Differential disconnection system

Abstract

A differential disconnect system for a vehicle includes a housing arranged to receive motor torque, a first clutch element, and a differential. The housing includes radially inwardly facing teeth, and the first clutch element is drivingly engaged with and axially slidable on the radially inwardly facing teeth. The first clutch element includes a first face spline. The differential unit is arranged to drivingly engage the pair of axle shafts and includes a second clutch element having a second face spline arranged to engage the first face spline for selective torque transfer between the housing and the differential unit.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. non-provisional application 18 / 583,999, filed February 22, 2024, which is a continuation-in-part of U.S. non-provisional application 18 / 209,478, filed June 14, 2023, and claims the benefit of U.S. provisional application 63 / 534,886, filed August 28, 2023, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates generally to differentials, and more specifically to differential disconnection systems. Background Technology

[0003] Disconnection mechanisms in differentials are known. An example is shown and described in PCT Publication No. WO 2022 / 217355 of MAGNA POWERTRAIN, INC. entitled “DISCONNECTING DIFFERENTIAL SIDE GEAR MECHANISM”. Summary of the Invention

[0004] The example implementation broadly includes a differential disconnect system for a vehicle, comprising: a housing arranged to receive motor torque, a first clutch element, and a differential. The housing includes radially inward-facing teeth, and the first clutch element is drivably engaged with and axially slideable on the radially inward-facing teeth. The first clutch element includes a first end-face spline. The differential unit is arranged to drivably engage with a pair of axle shafts and includes a second clutch element having a second end-face spline arranged to engage the first end-face spline for selective torque transmission between the housing and the differential unit.

[0005] In some example embodiments, the differential disconnect system has an actuation arm extending through a housing to axially displace a first clutch element, thereby engaging and disengaging with a second clutch element. In one example embodiment, the actuation arm includes a ring portion and a plurality of axial protrusions, the ring portion being axially fixed to the first clutch element and the plurality of axial protrusions extending through corresponding openings in the housing. In another example embodiment, the differential disconnect system includes a shift sleeve arranged to displace via a shift fork, thereby displacing the actuation arm.

[0006] In some example embodiments, the differential unit includes a differential housing, and a second clutch element is fixed to the differential housing. In some example embodiments, the differential disconnect system has a first radial bearing supporting the differential housing within the housing. In example embodiments, the differential disconnect system includes a second radial bearing supporting the differential housing within the housing.

[0007] In an example embodiment, the housing includes a first housing half and a second housing half. The first housing half has a first tubular protrusion extending away from the differential unit in a first axial direction, and the second housing half has a second tubular protrusion extending away from the differential unit in a second axial direction opposite to the first axial direction. In an example embodiment, the differential unit includes: a pair of side gears having internal splines for drivably engaging with a pair of axle shafts; a shaft; and a pair of star gears rotatable on the shaft and each engaging with both of the pair of side gears.

[0008] In some example embodiments, the differential disconnect system includes a final drive gear. The housing includes radially outward-facing teeth, and the final drive gear includes radially inward-facing teeth, which drively engage with the radially outward-facing teeth. In example embodiments, the radially inward-facing teeth and the radially outward-facing teeth of the housing form a corrugated cylindrical portion of the housing. In example embodiments, the final drive gear is bolted to the housing. In some example embodiments, the housing has: a first housing half having a radial flange and a plurality of openings, the radial flange being bolted to the final drive gear; and a second housing half having a plurality of axial protrusions extending through the plurality of openings. In example embodiments, when the radial flange is bolted to the final drive gear, the plurality of axial protrusions are axially fixed within the first housing half.

[0009] In an example implementation, the differential disconnect system includes a final drive gear. The housing includes a first housing half and a second housing half, the first housing half having a radial flange bolted to the final drive gear, and the second housing half being fixed to the final drive gear by welding. Attached Figure Description

[0010] Figure 1 A perspective view of a differential disconnection system according to a first exemplary embodiment is shown.

[0011] Figure 2 The diagram shows... Figure 1 A cross-sectional view of the differential disconnection system.

[0012] Figure 3 The diagram shows the device in the disconnected position. Figure 1Detailed cross-sectional view of the differential disconnection system.

[0013] Figure 4 The diagram shows the part in the engagement position. Figure 1 Detailed cross-sectional view of the differential disconnection system.

[0014] Figure 5 The diagram shows... Figure 1 A partial exploded view of the differential disconnection system.

[0015] Figure 6 A cross-sectional view of a differential disconnection system according to a second exemplary embodiment is shown.

