Differential cutting system

Abstract

A differential disconnection system for a vehicle includes a housing disposed to receive motor torque, a first clutch element, and a differential. The housing includes radially inward-facing teeth, and the first clutch element is drive-engaged with the radially inward-facing teeth and is axially slidable on the radially inward-facing teeth. The first clutch element includes a first face spline. The differential unit includes a second clutch element disposed to drive-engage with a pair of axle shafts and having a second face spline disposed to engage with the first face spline for selective torque transmission between the housing and the differential unit.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Non - Provisional Application No. 18 / 583,999, filed on Feb. 22, 2024, which is a continuation - in - part of U.S. Non - Provisional Application No. 18 / 209,478, filed on Jun. 14, 2023, and claims the benefit of U.S. Provisional Application No. 63 / 534,886, filed on Aug. 28, 2023, the entire disclosures of which are incorporated herein by reference.

[0002] Technical Field The present disclosure generally relates to differential devices, and more specifically to differential disconnect systems.

Background Art

[0003] Cutting mechanisms in differential devices are known. An example is illustrated and described in International Publication No. WO 2022 / 217355 titled "DISCONNECTING DIFFERENTIAL SIDE GEAR MECHANISM" by MAGNA POWERTRAIN, INC.

Summary of the Invention

Means for Solving the Problems

[0004] Exemplary embodiments broadly comprise a differential disconnect system for a vehicle, including a housing arranged to receive motor torque, a first clutch element, and a differential device. The housing includes radially inward teeth, the first clutch element is drivingly engaged with the radially inward teeth and is axially slidable thereon. The first clutch element includes a first face spline. The differential unit includes a second clutch element having a second face spline arranged to drivingly engage a pair of axle shafts and to engage with the first face spline for selective torque transmission between the housing and the differential unit.

[0005] In some exemplary embodiments, the differential disconnection system has an actuating arm extending through a housing to axially displace a first clutch element in order to engage and disengage a second clutch element. In exemplary embodiments, the actuating arm includes a ring portion axially fixed to the first clutch element and a plurality of axial projections extending through respective openings within the housing. In exemplary embodiments, the differential disconnection system has a shift sleeve disposed for displacement by a shift fork to displace the actuating arm.

[0006] In some exemplary embodiments, the differential unit includes a differential housing, and the second clutch element is fixed to the differential housing. In some exemplary embodiments, the differential disconnection system has a first radial bearing that supports the differential housing within the housing. In exemplary embodiments, the differential disconnection includes a second radial bearing that supports the differential housing within the housing.

[0007] In an exemplary embodiment, the housing includes a first housing half having a first tubular projection extending away from the differential unit in a first axial direction, and a second housing half having a second tubular projection extending away from the differential unit in a second axial direction opposite to the first axial direction. In an exemplary embodiment, the differential unit includes a pair of side gears having internal splines for drive engagement with a pair of axle shafts, a shaft, and a pair of spider gears rotatable on the shaft, each meshing with both of the pair of side gears.

[0008] In some exemplary embodiments, the differential cutting system includes a final drive gear. The housing includes radially outward-facing teeth, and the final drive gear comprises radially inward-facing teeth that are drive-engaged with the radially outward-facing teeth. In exemplary embodiments, the radially inward-facing teeth of the housing and the radially outward-facing teeth of the housing form a ridged cylindrical portion of the housing. In exemplary embodiments, the final drive gear is bolted to the housing. In some exemplary embodiments, the housing comprises a first housing half having a radial flange and a plurality of apertures bolted to the final drive gear, and a second housing half having a plurality of axial tabs extending through the plurality of apertures. In exemplary embodiments, the plurality of axial tabs are axially fixed within the first housing half when the radial flange is bolted to the final drive gear.

