COMPACT DIRECT-ACTING E-LOCK AND METHOD THEREFOR

Abstract

A lockable differential assembly includes a locking plate rotatable about a rotational axis. The differential assembly also includes an actuator assembly having a stator and an armature, the actuator assembly being switchable between an energized state and a de-energized state. Radial alignment of the stator is achieved via a guide provided on the outer diameter of the stator housing. A slip ring assembly is provided, configured to translate axially depending on the locked or unlocked state of the differential assembly, comprising a slip ring contacting the armature at a sliding surface and one or more pins rotatably connecting the slip ring to the locking plate.The slip ring assembly is configured to transmit an axial locking force and an axial return force between the actuator assembly and the locking plate.

Description

PRIORITY

[0001] This application claims the benefit of Indian Provisional Patent Application No. 202211048231, filed August 24, 2022, under 35 USC § 119(a), and U.S. Provisional Patent Application No. 63 / 400,615, filed August 24, 2022, under 35 USC § 119(e), which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present disclosure relates generally to vehicle powertrains and, more particularly, to mechanisms for electronically locking differential assemblies. BACKGROUND

[0003] Vehicle differential assemblies are torque control devices that allow axle shafts to operate at different speeds, such as when a vehicle is cornering. Lockable differential assemblies allow the axle shafts to be locked so they operate at the same speed, such as when road traction is low. Electronically lockable differential assemblies allow a user to selectively engage or disengage the locking function through electronically actuated means, such as a switch, button, or other user interface element located within the vehicle.

[0004] Increasingly demanding packaging constraints, safety requirements, and reliability targets are motivating design improvements for electronically locking differential assemblies. Specific considerations for electric vehicles are another reason for innovations in design, packaging, and vehicle integration.

[0005] The description provided herein is intended to provide a general context for the disclosure. Work by the inventors identified herein, to the extent described in this section, as well as aspects of the description that could not be considered prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. SUMMARY OF CERTAIN EMBODIMENTS

[0006] In certain embodiments, a lockable differential assembly is disclosed, the differential assembly comprising a locking plate disposed within a differential housing and rotatable about a rotational axis, the differential assembly configured to be in a locked state or an unlocked state based on selective axial engagement of the locking plate relative to a locking gear; an actuator assembly configured to be switchable between an energized state and a de-energized state, the actuator assembly comprising an armature and a stator, the stator comprising a stator coil disposed within a stator housing, wherein radial orientation of the stator is based on a first guide member disposed on an outer diameter of the stator housing;and a slip ring assembly configured to translate axially according to the locked state or the unlocked state of the differential assembly, and comprising: a slip ring engaging the armature at a sliding surface configured to allow relative rotation between the slip ring and the armature; and one or more pins rotatably connecting the slip ring to the locking plate, wherein the slip ring assembly is configured to transmit an axial locking force from the actuator assembly to the locking plate when the actuator assembly is energized, wherein the slip ring assembly is configured to transmit an axial restoring force from the locking plate to the actuator assembly when the actuator assembly is de-energized.;

[0007] In particular embodiments that may combine the features of some or all of the above embodiments, the differential housing includes a second guide feature, and wherein the first guide feature cooperates with the second guide feature to facilitate radial alignment of the stator. In particular embodiments that may combine the features of some or all of the above embodiments, the stator is further radially aligned due to the mutual engagement with the slip ring at an inner diameter of the stator housing.

[0008] In particular embodiments that may combine the features of some or all of the above embodiments, the differential assembly further includes a retaining ring configured to axially constrain the stator housing relative to the differential housing. In particular embodiments that may combine the features of some or all of the above embodiments, the retaining ring is a multi-piece retaining ring.

[0009] In particular embodiments that may combine the features of some or all of the above embodiments, the differential assembly further includes a lock detection sensor assembly having a sensor and a target, the lock detection sensor assembly configured to detect an axial distance between the stator and the armature. In particular embodiments that may combine the features of some or all of the above embodiments, one of the sensor and the target is coupled to the armature, and the other of the sensor and the target is coupled to the stator.

[0010] In particular embodiments that may combine the features of some or all of the above embodiments, a differential assembly further comprises an anti-rotation assembly having an elongated member, wherein the stator housing of the actuator assembly is coupled to a non-rotating external structure by the elongated member, wherein the elongated member is configured to prevent rotation of the stator housing about the rotation axis, and wherein the elongated member is configured to carry the electrical wiring of the stator coil and the lock detection sensor assembly. In particular embodiments that may combine the features of some or all of the above embodiments, the non-rotating external structure is an axle housing or a cover.In particular embodiments that may combine the features of some or all of the above embodiments, the elongated member comprises a sheet metal structure. In particular embodiments that may combine the features of some or all of the above embodiments, the anti-rotation assembly further comprises a second elongated member that rotatably couples the armature and the stator housing, such that the second elongated member prevents rotation of the armature about the rotation axis.

[0011] In particular embodiments that may combine the features of some or all of the above embodiments, the detection of the axial distance between the stator and the armature by the lock detection sensor assembly is based on the detection of a magnetic field strength, and wherein the slip ring is symmetrical about a longitudinal plane passing through the rotation axis and the lock detection sensor assembly to enable increased accuracy of lock detection. In particular embodiments that may combine the features of some or all of the above embodiments, the detection of the axial distance between the stator and the armature by the lock detection sensor assembly is based on the detection of a magnetic field strength, and wherein the one or more pins are distributed symmetrically around the rotation axis to enable increased accuracy of lock detection.

[0012] In particular embodiments, which may combine the features of some or all of the above embodiments, energizing the actuator assembly includes passing electric current through the stator coil to generate a magnetic field, and wherein the armature experiences a magnetic force toward the stator coil based on the magnetic field generated when the actuator assembly is energized.

[0013] In particular embodiments that may combine the features of some or all of the above embodiments, the slip ring is configured to radially align the armature relative to the axis of rotation. In particular embodiments that may combine the features of some or all of the above embodiments, the slip ring assembly further includes one or more features for axially confining the armature relative to the slip ring. In particular embodiments that may combine the features of some or all of the above embodiments, the one or more features include a groove or raised edge in the slip ring. In particular embodiments that may combine the features of some or all of the above embodiments, the one or more features include a washer or snap ring.

