Friction clutch mechanism for electronic locking differential

Abstract

The present disclosure relates to an electronic lock differential gear mechanism having a lock detection mechanism for sensing and indicating a locked state and an unlocked state of a lock mechanism. The electronic locking differential gear mechanism includes an electronic stator that, when activated, forms frictional contact with the grooved surface of the ramp collar, whereby the ramp collar rotates about the axis of the mechanism. The ramp of the ramp collar axially displaces the plurality of pushrods, which displaces and engages the locking collar with the locking gear, placing the mechanism in a locked state.

Description

Background Art

[0001] A vehicle driveline may include a differential mechanism that includes a gear set that allows torque to be applied differently to multiple wheels of the same axle during operation of the vehicle. In some cases (e.g., in low-traction road conditions such as ice, mud, snow, etc.), it may be desirable to include a locking mechanism in the differential so that all torque is transferred equally to both wheels of the axle. Locking differentials, including electronic locking differentials, are well known in the art. For a locking differential, a sufficient amount of drag torque may be required between the interacting components to achieve permanent engagement of the locking mechanism. Summary of the Invention

[0002] In some aspects, a locking mechanism is included in the differential mechanism so that all available torque is equally transferred to both wheels of the axle, locking the wheels to rotate synchronously with each other. The locking mechanism can include a rotatable ramp collar that contacts a stator housing surface. This contact generates a drag torque that changes the rotational speed of the ramp plate and causes the locking mechanism to engage. Surface features that increase friction and drag torque between the ramp collar and the stator housing surface can make locking more efficient and increase engagement durability and performance for a given duty cycle.

[0003] Thus, the present application describes, in one exemplary aspect, a differential assembly comprising: a first housing; a first half-shaft output portion; a second half-shaft output portion; a power input location; a gear set disposed within the first housing and operably connecting the first half-shaft output portion, the second half-shaft output portion, and the power input location; and an electrically activated locking assembly comprising a second housing mounted to the first housing and operable between a locked position and an unlocked position, wherein the first half-shaft output portion and the second half-shaft output portion are prevented from rotating relative to each other, and the first half-shaft output portion and the second half-shaft output portion are prevented from rotating relative to each other, and the first half-shaft output portion and the second half-shaft output portion are prevented from rotating relative to each other, The half-shaft output portions are rotatable relative to each other, wherein the locking assembly includes a stator mounted within a second housing, a rotatable ramp collar actuated by the stator, a plurality of push rods axially displaceable by rotation of the ramp collar, and a locking collar axially displaceable by movement of the plurality of push rods, wherein a grooved surface of the ramp collar is in frictional contact with the second housing when the locking assembly is in a locked condition, wherein the locking collar engages a locking gear of the gear set when the locking assembly is in a locked position, and wherein the locking collar is disengaged from the locking gear when the locking assembly is in an unlocked position.

[0004] In one aspect, the ramp collar of the differential assembly is located axially between the stator and the locking gear.

[0005] In one aspect, a ramp collar of a differential assembly includes one or more ramp valleys and one or more ramp peaks on a second surface opposite the grooved surface.

[0006] In one aspect, when the locking assembly of the differential assembly is in a locked condition, the plurality of push rods are axially displaced and contact the one or more ramp peaks at a first end.

[0007] In one aspect, the grooved surface of the differential assembly includes helical grooves.

[0008] In one aspect, the grooves of the differential assembly are machined into the ramp collar.

[0009] In one aspect, when the locking assembly of the differential assembly is in an unlocked condition, the grooved surface of the ramp collar is not in contact with the second housing.

[0010] In one aspect, when the locking assembly of the differential assembly is in a locked condition, the grooved surface of the ramp collar is in frictional contact with at least one interface surface of the second housing.

[0011] In one aspect, the second housing of the differential assembly is non-rotatable relative to the first housing.

[0012] In one aspect, activating the stator causes the ramp sleeve of the differential assembly to rotate about an axis.

[0013] In one aspect, the stator of the differential assembly is surrounded on at least two sides by the second housing, and the stator is held free from contact with the grooved surface.

