Ebeam axle with two-speed input to differential assembly and locking mechanism

Abstract

An electric beam axle having a transmission that transmits rotary power between a motor assembly and a differential input member of a differential assembly. The transmission includes a multi-speed reduction having a planetary gearset and a range sleeve. The planetary gearset includes a ring gear, a planet carrier, which is rotatably coupled to the differential input member, a sun gear and a plurality of planet gears that are journally supported by the planet carrier and meshingly engaged with the ring gear and the sun gear. The sun gear is disposed within the planet carrier. The ring gear, sun gear and planet gears have helical gear teeth. The range sleeve is coaxially received in the sun gear and is movable between a first position, which rotationally immobilizes the sun gear, and a second position that locks the planetary gearset so that the sun gear rotates with the ring gear.

Description

eBEAM AXLE WITH TWO-SPEED INPUT TO DIFFERENTIAL ASSEMBLY AND LOCKING MECHANISMCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States provisional application no. 63 / 552,106, filed February 10, 2024, which is hereby incorporated by reference as though fully set forth herein.FIELD

[0002] The present disclosure relates to an electric beam (eBeam) axle with a two-speed input to a differential assembly and a locking mechanism.BACKGROUND

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] There is increasing interest in vehicle driveline electrification, particularly for larger vehicles such as vans and trucks. Many electrified driveline configurations employ a single-speed transmission between an electric motor and a differential assembly. While such configurations are satisfactory for their intended purpose, such configurations may not provide desired adaptability to varying power requirements and / or efficiency when the vehicle is operated under widely varying speeds and / or loads.

[0005] Two-speed axle assemblies have been employed in vehicle drivelines that are powered by an internal combustion engine. One such two-speed axle assembly employs a two-speed planetary reduction that provides rotary power to the input of the differential assembly. The two-speed planetary reduction employs a sun gear that is slidable between a first position, which permits the two- speed planetary reduction to perform a speed reduction / torque multiplication operation for low-speed operation, and a second position that “locks” the two- speed planetary reduction for high-speed operation. Due to the need for the sun gear to slide, the teeth of the gearing in the two-speed planetary reduction are configured as straight involute gears, which can be relatively noisy in operation. Moreover, the teeth of the sun gear can clash with the teeth of other components when the sun gear is being moved into either of the first and second positions, which can degrade the teeth of the sun gear over time.

[0006] Accordingly, there remains a need in the art for a heavier-duty electrified axle assembly that employs a relatively robust two-speed transmission.SUMMARY

[0007] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0008] In one form, the teachings of the present disclosure provide an electric beam axle that includes a housing assembly, a motor assembly, a differential assembly, a transmission, a first axle shaft and a second axle shaft. The housing assembly defines an output axis and has a carrier housing and a pair of axle tubes. The carrier housing has first and second carrier housing members that are mated to one another about a plane that is perpendicular to the outputaxis. Each of the first and second carrier housing members defines a tube mount into which an associated one of the axle tubes is received. The motor assembly is coupled to the housing assembly. The differential assembly is received in the housing assembly and has a differential input member, which is rotatable about the output axis, and first and second differential output members. The transmission transmits rotary power between the motor assembly and the differential assembly and includes a multi-speed reduction having a ring gear, a planet carrier, a plurality of planet gears, a sun gear, a set of first range teeth, a set of second range teeth, a set of third range teeth, and a range sleeve. The ring gear is rotatable about the output axis relative to the housing assembly. The planet carrier is coupled for rotation with the differential input member. Each of the planet gears is rotatably mounted on the planet carrier and meshingly engaged with a set of internal teeth formed on the ring gear. The sun gear is disposed along the output axis within the planet carrier and is meshingly engaged with the planet gears. The set of first range teeth is formed on an interior surface of the sun gear. The set of second range teeth is formed on an interior surface of one of the ring gear and the planet carrier. The set of third range teeth is fixedly coupled to the carrier housing. The range sleeve is concentrically received in the sun gear and has a set of first mating range teeth, which are engaged with the set of first range teeth, and a set of second mating range teeth that are spaced apart from the set of first mating range teeth along the output axis. The range sleeve is slidable between a high- range position, in which the set of second mating range teeth are engaged with the set of second range teeth and disengaged from the set of third range teeth, aneutral position, in which the set of second mating range teeth are disengaged from the set of second range teeth and the set of third range teeth, and a low- range position, in which the set of second mating range teeth is disengaged from the set of second range teeth and engaged with the set of third range teeth. The ring gear, the planet gears and the sun gear have helical gear teeth. The first axle shaft is received through a first one of the axle tubes and is coupled to the first differential output for rotation therewith. The second axle shaft is received through the other one of the axle tubes and is coupled to the second differential output for rotation therewith. The second axle shaft is received through the range sleeve.

[0009] 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

[0010] 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.

[0011] Figure 1 is a perspective view of an exemplary electric beam axle constructed in accordance with the teachings of the present disclosure;

[0012] Figure 2 is a sectional view of the electric beam axle of Figure 1 ;

[0013] Figure 3 is an enlarged portion of Figure 2;

[0014] Figures 4 and 5 are perspective views of a portion of the electric beam axle of Figure 1 , illustrating a multi-speed reduction and a differential assembly;

[0015] Figure 6 is a perspective view illustrating a portion of the multi-speed reduction and the differential assembly;

[0016] Figure 7 is a perspective view of a range sleeve of the multi-speed reduction;

[0017] Figures 8, 9 and 10 are sectional views of a portion of the electric beam axle of Figure 1 illustrating the range sleeve in high-range, neutral-range, and low-range positions, respectively;

[0018] Figures 11 and 12 are perspective views of a portion of the electric beam axle of Figure 1 , illustrating a locking sleeve of a locking mechanism in first and second positions, respectively;

[0019] Figure 13 is a view similar to that of Figure 3 but depicting the locking sleeve of the locking mechanism in the second position;

[0020] Figure 1 is an enlarged portion of Figure 4 depicting the contouring of the end faces of a set of locking teeth;

[0021] Figure 15 is an exploded perspective view of a twin-fork actuator;

[0022] Figure 16 is an isometric view of a portion of the fork actuator illustrating the motor, transmission, and a portion of the fork actuator housing in greater detail;

[0023] Figure 17 is a top view of the fork actuator with a top portion of the actuator housing removed; and

[0024] Figure 18 is a bottom view of a portion of the fork actuator;

[0025] Figure 19 is an isometric view of a further implementation of a range sleeve; and

[0026] Figures 20-23 are diagrammatic views showing the progressive engagement of a set of second range teeth and a set of second mating range teeth.