[0014] In particular embodiments that may combine the features of some or all of the above embodiments, an electronically lockable differential assembly capable of lock detection is disclosed, the differential assembly comprising: a differential case; a locking gear rotatably provided in the differential case; a locking plate rotatable about a rotational axis, the differential assembly configured to be in a locked state or an unlocked state based on selective axial displacement of the locking plate relative to the locking gear; a biasing member configured to axially bias the locking gear away from the locking plate;an actuator assembly having a stator and an armature, the actuator assembly configured to be switchable between an energized state and a de-energized state; a lock detection sensor assembly having a sensor and a target, the lock detection sensor assembly configured to detect an axial distance between the stator and the armature; and a slip ring assembly configured to translate axially according to the locked state or the unlocked state of the differential assembly, the slip ring assembly comprising: a slip ring engaging the armature at a slip surface configured to allow relative rotation between the slip ring and the armature;and one or more pins rotatably connecting the slip ring to the locking plate, wherein the slip ring assembly is configured to transmit an axial locking force from the actuator assembly to the locking plate when the actuator assembly is energized, wherein the slip ring assembly is configured to transmit an axial restoring force from the locking plate to the actuator assembly when the actuator assembly is de-energized, and wherein radial alignment of the stator is provided based on a first guide feature cooperatively engaging a second guide feature, wherein the first guide feature is disposed on an outer diameter of a stator housing and the differential housing includes the second guide feature.;

[0015] In particular embodiments that may combine the features of some or all of the above embodiments, a method of assembling a lockable differential assembly is disclosed, the method comprising: providing a locking gear and a locking plate in a differential case, the locking gear and locking plate rotatable about a rotational axis and axially urged apart by a biasing member; rotatably coupling the locking plate to a slip ring via one or more pins, a slip ring assembly comprising the slip ring and the one or more pins;Providing an actuator assembly comprising a stator and an armature, wherein the slip ring is axially coupled to the armature and a slip interface between the slip ring and the armature is configured to allow relative rotation therebetween, the armature being configured to translate axially toward the stator upon energization of the actuator assembly; radially aligning the stator based on a first guide feature cooperating with a second guide feature, the first guide feature being disposed on an outer diameter of a stator housing and the differential housing including the second guide feature;and providing a lock detection sensor assembly having at least one sensor component coupled to each of the armature and the stator, the lock detection sensor assembly configured to sense an axial distance between the stator and the armature, the slip ring assembly configured to transmit an axial locking force from the actuator assembly to the locking plate when the actuator assembly is energized, and the slip ring assembly configured to transmit an axial restoring force from the locking plate to the actuator assembly when the actuator assembly is de-energized.; BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present disclosure will be described in more detail below with reference to the example figures. The disclosure is not limited to the example embodiments. Other features and advantages of the various embodiments of the present disclosure will become apparent by reading the following detailed description with reference to the accompanying drawings, which illustrate the following: Fig. 1 shows a schematic cross-sectional side view of an electronically locking differential assembly according to certain embodiments. Fig. 2 shows a schematic, enlarged sectional side view of an electronically locking differential assembly according to certain embodiments. Fig. 3 shows a schematic, enlarged sectional side view of an electronically locking differential assembly according to certain embodiments. Fig. 4 shows a schematic side view of an electronically locking differential assembly according to certain embodiments. Fig. 5 shows a schematic front perspective view of an electronically locking differential assembly according to certain embodiments. The Fig. 6A and B show schematic, enlarged sectional side views of embodiments of electronically locking differential assemblies illustrating specific design features according to certain embodiments. Fig. 7A shows schematic front perspective views of slip rings according to certain embodiments. Fig. 7B shows a schematic front perspective view of an electronically locking differential assembly according to certain embodiments. Fig. 8 is a schematic front view of an electronically locking differential assembly mounted in an axle housing, with the axle housing cut away and illustrating an exemplary anti-rotation bracket and an exemplary cable guide bracket according to certain embodiments. Fig. 9 is a schematic enlarged front perspective view of an electronically locking differential assembly mounted in an axle housing, with the axle housing in section and illustrating an exemplary anti-rotation device according to certain embodiments. Fig. 10 is a schematic enlarged front perspective view of an electronic locking differential assembly mounted in an axle housing, with the axle housing in section and illustrating an exemplary cable routing bracket in accordance with certain embodiments. Fig. 11 is a schematic front view of an electronically locking differential assembly mounted in an axle housing, with the axle housing in section and illustrating an exemplary anti-rotation bracket and an exemplary cable guide bracket according to certain embodiments. Fig. 12 is a schematic, enlarged side view of an electronic locking differential assembly with an assembled and sectioned cover, showing an exemplary anti-rotation bracket in contact with the cover, according to certain embodiments. Fig. 13 shows a schematic front perspective view of an electronically locking differential assembly illustrating an exemplary combined anti-rotation / cable guide bracket according to certain embodiments. Fig. 14 is a schematic front perspective view of an electronically locking differential assembly mounted in an axle housing, with the axle housing in section and illustrating an exemplary combined anti-rotation / cable guide bracket in accordance with certain embodiments.

[0017] It should be noted that the figures may be depicted schematically rather than literally or accurately; furthermore, the components and aspects of the figures may not necessarily be to scale. Although like reference numerals may, in many cases, designate corresponding parts in the different views, like parts need not always be designated by the same reference numerals in every view. DESCRIPTION OF EMBODIMENTS

[0018] In accordance with various embodiments of the present disclosure, various mechanisms, assemblies, arrangements, and methods for operating, manufacturing, and / or assembling vehicle drivetrains, locking differential assemblies, and / or related subsystems are disclosed herein. For clarity, while certain aspects are described and / or illustrated to facilitate understanding, not all features of each embodiment are described in this description.

[0019] With reference to the figures, the Fig. 1-4 are schematic views of an electronically locking differential assembly according to certain embodiments. In certain embodiments, a lockable differential assembly 110 may include a locking plate 140 rotatable about a rotational axis within a differential case 130. In certain embodiments, the differential assembly 110 may be configured to be in a locked or unlocked state based on a relative axial position of a locking plate 140 and / or a selective axial engagement of the locking plate 140 relative to a locking gear 135.

[0020] By way of example and without limitation, in the absence of an applied locking force, the locking plate 140 may be biased, e.g., mechanically by return springs, to maintain the differential assembly 110 in an unlocked state, wherein the locking plate 140 may be disengaged from a locking gear 135 and the axle shafts 120 may freely rotate at different speeds. In certain embodiments, a return spring force, e.g., by the return spring 150, may act on the locking plate 140 (toward the left side in the frame of Fig. 1), thereby maintaining an unlocked differential condition. When sufficient locking force is applied to the locking plate 140 to displace it axially to the right against the return spring force (again in the reference frame of Fig. 1), in certain embodiments, a locked state of the differential assembly 110 can be established in which the axle shafts 120 can be forced to rotate at identical speeds.