[0014] The present application describes, in one exemplary aspect, a locking system for a differential assembly, the locking system comprising: a locking element of the differential assembly, operable between a locked state and an unlocked state; one or more push rods displaceable along the axis of the differential assembly, connected to a locking collar of the locking element at a first end and in contact with a rotatable ramp collar at a second end, wherein: the rotatable ramp collar is rotatable about the axis, the rotatable ramp collar includes one or more ramp valleys and one or more ramp peaks, and the one or more push rods are displaceable through the one or more ramp valleys and one or more ramp peaks; a stator mounted in a stator housing, wherein the rotatable ramp collar is actuated by the stator, wherein in the locked state, a grooved surface of the ramp collar is in frictional contact with the stator housing, wherein in the locked state, the locking collar engages with a locking gear of the locking element, and wherein in the unlocked state, the locking collar is disengaged from the locking gear.

[0015] In one aspect, the grooved surface of the locking system includes a helical groove.

[0016] In one aspect, when the locking assembly of the locking system is in the unlocked state, the grooved surface of the ramp collar does not contact the stator housing.

[0017] In one aspect, when the locking assembly of the locking system is in the locked state, the grooved surface of the ramp collar is in frictional contact with at least one interface surface of the stator housing.

[0018] In one aspect, the at least one interface surface of the locking system includes two concentric annular interface surfaces.

[0019] In one aspect, the stator activates the locking system to cause the ramp sleeve to rotate about the axis.

[0020] The present application describes, in one example aspect, a method of locking a differential assembly, the method comprising: receiving a voltage signal at a stator; rotating a ramp collar about an axis of the differential assembly via activation from the stator; contacting a grooved surface of the ramp collar with an interface surface of a stator housing, thereby generating a drag torque between the grooved surface and the interface surface; displacing a push rod along the axis by the rotation of the ramp collar, the push rod contacting the ramp collar at a first end; and displacing a locking collar of a locking element along the axis by the displacement of the push rod, wherein the locking collar is connected to the push rod at a second end.

[0021] In one aspect, the method further includes maintaining the stator housing in a non-rotating position.

[0022] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Non-limiting and non-exhaustive examples are described with reference to the following figures.

[0024] Figure 1 A perspective view of an electronic locking differential gear mechanism constructed in accordance with the principles of the present disclosure is shown, according to one example.

[0025] Figure 2 According to an example Figure 1 Side view of the electronic locking differential gear mechanism.

[0026] Figure 3 According to an example Figure 1 Cross-section of the electronic locking differential gear mechanism.

[0027] Figure 4 According to an example Figure 1Exploded perspective view of the electronic locking differential gear mechanism.

[0028] Figure 5 According to an example Figure 1 A close-up cross-section of a portion of the electronic locking differential gear mechanism, showing details of the ramp collar and stator assembly.

[0029] Figure 6 According to an example, a Figure 1 Rear perspective view of the ramp collar of the electronic locking differential gear mechanism.

[0030] Figure 7 According to an example, a Figure 1 Front perspective view of the ramp collar of the electronic locking differential gear mechanism.

[0031] Figure 8 According to an example, a Figure 1 Front view of the ramp collar of the electronic locking differential gear mechanism.

[0032] Figure 9 According to an example, a Figure 1 Rear view of the ramp collar of the electronic locking differential gear mechanism.

[0033] Figure 10 According to an example, a Figure 1 Side view of the ramp collar of the electronic locking differential gear mechanism.

[0034] Figure 11 According to an example, a Figure 1 Cross-section of the ramp collar of the electronic locking differential gear mechanism.

[0035] Figure 12 According to an example, a Figure 1 A close-up perspective cross-sectional view of the front surface of the ramp collar of the electronic locking differential gear mechanism.

[0036] Figure 13 According to an example, a Figure 1 A cross-sectional view of a surface groove on the front surface of a ramp collar of an electronic locking differential gear mechanism.

[0037] Figure 14 According to an example, a Figure 1 A rear perspective view of the stator assembly of the locking differential gear mechanism.

[0038] Figure 15 According to an example, a Figure 1 A front perspective view of the stator assembly of the locking differential gear mechanism.

[0039] Figure 16 According to an example, a Figure 1 Rear view of the stator assembly of the locking differential gear mechanism.

[0040] Figure 17 According to an example, a Figure 1 Front view of the stator assembly of the locking differential gear mechanism.

[0041] Figure 18 According to an example, a Figure 1 Side view of the stator assembly of the electronic locking differential gear mechanism.

[0042] Figure 19 According to an example, a Figure 1 Cross-sectional view of the stator assembly of the electronic locking differential gear mechanism.

