CN221221331U - Axle with gear mounted thereon and vehicle differential - Google Patents

Abstract

The present utility model relates to a shaft and a vehicle differential to which gears are mounted. The vehicle differential includes: a housing; a pinion shaft mounted in the housing; a first pinion and a second pinion, both mounted on the pinion shaft; and a first side gear and a second side gear engaged with the pinion gear. The pinion shaft has a central axis, an outer surface radially spaced from the central axis, axially opposite ends, a first void formed between the axially opposite ends and at least partially overlapping the first pinion, and a second void formed between the axially opposite ends and at least partially overlapping the second pinion. Each of the first and second voids has an axially inner end spaced from an axially outer end, and a circumferentially spaced side, and at least one void has a cross-sectional area taken in a plane extending radially relative to the central axis, the cross-sectional area being different at different portions of the axial extent of the at least one void.

Description

Axle with gear mounted thereon and vehicle differential

Citation of related application

The application claims the benefit of U.S. provisional application Ser. No.63/357,679, filed on 7/1/2022, the entire contents of which are incorporated herein by reference.

Technical Field

The present utility model relates generally to pinion shafts and differentials having lubrication features.

Background

The automotive differential may be fitted in an automotive driveline, for example, between the side axles of the front axle, between the side axles of the rear axle or between the front and rear axles. In general, differentials may have different designs and configurations, larger AWD automotive driveline architectures, upstream and downstream driveline components, packaging requirements, and torque output requirements, depending on other possible impacts.

Disclosure of utility model

The present utility model discloses a shaft on which a gear is mounted, characterized in that the shaft has a central axis, an outer surface radially spaced from the central axis, axially opposite ends and at least one void formed between the axially opposite ends, the at least one void having an axially inner end spaced from an axially outer end and circumferentially spaced sides, and the at least one void having a cross-sectional area taken in a plane extending radially with respect to the central axis, the cross-sectional area being different at different portions of the axial extent of the at least one void.

The utility model also discloses a vehicle differential, which is characterized by comprising

A housing;

a pinion shaft mounted in the housing;

A first pinion and a second pinion, both mounted on the pinion shaft;

A first side gear within the housing that is engaged with the first pinion and the second pinion;

A second side gear within the housing engaged with the first and second pinions, wherein the pinion shaft has a central axis, an outer surface radially spaced from the central axis, axially opposite ends, a first void formed between the axially opposite ends and at least partially overlapping the first pinion, and a second void formed between the axially opposite ends and at least partially overlapping the second pinion, wherein each of the first and second voids has an axially inner end spaced from an axially outer end, and a circumferentially spaced side, and the at least one void has a cross-sectional area taken in a plane extending radially relative to the central axis, the cross-sectional area being different at different portions of the axial extent of the at least one void.

Drawings

The following detailed description of the preferred embodiments and best mode will be set forth with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view and partial cross-sectional view of a differential with a housing, side gears, and a portion of a pinion gear in section;

FIG. 2 is a front view of the differential of FIG. 1;

FIG. 3 is an end view of the differential with the side gears removed and with the pinion gears in cross section to show lubricant clearance in the pinion shaft;

FIG. 4 is a cross-sectional side view of the differential showing lubricant voids in the pinion shaft;

Fig. 5 is a side view of the pinion shaft.

FIG. 6 is a side view of a portion of a pinion shaft and illustrates a typical wear pattern caused by engagement of the pinion with the pinion shaft;

FIG. 7 is a side view of a pinion shaft;

FIG. 8 is a perspective view of a pinion shaft; and

Fig. 9 is a perspective view of the pinion shaft.

Detailed description of the preferred embodiments

Referring in more detail to the drawings, the automotive differential 10 may be assembled in an automotive driveline, for example, between the side axles of a front axle, between the side axles of a rear axle, or between the front and rear axles. In general, the differential 10 may have different designs and configurations, larger AWD automotive driveline architectures, upstream and downstream driveline components, packaging requirements, and torque output requirements, depending on other possible impacts. In the embodiment presented in the figures, differential 10 includes a housing 12, a first pinion gear 14, a second pinion gear 16, a first side gear 18, and a second side gear 20; however, more, fewer, and/or different components may be included in other embodiments. For example, differential 10 may have more than two pinions, and may have three or four or more pinions. The housing 12 may have an input gear (such as a ring gear) at an exterior thereof that engages an upstream output gear (such as an output gear of a transmission in a front axle layout or an output gear of a drive shaft (propellershaft) of an automotive driveline). When actuated, the housing 12 rotates about axis a. Within the interior 22, the housing 12 defines a cavity adapted to receive the pinion gears 14, 16 and side gears 18, 20 therein.

