Multi-speed electric drive axle using a multi-layshaft transmission

Abstract

An actuator assembly configured to be coupled to a multi-speed electric drive axle, comprising: an output assembly including an axially movable member configured to be coupled to a multi-speed input portion of the multi-speed electric drive axle; a ball screw having an external threaded portion; and a coupler attached to the axially movable member, the coupler having an internally threaded hub that meshes and engages with the external threaded portion of the ball screw so as to move the coupler and the axially movable member in a straight line as the ball screw rotates.

Description

[Technical Field]

[0001] The present disclosure relates to a multi-speed electric drive axle using a multi-layshaft transmission. [Background Art]

[0002] The present disclosure relates to a multi-speed electric drive axle using a multi-layshaft transmission. The multi-speed electric drive axle may employ an actuator assembly to control gear selection in the multi-layshaft transmission. [Summary of the Invention]

[0003] In one embodiment of the present disclosure, there is provided an actuator assembly configured to be coupled to a multi-speed electric drive axle, the actuator assembly comprising: an output assembly including an axially movable member configured to couple to a multi-speed input portion of the multi-speed electric drive axle; a ball screw having an externally threaded portion; and a coupler attached to the axially movable member, the coupler having an internally threaded hub meshingly engaged with the externally threaded portion of the ball screw such that rotation of the ball screw linearly moves the coupler and the axially movable member.

[0004] In other embodiments of the present disclosure, an actuator assembly is provided configured to be coupled to a multi-speed electric drive axle, the actuator assembly comprising: an output assembly including an axially movable member configured to be coupled to a multi-speed input portion of the multi-speed electric drive axle; a ball screw having an externally threaded portion; a coupler attached to the axially movable member, the coupler having an internally threaded hub that meshes and engages with the externally threaded portion of the ball screw so as to move the coupler and the axially movable member in a linear manner as the ball screw rotates; and a biasing spring configured to apply a biasing force to the multi-speed input portion of the multi-speed electric drive axle so as to bias the multi-speed input portion to a high-speed position.

[0005] In yet another embodiment of the present disclosure, an actuator assembly is provided configured to be coupled to a multi-speed electric drive axle on a vehicle, the actuator assembly comprising: a ball screw having an externally threaded portion; a coupler having an internally threaded hub that meshes and engages with the externally threaded portion of the ball screw so as to move the coupler linearly as the ball screw rotates; an axially movable member configured to be coupled to the multi-speed input portion of the multi-speed electric drive axle and the coupler; and a pivot fork assembly comprising a first fork member, a second fork member, at least one first pivot pin pivotally coupling the first end of the first fork member to the coupler, a second pivot pin pivotally coupling the first fork member to the second fork member, a pair of connecting pins pivotally coupling the first fork member to the second fork member, and one or more compliance springs biasing the second fork member in a first pivot direction around the second pivot pin. [Brief explanation of the drawing]

[0006] The drawings described herein are for illustrative purposes only and do not illustrate all possible embodiments, nor are they intended to limit the scope of this disclosure.

[0007] [Figure 1] Figure 1 is a perspective view of an exemplary electric drive axle configured according to the teachings of this disclosure.

[0008] [Figure 2] Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1.

[0009] [Figure 3] Figure 3 is an exploded perspective view of a portion of the electric drive axle shown in Figure 1, and shows the gear case, transmission, and differential assembly of the housing assembly in more detail.

[0010] [Figure 4] Figure 4 is a cross-sectional view of a portion of the electric drive axle shown in Figure 1, cut through the motor shaft of the electric motor.

[0011] [Figure 5] Figure 5 is a schematic diagram of a portion of the electric drive axle shown in Figure 1, and provides a more detailed view of the transmission.

[0012] [Figure 6] Figure 6 is a perspective view of a portion of the electric drive axle shown in Figure 1, and provides a more detailed view of the transmission.

[0013] [Figure 7] Figure 7 is a cross-sectional view of a portion of the transmission cut along the motor shaft.

[0014] [Figure 8] Figure 8 is a perspective view of the transmission.

[0015] [Figure 9] Figure 9 is a cross-sectional view of a portion of the transmission, cut through the motor shaft and the first intermediate shaft of the first composite gear.

[0016] [Figure 10] Figure 10 is an exploded perspective view of the multi-speed input section of the transmission.

[0017] [Figure 11] Fig. 11 is an enlarged partial view of Fig. 7, showing the input shaft of the multi-speed input portion of the transmission in the high-speed position. [Figure 12] Fig. 12 is an enlarged partial view of Fig. 7, showing the input shaft of the multi-speed input portion of the transmission in the neutral position. [Figure 13] Fig. 13 is an enlarged partial view of Fig. 7, showing the input shaft of the multi-speed input portion of the transmission in the low-speed position.

[0018] [Figure 14] Fig. 14 is a perspective view of a portion of the electrically driven axle of Fig. 1, showing a portion of the transmission including a mounting plate.

[0019] [Figure 15] Fig. 15 is a cross-sectional view of a portion of an electrically driven axle, showing one layshaft of the transmission mounted between the mounting plate and a portion of the housing assembly.

[0020] [Figure 16] Fig. 16 is a perspective view of a portion of the electrically driven axle of Fig. 1, showing in more detail the actuator assembly for actuating the multi-speed input portion of the transmission and the parking lock mechanism.

[0021] [Figure 17] Fig. 17 is a cross-sectional view of a portion of the electrically driven axle of Fig. 1, showing the connection between the actuator assembly and the input shaft.

[0022] [Figure 18] Fig. 18 is a perspective view of the electrically driven axle of Fig. 1, showing the actuator assembly in more detail.

[0023] [Figure 19] Fig. 19 is a perspective view of a portion of the electrically driven axle of Fig. 1, showing various parts of the actuator assembly in more detail.

[0024] [Figure 20] Figure 20 is a perspective view of the parking lock mechanism.

[0025] [Figure 21] Figure 21 is a perspective view of a portion of the electric drive axle shown in Figure 1, illustrating the parking lock mechanism in more detail.

[0026] [Figure 22] Figure 22 is a cross-sectional view of a portion of the parking lock mechanism, showing the parking lock plunger assembly operatively associated with the guide and parking claw material.