[0021] With reference to the Fig. 1-4, in certain embodiments, an actuator assembly, such as the electronic actuator assembly 210, which may include an armature 220 and a stator 230 with a stator coil 234, may be used to effect the electronic locking of the differential assembly 110. In certain embodiments, the electronic actuator assembly 210 may be configured to be switchable between a powered state and a de-powered state.

[0022] In certain embodiments, the armature 220 and the stator coil 234 (located within the stator housing 232) may be substantially annular components that can be arranged to be concentric with the rotational axis of the differential assembly 110. In certain embodiments, which will be discussed in more detail herein, the armature 220 and / or the stator coil 234 may need to be constrained and / or controlled along one or more axes to assume or maintain certain configurations and / or positions. In certain embodiments, the stator housing 232 may include one or more electrical leads 240 for supplying power to the stator coil 234 and / or channels for routing the electrical leads 240. In certain embodiments, the electrical leads 240 may be connected to an electrical system of the vehicle, e.g., through an electrical wiring harness.

[0023] In certain embodiments, the electronic actuator assembly 210 may be energized and / or de-energized. By way of example and without limitation, energizing the electronic actuator assembly 210 may include passing an electrical current through the stator coil 234 to create a magnetic field, and the armature 220 may experience a magnetic force toward the stator coil 234 based on the magnetic field created when the electronic actuator assembly 210 is energized.

[0024] When the stator coil 234 is electrically energized, the armature 220 may experience an electromagnetic force of attraction toward the stator coil 234 sufficient to axially displace the armature 220 (toward the right side in the frame of reference of Fig. 1). According to this axial displacement, the armature 220 can exert a rightward axial force, for example through a slip ring 320 and / or one or more transmission pins 340, wherein the slip ring 320 and / or the pins 340 can in turn exert a force on the locking plate 140 (to the right, in the reference frame of Fig. 1). In certain embodiments, such an axial force exerted directly or indirectly by the electronic actuator assembly 210 on the locking plate 140, which engages the locked state of the differential assembly 110, may act against a restoring force, such as may be provided by a biasing element such as the return spring 150.

[0025] In certain embodiments, without limitation, the transfer pins 340 may be referred to as push pins, indexing pins, or simply pins.

[0026] During a normal operating condition of the differential assembly 110, several components of the differential assembly 110 may rotate about a rotational axis of the differential assembly 110. In certain embodiments, as a non-limiting example, certain components that may be rotationally fixed relative to the rotating components may include one or more of the electronic actuator assembly 210 (including stator 230, including stator coil 234 in stator housing 232, and / or armature 220). By way of example and without limitation, other components that may separately or additionally be rotationally fixed in some embodiments may include the lock detection sensor assembly 410 (which further includes a lock detection sensor 420 and a sensor target 430).In certain embodiments, one or more of these components may be non-rotatably secured to the rotating components of differential assembly 110 by mechanical coupling to non-rotatable vehicle structures and / or to each other. By way of example and without limitation, an axle housing 510 (e.g., as shown in FIG. Fig. 8) provide a non-rotatable anchoring structure or reference frame to constrain certain portions of the differential assembly 110 to be non-rotatably held relative to the rotating components.

[0027] In certain embodiments, a slip ring assembly 310 may be used to allow the stator housing 232 and / or the armature 220 to slide, i.e., remain rotationally fixed, for example, with respect to rotating components of the differential assembly 110. In certain embodiments, the slip ring assembly 310 may include a slip ring 320.

[0028] In certain embodiments, slip ring 320 may engage armature 220 at a sliding surface configured to allow relative rotation between slip ring 320 and armature 220. By way of example and without limitation, slip ring 320 may be constructed from various materials, such as brass and / or other metals or non-metallic materials. In certain embodiments, slip ring 320 may be constructed from certain materials, e.g., non-metallic materials, which at least has the advantage of not interfering with sensitive magnetic sensing devices connected to differential assembly 110, such as a lock detection sensor assembly 410, which is further discussed herein.

[0029] In particular embodiments, a geometry, material, and / or manufacturing method for the slip ring 320 may address one or more of the following requirements: (a) load-bearing requirements for axial and / or radial alignment and / or clamping of particular interconnecting elements; (b) friction requirements for relative slippage for particular interconnecting requirements; (c) fatigue, hardness, and / or other structural requirements for operational lifetime, e.g., without requiring replacement; (d) magnetic performance, e.g., for shaping, confining, guiding, and / or reducing magnetic losses. By way of example and without limitation, FIG. 1 shows and discloses Fig. 8A geometric features of certain embodiments to meet the above requirements.

[0030] In certain embodiments, slip ring 320 may be manufactured using suitable methods to achieve one or more of the desired performance characteristics disclosed herein. For example, slip ring 320 may be manufactured from a powdered or sintered blank, optionally with subsequent finish machining. In certain embodiments, slip ring 320 may be manufactured from one or more non-magnetic materials. In particular embodiments, one or more materials may be selected for fabricating slip ring 320 based on their magnetic properties to reduce magnetic losses.In certain embodiments, one or more materials for fabricating slip ring 320 may be selected based on at least their magnetic permeability properties to shape, direct, focus, and / or otherwise interact with magnetic fields near the magnetic influence of slip ring 320.

[0031] In certain embodiments, a slip ring assembly 310 may be configured to axially translate according to the locked state or the unlocked state of the differential assembly 110. In certain embodiments, the slip ring assembly 310 may be configured to transmit an axial locking force from the electronic actuator assembly 210 to the locking plate 140 when the electronic actuator assembly 210 is energized. By way of example and without limitation, an axial locking force may be generated when the armature 220 experiences a magnetic force toward the stator coil 234 when the electronic actuator assembly 210 is energized.

[0032] In certain embodiments, the slip ring assembly 310 may be configured to transmit an axial restoring force from the locking plate 140 to the electronic actuator assembly 210 when the electronic actuator assembly 210 is de-energized. By way of example and without limitation, an axial restoring force may be based on a restoring or re-engaging force acting to separate the locking plate 140 from the locking gear 135 and / or acting to axially displace the locking plate 140 away from the locking gear 135 and toward the electronic actuator assembly 210 (i.e., toward the left side in the frame of reference of Fig. 1).

[0033] In certain embodiments, slip ring 320 may be configured to focus the magnetic field and / or enhance the magnetic flux generated in the powered state of electronic actuator assembly 210, for example, through an air gap between armature 220 and stator 230. In certain embodiments, slip ring 320 may be separately or additionally configured to minimize magnetic losses to a hub. By way of example and without limitation, in certain embodiments, slip ring 320 may focus, shape, guide, and / or confine magnetic field lines between an armature / stator gap located radially outward of slip ring 320.By way of example, and not as a limitation, in certain embodiments, slip ring 320 may focus, shape, guide, and / or confine magnetic field lines to minimize magnetic losses to a hub, which may be located radially within slip ring 320, and / or a differential housing 130. In certain embodiments, slip ring 320 may be separately or additionally configured to axially optimize the magnetic field, for example, to maximize the magnetic attraction force acting on armature 220 when electronic actuator assembly 210 is energized.