The first and second pinions 14, 16 interact with the first and second side gears 18, 20 to perform the function of an automotive differential. Each of the gears 14, 16, 18, 20 has teeth formed around its exterior. In this embodiment, in the assembly and use of the automotive differential 10, the teeth of the first pinion gear 14 mesh with the teeth of the first side gear 18 and the second side gear 20, and similarly, the teeth of the second pinion gear 16 mesh with the teeth of the first side gear 18 and the second side gear 20. The first and second pinions 14, 16 include a channel defining an inner surface 24 of the pinions 14, 16 through which a pinion shaft 26 extends. Pinion shaft 26 has a central axis 28 and is mounted in an opening 30 in an opposite side of differential housing 12. The first side gear 18 has a set of internal splines 32 for connection to a first side shaft, an end of which is received in an opening 34 of the housing 12, and the second side gear 20 has a set of internal splines 36 for connection to a second side shaft, an end of which is received in a generally oppositely facing opening 38 in the housing 12. As shown in fig. 1 and 2, a pinion spacer 40 may be located between the housing 12 and the first and second pinions 14 and 16, and a side gear spacer 42 may be located between the housing 12 and the first and second side gears 18 and 20.

As shown in fig. 1-3, pinion shaft 26 may include a bore 44, with a pin 46 received within an aligned bore 48 (fig. 2) of housing 12, pin 46 or a bolt being inserted through bore 44 to couple pinion shaft 26 to housing 12. So arranged, pinion shaft 26 rotates with housing 12 about axis a, pinions 14, 16 rotate about axis B (which is a central/longitudinal axis 28 of pinion shaft 26 and which is perpendicular to axis a) about pinion shaft 26, and side gears 18, 20 rotate concentric with and about axis a.

To facilitate smooth operation of differential 10, lubricant is provided for the interface between the relatively moving parts, including gears 14-20, shims 40, 42, pinion shaft 26 (about which pinions 14, 16 rotate), and housing 12. To facilitate lubricant flow within the differential, pinion shaft 26 includes a void 50, with void 50 aligned with pinion gears 14, 16 and pinion shaft 26 and adapted to assist in lubricant flow between pinion gears 14, 16 and pinion shaft 26. Pinion shaft 26 includes at least one void 50 axially aligned (relative to axis B) with each pinion 14 and 16. In the embodiment shown in fig. 1-5, pinion shaft 26 includes two circumferentially spaced voids 50 axially aligned with each of pinion gears 14 and 16, i.e., four voids 50 are included in pinion shaft 26, with two voids 50 aligned with first pinion gear 14 and two voids 50 aligned with second pinion gear 16.

In more detail, in at least some embodiments, pinion shaft 26 has an outer surface 52 that is a right cylinder except for the region that includes void 50. Void 50 extends into outer surface 52 and provides the following areas of pinion shaft 26: which has a reduced width compared to the area spaced from void 50. The axial extent of the void 50 may be greater than the axial extent of the inner surfaces 24 of the pinion gears 14, 16 through which the pinion shaft 26 extends to facilitate flow into and through the void 50. The radial extent of void 50 may be large enough to allow for the desired flow rate or flowability of the lubricant, which may vary with the viscosity of the lubricant, but not so large that pinion shaft 26 is not strong enough for its intended use. The circumferential extent of the gap 50 may be selected to allow a desired lubricant flow rate or flowability through the gap 50 without unduly reducing the load bearing surface area of the pinion shaft 26 relative to the pinion gears 14, 16 (the pinion gears 14, 16 providing a load on the shaft 26 when the housing 12 is rotated in use). Finally, the circumferential position of the void 50 on the pinion shaft 26 may be offset from the center of the primary load bearing surface area 54 of the pinion shaft 26 relative to the pinions 14, 16. In more detail, the housing rotates about an axis a and is parallel to a plane C (as shown in fig. 2 and 4), where the plane C defines the center of the load bearing surface area 54. In at least some embodiments, the centerline 56 of each void 50 parallel to axis B may be circumferentially offset from plane C by 90 degrees such that voids 50 are equally offset from plane C.