[0027] [Figure 23] Figure 23 is a perspective view of a portion of another electric drive axle having an actuator assembly with a different configuration.

[0028] [Figure 24] Figure 24 is an end view of the electric drive axle shown in Figure 23.

[0029] [Figure 25] Figure 25 is a cross-sectional view taken along line AA in Figure 24.

[0030] [Figure 26] Figure 26 is an exploded perspective view of a portion of the electric drive axle shown in Figure 23.

[0031] [Figure 27] Figure 27 is an enlarged section of Figure 25.

[0032] [Figure 28] Figure 28 is a side view of the actuator assembly.

[0033] Throughout the drawings, the corresponding reference numbers indicate the corresponding parts. [Modes for carrying out the invention]

[0034] Referring to Figures 1 and 2, an exemplary electric drive axle constructed in accordance with the teachings of this disclosure is denoted collectively by reference numeral 10. The multi-speed electric drive axle 10 comprises a number of main assemblies or components, such main assemblies or components include a housing assembly 12, an electric motor 14, a transmission 16, a differential assembly 18, and a pair of axle shafts 20.

[0035] Referring particularly to Figures 2 and 3, the housing assembly 12 in this example includes a first housing member 30 and a second housing member 32, respectively, and a pair of axle tubes 34 in which the axle shaft 20 is rotatably disposed. The housing assembly 12 is configured to handle beaming loads and, as a result, provides the multi-speed electric drive axle 10 with a "beam" or "rigid" axle configuration. However, it should be understood that the housing assembly 12 may be configured differently, for example, to be used with the multi-speed electric drive axle 10 in conjunction with independent suspension.

[0036] The first housing member 30 and the second housing member 32 have a “clamshell” configuration and, working together, define a gear case having a transmission cavity 38 and a differential cavity 40, the transmission cavity 38 intersecting the differential cavity 40. Each of the first and second housing members 30 and 32 may define a coupling flange 44, a differential bearing mounting portion 46, and an axle tube mounting portion 48. The first housing member 30 may further include a motor mounting portion 50. The coupling flanges 44 can abut each other, and threaded fasteners may be used to secure the coupling flanges 44 to each other. A gasket or sealant (not shown) may also be placed between the first and second housing members 30 and 32 (for example, in contact with adjacent surfaces of the coupling flanges 44), thereby further sealing and coupling the first and second housing members 30 and 32 to each other. Each of the differential bearing mounting sections 46 is formed on the inner surface of one of the first and second housing members 30 and 32 and is configured to receive therein a differential bearing 54 that supports the differential assembly 18 in rotating around the output shaft 58. Each of the axle tube mounting sections 48 defines an axle tube opening configured therein to receive one of the axle tubes 34.

[0037] Each axle tube 34 is received into one of the relevant axle tube openings and can be fixedly coupled to one of the relevant axle tube mounting portions 48 in any desired manner. In the illustrated example, the axle tube 34 is press-fitted into the axle tube opening, and conventionally known welding slag (not specifically shown) is employed to restrain both axial and rotational movement of the axle tube 34 along or around the output shaft 58 relative to the first and second housing members 30 and 32.

[0038] Referring to Figure 4, the electric motor 14 can be configured as any type of electric motor and includes a motor housing 64, a stator 66 housed within the motor housing 64 and fixedly coupled to the motor housing 64, a rotor 68 housed within the stator 66 and rotatable relative to the stator 66 about the motor shaft 70, and a motor output shaft 72 fixedly coupled to the rotor 68. The motor housing 64 may define motor bearing mounting areas (not specifically shown) and seal mounting areas. The motor output shaft 72 may extend through the motor housing 64 along the motor shaft 70 and, optionally, extend within the transmission cavity 38 of the housing assembly 12. The motor output shaft 72 is hollow and may define a plurality of first internal spline teeth 80. A motor bearing 82 may be housed between the motor housing 64 and the motor output shaft 72 and may support the motor output shaft 72 to rotate relative to the motor housing 64 about the motor shaft 70. The rotary shaft seal 84 can be mounted on the seal mounting portion and can form a seal between the motor housing 64 and the motor output shaft 72 to suppress fluid transfer between the transmission cavity 38 and the inside of the motor housing 64 through the motor shaft opening of the motor housing 64. Fasteners (not specifically shown) can be used to fix the motor housing 64 to the motor mounting portion 50 of the first housing member 30. Alternatively, the motor housing 64 may be formed integrally with the first housing member 30. The motor output shaft 72 may extend through the motor shaft opening or be positioned in a straight line with the motor shaft opening.

[0039] As shown in Figures 5 and 6, the transmission 16 provided in this example is a multi-speed transmission, but it is understood that the transmission 16 can be any type of transmission, including a single-speed transmission. The illustrated transmission 16 includes a mounting plate 90, a multi-speed input section 92, and a single-speed output section 94. The mounting plate 90 will be described in more detail later, but here it is sufficient to show that the mounting plate 90 is received within the transmission cavity 38 and fixedly coupled to the first housing member 30, and that most of the multi-speed input section 92 is located between the first housing member 30 and the mounting plate 90.

[0040] Referring to Figures 5 and 7, the multi-speed input section 92 includes a first gear 100, a second gear 102, a third gear 104, a first composite gear 106, an input shaft 108, and a coupling sleeve 110. The first gear 100 may have gear teeth having a helical gear tooth profile arranged around a first gear hub 112. The first gear hub 112 is hollow and may define a plurality of second internal spline teeth 114. A bearing 116 is mounted between the first housing member 30 and the first gear hub 112 and supports the first gear 100 to rotate around the motor output shaft 58. The second gear 102 may have gear teeth having a helical gear tooth profile arranged around a second gear hub 122. The second gear hub 122 is hollow and may define a plurality of third internal spline teeth 124. A pair of bearings 126 are mounted between the mounting plate 90 and the second gear hub 122, supporting the second gear 102 both axially along the motor output shaft 58 and radially around the motor output shaft 58. The first gear 100 is positioned along the motor output shaft 58, between the motor output shaft 72 and the second gear 102. Optionally, a portion of the first gear hub 112 may be concentrically received within a portion of the second gear hub 122.

