Axle configuration having full time drive of one wheel and selective drive of a second wheel

Abstract

An axle assembly with a housing, a gear received in the housing and rotatable about an output axis, a spindle coupled to the second gear for rotation therewith, a first shaft that is rotatably coupled to the spindle, a second shaft that is rotatable about the output axis relative to the spindle, a first shaft bearing received between the second shaft and the spindle and supporting the second shaft for rotation relative to the spindle, and a mode collar slidably movable along the output axis between a first position, in which the second shaft is rotatable relative to the spindle, a second position, in which the second shaft is coupled to the spindle for rotation therewith, and a third position in which the spindle and the second shaft are non-rotatably coupled to the housing.

Description

AXLE CONFIGURATION HAVING FULL TIME DRIVE OF ONE WHEEL ANDSELECTIVE DRIVE OF A SECOND WHEELFIELD

[0001] The present disclosure relates to an axle configuration having full time drive of one wheel and selective drive of a second wheel.BACKGROUND

[0002] This section provides background information related to the present disclosure which is not necessarily prior art.

[0003] Utility terrain vehicles are typically small vehicles suited for two or more passengers and are commonly employed for outdoor work and recreation activities. It is often times desirable that the wheels on an axle assembly for a utility terrain vehicle be “lockable” so that rotary power delivered to the axle assembly is capable of being transmitted through each of the wheels of the axle assembly. Configuration in this manner permits transmission of power through one of the wheels of the axle assembly in situations where the other wheel of the axle assembly is slipping (e.g. , on ice, in mud or elevated so as to not be in contact with the ground on which the utility terrain vehicle is operating).

[0004] It is known in the art to configure an axle assembly with a differential mechanism and some sort of locking mechanism to selectively inhibit relative rotation of the outputs of the differential mechanism. While this configuration is well suited for its intended purpose, it is nevertheless relatively expensive.Accordingly, there remains a need in the art for an axle assembly that is capable of selectively driving a pair of wheels but which is relatively less complex and costly.SUMMARY

[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0006] In one form, the present disclosure provides an axle assembly with a housing, a gear received in the housing and rotatable about an output axis, a spindle coupled to the second gear for rotation therewith, a first shaft that is rotatably coupled to the spindle, a second shaft that is rotatable about the output axis relative to the spindle, a first shaft bearing received between the second shaft and the spindle and supporting the second shaft for rotation relative to the spindle, and a mode collar slidably movable along the output axis between a first position, in which the second shaft is rotatable relative to the spindle, a second position, in which the second shaft is coupled to the spindle for rotation therewith, and a third position in which the spindle and the second shaft are non-rotatably coupled to the housing.

[0007] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.DRAWINGS

[0008] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0009] Figure 1 is a perspective view of an utility terrain vehicle equipped with an exemplary axle assembly constructed in accordance with the teachings of the present disclosure;

[0010] Figure 2 is a bottom plan view of the utility terrain vehicle of Figure 1 ;

[0011] Figure 3 is an exploded perspective view of a portion of the utility terrain vehicle of Figure 1 that depicts a portion of the rotary power source and driveline in more detail;

[0012] Figure 4 is a simplified section view of a portion of the utility terrain vehicle of Figure 1 , illustrating a portion the axle assembly of the driveline in more detail;

[0013] Figure 5 is an exploded perspective view of a portion of the axle assembly;

[0014] Figures 6 and 7 are views similar to that of Figure 4 but depicting differently configured actuators for operating the axle assembly.

[0015] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0016] With reference to Figures 1 through 3 of the drawings, an exemplary utility terrain vehicle (UTV) constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 8. The UTV 8 can include a source of rotary power 10, a transmission 12 and a driveline 14 that can include one or more driven axles. The rotary power source 10 can be an internal combustion engine and / or an electric motor. In the example provided the rotary power source 10 is an electric motor 16. The transmission 12 is configured to transmit rotary power between the rotary power source 10 and the driveline 14 and can include one or more stages that can be configured as belt drives (e.g., employing a cogged belt), chain drives, gear reductions, or combinations thereof. It will be appreciated that the one or more stages can include one or more multispeed reductions and / or one or more fixed reductions. The driveline 14 can include one or more driven axles. In the particular example shown, the driveline 14 includes a rear axle 18 that is configured to drive a first rear wheel 20a on a full- time basis and to selectively drive a second rear wheel 20b.

[0017] It will be appreciated, however, that the source of rotary power 10 could include an internal combustion engine (not shown) in addition to or in lieu of the electric motor 16, and that the driveline 14 could include a front axle that is driven by the source of rotary power 10 and the transmission 12 in addition to or in lieu of the rear axle 18.

[0018] With reference to Figures 3 and 4, the rear axle 18 can include an axle housing 30, a first gear 32, a second gear 34, a spindle 36, a first shaft 38, asecond shaft 40, and a mode collar 42. The rear axle 18 can optionally include a third shaft 44 and / or an actuator 46.