[0027] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.DETAILED DESCRIPTION

[0028] With reference to Figures 1 and 2, an exemplary electric beam (eBeam) axle constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. The eBeam axle 10 can include a housing assembly 12, a motor assembly 14, a transmission 16, a differential assembly 18, first and second output shafts 20 and 22, respectively, and a differential locking mechanism 24.

[0029] The housing assembly 12 can include a carrier housing 30 and a pair of axle tubes 32. The carrier housing 30 can be configured in any desired manner. In the example provided, the carrier housing 30 is formed of first and second carrier housing members 36 and 38, respectively, that are mated to one another about a plane that is perpendicular to an output axis 40 about which the first and second output shafts 20 and 22 rotate. Each of the first and second carrier housing members 36 and 38 defines a tube mount 42. Each axle tube 32 is received intoa respective one of the tube mounts 42 and is fixedly coupled to an associated one of the first and second carrier housing members 36 and 38 in a desired manner. For example, each axle tube 32 can be press-fit into a corresponding one of the tube mounts 42 and secured to the associated one of the first and second carrier housing members 36 and 38 via a plurality of slug welds (not shown).

[0030] The motor assembly 14 can be conventional in its configuration and can include a motor housing 48 and an electric motor (not shown) having a motor output shaft (not shown) that is rotatable relative to the motor housing 48 for delivering rotary power. The electric motor 14 can be any type of electric motor, such as an AC induction motor or a permanent magnet motor. The motor housing 48 can be fixedly coupled to the carrier housing 30. In the example provided, the motor housing 48 is a discrete component that is assembled to the first carrier housing member 36. It will be appreciated, however, that the motor housing 48 and the first carrier housing member 36 could be unitarily and integrally formed.

[0031] With reference to Figure 3, the transmission 16 is received in the carrier housing 30 and is configured to transmit rotary power between the motor output shaft and the differential assembly 18. The transmission 16 includes a multi-speed reduction 50 and can employ one or more gear reductions (not shown) between the motor output shaft and the multi-speed reduction 50. The multi-speed reduction 50 includes a ring gear 52, a planet carrier 54, a plurality of planet gears 56, a sun gear 58, a set of first range teeth 60, a set of second range teeth 62, a set of third range teeth 64 and a range sleeve 66.

[0032] With reference to Figures 3 through 5, the ring gear 52 is rotatable about the output axis 40 relative to the carrier housing 30 and includes a set of external teeth 70, which are meshingly engaged by an output gear (not shown) of the one or more gear reductions that are driven by the motor output shaft, and a set of internal teeth 72. In the example provided, the ring gear 52 includes first and second gear carrier members 74 and 76, respectively, each of which defining a trunnion 78. A tapered roller bearing 80 is disposed between each trunnion 78 and a corresponding bearing mount 82 that is formed in the carrier housing 30.

[0033] With reference to Figures 3 and 6, the planet carrier 54 is rotatable about the output axis 40 relative to the ring gear 52 and includes a carrier plate 90, a carrier body 92 and a plurality of pins 94 that are mounted to the carrier plate 90 and the carrier body 92. Each of the planet gears 56 is rotatably received on a corresponding one of the pins 94. In the example provided, a needle bearing is received between each planet carrier 54 and pin 94. Each of the planet gears 56 is meshingly engaged with the set of internal teeth 72 on the ring gear 52.

[0034] Returning to Figure 3, the sun gear 58 is rotatable about the output axis 40 relative to the ring gear 52 and the planet carrier 54. The sun gear is received in the planet carrier 54 between the carrier plate 90 and the carrier body 92 and is meshingly engaged with the planet gears 56. Optionally, thrust bearings 98 can be disposed between the opposite axial ends of the sun gear 58 and the carrier plate 90 and the carrier body 92. In an implementation, the thrust bearings 98 may comprise washers.

[0035] With reference to Figures 3, 5 and 6, the set of first range teeth 60 can be an internal set of teeth that are formed on the sun gear 58 and which are disposed concentrically about the output axis 40.

[0036] With reference to Figures 3 and 5, the set of second range teeth 62 can also be an internal set of teeth that is coupled for rotation with either the ring gear 52 or the planet carrier 54. In the example provided, the set of second range teeth 62 is formed on the second gear carrier member 76 and is disposed concentrically about the output axis 40.

[0037] Returning to Figure 3, the set of third range teeth 64 can be fixedly coupled to the carrier housing 30 and can be disposed concentrically about the output axis 40. In the example provided, the set of third range teeth 64 are formed in a plate 100 that is mounted (via threaded fasteners 102) to the second carrier housing member 38 and the plate 100 defines the bearing mount 82 into which the tapered roller bearing 80 that supports the trunnion 78 on the carrier plate 90.