[0009] In an exemplary embodiment, the differential cutting system includes a final drive gear. The housing includes a first housing half having a radial flange bolted to the final drive gear, and a second housing half fixed to the final drive gear by welding. [Brief explanation of the drawing]

[0010] [Figure 1] A perspective view of a differential cutting system according to a first exemplary embodiment is illustrated below. [Figure 2] Figure 1 illustrates the cross-sectional view of the differential cutting system. [Figure 3] A detailed cross-sectional view of the differential cutting system shown in Figure 1, indicated by the cutting position, is illustrated as an example. [Figure 4] A detailed cross-sectional view of the differential cutting system shown in Figure 1, indicated by the engagement position, is illustrated as an example. [Figure 5] Let's illustrate this with an example using the partially exploded perspective view of the differential cutting system shown in Figure 1. [Figure 6] A cross-sectional view of a differential cutting system according to a second exemplary embodiment is illustrated below. [Figure 7] Figure 6 illustrates this point with an oblique cross-sectional view of the differential cutting system. [Figure 8] Figure 6 illustrates this with an exploded perspective cross-sectional view of the differential cutting system. [Modes for carrying out the invention]

[0011] Embodiments of the Disclosure are described herein. It should be understood that similar drawing numbers appearing in different drawings identify identical or functionally similar structural elements. It should also be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms. The drawings are not necessarily to scale, and some features may be exaggerated or minimized to illustrate details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as representative criteria for teaching those skilled in the art to use the embodiments in various ways. As those skilled in the art will understand, various features illustrated and described with reference to any one of the drawings can be combined with features illustrated in one or more other drawings to create embodiments not expressly illustrated or described. Combinations of illustrated features provide representative embodiments for typical applications. However, various combinations and modifications of features consistent with the teachings of the Disclosure may be desired for specific applications or implementations.

[0012] The terms used herein are for the sole purpose of describing specific aspects and are not intended to limit the scope of this disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this disclosure pertains. Any method, apparatus, or material similar or equivalent to those described herein may be used in the implementation or testing of this disclosure, but the following exemplary methods, apparatus, and materials are described herein.

[0013] The following explanation will be made with reference to Figures 1 to 5. Figure 1 illustrates a perspective view of the differential cutting system 100. Figure 2 illustrates a cross-sectional view of the differential cutting system in Figure 1. Figure 3 illustrates a detailed cross-sectional view of the differential cutting system in Figure 1, indicated by the cutting position. Figure 4 illustrates a detailed cross-sectional view of the differential cutting system in Figure 1, indicated by the engagement position. Figure 5 illustrates a partially exploded perspective view of the differential cutting system in Figure 1.

[0014] The differential disconnection system 100 may be installed within a vehicle. For example, in some electric vehicles, it may be desirable to disconnect the axle from the electric motor to avoid rotational losses due to the gears and / or motor. To improve efficiency, the system 100 allows the axle shaft of the vehicle to rotate freely without rotating the final drive gear or electric motor. As will be discussed below, the differential disconnection system may be engaged and disengaged by electric actuators to connect and disconnect the drive gear and motor from the axle shaft.

[0015] The differential disconnection system 100 includes a housing 102 disposed to receive motor torque (e.g., from an electric motor, not shown), a clutch element 104, and a differential unit 106 disposed to drive-engage with a pair of axle shafts (not shown). The housing 102 includes radially inward-facing teeth 108, and the clutch element 104 is drive-engaged with the radially inward-facing teeth and is axially slidable on the radially inward-facing teeth. The clutch element 104 includes a surface spline 110, and the differential unit 106 includes a clutch element 112 having a surface spline 114 disposed to engage with the surface spline 110 for selective torque transmission between the housing and the differential unit. In other words, when the surface splines are engaged, torque (e.g., motor torque) is transmitted from the housing to the differential unit, and road surface torque (e.g., from axle shafts) is transmitted from the differential unit to the housing. A face spline refers to a complementary set of radially extending teeth that can be engaged for torque transmission when two splines are pressed against each other axially. An exemplary face spline is illustrated and described in U.S. Patent No. 8,444,322 by Langer et al., entitled “FACE SPLINE FOR A DRIVEN WHEEL HUB,” by the same applicant, which is incorporated herein by reference as if it were fully described herein. Although inclined teeth are shown in the above reference drawings, face splines 110 and 114 may be a pair of radially extending teeth engaged in any axial direction (e.g., teeth with flat sides as shown in the figures).