[0019] The axle housing 30 can define an output axis 50 and can include a first housing member 52, a second housing member 54, and an intermediate housing member 56 that can be disposed beween and fixedly coupled to the first and second housing members 52 and 54. The first housing member 52 can cooperate with the intermediate housing member 56 to define a first cavity 60 into which the second gear 34 can be received. The intermediate housing member 56 and the second housing member 54 can cooperate to define a second cavity 62 into which the mode collar 42 can be received.

[0020] The first gear 32 can be disposed within or extend into the first cavity 60 and is rotatable about an axis (not shown). The second gear 34 is disposed within the first cavity 60, is rotatable about the output axis 50, and is meshed with the first gear 32. In the example provided, the first and second gears 32 and 34 are helical gears that are rotatable about parallel axes. It will be appreciated, however, that the first and second gears 32 and 34 could be configured differently, such as with a bevel configuration (e.g., straight bevel, spiral bevel, hypoid).

[0021] The spindle 36 can be received in the first cavity 60 and extends into the second cavity 62. The spindle 36 is supported for rotation about the output axis 50 relative to the axle housing 30 by first and second spindle bearings 70 and 72, respectively, that are mounted in first and second bearing mounts 74 and 76, respectively, that are formed in the first housing member 52 and the intermediate housing member 56, respectively. The spindle 36 is coupled to the second gear34 for rotation therewith. In the example provided, the second gear 34 and the spindle 36 are unitarily and integrally formed.

[0022] The first shaft 38 can be coupled to the spindle 36 for rotation therewith. In the example provided, the first shaft 38 has an externally splined segment 80 that is received into and engaged with the splines of an internally splined aperture 82 that is formed in the spindle 36. The first shaft 38 is drivingly coupled to the first rear wheel 20a (Fig. 2).

[0023] The second shaft 40 is received in the second cavity 62 and is rotatable about the output axis 50 relative to the spindle 36. One of the spindle 36 and the second shaft 40 can be supported for rotation on the other one of the spindle 36 and the second shaft 40. In the example shown, the spindle 36 includes a hub portion 90, which is disposed on an axial end of the spindle 36 opposite the internally splined aperture 82, the second shaft 40 includes a bore 94 that is received over the hub portion 90, and a first shaft bearing 96 is disposed between the hub portion 90 and the second shaft 40. A second shaft bearing 98 can be mounted to a third bearing mount 100 that is formed by the second housing member 54 and can support an end of the second shaft 40 that is opposite the first shaft bearing 96 for rotation relative to the axle housing 30. The second shaft 40 can be drivingly coupled to the second rear wheel 20b (Fig. 2).

[0024] The third shaft 44, if included, can be coupled to the second shaft 40 for rotation therewith and can be disposed in a power transmission path between the second shaft 40 and the second rear wheel 20b (Fig. 2). In the example shown, the third shaft 44 has an externally splined segment 110 that is received into andengaged with the splines of an internally splined aperture 112 that is formed in the second shaft 40.

[0025] The mode collar 42 is disposed in the second cavity 62 concentric with the spindle 36 and the second shaft 40 and is operable for selectively coupling the spindle 36 and the second shaft 40 to one another for common rotation about the output axis 50 and for selectively coupling the spindle 36 and the second shaft 40 to the axle housing 30 to inhibit rotation of the spindle 36 and the second shaft 40 about the output axis 50 relative to the axle housing 30. More specifically, the mode collar 42 is slidably disposed on at least one of the spindle 36 and the second shaft 40 and is movable along the output axis 50 between a first position, a second position and a third position.

[0026] With reference to Figures 4 and 5, the mode collar 42 shown in the example provided has a set of internal spline teeth 120, which are engaged on a full-time basis to a set of first external spline teeth 122 on the second shaft 40 and which are engagable to a set of second external spline teeth 124 on the spindle 36, as well as a set of first face teeth 126 that are engagable to a set of second face teeth 128 that are coupled to the intermediate housing member 56. The set of internal spline teeth 120 on the mode collar 42 are engaged only with the set of first external spline teeth 122 when the mode collar 42 is in the first position. The set of internal spline teeth 120 on the mode collar 42 are engaged with the set of first external spline teeth 122 and the set of second external spline teeth 124 when the mode collar 42 is in the second position. When the mode collar 42 is in the third position, the set of first face teeth 126 are engaged to the set of second faceteeth 128, and the set of internal spline teeth 120 on the mode collar 42 are engaged with the set of first external spline teeth 122 and the set of second external spline teeth 124. In the example shown, the set of second face teeth 128 are unitarily and integrally formed with the intermediate housing member 56, but it will be appreciated that the set of second face teeth 128 could be formed as a discrete component (e.g., a ring-shaped structure) that is fixedly coupled to the intermediate housing member 56. It will also be appreciated that the set of second face teeth 128 could be mounted to the second housing member 54, and that the set of internal spline teeth 120 on the mode collar 42 could be engaged to the set of second external spline teeth 124 on the spindle 36 on a full-time basis and selectively engagable to the set of first external spline teeth 122 on the second shaft 40.

