112 can be repeatedly removed from the channel 104 and reused.
It should be appreciated that the channel 104 can be oriented such that when the locking device 110 is threaded through the channel 104 it engages with the bearing cap 44. This method also locks the bearing adjuster 102 to the differential carrier 12 and the bearing cap 44.
A preferred method of using the invention depicted in
The shaft 164, having the thread deforming structure 162 thereon, is threaded into the channel 168 of the differential carrier 120. The shaft 164 is advanced into the channel 168 until the thread deforming structure 162 deforms the threads 140 of the input bearing adjuster 138. The input bearing adjuster 138 is thus locked in place. An adhesive 170 may be applied to the shaft 164 where it enters channel 168 to secure the shaft 164 in place. While the threads 140 of the input bearing adjuster 138 are deformed by the thread deforming structure 162, it is a discovery of the present invention that the threads 140 are not deformed to the extent that their performance is diminished.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiments. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
This application is a continuation-in-part of U.S. application Ser. No. 10/724,267 filed Nov. 26, 2003, herein incorporated by reference in its entirety.
Number | Date | Country | |
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Parent | 10724267 | Nov 2003 | US |
Child | 11454333 | Jun 2006 | US |