[0016] The differential disconnection system 100 includes an actuating arm 116 that extends through a housing to axially displace a clutch element 104 for engaging and disengaging a clutch element 112. The actuating arm 116 includes, for example, a ring portion 118 that is axially fixed to the clutch element 104 between the radial wall 120 of the clutch element 104 and a snap ring 122, and axial projections 124 that extend through respective openings 126 in the housing. The ring portion 118 includes an annular portion 128 and a cylindrical portion 130, and the projections 124 extend from the cylindrical portion. A shift sleeve 132 is disposed for displacement by a shift fork 134 (via a shift ring 136) to displace the actuating arm. That is, the electric actuator 138 includes an electric motor 140 that operates a gear train 142 to rotate a ball screw 144. The ball nut 146 engages with the ball screw 144 and is displaced axially as the ball screw rotates, pivoting the shift fork around the pin 148. The pivotable tab 150 is positioned in a groove 152 of the sleeve 132 to displace the sleeve axially. The sleeve 132 is engaged with the shift ring 136 such that the displacement of the sleeve displaces the ring. The ring 136 includes a distal end 154 positioned to contact the annular portion 128 to engage with the face spline. The dovetail ball 155 is radially displaced by the ring 136 to maintain the axial position of the actuating arm 116 without additional force to push the face clutch together. A snap ring 156 positioned in a groove 158 of the projection 124 pulls the actuating arm (and clutch element 104) to disengage the face spline when the electric actuator is reversed.

[0017] The differential unit 106 includes a differential housing 160, and the clutch element 112 is fixed to the differential housing, for example, by welding. Although this specification specifically refers to welding, other methods for fixing components together may be used throughout. For example, various components may be fixed together using adhesives, brazing, mechanical deformation (e.g., riveting), or other known methods. The differential cutting system 100 also includes radial bearings 162 and 164 that support the differential housing 160 within the housing 102. The differential housing 160 includes a housing half 166 supported by bearings 170 and having a tubular projection 168 extending away from the differential unit, and a housing half 172 supported by bearings 175 and having a tubular projection 174 extending away from the differential unit. The bearings 170 and 175 are arranged, for example, to support the differential unit within an axle housing (not shown). The differential unit 106 also includes side gears 176 and 178, each having an inner spline 180 and 182 for drive engagement with a pair of axle shafts (not shown), a shaft 184, and spider gears 186 and 188, which are rotatable on the shaft and each meshes with both of the side gears 176 and 178.

[0018] The differential cutting 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 that are driven-engaged with the radially outward-facing teeth. The radially inward-facing teeth 108 and the radially outward-facing teeth 192 form the undulating 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 a generally uniform thickness throughout the cylindrical portion. The final drive gear 190 is bolted to the housing, for example, by bolts 196.

[0019] The housing half 166 includes a radial flange 197 bolted (e.g., with bolts 196) to the final drive gear 190 and an aperture 198. The housing half 172 includes an axial tab 199 that extends through the aperture 198. The axial tab 199 is axially fixed within the housing half 166 by riveting. That is, the axial distal end of the tab 199 that extends through the aperture is "set" (e.g., physically deformed) within the aperture to thereby connect the housing halves 166 and 172 together.

[0020] The following description is made with reference to FIGS. 6-8. FIG. 6 illustrates a cross-sectional view of a differential cutting system 200. FIG. 7 illustrates a perspective cross-sectional view of the differential cutting system of FIG. 6. FIG. 8 illustrates a perspective cross-sectional exploded view of the differential cutting system of FIG. 6. The differential cutting system 200 generally operates in the same manner as the differential cutting system 100 described above, except as described below.

[0021] The differential cutting system 200 includes a final drive gear 290. The housing 202 includes a housing half 266 having a radial flange 297 bolted (with bolts 296) to the final drive gear and a housing half 272 fixed to the final drive gear by welding. In contrast to the differential cutting system 100 described above, the final drive gear 290 does not include radially inward teeth, but instead is drivingly engaged with the housing 202 by welding of the housing half 272. In this case, the welded final drive gear and housing half 272 are provided as a subassembly prior to final assembly of the differential cutting system. When components (e.g., differential unit 206) are installed within the housing half 272, the housing half 266 is bolted to the final drive gear.

[0022] Although the exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The terms used in this specification are terms for explanation rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the present disclosure. As described above, it is possible to combine the features of the various embodiments to form further embodiments of the present disclosure that may not be explicitly described or illustrated. The various embodiments have been described as providing advantages with respect to one or more desired characteristics, or as being more preferable than other embodiments or prior art implementations, but those skilled in the art will recognize that it is possible to compromise on one or more features or characteristics to achieve the desired overall system attributes that depend on the specific application and implementation. These attributes can include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, as long as any embodiment is not described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the present disclosure and may be desirable for a particular application.