[0027] With renewed reference to Figures 3 and 4, the actuator 46 can be operable for moving the mode collar 42 between the first, second and third positions and can be configured in any desired manner. In the example provided, the actuator 46 includes a fork 150 that is received into an annular groove 152 that is formed about the mode collar 42. The fork 150 can be mounted on a rail 154 that can be fixedly mounted to or slidably coupled to the axle housing 30. In the example shown, the fork 150 is fixedly coupled to the rail 154 and the rail 154 is slidably coupled to the axle housing 30 for movement along an actuator axis 156 that is parallel to, but offset from, the output axis 50.

[0028] In the example of Figure 4, the actuator 46 is schematically shown to include an input lever 160 and a linkage 162 that connects the input lever 160to the rail 154. The input lever 160 is configured to receive a manual input from an operator of the UTV 8 (Fig. 1). The linkage 162 can comprise one or more links (not specifically shown) that can be coupled together in an appropriate manner (e.g., pivotably). Movement of the input lever 160 is communicated through the linkage 162 to cause movement of the fork 150 in a desired manner along the actuator axis 156 to in turn cause corresponding motion of the mode collar 42 along the output axis 50.

[0029] It will be appreciated, however, that the actuator 46 could be configured with an electromechanical configuration. In the example of Figure 6, the actuator 46 is schematically shown to include a rotary actuator motor 170, a cam 172, a cam follower 174, a compliance spring 176 and a biasing spring 178. The rotary actuator motor 170 has an actuator motor output shaft 180 that is rotatable about an axis 182 that is perpendicular to the actuator axis 156. The cam 172 is driven by the rotary actuator motor 170 and is configured such that rotation of the cam 172 causes corresponding axial motion of the fork 150. In the example shown, the cam 172 is rotationally coupled directly to the actuator motor output shaft 180 for rotation therewith. It will be appreciated, however, that an actuator transmission (not shown) could be employed between the rotary actuator motor 170 and the cam 172. The actuator transmission can have two or more gears and can include an actuator transmission input gear, which is coupled to the actuator motor output shaft 180 for rotation therewith, and an actuator transmission output gear that can be coupled to the cam 172 for common rotation. For example, the actuator transmission input gear can be a worm, a straight involute gear or a helicalgear, and the actuator transmission output gear can be a worm wheel, or a straight or helical gear, which could be configured as a sector worm wheel or gear, that can be meshed directly with the actuator transmission input gear or with another gear that is in a gear drive between the actuator transmission input gear and the actuator transmission output gear. The cam follower 174 can be slidably mounted to the rail 154 so as to slide along the actuator axis 156 relative to the rail 154. The cam follower 174 can contact a cam surface 200 of the cam 172 and can responsively move along the actuator axis 156. The compliance spring 176 can be disposed in a force transmission path between the cam follower 174 and the rail 154. The compliance spring 176 is configured to compress in situations where movement of the mode collar 42 from the first position to the second position, or from the second position to the third position is blocked due to tooth-on-tooth contact between the set of internal spline teeth 120 on the mode collar 42 and the set of second external teeth 124 on the spindle 36, or between the sets of first and second face teeth 126 and 128 on the mode collar 42 and the axle housing 30. The biasing spring 178 can be disposed in a force transmission path between the axle housing 30 and the rail 154 and can be configured to bias the rail 154 along the actuator axis 156 such that the mode collar 42 is correspondingly biased toward a desired position. For example, biasing spring 178 can be configured to bias the mode collar toward the first position, or toward the third position.

[0030] With additional reference to Figure 7, the cam surface 200 can be configured with a base portion 210, a first lobe 212, a second lobe 214, a first transition portion 216, and a second transition portion 218. The base portion 210has a radius of a first dimension, the first lobe 212 has a radius of a second dimension that is larger than the first dimension, and the second lobe 214 has a radius of a third dimension that is larger than the second dimension. The first transition portion 216 slopes between the base circle portion and the first lobe 212, while the second transition portion 218 slopes between the first and second lobes 212 and 214.

[0031] The mode collar 42 can be disposed in the first position when the base portion 210 of the cam surface 200 contacts the rail 154. The mode collar 42 can be disposed in the second position when the first lobe 212 on the cam surface 200 contacts the rail 154. The mode collar 42 can be disposed in the third position when the second lobe 214 on the cam surface 200 contacts the rail 154.