In at least some embodiments, void 50 opens to the exterior of pinion shaft 26 and includes axially spaced apart inner and outer ends 58, 60, respectively, and circumferentially spaced apart sides 62, 64, wherein sides 62, 64 define an outwardly facing bottom surface 66. If desired, the ends 58, 60 may include an angled end portion 68 that extends from the axially outermost edge to the bottom surface 66 at an angle other than 90 degrees. In addition, the cross-sectional area of the void 50 varies along the axial extent of the void 50. The cross-sectional area of the void 50 at a given axial location is the area between the shaft 26 within the void and an imaginary right cylinder coincident with the outer surface 52 of the shaft 26 axially spaced from the void 50. In at least some embodiments, the cross-sectional area of void 50 varies along the axial extent of bottom surface 66 (excluding any disposed beveled end portions 68). The variable cross-sectional area may be provided by void 50 having a varying circumferential extent, a varying depth, or both.

In at least some embodiments, the sides 62, 64 are parallel to one another and the depth of the void 50 differs at each end 58, 60 (excluding any sloped end portions 68), where the depth is the radial dimension from where the outer surface 52 of the shaft 26 is located (in the absence of the void 50) to the bottom surface 66 of the void 50. Depth may also be considered as the distance from centerline 56 (represented by dashed lines in fig. 3) of bottom surface 66 (excluding any beveled end portion 68) of void 50 to axis B of pinion shaft 26. In at least some embodiments, such as shown in fig. 1-6, the depth at the axially inner end 58 of the void 50 is greater than the depth at the axially outer end 60 of the void 50, wherein the axially inner end 58 is farther from the end of the pinion shaft 26 than the axially outer end 60 of the void 50. In at least some embodiments, the bottom surface 66 is planar and has a first depth at the axially outer end 60 of the bottom surface 66 (not including any beveled end portions) and a second depth at the axially inner end 58 of the bottom surface 66 (not including any beveled end portions), wherein the first depth is different from the second depth. In this example, the bottom surface 66 is at a varying depth between the ends of the bottom surface 66. The separate planes that include the bottom surfaces 66 of the axially aligned voids 50 (e.g., voids 50 at the same axial location on the shaft 26 that are overlapped by the same pinion in the assembled differential) are not parallel to each other and instead converge toward each other when viewed from the end of the pinion shaft 26. In at least some embodiments, the planar bottom surface 66 has a varying depth along its circumferential extent and may blend to zero depth at the sides 62, 64 of the void 50, or the sides 62, 64 may be defined by an inward step (step) at any desired angle.

In at least some embodiments, the maximum radial depth of the void that may be at centerline 56 may be 6% of the diameter of pinion shaft 26. In at least some embodiments, the circumferential extent of the void may be in a range between 30 degrees and 60 degrees, and the axial length may be 5% greater than the axial dimension of the adjacent inner surface of the pinion gear.

In at least some embodiments, such as the shaft 26' shown in fig. 7 and 8, the depth of the void 70 varies along the axial extent of its bottom surface 72, with the depth between the axial ends of the bottom surface 72 being greater than the depth at the axial ends of the bottom surface 72. In such examples, the depth at the axial end of the bottom surface 72 (excluding any sloped end portions) may be the same or different as desired, with at least some embodiments including voids 70 having an axially inner end 74 that is deeper than an axially outer end 76. In at least some embodiments, a straight line 78 (fig. 8) perpendicular to the axis B can be drawn along the bottom surface 72 between circumferentially spaced sides 80, 82 of the void 70 (i.e., the line 78 contacts the bottom surface 72 along the length of the line). In other words, in at least some embodiments, between the sides 80, 82, the bottom surface 72 of the void 70 is linear along the entire axial extent of the void 70. This may also be true in the inclined end portion if any is provided. The bottom surface 72 of the void 70 in the shaft 26' shown in fig. 7 is not planar along the axial extent of the bottom surface 72 and instead is inclined in at least two directions. In other words, the void 50 has at least two portions of different depths, and may have more than two portions, from the axially inner edge to the axially outer edge of the bottom surface 72. Those portions may themselves be planar (inclined at a given angle) or wavy at a given radius or freely formed at various radii, as desired. In the example shown in fig. 7, the first portion 84 extends from the axially outer end 76 to an axial location having a maximum depth, and the second portion 86 extends from the location having the maximum depth to the axially inner end 74, wherein the first portion 84 and the second portion 86 are planar.

In at least some embodiments, the radial depth of each void at the centerline (e.g., similar to centerline 56 shown on shaft 26) may vary along the axial length of the void by an amount between 5% and 15% of the diameter of pinion shaft 26'. The Zhou Xiangfan girth and axial extent of the void may be as mentioned above with respect to the examples of fig. 1-6.