[0043] Figure 20 A schematic diagram illustrating a vehicle in which an electronic locking differential gear mechanism may be used. DETAILED DESCRIPTION

[0044] In the following detailed description, reference is made to the accompanying drawings, which form a part thereof, and in the accompanying drawings, specific embodiments or examples are shown by way of illustration. These aspects may be combined, other aspects may be utilized, and structural changes may be made without departing from the present disclosure. The examples may be practiced as methods, systems, or devices. Therefore, the following detailed description should not be understood in a restrictive sense, and the scope of the present disclosure is defined by the appended claims and their equivalents.

[0045] A vehicle driveline can include a differential mechanism comprising a gear set that allows torque to be applied differently to multiple wheels on the same axle during vehicle operation. In some aspects, a drive shaft, which transmits torque from an engine or motor, can transmit torque to a transmission ring gear (e.g., a flange mounted to the transmission) via a drive pinion, which engages a ring gear. The ring gear meshes with a plurality of internal pinion gears (or spider gears) 52. In one aspect, the internal pinion gears 52 mesh with two side gears 54, 56, each of which also has internal splines 58, 60 corresponding to a halfshaft output (e.g., corresponding to the left rear axle 111 and the right rear axle 112). In one aspect, the ring gear is located outside of the housing or casing, and the gear set including the internal pinion gears 52 and the side gears 54, 56 (which operatively connects the halfshaft outputs to the power input location (drive shaft)) is located within the housing / casing.

[0046] In some aspects, a locking mechanism is included in the differential mechanism, enabling all available torque to be equally transferred to both wheels of the axle, locking the wheels to rotate synchronously with each other. In some aspects, the locking mechanism is electrically actuated to move between a locked state and an unlocked state. In some aspects, the electrical actuation includes an electrically powered stator. In some aspects, the vehicle driver or other user can activate the electrical locking mechanism via a button, switch, or similar interactive device.

[0047] refer to Figure 20 , shows an example vehicle driveline according to the above description and the present disclosure, within which the disclosed electronic locking differential gear assembly 10 may be used. As shown, the vehicle driveline is provided with a powerplant 106 (such as an internal combustion engine or an electric motor), a transmission 107, and a power transfer unit 108. The powerplant, transmission, and power transfer unit are operatively connected at the front of the vehicle to transmit torque directly to the left front axle 100 and the right front axle 101, so that the wheels 102 and 103 receive torque via wheel hubs 115 and 116 to provide traction to the vehicle. Via mechanisms in the power transfer unit 108 (such as hypoid gears and pinions), a drive shaft 109 receives the torque and transmits it to the rear of the vehicle. As shown, an all-wheel drive coupling 120 is connected to the drive shaft 109, and a rear drive unit 110 can accommodate the disclosed locking differential assembly 10 within the rear differential assembly. As discussed further herein, the locking differential assembly 10 can operate in an open mode or a locked mode. In the open mode, the left rear wheel 113 can rotate at a different speed than the right wheel 114 via the wheel hub 117 and the left rear axle 111. Similarly, the right rear wheel 114 can rotate at a different speed than the left rear wheel 113 via the wheel hub 118 and the right rear axle 112. In the locked mode, the left rear wheel 113 and the right rear wheel 114 receive the same torque because the left rear axle 111 and the right rear axle 112 are locked together to prevent relative rotation via internal components in the rear differential. An example of a differential mechanism is described in more detail in U.S. Patent No. 9,657,827 B2, the entire disclosure of which is incorporated herein by reference, except for any definitions, disclaimers, disclaimers, and inconsistencies therein.

[0048] The figure shows an electronic locking differential gear mechanism (e.g., differential assembly) 10, which includes a cam / ramp actuated electronic locking function. The gear set 50 of the electronic locking differential gear mechanism 10 is located in the housing 20 (refer to Figure 1 ), and in some examples, torque can be transmitted to gear set 50 via a ring gear mounted to flange 23. Therefore, flange 23 can be referred to as a power input location.

[0049] In one aspect, the electric actuator mechanism (e.g., an electrically actuated locking assembly or locking element) 12 of the electronic locking differential gear mechanism 10 includes a stator housing 40. The stator housing 40 is mounted to a housing (e.g., a casing) 20. The stator housing 40 is operable between a locked state in which the first and second half-shaft outputs (e.g., the left rear axle 111 and the right rear axle 112) are prevented from rotating relative to each other and an unlocked state in which the first and second half-shaft outputs are enabled to rotate relative to each other. The stator housing 40 includes an electric stator 16 that, in some aspects, causes a ramped collar 18 to be rotationally actuated relative to the stator housing 40. In one aspect, the ramped collar 18 rotates about an axis X (reference Figure 3 ).