[0038] With reference to Figures 3 and 7, the range sleeve 66 is a tubular structure that is disposed concentrically about the output axis 40 and movable between a high-range position (Fig. 8), a neutral-range position (Fig. 9), and a low- range position (Fig. 10). The range sleeve 66 defines a set of first mating range teeth 110 and a set of second mating range teeth 112 that is spaced apart from the set of first mating range teeth 110 along the output axis 40. The set of first mating range teeth 110 is engaged with the set of first range teeth 60 to non- rotatably but axially slidably couple the range sleeve 66 to the sun gear 58. The set of first mating range teeth 110 engage with the set of first range teeth 60 whenthe range sleeve 66 is positioned in each of the high-range, neutral-range, and low-range positions. The set of second mating range teeth 112 is engaged with the set of second range teeth 62 to rotationally couple the range sleeve 66 to the one of the ring gear 52 and the planet carrier 54 (i.e., the ring gear 52 in the example shown) when the range sleeve 66 is in the high-range position. The set of second mating range teeth 112 is engaged with the set of third range teeth 64 to inhibit rotation of the range sleeve 66 relative to the housing assembly 12 when the range sleeve 66 is in the low-range position. The set of second mating range teeth 112 is not engaged with any of the sets of first, second and third range teeth 60, 62 and 64 when the range sleeve 66 is disposed in the neutral-range position, which is intermediate the high-range and low-range positions.

[0039] From the foregoing, it will be appreciated that the sun gear 58 is rotationally coupled to the planet carrier 54 and the ring gear 52 when the range sleeve 66 is disposed in the high-range position so that the multi-speed reduction 50 operates in a 1 :1 speed ratio (i.e., the planet carrier 54 rotates at the same rotational speed as the ring gear 52), that the planet carrier 54 is rotationally decoupled from the ring gear 52 when the range sleeve 66 is in the neutral-range position so that no rotary power is transmitted through the multi-speed reduction 50, and that rotation of the sun gear 58 relative to the housing assembly 12 is inhibited when the range sleeve 66 is in the low-range position so that the multispeed reduction performs at a desired speed reduction ratio, such as 1 .57:1 .

[0040] Because relative axial movement between the ring gear 52, planet gears 56 and sun gear 58 along the output axis 40 is not required to change thespeed ratio of the multi-speed reduction 50, the set of internal teeth 72 on the ring gear 52, the teeth of the planet gears 56 and the teeth of the sun gear 58 are configured as helical gear teeth in the example provided.

[0041] Returning to Figures 1 and 3, the range sleeve 66 can be moved between the high-range, neutral-range, and low-range positions in any desired manner. In the example provided, a range actuator 120 having a range fork 122 is employed for movement of the range sleeve 66. The range fork 122 can have a generally U-shaped fork member (not specifically shown in Figures 1 and 3) having a pair of tines (not specifically shown in Figures 1 and 3) that can be received into an annular groove 124 that is formed on the range sleeve 66. Accordingly, movement of the range fork 122 along the output axis 40 will cause corresponding movement of the range sleeve 66. Any desired means can be employed to move the range fork 122. In the example provided, a linear motor (not specifically shown in Figures 1 and 3) that is somewhat similar to that which is described in commonly assigned U.S. Patent No. 10,112,482 (United States application no. 15 / 340,090 filed November 1 , 2016), the disclosure of which is incorporated by reference as if set forth in its entirety herein, as being used to move the range fork is employed. In this regard, the range actuator 120 can include the rotary actuator motor, the actuator transmission, the lead screw, the (first) rail, the cradle assembly, the range fork and the (first) arm spring that are disclosed in U.S. Patent No. 10,112,482.

[0042] With specific reference to Figures 3 and 6, the differential assembly 18 can include a differential input member 130, and a means for providing speeddifferentiation having a pair of differential output members 132. The differential input member 130 can be coupled to the planet carrier 54 for rotation therewith about the output axis 40. The differential assembly 18 constitutes the means for providing speed differentiation that is configured to receive rotary power from the differential input member 130 and distributing rotary power to the differential output members 132. The means for providing speed differentiation can include a differential gearset, or one or more friction clutches, for example. In the particular example provided, the means for providing speed differentiation comprises a differential gearset having a cross-pin 140, which is coupled to the differential input member 130 for rotation therewith, a pair of differential pinions 142, which are rotatably received on the cross-pin 140, and a pair of side gears, which are the differential output members 132 in the particular example shown, that are meshingly engaged with the differential pinions 142 and which are rotatable about the output axis 40 relative to the differential input member 130.

[0043] With reference to Figure 3, the first and second output shafts 20 and 22 can be received through the axle tubes 32 and can be rotatably coupled to an associated one of the side gears (differential output members 132). Each of the first and second output shafts 20 and 22 can have a set of external input splines 150 that is meshingly engaged with a set of internal splines 152 formed into an associated one of the side gears (differential output members 132). The first output shaft 20 can be received through a hollow, tubular hub 160 that is formed on the differential input member 130. The hollow, tubular hub 160 is concentric with the trunnion 78 that is formed on the first gear carrier member 74 and extendsalong the output axis 40 through the trunnion 78 on the first gear carrier member 74 and terminates in a cavity 168 in the first carrier housing member 36 that is disposed between the axle tube mount 42 and the bearing mount 82. The second output shaft 22 is received through the range sleeve 66.