[0041] The third gear 104 may comprise gear teeth having a helical gear tooth profile, arranged around the third gear hub 132. The third gear hub 132 is hollow and may define a plurality of fourth internal spline teeth 134 and a plurality of first surface teeth 135 formed on or within the axial end face of the third gear hub 132 facing or adjacent to the second gear 102. Bearings 136a and 136b are employed to support the third gear 104 so as to rotate around the motor shaft 70. Bearing 136a is mounted between the mounting plate 90 and the third gear hub 132, adjacent to the second gear 102, and bearing 136b is mounted between the gear case and the third gear hub 132 at the axial end of the third gear 104 opposite to bearing 136a.

[0042] Referring to Figures 5, 8, and 9, the first composite gear 106 includes a first layshaft 140, a first intermediate gear 142, and a second intermediate gear 144. The first layshaft 140 is hollow and can be supported by first and second bearings 146a and 146b, respectively, to rotate around a first intermediate shaft 148 that is parallel to the motor shaft 70 but offset from it (i.e., not coincident). The first bearing 146a may be positioned between a first intermediate bearing mounting portion 150 formed by a first housing member 30 and the first end of the first layshaft 140, and the second bearing 148b may be positioned between a second intermediate bearing mounting portion 152 formed by a mounting plate 90 and the second end of the first layshaft 140 opposite to the first end. The first intermediate gear 142 is fixedly coupled to the first layshaft 140 so as to rotate together with the first intermediate shaft 148, and includes gear teeth that mesh and engage with the gear teeth of the first gear 100. The second intermediate gear 144 is fixedly coupled to the first layshaft 140 so as to rotate together with the first intermediate shaft 148, and includes gear teeth that mesh and engage with the gear teeth of the second gear 102.

[0043] Referring to Figures 7 and 10, the input shaft 108 is received concentrically through the first, second, and third gear hubs 112, 122, and 132 and is rotatable around the motor shaft 70. The input shaft 108 includes a plurality of first external spline teeth 160 located at the first axial end of the input shaft 108, which is positioned within the motor output shaft 72; a plurality of second external spline teeth 162 spaced apart from the first external spline teeth 160 along the motor shaft 70; and a circumferential rib 164 positioned along the motor shaft 70 between the first external spline teeth 160 and the second external spline teeth 162. A lubrication bore 166 may be formed through the input shaft 108, and a plurality of lubrication passages 168 may be formed to intersect the lubrication bore 166 and pass radially through the input shaft 108 at desired positions. The lubrication nozzle may be received within the axial end of the input shaft 108 adjacent to the third gear 104 and configured to discharge a flow of pressurized lubricating fluid into the lubrication bore 166. The pressurized lubricating fluid in the lubrication bore 166 may be delivered to the lubrication passage 168 to cool and / or lubricate various components such as bearings or sliding interfaces, and optionally, the pressurized lubricating fluid may be delivered into the motor output shaft 72 to cool and / or lubricate various components of the electric motor 14 within the motor output shaft 72. In the presented example, the lubrication nozzle is mounted on an auxiliary cover attached to the side of the second housing member 32 opposite to the transmission cavity 38, and the lubrication nozzle is not in contact with the input shaft 108 and is not sealed to the input shaft 108.

[0044] Various bearings are employed to provide radial support to the input shaft 108 while allowing axial movement of the input shaft 108 along the motor shaft 70. In the presented example, a first needle bearing 170 is positioned between the first gear hub 112 and a first cylindrical bearing surface formed on the input shaft 108, and a second needle bearing 172 is positioned between the third gear hub 132 and a second cylindrical bearing surface formed on the input shaft 108.

[0045] The coupling sleeve 110 is concentrically received around the input shaft 108 and is rotatable around the motor shaft 70 relative to the input shaft 108. The coupling sleeve 110 can define a shoulder that can abut against the first side of the circumferential rib 164 of the input shaft 108. An internal retaining ring can be received in a groove formed within the coupling sleeve 110 and can abut against the second side of the circumferential rib 164 on the opposite side of the shoulder. In this way, as the input shaft 108 translates along the motor shaft 70, the coupling sleeve translates correspondingly along the motor shaft 70. The coupling sleeve 110 defines a plurality of third external spline teeth 180 and a plurality of second surface teeth 182. The third external spline teeth 180 mesh with the third internal spline teeth 124 formed on the second gear hub 122 so as to connect the coupling sleeve 110 to the second gear 102, thereby allowing axial sliding or translation of the coupling sleeve 110 relative to the second gear 102 while suppressing relative rotation.

[0046] The input shaft 108 is movable along the motor shaft 70 between a high-speed position (Figure 11), a neutral position (Figure 12), and a low-speed position (Figure 13). The first external spline teeth 160 on the input shaft 108 mesh with the first internal spline teeth 80 on the motor output shaft 72 at each of the high-speed, neutral, and low-speed positions (therefore, the input shaft 108 is coupled to the motor output shaft 72 so as to rotate together with the motor shaft 70).

[0047] When the input shaft 108 is positioned in the high-speed position shown in Figure 11, the first external spline teeth 160 on the input shaft 108 are engaged only with the first internal spline teeth 80 on the motor output shaft 72, the second external spline teeth 162 on the input shaft 108 are engaged with the fourth internal spline teeth 134 formed on the third gear 104, and the second surface teeth 182 on the coupling sleeve 110 are separated from and disengaged from the first surface teeth 135 on the third gear 104. As a result, the rotational power output from the electric motor 14 (Figure 1) via the motor output shaft 72 is input to the input shaft 108, transmitted to the third gear 104, and drives the third gear 104 at the rotational speed of the electric motor 14 (Figure 1).

[0048] When the input shaft 108 is positioned in the neutral position shown in Figure 12, the first external spline teeth 160 on the input shaft 108 are engaged only with the first internal spline teeth 80 on the motor output shaft 72, the second external spline teeth 162 on the input shaft 108 are disengaged from the fourth internal spline teeth 134 formed on the third gear 104, and the second surface teeth 182 on the coupling sleeve 110 are disengaged from the first surface teeth 135 on the third gear 104. As a result, the rotational power output from the electric motor 14 (Figure 1) via the motor output shaft 72 is input to the input shaft 108, but is not transmitted to any of the first gear 100, second gear 102, and third gear 104.