[0016] Figure 7 The diagram shows... Figure 6 A three-dimensional cross-sectional view of the differential disconnection system.

[0017] Figure 8 The diagram shows... Figure 6 An exploded three-dimensional cross-sectional view of the differential disconnection system. Detailed Implementation

[0018] Embodiments of this disclosure are described herein. It should be understood that similar reference numerals appearing in different views of the accompanying drawings indicate the same or functionally similar structural elements. Furthermore, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show detail of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but rather as a representative basis for teaching those skilled in the art to adopt embodiments in various ways. As will be understood by those skilled in the art, various features illustrated and described with reference to any of the figures in this disclosure may be combined with features illustrated in one or more other figures to produce embodiments not explicitly illustrated or described. The combinations of illustrated features provide representative embodiments for typical applications. However, for a particular application or implementation, various combinations and modifications of features consistent with the teachings of this disclosure may be desired.

[0019] The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Although any methods, apparatus, or materials similar to or equivalent to those described herein may be used in practice or testing of this disclosure, the following example methods, apparatus, and materials will now be described.

[0020] Reference Figures 1 to 5 Please describe it as follows. Figure 1 The illustration shows a perspective view of the differential disconnection system 100. Figure 2 The diagram shows... Figure 1 A cross-sectional view of the differential disconnection system. Figure 3 The diagram shows the device in the disconnected position. Figure 1 Detailed cross-sectional view of the differential disconnection system. Figure 4 The diagram shows the part in the engagement position. Figure 1 Detailed cross-sectional view of the differential disconnection system. Figure 5 The diagram shows... Figure 1 A partial exploded view of the differential disconnection system.

[0021] The differential disconnection system 100 can be arranged in a vehicle. For example, in some electric vehicles, it may be desirable to disconnect the axle from the electric motor to avoid rotational losses through gears and / or the motor. System 100 allows the vehicle axle shaft to rotate freely without the need for the final drive gear or electric motor to rotate, for the purpose of improving efficiency. As will be discussed below, the differential disconnection system can be engaged and disengaged by an electric actuator to connect the drive gear and motor to the axle shaft and to disconnect the drive gear and motor from the axle shaft.

[0022] The differential disconnect system 100 includes: a housing 102 arranged to receive motor torque (e.g., from an electric motor, not shown); a clutch element 104; and a differential unit 106 arranged to drively engage with a pair of axle shafts (not shown). The housing 102 includes radially inward-facing teeth 108, and the clutch element 104 drively engages with and is axially sliding on the radially inward-facing teeth. The clutch element 104 includes a face spline 110, and the differential unit 106 includes a clutch element 112 having a face spline 114 arranged to engage the face spline 110 for selective torque transmission between the housing and the differential unit. In other words, when the face splines are engaged, torque (e.g., motor torque) is transmitted from the housing to the differential unit, and road torque (e.g., from the axle shafts) is transmitted from the differential unit to the housing. The face spline we refer to is a complementary set of radially extending teeth that can engage for torque transmission when two splines are axially pressed together. An example face spline is shown and described in commonly assigned U.S. Patent No. 8,444,322, entitled *FACE SPLINE FOR A DRIVEN WHEEL HUB*, by Langer et al., which is incorporated herein by reference as fully set forth herein. Although the above reference shows angled teeth, face splines 110 and 114 can be any axially engaged set of radially extending teeth (e.g., flat-sided teeth as shown in the figure).

[0023] The differential disconnect system 100 includes an actuator arm 116 extending through a housing to axially displace a clutch element 104, thereby engaging and disengaging it from a clutch element 112. The actuator arm 116 includes a ring portion 118 and an axial projection 124, the ring portion being axially fixed to the clutch element 104, for example, between a radial wall 120 and a retaining ring 122, and the axial projection extending through a corresponding opening 126 in the housing. The ring portion 118 includes an annular portion 128 and a cylindrical portion 130, with the projection 124 extending from the cylindrical portion. A shift sleeve 132 is arranged to displace via a shift fork 134 (via a shift ring 136) to displace the actuator arm. That is, an electric actuator 138 includes an electric motor 140 that operates a gear train 142 to rotate a ball screw 144. A ball nut 146 engages with a ball screw 144 and is axially displaced as the ball screw rotates, thereby pivoting the shift fork about pin 148. A pivotable protrusion 150 is disposed in a groove 152 of a sleeve 132 to allow axial displacement of the sleeve. The sleeve 132 engages with a shift ring 136 such that displacement of the sleeve displaces the ring. The ring 136 includes a distal end 154 arranged to contact an annular portion 128 to engage the face spline. A stop ball 155 is radially displaced by the ring 136 to maintain the axial position of the actuator arm 116 without the additional force required to push the face clutch together. A retaining ring 156 disposed in the groove 158 of the protrusion 124 pulls the actuator arm (and clutch element 104) to disengage the face spline when the electric actuator reverses.