[0032] In Figure 7, the cam mechanism of Figure 6 is replaced with a lead screw 230, a nut 232 and a compliance spring 176. The lead screw 230 is coupled to the actuator motor output shaft 180 for rotation therewith to drive the nut 232, which is threaded to the lead screw 230, along the actuator axis 156. The compliance spring 176 can be disposed between the nut 232 and an axial end of the rail 154.

[0033] From the foregoing, it will be appreciated that the actuator 46 can include a linear motor (e.g., the rotary actuator motor 170, the cam 172, the cam follower 176 and the compliance spring 176 of Figure 6 or the lead screw 230, the nut 232 and the compliance spring 176 of Figure 7) and that compliance in the force transmission path to the mode collar 42 (i.e., the compliance spring 176 in the examples shown) is optional.

[0034] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMSWhat is claimed is:1 . An axle assembly comprising: a housing; an first gear at least partly disposed in the housing; a second gear received in the housing, the second gear being rotatable about an output axis and being meshed with the first gear; a spindle received in the housing and being coupled to the second gear for rotation therewith; a first shaft that is coupled to the spindle for rotation therewith about the output axis; a second shaft that is rotatable about the output axis relative to the spindle; a first shaft bearing received between the second shaft and the spindle, the first shaft bearing supporting the second shaft for rotation relative to the spindle; and a mode collar slidably disposed on at least one of the spindle and the second shaft, the mode collar being movable along the output axis between a first position, a second position and a third position, wherein the mode collar is rotatably disengaged from one of the spindle and the second shaft when the mode collar is in the first position, wherein the mode collar is engaged to both the spindle and the second shaft to thereby couple the second shaft to the spindle for rotation therewith when the mode collar is in the second position, and wherein the mode collar couples the spindle and the second shaft to the housing to inhibit relative rotationof the spindle and the second shaft relative to the housing when the mode collar is in the third position.

2. The axle assembly of Claim 1 , wherein the second gear is one of a bevel gear, a spiral bevel gear and a hypoid gear.

3. The axle assembly of Claim 1 , wherein the spindle has a set of first external teeth, wherein the second shaft has a set of second external teeth, and wherein the mode collar has a set of internal teeth that are meshingly engaged with the set of first external teeth and the set of second external teeth when the mode collar is in the second position.

4. The axle assembly of Claim 1 , wherein the mode collar has a plurality of first face teeth, wherein the housing has a plurality of second face teeth, and wherein the first face teeth are meshed with the second face teeth when the mode collar is in the third position.

5. The axle assembly of Claim 4, wherein the second face teeth are unitarily and integrally formed with the housing.

6. The axle assembly of Claim 1 , wherein the housing includes a first housing member, a second housing member and an intermediate housing member that is disposed between the first and second housing members, wherein thespindle is supported on first and second spindle bearings, the first spindle bearing being mounted in the first housing member, the second spindle bearing being mounted in the intermediate housing, and wherein the second shaft is further supported by a second shaft bearing that is mounted to the second housing member.

7. The axle assembly of Claim 1 , wherein the spindle defines an aperture that defines a set of internal splines, wherein the first shaft includes a plurality of external splines that are received into the aperture in the spindle and engaged with the set of internal splines.

8. The axle assembly of Claim 1 , wherein the spindle has a hub portion, wherein the first shaft bearing is received on the hub portion, and wherein the second shaft is received over the first shaft bearing.

9. The axle assembly of Claim 1 , further comprising an actuator that is configured to move the mode collar between the first, second and third positions, the actuator comprising a fork, the fork being received into an annular groove that is formed about the mode collar.

10. The axle assembly of Claim 9, wherein the actuator further comprises an axially movable member, a linkage and a lever, the axially movable member being coupled to the fork, the linkage coupling the axially movablemember to the lever such that movement of the lever causes corresponding movement of the axially movable member.11 . The axle assembly of Claim 9, wherein the actuator further includes a linear motor having an output member that is movable along an actuation axis that is parallel to the output axis, the fork being coupled to the output member for movement therewith along the actuation axis.

12. The axle assembly of Claim 11 , wherein the linear motor comprises a rotary motor, a lead screw that is driven by the rotary motor, and a threaded element that threadably coupled to the lead screw.

13. The axle assembly of Claim 12, wherein the actuator further comprises a compliance spring that is disposed between the threaded element and the fork.

14. The axle assembly of Claim 11 , wherein the linear motor comprises a rotary motor and a cam that is driven by the rotary motor.

15. The axle assembly of Claim 1 , wherein the spindle and the second gear are integrally and unitarily formed.

16. The axle assembly of Claim 1 , further comprising a third shaft coupled to the second shaft for rotation therewith, wherein the second shaft is disposed along the output axis between the spindle and the third shaft.

17. The axle assembly of Claim 1 , wherein the first gear is rotatable about an intermediate axis that is parallel to the output axis.

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