[0049] When the input shaft 108 is positioned at the low-speed location shown in Figure 13, the first external spline teeth 160 on the input shaft 108 engage with both the first internal spline teeth 80 on the motor output shaft 72 and the second internal spline teeth 114 on the first gear 100, the second external spline teeth 162 on the input shaft 108 are disengaged from the fourth internal spline teeth 134 formed on the third gear 104, and the second surface teeth 182 on the coupling sleeve 110 engage with the first surface teeth 135 on the third gear 104. As a result, the rotational power output from the electric motor 14 (Figure 1) via the motor output shaft 72 is input to the input shaft 108, transmitted to the first gear 100, and drives the first intermediate gear 142 (Figure 8) to bring about a first reduction. The second intermediate gear 144 (Figure 8), which rotates together with the first intermediate gear 142 (Figure 8), drives the second gear 102 to provide a second reduction. The coupling sleeve 110 is rotationally coupled to both the second gear 102 (via the mating engagement between the third external spline teeth 180 and the third internal spline teeth 124) and the third gear 104 (via the mating engagement between the second surface teeth 182 and the first surface teeth 135), so that the third gear 104 rotates at the rotational speed of the second gear 102.

[0050] Returning to Figures 5 and 8, the single-speed output section 94 receives rotational power from the third gear 104 and includes an output gear 200 rotatable around the output shaft 58. Optionally, the single-speed output section 94 may include one or more reduction stages between the third gear 104 and the output gear 200. In the presented example, the single-speed output section 94 includes a pair of second compound gears 210, which provide the single-speed output section 94 with two reduction stages between the third gear 104 and the output gear 200.

[0051] Each of the second composite gears 210 includes a second layshaft 212, a third intermediate gear 214, and a fourth intermediate gear 216. The second layshaft 212 is hollow and can be supported by first and second bearings 220a and 220 to rotate around a second intermediate shaft 222 which is parallel to both the motor shaft 70 and the output shaft 58 but offset from these shafts (i.e., not coincident). The first bearing 220a may be positioned between a first intermediate bearing mounting portion formed by a first housing member 30 and a first end of the second layshaft 212, and the second bearing 220b may be positioned between a second intermediate bearing mounting portion formed by a second housing member 32 and a second end of the second layshaft 212 opposite to the first end. The third intermediate gear 214 is fixedly coupled to the second layshaft 212 so as to rotate together with the second intermediate shaft 222 and has gear teeth that mesh with and engage with the gear teeth of the third gear 104. The fourth intermediate gear 216 is fixedly coupled to the second layshaft 212 so as to rotate together with the second intermediate shaft 222 and has gear teeth that mesh with and engage with the gear teeth of the output gear 200. In the presented example, the second compound gear 210 is positioned along the second intermediate shaft 222, and the third intermediate gear 214 is positioned further from the first gear 100 than the fourth intermediate gear 216. This configuration allows the transmission 16 to be relatively compact in the axial direction (e.g., along the output shaft 58).

[0052] Referring to Figures 5 and 8, the differential assembly 18 may include a differential input member 230 coupled to the output gear 200 so as to rotate together, and a pair of differential output members 232 rotatable around the output shaft 58 relative to the differential input member 230. The differential assembly 18 can be configured in any desired manner. For example, the differential assembly 18 may be configured using a bevel gear set having (straight) bevel side gears and differential pinions, and the differential input member 230 may be a differential case housing the side gears and differential pinions. In the presented example, the differential assembly 18 is configured as a planetary or epicyclic differential assembly having an internal gear (not specifically shown), a sun gear (not specifically shown), a planetary carrier (not specifically shown), and a plurality of sets of planetary gears (not specifically shown). The internal gear may be fixedly coupled to the output gear 200 of the transmission 16 (for example, formed integrally and together with it). The sun gear is positioned concentrically inside the internal gear and is rotatable around the output shaft 58. The planetary carrier is rotatable around the output shaft 58. Each set of planetary gears meshes with both the internal gear and the sun gear and includes one or more planetary gears journalally supported by the planetary carrier. If each set of planetary gears includes two or more planetary gears, each planetary gear meshes with one of the other planetary gears, one of which meshes with the internal gear and the other meshes with the sun gear. In the illustrated example, each set of planetary gears includes a first planetary gear and a second planetary gear, the first planetary gear meshes with and engages with the internal gear and is journalally supported by the planetary carrier, and the second planetary gear meshes with and engages with both the first planetary gear and the sun gear and is also journalally supported by the planetary carrier. In this configuration, the sun gear and planetary carrier constitute the differential output member 232 of the differential assembly 18. A differential bearing 54 may be radially mounted between the gear case and a hub (not specifically shown) formed on the planetary carrier to support the differential input member 230 so as to rotate around the output shaft 58. In the illustrated example, the differential bearing 54 is a tapered roller bearing and further provides axial support for the differential assembly 18 along the output shaft 58.

[0053] Referring to Figures 2 and 5, each axle shaft 20 is received through one of the corresponding axle tubes 34 and coupled to rotate with one of the corresponding differential output members 232. Various bearings (not specifically shown) may be employed to support the axle shaft 20 against the housing assembly 12. In the presented example, the multi-speed electric drive axle 10 has a "full-floating" axle configuration, in which the axle shaft 20 is rotatably coupled to the wheel hub 250 supported (axially and rotationally) on the axle tube 34, so that the axle shaft 20 transmits rotational torque between the differential assembly 18 and the corresponding wheel (not shown), but does not support the vehicle weight. However, it should be understood that the multi-speed electric drive axle 10 may be configured differently and may have any desired configuration (e.g., semi-floating, three-quarter floating, or independent).