[0034] By way of example, and not by way of limitation, configuring slip ring 320 to focus the magnetic field and / or minimize magnetic losses to the hub and / or other components of differential assembly 110 may enable increased efficiency in the power requirements for electronic actuator assembly 210 to actuate a locked state of differential assembly 110. Accordingly, in certain embodiments, a smaller, lighter, and / or lower-power electronic actuator assembly 210 may be used to actuate a locked state.

[0035] Separately or additionally, in certain embodiments, slip ring 320 may provide radial support, constraint, and / or guidance for certain components associated with slip ring 320. In certain embodiments, controlling a component may consist of mechanically urging that component into a concentric position about a rotational axis of differential assembly 110. By way of example, and not limitation, non-rotatable components such as the armature and stator housing relative to the rotating components of the differential assembly may need to be controlled to remain concentrically disposed about the same axis as the rotating components.Piloting these components may require resisting forces and moments that may cause relative tilt and / or offset of the axes of these components relative to a rotational axis of interest, such as that of the differential assembly 110.

[0036] In certain embodiments, the slip ring 320 may be configured to radially align and / or pilot the armature 220 relative to a rotational axis of the differential assembly 110. By way of example and not limitation, as shown in the Fig. 1, Fig. 4 and Fig. 6, the armature 220 may be partially or completely radially guided onto or through the slip ring 320 (in Fig. 6 as 256). In certain embodiments, the slip ring 320 may be configured to radially align and / or pilot the pilot stator 230, e.g., the stator housing 232, relative to a rotational axis of the differential assembly 110. By way of example, and not limitation, the stator housing 232 may be partially or fully radially supported on or by the slip ring 320, as shown in Fig. 1 is shown.

[0037] From a mechanical perspective, it is understandable that large-area and / or large-radius mating surfaces are desirable for effective guidance of concentrically arranged components. However, recent applications (e.g., for electric vehicles) have led to more stringent packaging requirements and higher torque density, which can pose significant design challenges.

[0038] In certain embodiments, the electronic actuator assembly 210 may require the generation of sufficient magnetic forces to overcome one or more significant forces, for example, by energizing the stator 230. By way of example and without limitation, the significant forces that must be overcome by activating the electronic actuator assembly 210 may include frictional forces, spring forces, and / or viscous forces due to the viscosity of the hydraulic fluid (e.g., oil). For example, viscous forces may vary widely over a wide operating temperature range, e.g., between -40°C and 150°C, while acting over a wide range of supply voltages, e.g., between 9 V and 16 V. In certain embodiments, the stator 230 must generate magnetic forces between 482 N and 709 N to initiate a lock.

[0039] In certain embodiments, as described without limitation in the Fig. 4 and Fig. 6B, the stator housing 232 of the stator 230 may be radially constrained, aligned, and / or guided based on an inner diameter of the stator housing 232 that cooperates with a sliding surface of the slip ring 320 (denoted by reference numeral 254). In certain embodiments, the stator housing 232 of the stator 230 may be radially constrained, aligned, and / or guided on or by a variety of surfaces. By way of example, and not by way of limitation, the stator housing 232 may be Fig. 1-3, may be simultaneously radially clamped, aligned, and / or guided: (a) to a sliding surface of the slip ring 320 due to contact with an inner diameter of the stator housing 232 (indicated by 254), and (b) to a mutually contacting and / or cooperating feature or surface of the differential housing 130, such as a step, groove, and / or other guiding feature, due to contact with an outer diameter of the stator housing 232 (indicated by 252). As a non-limiting example of conflicting design challenges, the axial extension of the stator control area on the differential housing (as shown in the Fig. 2 and Fig. 3) may reduce the thickness of the flange 134 of the differential case 130, thereby weakening the flange 134 and / or reducing the torque-carrying capacity of the flange 134.

[0040] The relative configurations of two particular and non-limiting embodiments discussed herein for controlling the stator housing 232, which may differently optimize the packaging constraints and force requirements of the differential assembly 110, may be found in Fig. 6 can be visually compared. As an example and without limitation, the stator housing 232 can be Fig. 6A can be radially clamped, aligned, and / or guided on at least two surfaces: its outer diameter (OD) 236 on the differential housing 130 (designated as 252) and its inner diameter (ID) on the slip ring 320 (designated as 254). In contrast, the stator housing 232 in Fig. 6B is shown without restriction as being radially guided at its inner diameter on the slip ring 320.

[0041] In certain embodiments, certain features may be used in conjunction with the slip ring 320 to axially restrict the relative movement of certain components that interact with the slip ring 320 and / or to more rigidly restrict certain components from moving in close-coupled axial correspondence with the backup plate 140 and / or the transfer pins 340.

[0042] In certain embodiments, slip ring assembly 310 may further include one or more features to axially constrain a connecting component relative to slip ring 320, where a connecting component may include, as non-limiting examples, an armature 220, a stator 230, and / or transmission pins 340. By way of example and without limitation, a groove and / or a raised edge may be provided in slip ring 320 to axially secure a connecting component. Fig. 3 shows, by way of example and without limitation, slip ring 320 provided with a raised edge to receive and axially locate a leading edge of armature 220. Separately or additionally, an external structure, feature, and / or component may be used to axially locate a connecting component relative to slip ring 320. For example, and without limitation, one or more washers, a snap ring, a retaining ring, a C-clip, and / or an E-clip 326 may be used to provide axial containment. Fig. 7A shows, by way of example and not limitation, a groove 328 that may be used to receive and / or retain a snap ring 238 in certain embodiments.

[0043] In certain embodiments, as described without limitation in the Fig. 1, Fig. 2, Fig. 3 and Fig. 6A, one or more snap rings (e.g., 238), spirally wound rings, C-clips, and / or similar components may be used to axially secure a suitable component such as the armature 220 and / or the stator housing 232. The Fig. 2, Fig. 5 and Fig. 7B illustrate, by way of example and without limitation, the use of a snap ring 238 to axially constrain the armature 220 along one direction. In certain embodiments, as shown in Fig. 5 and Fig. 6B, a retaining ring 260 may be used to axially secure the stator housing 232. By way of example and without limitation, the retaining ring 260 may axially secure the stator housing 232 relative to the differential housing 130. In particular embodiments, as shown in Fig. 7B, as a non-limiting example, the retaining ring 260 may be a multi-piece retaining ring. In particular embodiments, the retaining ring 260 may comprise a discontinuous retaining ring.