[0050] In the open, unlocked position, the ramp collar 18 and the stator housing 40 do not contact each other and a gap 70 may exist between them (see FIG. Figure 5 In the locked position, when a voltage signal is received at the stator 16, the ramp collar 18 and the stator housing 40 will frictionally contact each other. The front interface surface 66 of the ramp collar 18 will contact the interface surface 64 of the stator housing.

[0051] In some aspects, the stator housing 40 has a substantially U-shaped cross-section (see Figure 5 、 Figure 19 ). The stator (coil) 16 is mounted within the stator housing 40 and is surrounded on three sides by the stator housing. The stator housing 40 may have two annular interface surfaces 64 that face (and, in the locked position, contact) a front interface surface 66 of the ramp collar 18. An unenclosed surface 68 of the stator coil 16 is recessed into the stator housing 40 relative to the interface surfaces 64 and does not contact the front interface surface 66 even in the locked state.

[0052] In the locked position, when the ramp collar 18 and the stator housing 40 are in frictional contact with each other, the front interface surface 66 and the interface surface 64 are in frictional contact with each other. This frictional contact generates a drag torque between the ramp collar 18 and the stator housing 40, which reduces the rotational speed of the ramp collar 18 relative to the housing 20, which in turn causes the push rod 14 to be actuated (as described below) and ultimately locks the differential assembly 10. If the friction between the front interface surface 66 and the interface surface 64 is insufficient (e.g., due to component misalignment, oil hydroplaning, or slippery surfaces), the resulting drag torque may be insufficient for locking.

[0053] In some aspects, the stator housing 40 is configured to include a high-hardness material and is configured such that the interface surface 64 has a low roughness. In some examples, the interface surface 64 is characterized by an Ra value of 0.5 μm or less. In some examples, the interface surface 64 is characterized by an Rz value of 4.0 μm or less. In some examples, the interface surface 64 is characterized by an Ra value of 3.2 μm or less. In some examples, the interface surface 64 is characterized by a flatness value of 0.13 μm or less.

[0054] In some aspects, the front interface surface 66 of the ramp collar 18 is configured to have a low hardness surface effect and a high roughness surface effect. In some aspects, at least with reference to Figure 7 、 Figure 8 、 Figure 12 and Figure 13 The front interface surface 66 of the ramp collar 18 includes a groove 72 that can increase physical friction and / or disrupt the oil film to maintain the friction surface. In some aspects, the groove 72 is machined into the front interface surface 66. In some aspects, the groove 72 is machined into a spiral design. The spiral design can be counterclockwise. The spiral design can run in a counterclockwise direction from an inner perimeter 74 of the front interface surface 66 to an outer perimeter 76 of the front interface surface 66.

[0055] In some aspects, the groove 72 maintains friction between the front interface surface 66 and the interface surface 64 even if the peaks of the groove 72 gradually smooth out due to wear, especially when the differential assembly 10 is held in a locked state for an extended period of time. In some aspects, the depth of the spiral groove 72 is defined so that the peaks of the groove are present on the front interface surface 66 to maintain the desired friction (e.g., maintaining sufficient friction for engagement and locking even when wear occurs on the peaks). This can contribute to the service life of the ramp collar 18 and the reliability and efficiency of the locking mechanism.

[0056] refer to Figure 12 and Figure 13 , the spiral groove 72 includes a plurality of peaks and valleys. In the specific example shown, the valley is arc-shaped, but other shapes (e.g., rectangular) are contemplated in other examples. In some examples, the radius R of the arc can be 0.4 mm, plus or minus a mechanical tolerance. In some examples, the radius R of the arc is between 0.3 mm and 0.5 mm, plus or minus a mechanical tolerance. In some examples, the radius R of the arc is between 0.2 mm and 0.8 mm, plus or minus a mechanical tolerance. The radius of the top nose of the tool used to machine the spiral groove 72 onto the front interface surface 66 can affect the radius R.

[0057] The distance D1 between the center points of the peaks of the spiral groove 72 can be substantially uniform throughout the spiral groove 72. In some examples, the peak-to-peak distance D1 can be 0.6 mm, plus or minus a mechanical tolerance. In some examples, the distance D1 can be between 0.5 mm and 0.7 mm, plus or minus a mechanical tolerance. In some examples, the distance D1 can be between 0.3 mm and 0.9 mm, plus or minus a mechanical tolerance. In some examples, the distance D1 can be between 0.6 mm and 0.8 mm, plus or minus a mechanical tolerance.