[0054] Referring to Figures 3, 9, and 14, the mounting plate 90 includes a mounting plate body 260, a flange member 262, a plurality of bearing mounting portions (bearing mounting portion 264a, bearing mounting portion 264b, and second intermediate bearing mounting portion 152), and a lubrication gallery 266. The flange member 262 is fixedly coupled to the mounting plate body 260 and extends around the mounting plate body 260. The flange member 262 is configured to abut the inner surface or inner surface of the first housing member 30. A plurality of threaded fasteners can be received through the flange member 262 and can be screw-engaged into corresponding threaded holes (not specifically shown) in the first housing member 30 to fix the mounting plate 90 to the first housing member 30. Positioning means, such as one or more dowel pins or a pair of roll pins, can be employed to position the mounting plate 90 relative to the first housing member 30. The mounting plate body 260 can be contoured to form a space or cavity for accommodating the gear teeth of the third gear 104 and the gear teeth of the first intermediate gear 142.

[0055] The bearing mounting portion 264a is located on the first side of the mounting plate body 260 (i.e., the side facing the first housing member 30) and is configured to receive one of the bearings 126 that support the second gear 102. The bearing mounting portion 164b is located on the second side opposite the mounting plate body 260 (i.e., the side facing the second housing member 32) and is configured to receive the bearing 136a that supports the third gear 104. The second intermediate bearing mounting portion 152 is formed on the first side of the mounting plate body 260 and is configured to receive the bearing 146b that supports the first layshaft 140 of the first composite gear 106.

[0056] Referring to Figures 14 and 15, the lubrication gallery 266 includes an inlet port 270, one or more fluid passages (e.g., fluid passages 272, 274, and 276), and one or more fluid outlets (e.g., an outlet nozzle 278, and / or one or more outlet orifices (not specifically shown)). The inlet port 270 is configured to be in fluid communication with a source or flow of pressurized lubricating fluid. In the presented example, the inlet port 270 is configured to be in fluid communication with a hose 280 that supplies pressurized lubricating fluid to the lubrication gallery 266. Each fluid passage is generally configured to guide the pressurized lubricating fluid through a mounting plate 90 between the inlet port 270 and each fluid outlet. In the presented example, the first fluid passage 272 receives the pressurized lubricating fluid from the inlet port 270 and sends the pressurized lubricating fluid to the second and third fluid passages 274 and 276, respectively, and to the outlet nozzle 278. The outlet nozzle 278 supplies pressurized lubricating fluid to the second intermediate bearing mounting section 152 to lubricate both the teeth of the second bearing 146b and the second intermediate gear 144, and also supplies pressurized lubricating fluid to the hollow interior of the first layshaft 140. The pressurized lubricating fluid traveling within the first layshaft 140 may be sent to the first intermediate bearing mounting section 150 to lubricate both the teeth of the first bearing 146a and the first intermediate gear 142. Each outlet orifice may be set to a desired position and size to provide lubrication to a desired area, such as the teeth of the bearing 146b and / or the third gear 104. In addition or alternatively, one or more fluid passages within the mounting plate 90 may supply pressurized lubricating fluid into the first housing member 30 for lubrication of various bearings (e.g., bearings mounted within the first housing member 30 and supporting the second composite gear 210) and / or gear meshing.

[0057] Referring to Figures 16 to 19, the multi-speed input section 92 of the transmission 16 may further include an actuator assembly 300 configured to move the input shaft 108 between a high-speed position, a neutral position, and a low-speed position. The actuator assembly 300 can have any configuration, but in the presented example it includes an output assembly 302, a lead screw 304, a coupler 306, first and second actuator bearings 308 and 310, and an actuator motor 312.

[0058] The output assembly 302 may include a bearing 320 and an axially movable member 322. The bearing 320 may be received on the input shaft 108 and may abut against a shoulder formed on the input shaft 108. The axially movable member 322 may extend between the motor shaft 70 and the rotation axis of the lead screw 304 and may define bearing openings and coupler mounting portions 330 at both ends thereof. The bearing 320 may be received within the bearing opening and fixedly coupled to the axially movable member 322 in any desired manner. In the presented example, an inner retaining ring is mounted in a retaining ring groove formed concentrically with the bearing opening b4 within the axially movable member 322 and on the axial end of the bearing 320 opposite to the axial end of the bearing 320 that abuts against the shoulder on the input shaft 108. Therefore, the axially movable member 322 is coupled to the input shaft 108 in such a manner that relative axial movement between the axially movable member 322 and the input shaft 108 is suppressed, while allowing rotation of the input shaft 108 relative to the axially movable member 322.

[0059] The lead screw 304 is rotatably positioned around the lead screw axis and includes a lead screw input 340 and an external threaded portion 342.

[0060] The coupler 306 may have a mounting flange 352 that can be mounted on the internally threaded hub 350 and the coupler mounting portion 330. The internally threaded hub 350 can be screw-engaged with the externally threaded portion 342 of the lead screw 304. It should be understood that the mounting flange 352 and the coupler mounting portion 330 can be configured in any desired manner. In the example presented, the mounting flange 352 has a non-circular cross-sectional area (in a cross-section perpendicular to the longitudinal axis of the internally threaded hub 350), and the coupler mounting portion 330 defines a slot into which a portion of the mounting flange 352 is received, so as to axially non-rotatably connect the mounting flange 352 to the coupler mounting portion 330. Thus, the rotation of the lead screw 304 results in corresponding translations for both the coupler 306 and the output assembly 302.

[0061] The first and second actuator bearings 308 and 310 can be mounted in the gear case and can support the lead screw 304 so as to rotate around the lead screw axis.

[0062] The actuator motor 312 is configured to provide rotational power to drive the lead screw 304 around the lead screw axis. The actuator motor 312 may be directly coupled to the lead screw input, or a reduction mechanism such as a reduction gear set may be placed between the actuator motor 312 and the lead screw input. In the presented example, a reduction gear set utilizing bevel gears is employed. More specifically, the reduction gear set includes an actuator input gear 360 driven directly by the actuator motor 312 around an axis perpendicular to the lead screw axis, and an actuator output gear 362 that meshes with the actuator input gear 360 and is rotatable around the lead screw axis. The reduction gear set may be configured differently, and it should be understood that the use of bevel gears is not required. The actuator output gear 362 may be coupled to the lead screw input in any desired manner. For example, the actuator output gear 362 may be directly coupled to the lead screw input so as to rotate the lead screw 304 directly together with the actuator output gear 362. Alternatively, a torsional elastic coupling may be employed between the actuator output gear 362 and the lead screw input 340 to provide compliance in one or both directions of rotation between the actuator output gear 362 and the lead screw 304. In the presented example, the torsional elastic coupling allows the actuator output gear 362 to rotate when the input shaft 108 is unable to translate (for example, due to 1) tooth-to-tooth contact between one of the external splines on the input shaft and one of the internal splines on either the first or third gear, or between the first and second face teeth, or 2) the magnitude of the torque applied through the input shaft 108, i.e., the torque load).