[0044] In certain embodiments, the differential housing 130 may also be referred to as a differential case.

[0045] In some embodiments, it may be desirable and / or required by regulation to verify the locking or unlocking state of the differential assembly 110 by physical sensing. For example, it may be unsafe and / or inefficient to operate the vehicle with a differential lock state that does not match the user's expectations or information.

[0046] In certain embodiments, detection of the differential lock condition may be accomplished using a lock detection sensor assembly 410. In certain embodiments, as described as non-limiting examples in the Fig. 1, Fig. 2, Fig. 5 and Fig. 5, the lock detection sensor assembly 410 may include a lock detection sensor 420 and / or a sensor target 430. In certain embodiments, the lock detection sensor assembly 410 may be configured to detect an axial distance between the armature 220 and the stator 230.

[0047] In certain embodiments, a lock detection sensor 420, such as a Hall effect sensor, may be configured to operate based on the detection of a magnetic field strength and / or related quantities, such as a magnetic field strength and / or magnetic flux. By way of example and without limitation, the lock detection sensor 420 may be configured to detect a magnitude and / or direction of such or other particular physical quantities. In certain embodiments, the lock detection sensor 420 may be calibrated to correlate a varying relative distance of a target, e.g., an axial distance of a sensor target 430, with a measured varying magnetic field strength and / or other physical quantities.In certain embodiments, the lock detection sensor 420 may be sensitive to the influence and disturbances of an ambient magnetic field from other adjacent components, whether desired or unwanted. By way of example and without limitation, an unintended variation in a measured magnetic field strength based on a distribution of rotating components around the lock detection sensor 420 may reduce the accuracy and / or precision of the lock detection sensor assembly 410 detecting an axial distance between the armature 220 and the stator 230.

[0048] In certain embodiments, to enable detection of an axial distance between the armature 220 and the stator 230 by the lock detection sensor assembly 410, either the lock detection sensor 420 or the sensor target 430 may be coupled to the armature 220, or the lock detection sensor 420 or the sensor target 430 may be coupled to the stator 230.

[0049] By way of example and without limitation, according to certain embodiments, the lock detection sensor 420 may be rigidly attached to the reference frame of the stator housing, for example, via a sensor post 450. By way of example and without limitation, in certain embodiments, a sensor target 430, e.g., a magnetic target, may be rigidly connected to an axially movable armature 220, e.g., via a sensor target mount 435.

[0050] In certain embodiments, the axial position of the armature 220 may serve as a proxy for the locked or unlocked state and / or the relative axial position of the locking plate 140 relative to the locking gear 135, for example, based on the armature 220 and the locking plate 140 ideally being perfectly axially coupled in both directions. Such detection of the relative axial distance (effective) between the armature 220 and the stator 230 to determine a locked or unlocked state and / or the axial position of the locking plate 140 relative to the locking gear 135 may also be accomplished by other suitable devices that detect proximity and / or physical contact.

[0051] By way of example and not limitation, in ideal operation as previously described, when the stator 230 is de-energized, no rightward force can act on the armature 220 (in the frame of reference of Fig. 1). Accordingly, in certain embodiments and in accordance with the framework of Fig. 1, the return spring 150, which urges the locking plate 140 to the left, may cause the locking plate 140 to axially shift in that leftward direction, which in turn may exert a force on the armature 220 and correspondingly cause the armature 220 to axially shift to the left via the transfer pins 340. According to this non-limiting example, a correspondingly increased distance between the sensor target 430 (attached to the armature 220) and the lock detection sensor 420 (attached to the stator 230) may be interpreted as an unlocked state of the differential assembly 110.

[0052] Conversely, when the stator 230 is energized, a magnetic attraction force on the armature 220 may pull the armature 220 to the right, which may be transmitted through one or more of the slip rings 320 and transfer pins 340 to the locking plate 140, thereby achieving a locked condition of the differential assembly 110, the same particular embodiment in the same frame of reference of Fig. 1. According to this non-limiting example, the correspondingly reduced distance between the sensor target 430 (attached to the armature 220) and the lock detection sensor 420 (attached to the stator 230) may then be interpreted as a locked state of the differential assembly 110.

[0053] As previously mentioned, independent verification of a locked or unlocked condition, such as that provided by the lock detection sensor assembly 410, may be important for the safe and / or efficient operation of a vehicle. However, due to certain vehicle designs and / or operating conditions, the respective axial positions of the armature 220 and the lock plate 140 may not perfectly match, which may result in the lock detection being inaccurate in determining or interpreting the locked or unlocked condition of the differential assembly 110.

[0054] By way of example and not limitation, in certain embodiments and / or under certain operating conditions, it is possible for the locking plate 140 to unexpectedly and / or undesirably remain in a locked position even though the stator 230 is de-energized, thereby releasing the armature 220 to move away from the stator due to a restoring force, e.g., by the return spring 150 (in the frame of Fig. 1 to the left).

[0055] In certain embodiments, such a state of mismatched axial movement of the armature 220 and the locking plate 140 may be due to a so-called "torque trap." For example, and without limitation, a "torque trap" may be due to the applied torque, tooth engagement forces, and / or frictional forces between the locking plate 140 and its contact surfaces that cause the locking plate 140 to remain engaged with the locking gear 135, e.g., by such torques and / or forces exceeding the ability of the return spring 150 to separate the locking plate 140 from the locking gear 135.In such an undesirable and / or unexpected situation, for example, a lock detection sensor assembly 410 may incorrectly interpret an axial position of the armature 220 as indicating an unlocked differential, while the lock plate 140 may continue to maintain the differential assembly 110 in a locked state, e.g., by continued engagement with the lock gear 135.

[0056] In certain embodiments, it may be separately or additionally possible for the armature 220 (and thus also a component of the lock detection sensor assembly 410, such as the sensor target 430, which may be coupled to the armature 220) to tilt, rotate, offset, translate, or otherwise move due to vibrations, shocks, and other disturbances encountered during operation. Such positional disturbance, variation, and / or disturbance of the armature 220 and / or a coupled component of the lock detection sensor assembly 410 may cause the sensor detection to interpret a locked or unlocked state that is inconsistent with the actual locked or unlocked state of the differential assembly 110.A deviation in the positionability of the armature 220 relative to its design intent may be referred to as runout, which may result in a change in the ability to accurately detect a locking position of the differential assembly 110.