[0044] With reference to Figures 3 and 8, the differential locking mechanism 24 can be constructed in any desired manner. In the example provided, the differential locking mechanism 24 includes a locking sleeve 180 that is slidable about the output axis 40 between a first position (Figs. 3 and 11 ), which does not inhibit relative rotation between the differential input member 130 and the first output shaft 20, and a second position (Figs. 12 and 13) that inhibits relative rotation between the differential input member 130 and the first output shaft 20. The differential locking mechanism 24 can include, for example, a first set of locking teeth 190, which are formed on an axial end of the hollow, tubular hub 160 of the differential input member 130, a second set of locking teeth 192, which are formed on a section of the first output shaft 20 that is disposed in the cavity 168, and third and fourth sets of locking teeth 194 and 196, respectively, which are formed on the locking sleeve 180 and which are engaged or engageable to the first and second sets of locking teeth 190 and 192, respectively. In the example provided, the first and second sets of locking teeth 190 and 192 are formed as external spline teeth, the third and fourth sets of locking teeth 194 and 196 are formed as internal spline teeth, the third set of locking teeth 194 on the locking sleeve 180 are engaged to the second set of locking teeth 192 on a full-time basis, and the fourth set of locking teeth 196 on the locking sleeve 180 are engageableto the first set of locking teeth 190 on the hollow, tubular hub 160 of the differential input member 130 (i.e., when the locking sleeve 180 is in the second position). The first, second, third and fourth sets of spline teeth 190, 192, 194 and 196 can have any desired tooth form, such as a straight involute tooth form. The first set of locking teeth 190 and / or the fourth set of locking teeth 196 can be contoured in any desired manner to ease or promote engagement of the locking sleeve 180 to the differential input member 130 when the locking sleeve 180 is moving toward the second position.

[0045] Figure 14 illustrates one exemplary manner in which the first set of locking teeth 190 may be contoured. It will be appreciated that the fourth set of locking teeth 196 (Fig. 11 ) could be contoured in a similar manner. In the example shown, the front or leading ends 200 of first set of locking teeth 190 taper both increasingly in a front-to-back direction (i.e., increasingly from the base of each tooth to its tip), and increasingly from the center of the tooth in lateral directions toward an associated lateral side (flank) of the tooth so that the front or lead end 200 of each tooth of the first set of locking teeth 190 has a pair of faces 202 that intersect one another along a line 206 that is contained in a plane that passes through the longitudinal center of the tooth and a central axis of the set of locking teeth (i.e., an axis that is coincident with the output axis 40).

[0046] Returning to Figures 1 and 3, the differential locking mechanism 24 can be operated in any desired manner. For example, a return spring (not shown) could be disposed axially between the hollow, tubular hub 160 and the locking sleeve 180 and can bias the locking sleeve 180 toward the first position, and alinear motor (not shown), such as a solenoid, a hydraulic cylinder, or a pneumatic cylinder, which can be disposed concentrically about the first output shaft 20, could be employed to selectively move the locking sleeve 180 toward the second position. In the particular example provided, the differential locking mechanism 24 includes an actuator 210 having a clutch fork 212 that is driven along the output axis 40 by a linear motor (not specifically shown in Figures 1 and 3). The clutch fork 212 includes a generally U-shaped fork (not specifically shown in Figures 1 and 3) with a pair of fork tines that are received into an annular groove 216 that is formed into the locking sleeve 180. Movement of the clutch fork 212 along the output axis 40 will cause corresponding movement of the locking sleeve 180. The linear motor can be configured in any desired manner. Optionally, a compliance spring (not specifically shown) can be disposed between an output of the linear motor and the clutch fork 212. In instances where the linear motor is operated to move the locking sleeve 180 to the second position but movement of the locking sleeve 180 into engagement with the hollow, tubular hub 160 is blocked due to tooth-on-tooth contact between the fourth and first sets of locking teeth 196 and 190, the compliance spring can be compressed to exert a force on the clutch fork 212 that urges the clutch fork 212 toward the second position when the tooth-on- tooth condition has abated.

[0047] Range actuator 120. Various approaches may be used to implement range actuator 120 to axially move the range sleeve 66 to and between the aforementioned high-range position, neutral-range position, and low-range position. It has been described that such axial movement may be accomplishedby actuator 120 using for example a linear motor that moves the aforementioned range fork 122. A description of an exemplary implementation of a twin-fork actuator is set forth below. For example only, the elements of the following described twin-fork actuator that can be used for the range actuator 120 can include the rotary actuator motor, the actuator transmission, the lead screw, the (first) rail, the cradle assembly, the range fork and the (first) arm spring.

[0048] With reference now to FIG. 15, the actuator A can include an actuator housing 1000 (FIG. 18), a motor 1002, a transmission 1004, a bearing 1006, a lead screw 1008, a first rail 1010, a second rail 1012, a cradle assembly 1014, a range fork 220, a mode fork 330, a first arm spring 1016, a second arm spring 1018, and a control system 1020.

[0049] The actuator housing 1000 can include a first cover member 1030 and a second cover member 1032 that can be sealingly coupled to the first cover member 1030 by any suitable means, such as a gasket or a sealing compound. With additional reference to FIG. 16, the first cover member 1030 can define a motor mount 1036, a transmission mount 1038 and a first bearing mount 1040. The motor 1002 can be fixedly coupled to the motor mount 1036. The transmission mount 1038 can comprise two or more wall members 1042 that can support elements of the transmission 1004. The first bearing mount 1040 can be configured to receive a portion of the bearing 1006.

[0050] With reference to FIGS. 15 and 17, the second cover member 1032 can be coupled to the first cover member 1030 to cover the motor 1002 and the transmission 1004. The second cover member 1032 can define a second bearingmount 1044, a pair of first rail apertures 1046, a pair of second rail apertures 1048 and a fork window 1050 through which the range fork 220 and the mode fork 330 can extend. The second bearing mount 1044 can cooperate with the first bearing mount 1040 to retain the bearing 1006 therebetween.

[0051] With renewed reference to FIGS. 15 and 16, the motor 1002 can be any means for providing rotary power, such as a brushed or brushless DC motor. The transmission 1004 can comprise any means for transmitting rotary power between the motor 1002 and the lead screw 1008, such as two or more pulleys, two or more sprockets and / or two or more gears. For example, the transmission 1004 can comprise an input spur pinion 1054, which can be mounted to the output shaft of the motor 1002 for rotation therewith, an output spur pinion 1056, which can be coupled to the lead screw 1008 for common rotation, and a plurality of intermediate spur gears 1058 that can transmit rotary power between the input spur pinion 1054 and the output spur pinion 1056. The intermediate spur gears 1058 can be mounted on axles 1060 that can be fixedly coupled to associated pairs of the wall members 1042. The transmission 1004 can provide a desired overall reduction ratio, such as an overall reduction ratio of about 250:1 to about 750:1 and preferably a reduction ratio of about 475:1 .