[0024] The differential unit 106 includes a differential housing 160, and the clutch element 112 is secured to the differential housing by, for example, welding. Although welding is specifically described in the specification, other methods of securing components together may also be used throughout. For example, adhesives, brazing, mechanical deformation (e.g., riveting), or other known methods may be used to secure various components together. The differential disconnect system 100 also includes radial bearings 162 and 164 supporting the differential housing 160 within a housing 102. The differential housing 160 includes: a housing half 166 having a tubular protrusion 168 supported by a bearing 170 and extending away from the differential unit; and a housing half 172 having a tubular protrusion 174 supported by a bearing 175 and extending away from the differential unit. For example, bearings 170 and 175 are arranged to support the differential unit in, for example, an axle housing (not shown). The differential unit 106 also includes: side gears 176 and 178, each having internal splines 180 and 182 for drivably engaging with a pair of axle shafts (not shown); a shaft 184; and star gears 186 and 188, which are rotatable on the shaft and each mesh with one of the side gears 176 and 178.

[0025] The differential disconnect system 100 also includes a final drive gear 190. The housing 102 includes radially outward-facing teeth 192, and the final drive gear 190 includes radially inward-facing teeth 194, which drively engage with the radially outward-facing teeth. The radially inward-facing teeth 108 and the radially outward-facing teeth 192 form a wavy cylindrical portion of the housing. That is, the housing is formed such that the gaps between the teeth 108 form the teeth 192, and vice versa, and the housing has approximately the same thickness throughout the cylindrical portion. For example, the final drive gear 190 is bolted to the housing using bolts 196.

[0026] Housing half 166 includes a radial flange 197 and an opening 198, the radial flange being bolted (e.g., using bolt 196) to the final drive gear 190. Housing half 172 includes an axial protrusion 199 extending through the opening 198. The axial protrusion 199 is axially secured in housing half 166 by riveting. That is, the axially distal end of the protrusion 199 extending through the opening is "forged" (e.g., physically deformed) to secure the protrusion in the opening, thereby connecting housing half 166 and 172 together.

[0027] Reference Figures 6 to 8 Please describe it as follows. Figure 6 The diagram shows a cross-sectional view of the differential disconnection system 200. Figure 7 The diagram shows... Figure 6 A three-dimensional cross-sectional view of the differential disconnection system. Figure 8 The diagram shows... Figure 6 An exploded three-dimensional cross-sectional view of the differential disconnect system. Except as described below, the differential disconnect system 200 generally operates in the same manner as the differential disconnect system 100 described above.

[0028] The differential disconnect system 200 includes a final drive gear 290. The housing 202 includes: a housing half 266 having a radial flange 297 bolted to the final drive gear (using bolts 296); and a housing half 272 fixed to the final drive gear by welding. Unlike the differential disconnect system 100 described above, the final drive gear 290 does not include radially inward-facing teeth, but instead engages drivably with the housing 202 by welding the housing half 272. In this case, the welded final drive gear and housing half 272 are provided as sub-assemblies prior to the final assembly of the differential disconnect system. Once components (e.g., differential unit 206) are installed in the housing half 272, the housing half 266 is bolted to the final drive gear.

[0029] While exemplary embodiments have been described above, it is not intended that these embodiments describe all possible forms covered by the claims. The language used in this specification is descriptive rather than restrictive, and it should be understood that various changes may be made without departing from the spirit and scope of this disclosure. As previously described, features of various embodiments may be combined to form other embodiments that may not be explicitly described or illustrated in this disclosure. Although various embodiments may have been described as providing an advantage or superiority over other embodiments or prior art implementations in one or more desired characteristics, those skilled in the art will recognize that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, cost, strength, durability, life cycle cost, merchantability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, any embodiment described as less desirable in one or more characteristics than other embodiments or prior art implementations does not exceed the scope of this disclosure and may be desirable for a particular application.