[0063] Referring to Figures 16 and 19-22, the parking lock mechanism 400 can be incorporated into the multi-speed electric drive axle 10 (Figure 1). In the presented example, the parking lock mechanism 400 is configured to suppress the rotation of the third gear 104, thereby suppressing the rotation of the differential input member 230 (Figure 5), and consequently the rotation of the differential output member 232 (Figure 5). The parking lock mechanism 400 may include a parking lock gear 402, a pivot pin 404, a parking claw material 406, and a parking lock plunger assembly 408.

[0064] The parking lock gear 402 can be fixedly coupled to the third gear 104 and may define a plurality of parking lock teeth and a plurality of grooves 420 arranged circumferentially between corresponding pairs of each parking lock tooth. The pivot pin 404 can be fixedly coupled to the second housing member 32. In the presented example, the pivot pin 404 is mounted on a bracket 424, which is further mounted on the second housing member 32. Any desired means may be employed to control the position and orientation of the bracket 424 relative to the second housing member 32. In the presented example, a pair of pins 426 are mounted on the bracket 424 and received in corresponding holes in the second housing member to position the pivot pin 404 in the desired position and to prevent the bracket 424 from rotating relative to the second housing member 32. One or more threaded fasteners may be employed to secure the bracket 424 to the second housing member 32.

[0065] The parking claw material 406 includes a claw material body 430 pivotally mounted on a pivot pin 404 and a claw member 432 fixedly coupled to the claw material body 430. The claw material body 430 can pivot with respect to the parking lock gear 402 between a first position or locked position in which the parking claw material 406 is received in the groove 420, thereby suppressing the rotation of both the parking lock gear 402 and the third gear 104 around the motor shaft 70, and a second position or unlocked position in which the parking claw material 406 is disengaged from the parking lock gear 402 and does not suppress the rotation of the parking lock gear 402 around the motor shaft 70. The parking claw material 406 may optionally include a guide structure 438 that can be mounted on the second housing member 32. The guide structure 438 may have guide members that can guide the claw material body 430 as it moves between the first and second positions. The movement of the guide structure 438 resulting from the corresponding movement of the plunger 450 may cause a corresponding pivotal movement of the claw material body 430 around the pivot pin 404.

[0066] A biasing spring, such as a torsion spring 440, may be used to bias the claw body 430 toward a second position. In the presented example, the torsion spring 440 has a helical winding portion that is received on a pivot pin 404, and the winding portion is positioned between two arms. One end of the arm is attached to a bracket 424, and the other end of the arm is attached to the claw body 430. A member such as a head or washer may be formed on or coupled to the pivot pin 404 so as to capture the helical winding portion of the torsion spring 440 on the side of the bracket 424 opposite to the parking claw 406.

[0067] The parking lock plunger assembly 408 may include a plunger 450, an input member 452, and a compliance spring 454. The plunger 450 is movable along an axis parallel to the motor shaft 70 and has a substantially cylindrical first plunger portion, a substantially cylindrical second plunger portion, and a tapered transition portion between them. The first plunger portion has a first diameter, the second plunger portion is spaced apart from the first plunger portion and has a larger second diameter, and the transition portion is positioned between the first and second plunger portions and is tapered such that the transition portion has a truncated conical outer surface. The plunger 450 can be translated between a first plunger position in which the first plunger portion is in contact with the parking claw material 406 and a second plunger position in which either the transition portion or the second plunger portion is in contact with the parking claw material 406. The first plunger portion is set to dimensions such that when the first plunger portion is engaged (in direct contact) with the claw body 430, the claw body 430 of the parking claw 406 is positioned at the second position. When the plunger 450 moves from the first plunger position to the second plunger position, a relatively large portion of the plunger 450 comes into contact with the claw body 430, thereby causing the claw body 430 to pivot toward the second claw position.

[0068] The input member 452 is movable around the translation axis of the plunger 450 and can be moved in any desired manner. In the presented example, an electric parking lock motor 460 and a manual parking lock input lever 462 are provided as alternative or redundant inputs for acting the parking lock mechanism 400, and an output lever 464 is employed to coordinate the movement of the input member 452. More specifically, the output lever 464 is coupled to the input member 452 and is pivotally coupled to the second housing member 32 so as to move between a first input position and a second input position. The manual parking lock input lever 462 is fixedly coupled to a portion of the output lever 464 that extends through the second housing member 32 (thus the manual parking lock input lever 462 is thus located outside the gear case). When the manual parking lock input lever 462 pivots around the pivot axis of the output lever 464, a corresponding pivoting motion of the output lever 464 occurs around the pivot axis of the output lever 464. The electric parking lock motor 460 is mounted on the outer surface of the second housing member 32 and includes an output shaft 470 extending into the transmission cavity 38. An intermediate lever 472 is coupled to the output shaft 470 of the electric parking lock motor 460 and can be moved by the electric parking lock motor 460 between a first intermediate lever position and a second intermediate lever position around the rotation axis of the output shaft 470. The end of the intermediate lever 472 opposite to the output shaft 470 includes a pin that is received in a slotted opening of the output lever 464. When the intermediate lever 472 moves from the first intermediate lever position to the second intermediate lever position (as a result of the rotation of the output shaft 470), the output lever 464 produces a pivotal motion from a first input position to a second input position around its pivot axis. The slotted opening of the output lever 464 allows the output lever 464 to be moved from the first input position to the second input position around its pivot axis without the corresponding movement of the intermediate lever 472.

[0069] The compliance spring 454 is positioned between the input member 452 and the plunger 450, allowing the claw body 430 to push the plunger 450 away from the claw body 430 when the output lever 464 is in the second input position. It should be understood that when the output lever 464 is in the second input position, the plunger 450 will normally be positioned in the second plunger position. However, if the claw member 432 cannot fall into or remain in the groove 420, the parking claw 406 pushes the plunger 450 toward the compliance spring 454, thereby compressing the compliance spring 454 and allowing the parking lock gear 402 to rotate.