Description of Reference Numerals

[0023] 100 Differential cutting system 102 Housing 104 Clutch element (first) 106 Differential unit 108 Radially inward teeth (housing) 110 Face spline (first) 112 Clutch element (second) 114 Face spline (second) 116 Actuating arm 118 Ring portion (actuating arm) 120 Radial wall (clutch element 104) 122 Snap ring (clutch element 104) 124 Axial protrusion (actuating arm) 126 Opening (housing) 128 Annular section (operating arm ring section) 130 Cylindrical section (operating arm ring section) 132 Shift Sleeve 134 Shift Fork 136 Shift Ring 138 Electric Actuator 140 Electric motors 142 Gear train (electric actuator) 144 Ball screw (electric actuator) 146 Ball nut (electric actuator) 148 pins (shift fork) 150 Pivotable tabs (shift forks) 152 grooves (shift sleeve) 154 Distal end (shift ring) 155 Moderate Ball 156 Snap ring (actuating arm) 158 Groove (Axial projection of the operating arm) 160 Differential Housing 162 Radial bearing (1st) 164 Radial bearing (2nd) 166 Housing Half (Part 1) 168 Tubular protrusion (1st) 170 bearings 172 Housing Half (2nd) 174 Tubular protrusion (2nd) 175 bearings 176 Side Gear 178 Side Gear 180 Inner spline (side gear 176) 182 Inner spline (side gear 178) 184 shaft 186 Spider Gear 188 Spider Gear 190 Final drive gear 192 Radially outward-facing teeth (housing) 194 Radially inward-facing teeth (final drive gear) 196 volts 197 Radial flange (housing half 166) 198 Aperture (Housing half 166) 199 Axial tab (housing half 172) 200 Differential Cutting System 202 Housing 266 Housing Half 272 Housing Half 290 Final drive gear 296 volts 297 Radial flange

Claims

1. A differential cutting system for vehicles, A housing arranged to receive motor torque, comprising a housing and teeth facing radially inward, A first clutch element that is drive-engaged with the radially inward teeth and is axially slidable on the radially inward teeth, comprising a first surface spline, A differential unit disposed for drive engagement with a pair of axle shafts, comprising a second clutch element having a second surface spline disposed to engage with the first surface spline for selective torque transmission between the housing and the differential unit, A differential cutting system equipped with the following features.

2. The differential cutting system according to claim 1, further comprising an actuating arm extending through the housing to displace the first clutch element in the axial direction for engaging with and disengaging the second clutch element.

3. The aforementioned operating arm is A ring portion fixed axially to the first clutch element, Multiple axial protrusions extending through each of the openings within the housing, The differential cutting system according to claim 2, comprising:

4. The differential cutting system according to claim 2, further comprising a shift sleeve disposed for displacement by a shift fork to displace the operating arm.

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

6. The differential cutting system according to claim 5, further comprising a first radial bearing supporting the differential housing within the housing.

7. The differential cutting system according to claim 6, further comprising a second radial bearing supporting the differential housing within the housing.

8. The aforementioned housing is A first housing half having a first tubular projection extending away from the differential unit in a first axial direction, A second housing half having a second tubular projection extending away from the differential unit in a second axial direction opposite to the first axial direction, A differential cutting system according to claim 1, comprising:

9. The differential unit is A pair of side gears having internal splines for drive engagement with the pair of axle shafts, The shaft and A pair of spider gears that are rotatable on the shaft and each meshes with both of the pair of side gears, The differential cutting system according to claim 1, further comprising:

10. It also has a final drive gear, The housing is provided with teeth facing radially outward, The differential cutting system according to claim 1, wherein the final drive gear comprises radially outward-facing teeth and radially inward-facing teeth that are driven-engaged.

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

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

13. The aforementioned housing is The first housing half, The radial flange bolted to the final drive gear, and A first housing half having multiple apertures, A second housing half comprising a plurality of axial tabs extending through the plurality of apertures, A differential cutting system according to claim 10, comprising:

14. The differential cutting system according to claim 13, wherein the plurality of axial tabs are fixed axially within the first housing half by riveting.

15. Further comprising a final drive gear, the housing is A first housing half having a radial flange bolted to the final drive gear, The differential cutting system according to claim 1, comprising a second housing half fixed to the final drive gear by welding.

Images