[0058] In some examples, the peak can be flat, pointed, or rounded. In the specific example shown, the peak is flat. In some examples, the width D2 of the flat top of the peak of the spiral groove 72 is 0.16 mm, plus or minus mechanical tolerances. In some examples, the peak width D2 is 0.12 mm, plus or minus mechanical tolerances. In some examples, the peak width D2 can be between 0.12 mm and 0.16 mm, plus or minus mechanical tolerances. In some examples, the peak width D2 can be between 0.11 mm and 0.17 mm, plus or minus mechanical tolerances. In some examples, the peak width D2 can be between 0.07 mm and 0.18 mm, plus or minus mechanical tolerances. In some examples, the peak width D2 can be 0.14 mm, plus or minus mechanical tolerances. In some examples, the peak width D2 can be between 0.10 mm and 0.14 mm, plus or minus mechanical tolerances. In some examples, peak width D2 may be between 0.14 mm and 0.18 mm, plus or minus mechanical tolerances.

[0059] In some examples, the depth D3 of the valley of the spiral groove 72 is 0.10 mm, plus or minus a mechanical tolerance. In some examples, the peak depth D3 is 0.07 mm, plus or minus a mechanical tolerance. In some examples, the peak depth D3 may be between 0.07 mm and 0.10 mm, plus or minus a mechanical tolerance. In some examples, the peak depth D3 may be between 0.06 mm and 0.11 mm, plus or minus a mechanical tolerance. In some examples, the peak depth D3 may be between 0.05 mm and 0.12 mm, plus or minus a mechanical tolerance. In some examples, the peak depth D3 may be between 0.085 mm, plus or minus a mechanical tolerance. In some examples, the peak depth D3 may be between 0.05 mm and 0.085 mm, plus or minus a mechanical tolerance. In some examples, the peak depth D3 may be between 0.085 mm and 0.12 mm, plus or minus a mechanical tolerance.

[0060] In some aspects, the groove 72 maintains friction between the front interface surface 66 and the interface surface 64 at least in part by breaking up the oil film, which can help maintain drag torque and improve the stability of the locking performance under high-speed conditions. This can also contribute to the service life of the ramp collar 18 and the reliability and efficiency of the locking mechanism.

[0061] At least for reference Figure 4 、 Figure 6 and Figure 10 In one aspect, the ramp collar 18 includes one or more ramps (e.g., one or more locations with a greater or lesser length in the axial direction). The ramp collar 18 includes one or more ramp valleys 17, where the axial length of the ramp collar 18 is minimized. The ramp collar 18 includes one or more ramp peaks 19, where the axial length of the ramp collar 18 is maximized.

[0062] In some examples, the electronic locking differential 10 includes at least one actuating push rod 14. Although three push rods 14 are depicted in the example embodiment of the Figures (see FIG. Figure 4 ), but other embodiments may include more than three push rods 14 or fewer than three push rods 14. The push rods 14 are operatively coupled to the motorized stator 16 via a ramp collar 18. In some aspects, the push rods 14 can be generally cylindrical or rod-shaped in shape. The push rods 14 contact the ramp collar 18 at the ends of the push rods 14. In some aspects, the push rods 14 pass through a hole in the housing 20 and do not rotate relative to the housing 20.

[0063] Pushrod 14 is coupled to locking collar 24. In some examples, pushrod 14 is coupled to locking collar 24 via a press-fit design, a threaded connection, or any suitable fastening or attachment means, or in some examples, without any rigid connection.

[0064] The push rod 14 is axially displaceable along (parallel to) the axis X of the differential assembly 10. The push rod 14 is axially displaceable by rotation of the ramp collar 18. The locking collar 24 is axially displaceable by the displacement movement of the push rod 14. By using the terms axial or axially displaceable, it is intended to define a direction parallel to the longitudinal axis X of the differential assembly 10.

[0065] The locking collar 24 includes teeth 26 formed on its inner diameter that selectively engage with external teeth 27 of the locking gear 28. When the teeth 26 of the locking collar 24 engage with the external teeth 27 of the locking gear 28, the electronic locking differential gear mechanism 10 is placed in the locked position. When the teeth 26 of the locking collar 24 disengage from the external teeth 27 of the locking gear 28, the electronic locking differential gear mechanism 10 is placed in the unlocked position.