[0070] Most of the components of both the actuator assembly 300 and the parking lock mechanism 400 can be assembled to the second housing member 32 before the second housing member 32 is assembled to the first housing member 30 to close the transmission cavity 38 and the differential cavity 40. In this regard, all or part of the reduction gear set (e.g., in the presented example, the actuator input gear 360 and the actuator output gear 362), bearings 308 and 310, lead screw 304, torsional elastic coupling (if included), and optionally the coupler 306 and / or actuator motor 312 in the actuator assembly 300 can be attached to the second housing member 32 before the second housing member 32 is mounted to the first housing member 30. In addition or alternatively, all components of the parking lock mechanism 400, except for the parking lock gear 402, can be assembled to the second housing member 32 before the second housing member 32 is mounted to the first housing member 30.

[0071] Referring to Figures 23 to 27, an alternative actuator assembly 300a is illustrated. The actuator assembly 300a is configured to move the input shaft 108 between a high-speed position, a neutral position, and a low-speed position, but is configured to provide constant compliance during speed changes as described later, and further to bias the input shaft 108 toward the high-speed position when the power supply to the actuator assembly 300a is interrupted. The actuator assembly 300a may include an output assembly 302a, a ball screw 304a, a coupler 306a, first and second actuator bearings 308 and 310, and an actuator motor (not specifically shown). Except as described below, the ball screw 304a and coupler 306a may be generally the same as the lead screw 304 and coupler 306 described above. However, it should be understood that the ball screw 304a and the coupler 306a each define an outer track and an inner track, with multiple spherical balls positioned between them, and that the rotation of the ball screw 304a causes a corresponding linear movement of the coupler 306a along the axis of the ball screw 304a.

[0072] The output assembly 302a may include a bearing 320, an axially movable member 322a, and a pivot fork assembly 500. The bearing 320 may be received (i.e., mounted) on the input shaft 108 and may abut against a shoulder formed on the input shaft 108. The axially movable member 322a may include a sleeve member 322a-1, which may be mounted on the outer raceway of the bearing 320 and may be arranged concentrically around the input shaft 108, and may also include one or more connecting elements (not specifically shown) that connect the sleeve member 322a-1 to the input shaft 108 in a manner that limits or suppresses relative axial movement along the motor shaft 70 while allowing relative rotation with respect to the input shaft 108. In the presented example, the connecting element is formed of a wire having a circular cross-sectional shape and includes a semicircular body (not specifically shown) which is received in a groove extending circumferentially in the input shaft 108 and includes a pair of lugs (not specifically shown) extending radially outward from both ends of the semicircular body through a first connecting element opening formed through the circumferential wall of the sleeve member 322a-1.

[0073] The pivot fork assembly 500 may include a first fork member 510, a second fork member 512, a plurality of first pivot pins 514, a second pivot pin 516, a pair of connecting pins 518, and one or more compliance springs 520. The first fork member 510 may define a pair of first pivot pin mounting portions 530, a second pivot pin mounting portion 532, a pair of first connecting pin openings 534, and a first compliance spring mounting portion 536. The second fork member 512 may define a third pivot pin mounting portion 540, a pair of second connecting pin openings 542, a pair of second connecting element openings 544, and a second compliance spring mounting portion 546.

[0074] Each of the first pivot pins 514 is received through a corresponding first pivot pin mounting portion 530 into a respective first pivot pin opening (not shown) formed within the coupler 306a, thereby pivotably connecting the first end of the first fork member 510 to the coupler 306a in a manner that allows it to pivot around the rotation axis of the ball screw 304a.

[0075] The second pivot pin 516 is received through the openings (not specifically shown) of the second pivot pin mounting portion 532 and the third pivot pin mounting portion 540, thereby pivotably connecting the first fork member 510 and the second fork member 512 in such a manner that they can pivot relative to each other around the longitudinal axis of the second pivot pin 516.

[0076] Each of the connecting pins 518 is positioned through the corresponding sets of first and second connecting pin openings 534 and 542. The connecting pins 518 and the first and second connecting pin openings 534 and 542 cooperate to control and limit the pivotal motion of the second fork member 512 in the first and second pivotal directions around the second pivot pin 516 relative to the first fork member 510. In the presented example, the first connecting pin opening 534 in the first fork member 510 is circular and configured to engage the connecting pin 518 in an interferential fit (e.g., press fit), and the second connecting pin opening 542 in the second fork member 512 is slotted. Thus, the connecting pin 518 can travel within the slot of the second connecting pin opening 542 as the second fork member 512 pivots around the second pivot pin 516 relative to the first fork member 510.

[0077] The second connecting element opening 544 can be positioned on both sides of the sleeve member 322a-1 and may have a slot-like shape. Each lug of the connecting element can be received through the corresponding second connecting element opening 544. The slot-like shape of the second connecting element opening 544 allows the second fork member 512 to exert a force on the lugs of the connecting element in a direction along the motor shaft 70 while moving relative to the lugs as it pivots around the second pivot pin 516.

[0078] The compliance spring 520 is mounted on the first and second compliance spring mounting portions 536 and 546, and can bias the second fork member 512 in the first pivot direction around the second pivot pin 516. The engagement of the connecting pin 518 with the (upper) end of the slot of the second connecting pin opening 542 can limit the amount of pivot movement of the second fork member 512 relative to the first fork member 510 around the second pivot pin 516.