[0052] The bearing 1006 can be a ball bearing having an outer bearing race 1070, which can be received in the first and second bearing mounts 1040 and 1044 to fixedly couple the outer bearing race 1070 to the actuator housing 1000, an inner bearing race 1072, which can support the lead screw 1008 for rotation about a firstaxis 1076, and a plurality of bearing elements (not specifically shown) between the outer and inner bearing races 1070 and 1072.

[0053] The lead screw 1008 can be unitarily and integrally formed and can comprise hub 1080 and a threaded portion 1082. The hub 1080 can be received in the inner bearing race 1072 and can be coupled to the output spur pinion 1056 of the transmission 1004 for rotation therewith.

[0054] The first rail 1010 can be received in the first rail apertures 1046 and fixedly coupled to the second cover member 1032 in any desired manner, such as a press-fit. The first rail 1010 can extend along a second axis 1090 that can be generally parallel to the first axis 1076. Similarly, the second rail 1012 can be received in the second rail apertures 1048 and fixedly coupled to the second cover member 1032 in any desired manner, such as a press-fit. The second rail 1012 can extend along a third axis 1092 that can be generally parallel to the first axis 1076.

[0055] The cradle assembly 1014 can comprise a cradle 2000, a cradle body 2002, a keeper 2004, one or more guides 2006 and a cradle spring 2008. The cradle 2000 can comprise a central body 2020, a first cradle yoke 2022, a second cradle yoke 2024, a third cradle yoke 2026, a pair of arms 2028, which can be coupled to opposite ends of the central body 2020, a first cradle drive lug 2030 and a second cradle drive lug 2032. Each of the first, second and third cradle yokes 2022, 2024 and 2026 can be coupled to the central body 2020. The first and third cradle yokes 2022 and 2026 can be slidably received on the first rail 1010, and the second cradle yoke 2024 can be slidably received on the second rail 1012. In theparticular example provided, the first cradle yoke 2022 is located between the second and third cradle yokes 2024 and 2026. Each of the arms 2028 can be bifurcated to define a pair of branches 2040 with an arm aperture 2042 therebetween. Additionally, each of the arms 2028 can define a pair of first guide slots 2048 that can be partly formed through the arms 2028. More specifically, each of the first guide slots 2048 can extend through an inboard side IS of an associated one of the arms 2028 but not an outboard side OS of the associated one of the arms 2028. The first and second cradle drive lugs 2030 and 2032 can be disposed on the cradle 2000 at a location between the first cradle yoke 2022 and the second cradle yoke 2024. In the particular example provided, the first and second cradle drive lugs 2030 and 2032 form the opposite faces of a single structure.

[0056] The cradle body 2002 can comprise a longitudinally extending body member 2050 and a head 2052 and can define a pair of second guide slots 2054. The body member 2050 can have a threaded internal bore 2060 and a pair of flanks 2062. The threaded internal bore 2060 can receive the threaded portion 1082 of the lead screw 1008 to threadably couple the cradle body 2002 to the lead screw 1008. The head 2052 can be coupled to the body member 2050 on an end opposite the flanks 2062 and can extend radially outwardly therefrom. The head 2052 can be received in the arm aperture 2042 of a corresponding one of the arms 2028 and can be sized to non-rotatably but axially slidably engage the branches 2040 of the corresponding one of the arms 2028. The second guide slots 2054 canbe longitudinally extending grooves formed in the body member 2050 and the head 2052 that are sized to partly receive the guides 2006.

[0057] The keeper 2004 can include a keeper head 2072 that can be received in the arm aperture 2042 of a corresponding one of the arms 2028 (opposite the arm 2028 that receives the head 2052 of the body member 2050) and can be sized to non-rotatably but axially slidably engage the branches 2040 of the corresponding one of the arms 2028. The keeper head 2072 can extend radially outwardly from the body member 2050 of the cradle body 2002. The keeper 2004 can be fixedly and non-rotatably coupled to the cradle body 2002 in any desired manner. In the particular example provided, the keeper 2004 includes a pair of keeper flanges 2064 that abut the flanks 2062 on the body member 2050 and a fastener, such as a pin (not specifically shown), is inserted through the keeper flanges 2064 and the flanks 2062 to couple the keeper 2004 to the cradle body 2002. A pair of third guide slots 2066 can be formed in the keeper head 2072. The third guide slots 2066 can be disposed in-line with the second guide slots 2054 in the cradle body 2002 when the keeper 2004 and the cradle body 2002 are assembled together. Those of skill in the art will appreciate that while the keeper 2004 and the cradle body 2002 have been described as being two discrete components that are assembled to one another, the keeper 2004 and the cradle body 2002 could be integrally and unitarily formed in the alternative.

[0058] The guides 2006 are configured to guide the keeper 2004 and the cradle body 2002 as they move along the first axis 1076 relative to the cradle 2000. In the example provided, two guides 2006 are provided and each guide 2006 is asteel rod that is received into a corresponding set of the first, second and third guide slots 2048, 2054 and 2066. It will be appreciated that as the first guide slots 2048 do not extend completely through the branches 2040 of the arms 2028, the guides 2006 are trapped between the arms 2028 while the cradle body 2002 and the keeper 2004 can slide on the guides 2006 so as to be capable of telescoping out of either end of the cradle 2000.