[0057] Therefore, it may be important to suitably cause the armature 220 to: (a) translate axially correctly and in close agreement with axial movement of the locking plate 140 in both the locked and unlocked states (e.g., by means of slip ring 320, transfer pins 340, and / or separately or additionally using other features), and (b) be controlled to remain concentric with the rotational axis of the differential assembly 110 and / or to withstand tilting, rotating, offsetting, and other movements due to disturbances during operation.

[0058] As previously mentioned, certain design features disclosed herein may be used to provide one or more of the following: (i) relative rotational movement (slip) between the armature 220 and the slip ring 320 to keep the armature 220 rotationally fixed relative to the rotating components of the differential assembly 110; (ii) transfer of axial forces and / or axial displacements between the armature 220 and the slip ring 320; (iii) more rigidly constraining the armature 220 to move in close axial alignment with the slip ring 320, the transfer pins 340, and / or the backup plate 140.

[0059] In special embodiments, as in Fig. 1 and in Fig. 2, the armature 220 may be radially clamped and / or guided by a surface of the slip ring 320 at the inner diameter of the armature 220. In some embodiments, the respective contact surfaces of the armature 220 and the slip ring 320 may not touch and / or may not completely coincide along one or both of their respective full axial lengths. In other embodiments, as in Fig. 4, a longer section or the entire inner diameter surface (ie, over the entire axial length) of the armature 220 can be guided at a contact surface with the slip ring 320.

[0060] In certain embodiments, the armature 220 may be supported, constrained, and / or guided along multiple dimensions. By way of example and without limitation, as shown in Fig. 2, the armature 220 may be connected at its inner diameter to a substantially flat portion of the slip ring 320 and / or axially clamped between a raised edge or lip portion of the slip ring 320 and / or by a snap ring 238. In certain embodiments, a longer portion or area of the entire inner diameter (i.e., along the entire axial length) of the armature 220 may be supported and / or guided at a contact point or contact surface with the slip ring 320.

[0061] The Fig. 6A and Fig. 6B show schematic enlarged side views of embodiments of electronically locking differential assemblies, illustrating and comparing specific design features according to certain embodiments.

[0062] In certain embodiments, the transmission pins 340 may be configured to be press-fitted into the locking plate 140. Separately or additionally, in certain embodiments, the transmission pins 340 may be configured to be press-fitted into the slip ring 320. One or both of the above features may separately or additionally restrict the axial travel of the armature 220 to follow the path of the locking plate 140 and / or otherwise be nearly equivalent, i.e., allow for greater consistency between the axial armature movement and the axial locking plate movement. In certain embodiments, one or more separate or additional features may be present, such as mechanical coupling features between the transmission pins 340 and the slip ring 320.By way of example and without limitation, additional features, devices, and / or methods may include interference fits, snap rings, keyways, and / or welds. In some embodiments, a mechanical connection may exist between the transfer pins 340 and the locking plate 140, e.g., through an interference fit, a snap ring, keyways, and / or welds.

[0063] In some embodiments, an additional component, such as a snap ring, may be used to further axially fix the fitting. Examples are described in Fig. 2, in which the snap ring 238 is located at the lower left corner of the armature (in the frame of reference of Fig. 2) to prevent the armature 220 from moving further to the left relative to the slip ring 320.

[0064] Fig. 7A shows a front perspective view of slip rings according to certain embodiments. As discussed herein, in certain embodiments, slip ring 320 may be designed and configured to perform one or more of the following functions: guiding and / or radially constraining armature 220 relative to the rotational axis of differential assembly 110; controlling and / or radially constraining stator housing 232 (with stator coil 234 therein) relative to the rotational axis of differential unit 110; enabling axial movement of armature 220 relative to stator housing 232; enabling armature 220 to slide (i.e., remain rotationally fixed) relative to the rotating components of differential assembly 110; thereby enabling stator housing 232 to rotationally slide (i.e., remain rotationally fixed) relative to the rotating components of differential assembly 110. to force the armature 220 to move in both directions, iein close agreement with one another, axially equivalent to the locking plate 140, optionally in conjunction with transfer pins 340 and further based on specific manufacturing / assembly techniques, e.g., press fitting; providing a symmetrical magnetic field to facilitate more accurate and / or precise detection of a locking or unlocking condition of the differential assembly 110 by the lock detection sensor assembly 410; focusing a magnetic field generated by the electronic actuator assembly 210 through a gap between the armature 220 and the stator 230. Accordingly, the slip ring 320 can be designed to provide the desired balancing of multiple requirements, several of which may conflict with one another.

[0065] In certain embodiments, slip ring 320 may be symmetrical about a longitudinal plane passing through the rotational axis of differential assembly 110 and lock detection sensor assembly 410 for lock detection to enable greater accuracy of lock detection. By way of example and without limitation, symmetry of slip ring 320 may refer to symmetry of the magnetic field based on slip ring 320 and / or magnetic field disturbance caused by slip ring 320. In certain embodiments, symmetry of slip ring 320 may be based on rotation of slip ring 320 about the rotational axis of differential assembly 110.

[0066] In special embodiments, as in Fig. 7A, as a non-limiting example, the slip ring 320 may include a bore 342 for each of one or more transmission pins 340 having a bore diameter configured to receive the respective transmission pin 340. In particular embodiments, as shown in the slip ring 320, one or more slots 322 may be present. In particular embodiments, one or more slots 322 may allow and / or enhance access to the transmission pins 340. In certain embodiments, the slot 322 may have a slot width 323 that is between one and ten times the bore diameter of the bore 342.

[0067] In particular embodiments, the slip ring 320 may include at least one axial groove or channel to allow the flow of a hydraulic fluid, such as oil. By way of example and without limitation, such a passage may provide improved lubrication. In certain embodiments, such as the oil flow channel 324 in Fig. 7A, an axial groove or channel may enable reduced hydraulic damping of the axial displacement of the slip ring assembly 310. An axial groove or channel for lubrication may, in certain embodiments, be combined with a corresponding device to enable reduced hydraulic damping.

[0068] As disclosed, certain embodiments incorporating the use of a slip ring 320 in conjunction with electronically locking differential assemblies 110 may provide performance benefits during operation under both design-conforming conditions and unexpected behavior in non-design-conforming situations. The use of a slip ring 320 in this context may separately or additionally provide advantages related to manufacturing, assembly, maintenance, repair, servicing, and / or interchangeability.

[0069] In particular embodiments, as previously discussed herein, the stator 230, including the stator housing 232 (and the stator coil 234 therein), may be rotationally fixed relative to certain rotating components of the differential assembly 110, such as a differential case. Separately or additionally, the armature 220 may be rotationally fixed relative to certain rotating components of the differential assembly 110 in several embodiments disclosed herein.