[0066] The locking collar 24 is disposed within a cavity defined at an outer boundary by the gear housing 20 and at an inner boundary by the locking gear 28 .

[0067] In some aspects, locking collar 24 is biased into the disengaged or unlocked position by a spring or other biasing member.

[0068] In one aspect, each of the push rods 14, which contacts the ramp collar 18 at its end, is in an initial position (corresponding to an unlocked state) with its end in contact with the ramp valley 17. When the ramp collar 18 rotates about the axis 2, each of the push rods 14 is axially displaced toward the locking gear 28 because the end in contact with the ramp collar 18 is moved to a maximum displacement position (corresponding to a locked state) in contact with the ramp peak 19. This moves the locking collar 24 toward the locking gear 28, causing the teeth 26 and the outer teeth 27 to engage.

[0069] In some examples, the electronic locking differential gear mechanism 10 includes a sensor assembly to determine a locking state / condition (eg, locked or unlocked) of the electronic locking differential gear mechanism 10 .

[0070] In one aspect, the stator housing 40 includes one or more anti-rotation ears or tabs 46 formed thereon or attached thereto. The stator housing 40 can be stationary (non-rotatable) relative to the housing 20 .

[0071] In example use, the electric actuator mechanism 12 is in a normal unlocked state. For example, the electric actuator mechanism can be biased to the unlocked state by a spring 78 or other biasing element. In the unlocked state, the locking collar 24 moves axially and disengages from the locking gear 28.

[0072] When the motorized stator 16 is activated / energized (which may be in response to a control signal from a control module or may be actuated in response to a user activating a switch), the ramp collar 18 rotates about the axis X and at least one push rod 14 is axially displaced. Figure 4 As shown in FIG, a bearing assembly 62 may be disposed within the inner peripheral opening of the stator housing 40 and the inner disc portion of the ramp collar 18 to facilitate relative movement between the components. The locking collar 24 is moved by displacement of one or more push rods 14 to engage the locking gear 28, which causes the electronic locking differential gear mechanism 10 to lock.

[0073] In some aspects, after the motorized stator 16 is de-energized, the electronic locking differential gear mechanism 10 returns to the unlocked position (eg, by the biasing element or spring 78 ), and the gap 70 will reappear between the front interface surface 66 and the interface surface 64 .

[0074] For purposes of this application, terms such as "left," "right," "front," "back," "upper," "lower," "upward," and "downward" are intended to be descriptive with reference to the orientations shown in the drawings for clarity and are not intended to be limiting, but examples that may be practiced and included within the scope of the claims may include examples of systems and devices in different orientations.

[0075] While specific uses of the present technology have been illustrated and discussed above, the disclosed technology can be used in a wide variety of environments according to many examples of the present technology. The above discussion is not intended to indicate that the disclosed technology is only suitable for implementation within the environments shown and described above. For example, although some of the techniques described herein are primarily described in the context of sealing battery housings, the techniques disclosed herein are generally applicable to sealing components.

[0076] This disclosure describes aspects of the present technology with reference to the accompanying drawings, in which only some of the possible aspects are shown. However, other aspects may be implemented in many different forms and should not be construed as limited to the aspects set forth herein. Rather, these aspects are provided so that this disclosure will be thorough and complete and will fully convey the scope of the possible aspects to those skilled in the art.

[0077] As will be appreciated, the various aspects described herein with respect to the accompanying drawings are not intended to limit the present technology to the specific aspects described. Therefore, additional configurations may be used to practice the technology herein, and / or some aspects described may not be included, without departing from the methods and systems disclosed herein.

[0078] Similarly, where operations of a process are disclosed, the purpose of describing these operations is to illustrate the present technology and is not intended to limit the present disclosure to a particular sequence of operations. For example, the operations may be performed in a different order, two or more operations may be performed simultaneously, additional operations may be performed, and the disclosed operations may not be included without departing from the present disclosure. Furthermore, each operation may be performed via one or more sub-operations. The disclosed process may be repeated.

[0079] Although specific aspects are described herein, the scope of the present technology is not limited to these specific aspects. Those skilled in the art will recognize other aspects or improvements that are within the scope of the present technology. Therefore, specific structures, actions, or operations are disclosed only as illustrative aspects. The scope of the present technology is defined by the following claims and any equivalents therein.