[0079] During operation, the ball screw 304a can be rotated (i.e., through the rotation of the actuator motor and, if necessary, the reduction gear set) to produce translation of the coupler 306a along the ball screw 304a. The translation of the coupler 306a produces a corresponding pivotal motion of the first fork member 510 around the first pivot pin 514 relative to the coupler 304a. When there is no contact between teeth and the input shaft 108 is therefore able to freely translate along the motor shaft 70, the second fork member 512 moves together with the first fork member 510 around the first pivot pin 514, which also produces a corresponding translation of the compliance spring 520, thereby causing the coupling elements to tend to translate correspondingly along the motor shaft 70, and as a result the sleeve member 322a-1 and the input shaft 108 move along the motor shaft 70. If the input shaft 108 cannot move freely along the motor shaft 70 (for example, due to contact between teeth or torque lock), the second fork member 512 cannot pivot completely together with the first fork member 510 around the first pivot pin 514. In such a case, a relative pivoting motion occurs between the first fork member 510 and the second fork member 512 around the second pivot pin 516, thereby compressing the corresponding compliance spring 520. The compression of the compliance spring 520 generates a force applied to the input shaft 108 via the second fork member 512 and the axially movable member 322a. This force is maintained until the input shaft 108 can move along the motor shaft 70 to one of the desired high-speed, neutral, and low-speed positions, depending on the position of the coupler 306a along the ball screw 304a. It should be understood that when the input shaft 108 moves due to the force applied by the compliance spring 520, the second fork member 512 undergoes a pivoting motion around the second pivot pin 516, thereby returning the second fork member 512 to its "normal" position relative to the first fork member 510.

[0080] The biasing spring 550 may be provided to generate a biasing force that can be applied directly or indirectly to the input shaft 108 in order to bias the input shaft 108 toward the high-speed position. In the presented example, the biasing spring 550 is a compression spring positioned between the ball screw 304a and the coupler 306a. If desired, a thrust washer or thrust bearing 552 may be positioned between the end of the biasing spring 550 and the relevant one of the ball screw 304a and the coupler 306a. Because the connection between the ball screw 304a and the coupler 306a is relatively low friction, the force exerted by the biasing spring 550 on the ball screw 304a and the coupler 306a causes a corresponding rotation of the ball screw 304a relative to the coupler 306, which in turn positions the coupler 306a along the ball screw 304a in a position associated with the input shaft 108 being positioned toward the high-speed position.

[0081] The above-described embodiments are provided for illustrative and explanatory purposes only. They are not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally interchangeable and usable in selected embodiments, even if not specifically illustrated or described, and are not limited to that particular embodiment. Similar elements or features may be modified in various ways. Such modifications will not be considered deviations from the disclosure, and all such modifications are intended to be within the scope of the disclosure.

Claims

1. An actuator assembly configured to be coupled to a multi-speed electric drive axle, An output assembly including an axially movable member configured to be coupled to the multi-speed input portion of the multi-speed electric drive axle, A ball screw having an external threaded portion, A coupler attached to a member that is movable in the axial direction, the coupler having an internally threaded hub that engages with the externally threaded portion of the ball screw so that the rotation of the ball screw causes the coupler and the member that is movable in the axial direction to move linearly, and An actuator assembly equipped with this component.

2. The actuator assembly according to claim 1, wherein the axially movable member moves the multi-speed input portion of the multi-speed electric drive axle parallel to the motor shaft of the electric motor that propels the vehicle.

3. The actuator assembly according to claim 1, wherein the multi-speed input portion of the multi-speed electric drive axle includes a first gear and a second gear.

4. The actuator assembly according to claim 1, wherein the multi-speed input portion of the multi-speed electric drive axle is the motor shaft of an electric motor that propels a vehicle.

5. The actuator assembly according to claim 1, wherein the axially movable member moves the multi-speed input portion of the multi-speed electric drive axle parallel to the motor shaft of the electric motor that propels the vehicle.

6. The actuator assembly according to claim 1, wherein the multi-speed input portion of the multi-speed electric drive axle includes a first gear and a second gear.

7. The actuator assembly according to claim 1, wherein the multi-speed input portion of the multi-speed electric drive axle is the motor shaft of an electric motor that propels a vehicle.

8. An actuator assembly configured to be coupled to a multi-speed electric drive axle, An output assembly including an axially movable member configured to be coupled to the multi-speed input portion of the multi-speed electric drive axle, A ball screw having an external threaded portion, A coupler attached to a member movable in the axial direction, the coupler having an internally threaded hub that engages with the externally threaded portion of the ball screw so as to move the coupler and the member movable in the axial direction in a straight line by the rotation of the ball screw, A biasing spring is configured to apply a biasing force to the multi-speed input portion of the multi-speed electric drive axle so as to bias the multi-speed input portion to the high-speed position. An actuator assembly equipped with this component.

9. The actuator assembly according to claim 8, wherein the biasing spring is disposed between the ball screw and the coupler.

10. The actuator assembly according to claim 8, wherein the biasing spring causes the ball screw to rotate relative to the coupler.

11. An actuator assembly configured to be coupled to a multi-speed electric drive axle on a vehicle, A ball screw having an external threaded portion, A coupler having an internally threaded hub that engages with the externally threaded portion of the ball screw so as to move the coupler linearly by the rotation of the ball screw, A multi-speed input portion of the multi-speed electric drive axle and an axially movable member configured to be coupled to the coupler, A pivot fork assembly, First fork member, Second fork member, At least one first pivot pin pivotably connects the first end of the first fork member to the coupler, A second pivot pin pivotally connects the first fork member to the second fork member. A pair of connecting pins pivotably connects the first fork member to the second fork member, and One or more compliance springs bias the second fork member in the first pivot direction around the second pivot pin. Including a pivot fork assembly and An actuator assembly equipped with this component.

12. The actuator assembly according to claim 11, wherein the pair of connecting pins restrict the pivotal movement of the first fork member relative to the second fork member.

13. The actuator assembly according to claim 11, further comprising a first connecting pin opening for receiving one of the connecting pins.

14. The actuator assembly according to claim 13, wherein the first connecting pin opening is circular.

15. The actuator assembly according to claim 11, further comprising a second connecting pin opening that accepts both of the aforementioned connecting pins.

16. The actuator assembly according to claim 15, wherein the second connecting pin opening is slot-shaped.

17. The actuator assembly according to claim 11, further comprising a biasing spring configured to apply a biasing force to the multi-speed input portion of the multi-speed electric drive axle so as to bias the multi-speed electric drive axle to a high-speed position.

18. The actuator assembly according to claim 17, wherein the biasing spring is disposed between the ball screw and the coupler.

19. The actuator assembly according to claim 17, wherein the biasing spring causes the ball screw to rotate relative to the coupler.

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