[0070] In certain embodiments, certain components may be non-rotatably supported relative to other rotating parts of the differential assembly 110 by rigidly connecting those components to one or more other non-rotatably supported members, such as an external structural member. A non-rotatably supported external structural member may be, for example, an axle housing, a cover, and / or an external casing. Some non-limiting examples of an axle housing 510 are shown in the Fig. 8, Fig. 11 and Fig. 14. A non-limiting example of a cover 515 is shown in Fig. 12 shown.

[0071] In certain embodiments, a structural element used to immobilize a particular component of the differential assembly 110 may be referred to herein as an anti-rotation element. In certain embodiments, the anti-rotation function may be performed by components specifically designed for this purpose, e.g., based on design requirements and packaging constraints. Anti-rotation may be provided, for example, by, but is not limited to, an anti-rotation tab and / or an anti-rotation bracket.

[0072] Based on design considerations regarding forces and space constraints in specific applications and vehicle integration schemes, certain embodiments may be advantageous. By way of example and without limitation, the Fig. 8 and Fig. 9 illustrates an embodiment of an anti-rotation bracket 275 configured to prevent rotation of the stator housing 232, wherein the anti-rotation bracket 275 is connected to an external support in the axle housing 510. In a particular embodiment shown in Fig. 11, a shorter anti-rotation bracket 275 is disclosed which, after assembly, can act by contact with a cover 515. A contact zone between the shorter anti-rotation bracket 275 and the assembled cover 515 is shown in the enlarged sectional view in Fig. 12. It will be appreciated that, although specific methods and devices for providing an anti-rotation function are illustrated, this disclosure contemplates all suitable devices and methods and / or combinations thereof for providing an anti-rotation function.

[0073] In certain embodiments, the armature 220 may be rotationally coupled to the stator housing 232 by a separate anti-rotation tab 270, as described without limitation in the Fig. 5, Fig. 13 and Fig. 14. In certain embodiments, the anti-rotation tab 270 may lock the armature 220 so that it is held rotationally fixed with respect to the stator housing 232 while allowing relative axial movement therebetween.

[0074] Component timing refers to the circumferential arrangement of concentric components relative to each other and / or to an external circumferential reference.

[0075] For example, in some embodiments, a lock detection sensor on the stator housing may be clocked to position it at a circumferentially determined location relative to a sensor target (see, for example, Fig. 2 or Fig. 5). Similarly, a sensor target on the armature can be clocked to position it correctly in relation to the lock detection sensor (e.g., in Fig. 5).

[0076] In certain embodiments, component timing may refer to the circumferential positioning of components, e.g., concentrically arranged components, relative to each other and / or relative to an external circumferential reference. By way of example and without limitation, in certain embodiments, a lock detection sensor 420 may be clocked with respect to the stator housing 232 to position the lock detection sensor 420 at a circumferentially determined location relative to a sensor target 430, which may be circumferentially co-located (see, e.g., Fig. 5). In certain embodiments, the sensor target 430 may be clocked based on the armature 220 to correctly position the sensor target 430 with respect to the lock detection sensor 420 (see, e.g., Fig. 5).

[0077] In particular embodiments, a tab or coupling tab may be used separately or in addition to the timing of the armature 220 relative to the stator housing 232. By way of example and without limitation, an anti-rotation tab 270, as shown in the Fig. 5 and Fig. 13, to rotatably couple the armature 220 to the stator housing 232 while allowing relative axial movement therebetween.

[0078] In special embodiments, a tab such as that shown in the Fig. 5 and Fig. 13, may be configured to rotatably couple the armature 220 to the stator housing 232 while allowing relative axial movement therebetween, may be used separately or additionally to clock the armature 220 in a fixed rotational position relative to a rotational position of the stator housing 232.

[0079] In certain embodiments, a combination of functions, such as anti-rotation, timing, and / or wire routing, as non-limiting examples, may be performed by one or more structures, which may be multifunctional structures. In certain embodiments, multifunctional structures may accommodate certain design and / or packaging constraints of the differential assembly 110.

[0080] As in the non-limiting example of Fig. 10, the timing for the electronic actuator assembly 210 and / or the lock detection sensor assembly 410 may be provided by a structural element, such as a bracket. In certain embodiments, a timing and / or anti-rotation bracket may be configured separately or additionally as a cable management bracket. By way of example and without limitation, the Fig. 10 may be configured to properly position one or more clocked components, such as the stator housing 232, and / or to constrain the clocked component relative to a conduit in the axle housing for routing electrical wires, such as the electrical conduits 240 for the electronic actuator assembly 210 and / or the electrical conduits 440 for the lock detection sensor assembly 410.

[0081] In some embodiments, multiple anti-rotation, timing, and / or wire guiding functions may be performed by one or more multifunctional structures to advantageously address design and packaging constraints.

[0082] As exemplified and without limitation in the Fig. 13 and Fig.14 by the bracket 280, a single structural member and / or an anti-rotation assembly including an elongated member, such as a bracket, may be used to perform combinations of functions. By way of example and without limitation, the illustrated bracket 280 may be configured to function as (a) an anti-rotation member (e.g., to restrict rotation of the stator housing 232 in this example by connecting the stator housing 232 to the axle housing 510); (b) as a clock (e.g., to position the lock detection sensor 420 relative to the sensor target 430 in this example), and / or (c) as a wire routing device (to route the electrical wiring between its main devices (e.g., the lock detection sensor assembly 410 and / or the electronic actuator assembly 210) and a conduit located, in this example, in the axle housing 510).In particular embodiments, such a torsion-proof wire housing retainer 280 may be fabricated from sheet metal. In certain embodiments, such a torsion-proof wire housing retainer 280 may be fabricated from other materials by other manufacturing means. Miscellaneous

[0083] The foregoing description of the embodiments is for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. While several embodiments of the apparatus, systems, and methods have been described in detail, including the best mode, those familiar with the art to which this disclosure relates will recognize various alternative designs and embodiments for practicing the teachings. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and may be used in a selected embodiment, even if not specifically shown or described.For example, it is possible that each of the features described in one of the embodiments may be combined with one or more other desired features from other embodiments, resulting in other embodiments not described in words or by reference to the drawings. It is to be understood that changes and modifications may be made by those skilled in the art within the scope of the disclosure, the illustrations, and / or the following claims. Such variations are fully intended herein and are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0084] The terms used in the claims should be construed to give them the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article "a" or "the" in introducing an element should not be construed to exclude a plurality of elements. Similarly, the mention of "or" should be construed such that the mention of "A or B" does not exclude "A and B" unless it is clear from the context or the preceding description that only one of A and B is intended. Furthermore, the phrase "at least one of elements A, B, and C" should be construed to mean one or more of a group of elements consisting of A, B, and C, and not to require at least one of each of the listed elements A, B, and C, whether A, B, and C are related as categories or otherwise.Furthermore, the mention of “A, B and / or C” or “at least one of A, B or C” should be interpreted to include any single entity of the listed elements, e.g., A, any subset of the listed elements, e.g., A and B, or the entire list of elements A, B and C.