[0059] The cradle spring 2008 can be mounted co-axially about the central body 2020 of the cradle body 2002 and can abut an inside surface of the head 2052 of the cradle body 2002 and an inside surface of the keeper head 2072 of the keeper 2004. The cradle spring 2008 can center the cradle body 2002 and the keeper 2004 relative to the arms 2028 of the cradle 2000. Additionally, the cradle spring 2008 can permit axial movement of the cradle body 2002 along the first axis 1076 relative to the cradle 2000 as will be described in more detail, below.

[0060] The range fork 220 can include a first fork member 2100, a first fork yoke 2102, a second fork yoke 2104, a first fork drive lug 2106 and a second fork drive lug 2108. The first fork member 2100 can comprise a semi-circular structure having a groove 2120 into which a collar member is received or in an alternative implementation a projection constituting the range fork 122 in FIG. 3 that is configured to be disposed in the annular groove 124 (FIG. 3). The first and second fork yokes 2102 and 2104 can be slidably engaged to the first rail 1010 and can be fixedly coupled to the first fork member 2100. In the particular example provided, the first and third cradle yokes 2022 and 2026 are disposed axially between the first and second fork yokes 2102 and 2104. The first fork drive lug2106 can be coupled to the second fork yoke 2104 and can be positioned in-line with the first cradle drive lug 2030 such that the first cradle drive lug 2030 can contact the first fork drive lug 2106 in some situations to coordinate movement of the range fork 220. The second fork drive lug 2108 can be coupled to the first fork yoke 2102 and can be positioned in-line with the second cradle drive lug 2032 such that the second cradle drive lug 2032 can contact the second fork drive lug 2108 in some situations to coordinate movement of the range fork 220.

[0061] The mode fork 330 can include a second fork member 2200, a third fork yoke 2202, and a fourth fork yoke 2204. The second fork member 2200 can comprise a semi-circular structure having a groove 2220 into which a collar member (not specifically depicted) is received or in an alternative implementation a projection configured to be disposed in the annular groove. The third and fourth fork yokes 2202 and 2204 can be slidably engaged to the second rail 1012 and can be fixedly coupled to the second fork member 2200. In the particular example provided, the second cradle yoke 2024 is disposed axially between the third and fourth fork yokes 2202 and 2204.

[0062] The first arm spring 1016 can be a compression spring that can be received on the first rail 1010 between the first fork yoke 2102 and the first cradle yoke 2022. Accordingly, the first arm spring 1016 can bias the first fork yoke 2102 (and thereby the range fork 220) axially along the first rail 1010 in a direction away from the cradle 2000. The second arm spring 1018 can be a compression spring that can be received on the second rail between second cradle yoke 2024 and the fourth fork yoke 2204. Accordingly, the second arm spring 1018 can bias the fourthfork yoke 2204 (and thereby the mode fork 330) axially along the second rail 1012 in a direction away from the cradle 2000.

[0063] With reference to FIGS. 15 and 18, the control system 1020 can comprise a controller 2300, a rotary sensor 2302, a first position sensor 2304 and a second position sensor 2306. The controller 2300 can be coupled to a vehicle controller 2300, a source of electrical power 2312 and the motor 1002. The controller 2300 and the vehicle controller 2300 can communicate with one another to transmit vehicle data, a desired range setting and a desired mode setting from the vehicle controller 2300 to the controller 2300, and to transmit operational data from the controller 2300 to the vehicle controller 2300. The controller 2300 can selectively couple the motor 1002 to the source of electrical power 2312 to control the rotational direction of the motor 1002 and the extent to which the motor 1002 operates.

[0064] The rotary sensor 2302 can be coupled to the actuator housing 1000 and can be configured to sense rotation of a component within the actuator A and responsively generate a rotary sensor signal. In the particular example provided, the rotary sensor 2302 comprises a sensor pinion 2320, which is driven by a first one of the intermediate spur gears 1058, a magnetic pulse wheel 2322, which is coupled to the sensor pinion 2320 for rotation therewith, and a Hall-effect sensor 2324 that is configured to sense rotation of the magnetic pulse wheel 2322 and generate a rotary sensor signal in response thereto.

[0065] The first position sensor 2304 can comprise a first sensor target 2330 and a first sensor 2332. The first sensor target 2330 can comprise a first magnetthat can be fixedly coupled to the range fork 220 for movement therewith along the first rail 1010. In the example provided, the first sensor target 2330 is fixedly mounted to the second fork yoke 2104. The first sensor 2332 can be any type of sensor that can sense a position of the first sensor target 2330 and responsively produce a first position signal. For example, the first sensor 2332 can comprise a plurality of Hall-effect sensors 2336 that are configured to sense the first sensor target 2330 and responsively produce respective position signals.

[0066] In the particular example provided, the first sensor 2332 comprises five Hall-effect sensors 2336 that are fixedly coupled to a circuit board 2338 of the controller 2300 and which are disposed along a first sensor axis 2340 that can be generally parallel to the second axis 1090. The five Hall-effect sensors 2336 cooperate with the first sensor target 2330 to permit the movement of the range fork 220 along the second axis 1090 to be monitored and reported so that the controller 2300 can identify at least three predetermined positions of the range fork 220, such as the aforementioned high-range position (high-speed position), the neutral-range (neutral-speed) position, and the low-range (low-speed) position, and optionally a first intermediate position, in which the range fork 220 is disposed in between the high-range and neutral-range positions, and a second intermediate position, in which the range fork 220 is disposed in between the neutral-range and low-range positions.

[0067] The second position sensor 2306 can comprise a second sensor target 2350 and a second sensor 2352. The second sensor target 2350 can comprise a second magnet that can be fixedly coupled to the mode fork 330 formovement therewith along the second rail 1012. In the example provided, the second sensor target 2350 is fixedly mounted to the fourth fork yoke 2204. The second sensor 2352 can be any type of sensor that can sense a position of the second sensor target 2350 and responsively produce a second position signal. For example, the second sensor 2352 can comprise a plurality of Hall-effect sensors 2356 that are configured to sense the second sensor target 2350 and responsively produce respective position signals.