Claims

1. A differential assembly comprising: a) a first housing; b) a first half-shaft output portion; c) a second half-shaft output portion; d) Power input position; e) a gear set disposed within the first housing and capable of operatively connecting the first half-shaft output, the second half-shaft output, and the power input location; and f) an electrically activated locking assembly comprising a second housing mounted to the first housing and operable between a locked position in which the first and second half-shaft outputs are prevented from rotating relative to each other and an unlocked position in which the first and second half-shaft outputs are enabled to rotate relative to each other; The locking assembly includes a stator mounted in the second housing, a rotatable ramp collar actuated by the stator, a plurality of push rods axially displaceable by rotation of the ramp collar, and a locking collar axially displaceable by movement of the plurality of push rods; wherein, when the locking assembly is in the locked position, the grooved surface of the ramp collar is in frictional contact with the second housing; wherein, when the locking assembly is in the locking position, the locking collar engages with the locking gear of the gear set; Wherein, when the locking assembly is in the unlocking position, the locking collar is disengaged from the locking gear.

2. The differential assembly according to claim 1, wherein: The ramp collar is located axially between the stator and the locking gear.

3. The differential assembly according to claim 1, wherein: The ramp collar includes one or more ramp valleys and one or more ramp peaks on a second surface opposite the grooved surface.

4. The differential assembly according to claim 3, wherein: When the locking assembly is in the locked position, the plurality of push rods are axially displaced and contact the one or more ramp peaks at a first end.

5. The differential assembly according to claim 1, wherein: The grooved surface includes helical grooves.

6. The differential assembly according to claim 5, wherein: The helical groove is machined into the ramp collar.

7. The differential assembly according to claim 1, wherein: When the locking assembly is in the unlocked position, the grooved surface of the ramp collar is not in contact with the second housing.

8. The differential assembly according to claim 1, wherein: When the locking assembly is in the locked position, the grooved surface of the ramp collar is in frictional contact with at least one interface surface of the second housing.

9. The differential assembly according to claim 1, wherein: The second housing cannot rotate relative to the first housing.

10. The differential assembly according to claim 1, wherein: Activating the stator causes the ramp sleeve to rotate about an axis.

11. The differential assembly according to claim 1, wherein: The stator is surrounded on at least two sides by the second housing, and wherein the stator is held out of contact with the slotted surface.

12. A locking system for a differential assembly, the locking system comprising: The locking element of the differential assembly is operable between a locked state and an unlocked state; One or more push rods, displaceable along the axis of the differential assembly, connected at a first end to a locking collar of the locking element and in contact with a rotatable ramp collar at a second end, wherein: The rotatable ramp collar is rotatable about the axis, The rotatable ramp collar includes one or more ramp valleys and one or more ramp peaks, and The one or more push rods are displaceable through the one or more ramp valleys and the one or more ramp peaks; a stator mounted in a stator housing, wherein the rotatable ramp collar is actuated by the stator; wherein, in the locked state, the grooved surface of the ramp-type collar is in frictional contact with the stator housing; wherein, in the locked state, the locking collar is engaged with the locking gear of the locking element; and Wherein, in the unlocked state, the locking collar is disengaged from the locking gear.

13. The locking system according to claim 13, wherein: The grooved surface includes helical grooves.

14. The locking system according to claim 13, wherein: When the locking assembly is in the unlocked state, the grooved surface of the ramp collar does not contact the stator housing.

15. The locking system according to claim 13, wherein: When the locking assembly is in the locked state, the grooved surface of the ramp collar is in frictional contact with at least one interface surface of the stator housing.

16. The locking system according to claim 15, wherein: The at least one interface surface includes two concentric annular interface surfaces.

17. The locking system according to claim 13, wherein: Activating the stator causes the ramp sleeve to rotate about the axis.

18. A method of locking a differential assembly, the method comprising: receiving a voltage signal at the stator; rotating the ramp sleeve about the axis of the differential assembly via activation from the stator; contacting the grooved surface of the ramp collar with an interface surface of a stator housing to generate a drag torque between the grooved surface and the interface surface; The push rod is displaced along the axis by rotation of the ramp collar, the push rod being in contact with the ramp collar at a first end; as well as By displacing the push rod, a locking collar of the locking element is displaced along the axis, wherein the push rod is connected to the locking collar at a second end.

19. The method according to claim 18, further comprising: The stator housing is held in a non-rotating position.

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