[0085] The numerical ranges specified in this application should be interpreted to include the endpoints of the specified ranges. Certain axes, such as one or more rotational, transverse, and / or longitudinal axes, which may be omitted from some figures, should be interpreted to be present in every figure or situation in which they are referred to. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 400,615

[0001]

Claims

[1] Lockable differential assembly comprising: a locking plate disposed within a differential housing and rotatable about a rotational axis, the differential assembly configured to be in a locked state or an unlocked state based on selective axial engagement of the locking plate relative to a locking gear; an actuator assembly configured to be switchable between an energized state and a de-energized state, the actuator assembly comprising an armature and a stator, the stator comprising a stator coil disposed within a stator housing, wherein radial alignment of the stator is provided based on a first guide feature disposed on an outer diameter of the stator housing; and a slip ring assembly configured to axially translate in accordance with the locked state or the unlocked state of the differential assembly, and comprising: a slip ring cooperating with the armature at a slip surface configured to allow relative rotation between the slip ring and the armature; and one or more pins that rotatably connect the slip ring to the locking plate, wherein the slip ring assembly is configured to transmit an axial locking force from the actuator assembly to the locking plate when the actuator assembly is energized, wherein the slip ring assembly is configured to transmit an axial restoring force from the locking plate to the actuator assembly when the actuator assembly is de-energized. [2] The differential assembly of claim 1, wherein the differential case includes a second guide feature, and wherein the first guide feature cooperates with the second guide feature to facilitate radial alignment of the stator. [3] The differential assembly of claim 1, wherein the stator is further radially aligned due to the mutual engagement with the slip ring at an inner diameter of the stator housing. [4] The differential assembly of claim 1, further comprising a retaining ring configured to axially constrain the stator housing relative to the differential housing. [5] Differential assembly according to claim 4, wherein the retaining ring is a multi-piece retaining ring. [6] The differential assembly of claim 1, further comprising a lock detection sensor assembly having a sensor and a target, the lock detection sensor assembly configured to detect an axial distance between the stator and the armature. [7] The differential assembly of claim 6, wherein either the sensor or the target is coupled to the armature or to the stator. [8] The differential assembly of claim 6, further comprising an anti-rotation assembly having an extended member, wherein the stator housing of the actuator assembly is coupled to a non-rotating external structure by the extended member, wherein the extended member is configured to prevent rotation of the stator housing about the axis of rotation, and wherein the extended member is configured to carry the electrical wiring of the stator coil and the lock detection sensor assembly. [9] The differential assembly of claim 8, wherein the non-rotating external structure is an axle housing or a cover. [10] The differential assembly of claim 8, wherein the elongated member comprises a sheet metal structure. [11] The differential assembly of claim 8, wherein the anti-rotation assembly further comprises a second elongated member rotatably coupling the armature and the stator housing such that the second elongated member prevents rotation of the armature about the rotation axis. [12] The differential assembly of claim 11, wherein the second elongated member is configured to allow relative axial movement between the armature and the stator housing. [13] The differential assembly of claim 1, wherein energizing the actuator assembly comprises passing electrical current through the stator coil to generate a magnetic field, and wherein the armature experiences a magnetic force toward the stator coil based on the magnetic field generated when the actuator assembly is energized. [14] The differential assembly of claim 1, wherein the slip ring is configured to radially align the armature relative to the axis of rotation. [15] The differential assembly of claim 1, wherein the slip ring assembly further comprises one or more features to axially fix the armature relative to the slip ring. [16] The differential assembly of claim 15, wherein the one or more features comprise a groove provided in the slip ring or a raised edge. [17] The differential assembly of claim 15, wherein the one or more features comprise a washer or a snap ring. [18] An electronically lockable differential assembly capable of lock detection, the differential assembly comprising: a differential housing; a locking gear rotatably mounted in the differential housing; a locking plate rotatable about a rotational axis, the differential assembly being configured to be in a locked state or an unlocked state based on selective axial displacement of the locking plate relative to the locking gear; a biasing member configured to bias the locking gear axially away from the locking plate; an actuator assembly comprising a stator and an armature, the actuator assembly configured to be switchable between an energized state and a de-energized state; a lock detection sensor assembly comprising a sensor and a target, the lock detection sensor assembly configured to detect an axial distance between the stator and the armature; and a slip ring assembly configured to axially translate in accordance with the locked state or the unlocked state of the differential assembly, the slip ring assembly comprising: a slip ring cooperating with the armature at a slip surface configured to allow relative rotation between the slip ring and the armature; and one or more pins that rotatably connect the slip ring to the locking plate, wherein the slip ring assembly is configured to transmit an axial locking force from the actuator assembly to the locking plate when the actuator assembly is energized, wherein the slip ring assembly is configured to transmit an axial restoring force from the locking plate to the actuator assembly when the actuator assembly is de-energized, and wherein radial alignment of the stator is provided based on a first guide feature cooperatively engaging a second guide feature, the first guide feature being disposed on an outer diameter of a stator housing and the differential housing including the second guide feature. [19] The differential assembly of claim 18, wherein one of the sensor and the target is coupled to the armature and the other of the sensor and the target is coupled to the stator. [20] A method of assembling a lockable differential assembly, the method comprising: Providing a locking gear and a locking plate in a differential housing, the locking gear and the locking plate being rotatable about a rotational axis and being urged axially apart by a biasing member; rotatably coupling the locking plate to a slip ring via one or more pins, wherein a slip ring assembly comprises the slip ring and the one or more pins; Providing an actuator assembly having a stator and an armature, wherein the slip ring is axially coupled to the armature, a slip interface between the slip ring and the armature configured to allow relative rotation therebetween, wherein the armature is configured to translate axially toward the stator upon energization of the actuator assembly; radially aligning the stator based on a first guide feature cooperatively engaged with a second guide feature, wherein the first guide feature is disposed on an outer diameter of a stator housing and the differential housing includes the second guide feature; and Providing a lock detection sensor assembly comprising at least one sensor component coupled to each of the armature and the stator, the lock detection sensor assembly being configured to detect an axial distance between the stator and the armature, wherein the slip ring assembly is configured to transmit an axial locking force from the actuator assembly to the locking plate when the actuator assembly is energized, and wherein the slip ring assembly is configured to transmit an axial restoring force from the locking plate to the actuator assembly when the actuator assembly is de-energized.

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