[0068] In the particular example provided, the second sensor 2352 comprises three Hall-effect sensors 2356 that are fixedly coupled to the circuit board 2338 of the controller 2300 and which are disposed along a second sensor axis 2360 that can be generally parallel to the third axis 1092. The three Hall-effect sensors 2356 cooperate with the second sensor target 2350 to permit the movement of the mode fork 330 along the third axis 1092 to be monitored and reported so that the controller 2300 can identify at least two predetermined positions of the mode fork 330, and optionally a third intermediate position between the first and second positions.

[0069] In operation, the controller 2300 can operate the motor 1002 to drive the cradle assembly 1014 (via the lead screw 1008) to coordinate movement of the range fork 220 and the mode fork 330. The rotary sensor 2302 can be employed by the controller 2300 to control the amount by which the motor 1002 rotates the lead screw 1008, while the first and second position sensors 2304 and 2306 can be employed by the controller 2300 to identify the positioning of the rangesleeve 66 (or the range fork 220 which can correspond to the aforementioned range fork 122 of FIG. 3) and the mode fork 330.

[0070] The lead screw 1008 can be rotated in a first rotational direction to drive the cradle assembly 1014 along the first axis 1076 in a first axial direction. In addition, the lead screw 1008 can be rotated in a second rotational direction (opposite the first rotational direction) to move the cradle assembly 1014 along the first axis 1076 in a second axial direction that is opposite the first axial direction.

[0071] The second arm spring 1018 can provide sufficient compliance to permit the cradle assembly 1014 to be fully moved by the lead screw 1008 despite the cessation of movement of the mode fork 330. The cradle spring 2008, through its compression between the head 2052 of the cradle body 2002 and the opposite arm 2028 of the cradle 2000, can provide sufficient compliance to permit the cradle assembly 1014 to be fully moved by the lead screw 1008 despite the cessation of movement of the range fork 220.

[0072] Figure 19 is an isometric view of a further implementation of the range sleeve, designated range sleeve 66a. The range sleeve 66a may be generally the same as range sleeve 66 except as described below. The range sleeve 66a includes a set of second mating range teeth 112a, which includes a first plurality of teeth 214 as well as a second plurality of axially longer teeth 218. In the illustrated implementation, every fourth tooth is an axially longer tooth 218 (i.e., three intervening teeth 214). Therefore, the axially longer teeth 218 are interleaved with the axially shorter teeth 214. It should be appreciated that in this further implementation of the range sleeve 66a, that the above-disclosed secondrange teeth 62 may be configured similarly having a plurality of axially longer teeth (the similarly configured second range teeth 62 not being specifically depicted). The longer teeth 218 extend proud of the rest of the teeth 214 so that when the mating spline (i.e., the second range teeth 62), which is similarly configured, slides into engagement at some relative speed difference, the proud teeth 218 have time to travel axially into an overlapping condition such that the flanks of the longer teeth 218 come solidly into contact synchronizing and aligning the splines (i.e., the external spline 112a and the internal spline such as the similarly configured second range teeth 62) such that the splines will axially slide into full engagement.

[0073] Figures 20-23 are diagrammatic views showing the progressive engagement of the set of second mating teeth 112a engaging a mating spline (e.g., a similarly configured set 62) that also has a plurality of axially longer teeth designated 222. As shown in Figure 20, the longer teeth 218, 222 extend proud of the rest of the teeth. As shown in Figure 21 , when the mating spline having the longer teeth 222 slides into engagement at some relative speed difference, the proud teeth 218 have time to travel axially into an overlapping condition such that the flanks of the longer teeth 218 come solidly into contact synchronizing and aligning the splines. As shown in Figure 22, the shorter teeth are now partially engaged. As shown in Figure 23, the splines have slid axially into full engagement.

[0074] 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, areinterchangeable 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 electric beam axle comprising: a housing assembly defining an output axis and having a carrier housing and a pair of axle tubes, the carrier housing having first and second carrier housing members that are mated to one another about a plane that is perpendicular to the output axis, each of the first and second carrier housing members defining a tube mount into which an associated one of the axle tubes is received; a motor assembly coupled to the housing assembly; a differential assembly received in the housing assembly, the differential assembly having a differential input member, which is rotatable about the output axis, and first and second differential output members; a transmission transmitting rotary power between the motor assembly and the differential assembly, the transmission having a multi-speed reduction having a ring gear, a planet carrier, a plurality of planet gears, a sun gear, a set of first range teeth, a set of second range teeth, a set of third range teeth, and a range sleeve, the ring gear being rotatable about the output axis relative to the housing assembly, the planet carrier being coupled for rotation with the differential input member, each of the planet gears being rotatably mounted on the planet carrier and meshingly engaged with a set of internal teeth formed on the ring gear, the sun gear being disposed along the output axis within the planet carrier and being meshingly engaged with the planet gears, the set of first range teeth being formed on an interior surface of the sun gear, the set of second range teeth being formedon an interior surface of one of the ring gear and the planet carrier, the set of third range teeth being fixedly coupled to the carrier housing, the range sleeve being concentrically received in the sun gear and having a set of first mating range teeth, which are engaged with the set of first range teeth, and a set of second mating range teeth that are spaced apart from the set of first mating range teeth along the output axis, wherein the range sleeve is slidable between a high-range position, in which the set of second mating range teeth are engaged with the set of second range teeth and disengaged from the set of third range teeth, a neutral position, in which the set of second mating range teeth are disengaged from the set of second range teeth and the set of third range teeth, and a low-range position, in which the set of second mating range teeth is disengaged from the set of second range teeth and engaged with the set of third range teeth, wherein the ring gear, the planet gears and the sun gear have helical gear teeth; a first axle shaft received through a first one of the axle tubes and being coupled to the first differential output member for rotation therewith; and a second axle shaft received through the other one of the axle tubes and being coupled to the second differential output member for rotation therewith, the second axle shaft being received through the range sleeve.