[0030] List of reference numerals 100 Differential Disconnection System 102 Casing 104 Clutch Components (First) 106 Differential Unit 108 radially inward-facing teeth (shell) 110 End face spline (first) 112 Clutch Components (Second) 114 End face spline (second) 116 Actuating Boom 118 Ring Section (Actuator Boom) 120 Radial wall (clutch element 104) 122 Snap ring (clutch element 104) 124 Axial protrusion (actuator arm) 126 Opening (shell) 128 Annular section (actuator boom ring section) 130 Cylindrical section (actuator boom ring section) 132 Shift Sleeve 134 Shift fork 136 Shift ring 138 Electric Actuator 140 electric motor 142 Gear system (electric actuator) 144 Ball screw (electric actuator) 146 Ball Nut (Electric Actuator) 148 pin (shift fork) 150 Pivotable protrusion (shift fork) 152 Groove (Shift Sleeve) 154 Distal end (shift ring) 155 stop ball bearings 156 Snap ring (actuator boom) 158 Groove (Axial protrusion of the actuator arm) 160 Differential housing 162 Radial bearing (first) 164 Radial bearing (second) 166 Shell half (first) 168 Tubular protrusion (first) 170 bearing 172 Shell half (second) 174 Tubular protrusion (second) 175 bearing 176 Side Gear 178 Side Gear 180 internal spline (side gear 176) 182 Internal spline (side gear 178) 184 shafts 186 star gear 188 star gear 190 Final drive gear 192. Radial outward-facing teeth (shell) 194 radially inward-facing teeth (final drive gear) 196 bolts 197 Radial flange (shell half 166) 198 Opening (166 on the shell half) 199 Axial protrusion (shell half 172) 200 Differential Disconnection System 202 Housing 266 Shell half 272 Shell half 290 Final drive gear 296 bolts 297 Radial flange

Claims

1. A differential disconnection system for a vehicle, the differential disconnection system comprising: A housing arranged to receive motor torque, the housing including radially inwardly facing teeth; A first clutch element is drivably engaged with the radially inward-facing teeth and is axially sliding on the radially inward-facing teeth, the first clutch element including a first end face spline; as well as A differential unit, the differential unit being arranged to drively engage with a pair of axle shafts, the differential unit including a second clutch element having a second end face spline arranged to engage a first end face spline for selective torque transmission between the housing and the differential unit.

2. The differential disconnection system of claim 1 further includes an actuating arm extending through the housing to axially displace the first clutch element, thereby engaging and disengaging with the second clutch element.

3. The differential disconnection system according to claim 2, wherein, The actuator arm includes: The ring portion, axially fixed to the first clutch element; and Multiple axial protrusions extend through corresponding openings in the housing.

4. The differential disconnection system according to claim 2 further includes a shift sleeve, the shift sleeve being arranged to shift the actuator arm by means of a shift fork.

5. The differential disconnection system according to claim 1, wherein: The differential unit includes a differential housing; and The second clutch element is fixed to the differential housing.

6. The differential disconnection system according to claim 5 further includes a first radial bearing supporting the differential housing within the housing.

7. The differential disconnection system according to claim 6 further includes a second radial bearing supporting the differential housing within the housing.

8. The differential disconnection system according to claim 1, wherein, The housing includes: A first housing half, the first housing half including a first tubular protrusion extending away from the differential unit in a first axial direction; and The second housing half includes a second tubular protrusion extending away from the differential unit in a second axial direction opposite to the first axial direction.

9. The differential disconnection system according to claim 1, wherein, The differential unit also includes: A pair of side gears, the pair of side gears including internal splines for driving engagement with the pair of axle shafts; Axis; and A pair of star gears, which are rotatable on the shaft and each meshes with two of the pair of side gears.

10. The differential disconnection system according to claim 1, further comprising a final drive gear, wherein: The housing includes radially outward-facing teeth; and The final drive gear includes radially inward teeth that drively engage with the radially outward teeth.

11. The differential disconnection system according to claim 10, wherein, The radially inward-facing teeth and the radially outward-facing teeth of the housing form the wavy cylindrical portion of the housing.

12. The differential disconnection system according to claim 10, wherein, The final drive gear is bolted to the housing.

13. The differential disconnection system according to claim 10, wherein, The housing includes: A first housing half, the first housing half comprising: A radial flange, which is bolted to the final drive gear; and Multiple openings; and The second housing half includes a plurality of axial protrusions extending through the plurality of openings.

14. The differential disconnection system according to claim 13, wherein, The plurality of axial protrusions are axially fixed in the first housing half by riveting.

15. The differential disconnection system according to claim 1, further comprising a final drive gear, wherein, The housing includes: A first housing half, the first housing half including a radial flange bolted to the final drive gear; and The second housing half is fixed to the final drive gear by welding.

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