In voids 50 having variable depths, sides 80, 82 may be parallel to one another, as shown in FIGS. 1-6 and 8, or void 88 may have sides 90, 92 arranged at non-parallel angles, as shown by axis 26 "of FIG. 9. Pinion shaft 26 "shown in fig. 9 includes sides 90, 92 circumferentially spaced farther apart at an axially inner end 94 than at an axially outer end 98 of bottom surface 96, although the opposite arrangement may be provided if desired. The void 88 having non-parallel sides 90, 92 may have a constant depth or a variable depth as desired, thereby providing a cross-sectional area that varies along the axial extent of the bottom surface 96 of the void 88. In at least some embodiments, a line 100 perpendicular to axis B can be drawn along the bottom surface 96 between the circumferentially spaced sides 90, 92 of the void 88. In other words, in at least some embodiments, between the sides 90, 92, the bottom surface 96 of the void 88 is linear along the entire axial extent of the void 50 (e.g., a line may be drawn at all locations along the axial extent of the bottom surface 96). This may also be true in the inclined end portion if provided.

In at least some embodiments, the circumferential extent of each void may vary between sides 90, 92 along the axial length of the void by an amount between 30 degrees and 60 degrees. The depth of the void and the axial extent may be as mentioned above with respect to the examples of fig. 1-6, or as mentioned above, the depth may be constant.

In the use of a differential, lubricant tends to flow outwardly under centrifugal force as the housing 12 and gears rotate. In at least some embodiments, the cross-sectional area of the voids 50, 70, 88 is smaller at the axially outer end than at a location spaced from the outer end. Such an arrangement may inhibit or slow the flow of lubricant axially outward in the voids 50, 70, 88 and facilitate the flow axially inward through the voids 50, 70, 88 under at least some operating conditions.

The forms of the invention disclosed herein constitute presently preferred embodiments and many others are possible. It is not intended herein to mention all of the possible equivalent forms or ramifications of the invention. It is to be understood that the terminology used herein is intended to be in the nature of words of description rather than of limitation, and that various changes may be made without departing from the spirit or scope of the invention.

Unless explicitly indicated to the contrary herein, all terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meaning as understood by those skilled in the art. In particular, the use of singular articles such as "a," "an," "the," etc. should be understood to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.

Claims (14)

1. A shaft to which a gear is mounted, the shaft having a central axis, an outer surface radially spaced from the central axis, axially opposite ends, and at least one void formed between the axially opposite ends, the at least one void having an axially inner end spaced from the axially outer end, and circumferentially spaced sides, and the at least one void having a cross-sectional area taken in a plane extending radially relative to the central axis, the cross-sectional area being different at different portions of the axial extent of the at least one void.

2. The shaft of claim 1, wherein the at least one void includes a beveled end portion extending from an axial end of the at least one void to a bottom surface of the at least one void at an angle other than perpendicular to the central axis, and the different portion does not include the beveled end portion.

3. The shaft of claim 1, wherein the sides are parallel to each other.

4. The shaft of claim 1, wherein the sides are not parallel to each other.

5. The shaft of claim 2, wherein the bottom surface is planar.

6. The shaft of claim 2, wherein the bottom surface is not planar.

7. The shaft of claim 1, wherein between the sides, a bottom surface of the void is linear along an entire axial extent of the at least one void.

8. A vehicle differential comprising

A housing;

a pinion shaft mounted in the housing;

A first pinion and a second pinion, both mounted on the pinion shaft;

A first side gear within the housing that is engaged with the first pinion and the second pinion;

A second side gear within the housing engaged with the first and second pinions, wherein the pinion shaft has a central axis, an outer surface radially spaced from the central axis, axially opposite ends, a first void formed between the axially opposite ends and at least partially overlapping the first pinion, and a second void formed between the axially opposite ends and at least partially overlapping the second pinion, wherein each of the first and second voids has an axially inner end spaced from an axially outer end, and a circumferentially spaced side, and the at least one void has a cross-sectional area taken in a plane extending radially relative to the central axis, the cross-sectional area being different at different portions of the axial extent of the at least one void.

9. The vehicle differential of claim 8, wherein each of the first and second voids includes an inclined end portion extending from an axial end of the at least one void to a bottom surface of the at least one void at an angle other than perpendicular to the central axis, and each of the first and second voids has a cross-sectional area taken in a plane extending radially relative to the central axis that differs at different portions of an axial extent of the void, wherein different portions do not include the inclined end portion.

10. The vehicle differential of claim 8, wherein the sides are parallel to each other.

11. The vehicle differential of claim 8, wherein the sides are not parallel to each other.

12. The vehicle differential of claim 9, wherein the bottom surface is planar.

13. The vehicle differential of claim 9, wherein the bottom surface is not planar.

14. The vehicle differential of claim 8, wherein a bottom surface of each of the first and second voids is linear along an entire axial extent of the at least one void between the sides.