2. The electric beam axle of Claim 1 , wherein the multi-speed reduction includes a pair of thrust bearings, each of the thrust bearings being received between an associated axial end of the sun gear and the planet carrier.

3. The electric beam axle of Claim 1 , wherein the ring gear includes a pair of gear carrier members, each of the gear carrier members defining a trunnion on which a bearing is received, the bearings supporting the ring gear for rotation relative to the housing assembly.

4. The electric beam axle of Claim 3, wherein the set of second range teeth are formed on the interior surface of one of the gear carrier members.

5. The electric beam axle of Claim 1 wherein the range sleeve includes an annular groove formed thereon.

6. The electric beam axle of Claim 1 wherein the range sleeve when in the high-range position locks the sun gear and the ring gear for rotation together.

7. The electric beam axle of Claim 1 wherein the range sleeve when in the low-range position locks the range sleeve to the housing assembly to inhibit rotation of the range sleeve relative to the housing assembly, wherein rotation of the sun gear relative to the housing assembly is inhibited.

8. The electric beam axle of Claim 1 , further comprising a locking sleeve that is received in the housing assembly and slidably received on one of the first axle shaft and the differential input member, the locking sleeve being movable along the output axis between a first position, in which the locking sleeveis rotatably decoupled from at least one of the first axle shaft and the differential input member, and a second position in which the locking sleeve rotatably couples the first axle shaft to the differential input member.

9. The electric beam axle of Claim 1 , wherein the set of second mating range teeth includes a first plurality of axially longer teeth extending proud of a remainder of the set of second mating range teeth and the set of second range teeth includes a second plurality of axially longer teeth extending proud of a remainder of the set of second range teeth, the first and second pluralities of axially longer teeth being configured to facilitate engagement of the set of second mating range teeth and the set of second range teeth.

10. The electric beam axle of Claim 9 wherein the plurality of axially longer teeth of the set of second mating range teeth are interleaved among the axially shorter teeth.

11. An electric beam axle assembly comprising: a housing assembly defining an output axis and having a carrier housing; a differential assembly received in the housing assembly having a differential input member that is rotatable about the output axis, and first and second differential output members; a transmission transmitting rotary power between a motor assembly and the differential assembly, the transmission having a multi-speed reduction having a ring gear, a planet carrier, a plurality of planet gears, and a sun gear wherein thering gear is rotatable about the output axis, the planet carrier is coupled for rotation with the differential input member, the planet gears are rotatably mounted on the planet carrier and meshingly engaged with internal teeth on the ring gear, the sun gear is disposed along the output axis within the planet carrier and meshingly engaged with the planet gears, the sun gear having first range teeth and the ring gear having second range teeth; and a range sleeve concentrically received in the sun gear and having first mating range teeth engaged with first range teeth, and second mating range teeth axially spaced apart from the first mating range teeth, the range sleeve being slidable between a high-range position where the second mating range teeth are engaged with the second range teeth and disengaged from third range teeth fixedly coupled to the carrier housing, a neutral position where the second mating range teeth are disengaged from the second range teeth and the third range teeth, and a low-range position where the second mating range teeth are disengaged from the second range teeth and engaged with the third range teeth.

12. An electric beam axle assembly of Claim 11 wherein the housing assembly includes a pair of axle tubes and the carrier housing has first and second carrier housing members that are mated to one another about a plane that is perpendicular to the output axis, each of the first and second carrier housing members defining a tube mount into which an associated one of the axle tubes is received.

13. The electric beam axle assembly of Claim 12 further comprising: a first axle shaft received through a first one of the axle tubes and being coupled to the first differential output member for rotation therewith; and a second axle shaft received through the other one of the axle tubes and being coupled to the second differential output member for rotation therewith, the second axle shaft being received through the range sleeve.

14. The electric beam axle assembly of Claim 11 wherein the planet gears and the sun gear have helical gear teeth.

15. The electric beam axle assembly of Claim 13 further comprising a locking sleeve that is received in the housing assembly and slidably received on one of the first axle shaft and the differential input member, the locking sleeve being movable along the output axis between a first position, in which the locking sleeve is rotatably decoupled from at least one of the first axle shaft and the differential input member, and a second position in which the locking sleeve rotatably couples the first axle shaft to the differential input member.

16. The electric beam axle of Claim 15, wherein a hollow, tubular hub of the differential input member extends through the ring gear, wherein a set of locking teeth are formed on an end of the hollow, tubular hub, and wherein a set of mating locking teeth on the locking sleeve is engaged with the set of locking teeth when the locking sleeve is in the second position.

17. The electric beam axle of Claim 16, wherein each of the teeth of the set of locking teeth has a leading end that tapers both increasingly from a base of the tooth to a tip of the tooth and increasingly from a center of the tooth in to each of lateral flank of the tooth so that the leading end of the tooth has a pair of faces that intersect one another along a line contained in a plane that passes through a longitudinal center of the tooth and the output axis.

18. The electric beam axle assembly of Claim 11 , wherein the multispeed reduction includes a pair of thrust bearings, each of the thrust bearings being received between an associated axial end of the sun gear and the planet carrier.

19. The electric beam axle assembly of Claim 11 , wherein the ring gear includes a pair of gear carrier members, each of the gear carrier members defining a trunnion on which a bearing is received, the bearings supporting the ring gear for rotation relative to the housing assembly.

20. The electric beam axle assembly of Claim 11 wherein the range sleeve includes an annular groove formed thereon.