ELECTRONIC LOCKING DIFFERENTIAL
The locking differential assembly with a movable locking collar and electromagnet actuation addresses uneven torque distribution issues, improving vehicle performance by ensuring even torque distribution across wheels with different traction.
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2026-03-12
AI Technical Summary
Existing differentials fail to effectively distribute torque evenly between wheels with significantly different coefficients of friction, leading to undesirable vehicle performance.
A locking differential assembly with a movable locking collar and armature assembly, actuated by an electromagnet, allows for controlled engagement and disengagement with a ratchet wheel to manage differential wheel speeds.
Ensures even torque distribution between wheels with varying traction conditions, enhancing vehicle performance and stability.
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Abstract
Description
REFERENCE TO RELATED REGISTRATIONS
[0001] This application claims priority over the Indian provisional patent application with serial number 202311037170, filed on May 30, 2023, the disclosure of which is hereby incorporated in its entirety by reference. BACKGROUND
[0002] During normal operation of a motor vehicle, it is common for not all four wheels to rotate at the same speed. Different wheel speeds occur most frequently when the vehicle is cornering, but can also be caused by braking or uneven road conditions. To compensate for these different wheel speeds and simultaneously distribute power to two wheels, a differential is configured to allow different wheel speeds between the driven wheels. The differential enables the wheels to rotate at different speeds while distributing torque to each wheel.
[0003] While this solution may be satisfactory under certain driving conditions, it is unsatisfactory when one of the driven wheels is traveling on a surface with a much lower coefficient of friction than the surface on which the other wheel(s) are traveling. Such conditions can prevent the transmission of torque to a wheel with more traction, resulting in undesirable vehicle performance. A locking mechanism can be provided to lock the differential and prevent different wheel speeds, thus ensuring that torque is distributed evenly between the two wheels, at least under certain circumstances. SUMMARY
[0004] According to certain aspects of the disclosure, a differential assembly includes a locking arrangement that is movable relative to a gear housing. The locking arrangement comprises a locking collar, an armature assembly, and a pin. The locking collar is movable relative to a ratchet wheel within the gear housing between a locked position and a non-locking position. The locking collar engages with the ratchet wheel to jointly connect the locking collar and the ratchet wheel in a rotationally fixed manner in the locked position. The locking collar is rotatable relative to the ratchet wheel in the non-locking position. The armature assembly includes an armature frame that is axially movable between a first and a second position. The armature frame is biased in the first position. The armature frame is formed from iron. A first end of the pin is axially fixed to the locking collar or locking sleeve, and a second end of the pin is axially fixed to the armature assembly.
[0005] In certain embodiments, the anchor assembly has a positioning collar that is axially attached to the anchor frame. The positioning collar is rotatable relative to the anchor frame. The second end of the pin is axially attached to the positioning collar.
[0006] In some examples, the second end of the pen is pressed into the positioning collar.
[0007] In other embodiments, the second end of the pin is held on the positioning collar by a snap ring.
[0008] In certain embodiments, the pin is one of several pins. A first end of each pin is axially attached to the locking collar, and a second end of each pin is axially attached to the anchor assembly.
[0009] According to other aspects of the disclosure, a method for operating a locking differential comprises: exciting an electromagnet to attract an iron-containing armature assembly against a preload force from a first position to a second position; and moving a locking collar in accordance with the armature assembly by pulling on a pin connecting the locking collar to the armature assembly, such that the locking collar moves from a non-locking position to a locking position.
[0010] In certain embodiments, the method also includes switching off the electromagnet so that the preload force can move the armature arrangement back to the first position.
[0011] According to other aspects of the disclosure, a limited-slip differential comprises a stator with an electromagnet, a gearbox housing rotatable relative to the stator, a differential gear set with a locking mechanism, and a locking assembly mounted on the gearbox housing. The locking assembly comprises a locking collar, an armature assembly, a preload element, and a pin. The locking collar is located inside the gearbox housing. The locking collar is movable relative to the locking mechanism between a locked position and a non-locked position. The armature assembly is located outside the gearbox housing. The armature assembly comprises an armature frame that is rotationally fixed relative to the stator. The armature frame is axially movable relative to the stator between a first and a second position. The armature frame is configured to move into the second position when the electromagnet is energized.The preload element is positioned between the stator and the armature frame to preload the armature frame into the first position. The pin extends between the locking collar and the armature assembly. The pin is configured to maintain a gap between the locking collar and the armature frame, ensuring that the locking collar is in the non-locked position when the armature frame is in the first position and in the locked position when the armature frame is in the second position.
[0012] In certain embodiments, the preload element is arranged outside the differential housing.
[0013] In certain embodiments, the armature assembly has a positioning collar located outside the gearbox housing. The pin is fixed axially relative to the positioning collar, and the positioning collar is fixed axially relative to the armature frame.
[0014] In some examples, the anchor frame has the protruding flange that is axially fixed between the groove defined by the positioning collar and a snap ring that axially secures the pin to the collar.
[0015] In other embodiments, the positioning collar has the protruding flange that extends into a groove defined by the anchor frame in order to axially fix the positioning collar to the anchor frame.
[0016] A multitude of further inventive aspects are set forth in the following description. These inventive aspects may relate to individual features or combinations of features. It is understood that both the preceding general description and the following detailed description are merely exemplary and explanatory and do not limit the broad inventive concepts on which the embodiments disclosed herein are based. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings, which are included in and form part of the description, illustrate various aspects of the present revelation. A brief description of the drawings is as follows: Fig. Figure 1 is a perspective view of an example of a locking differential configured according to the principles of the present disclosure. Fig. Figure 2 is a first perspective view of the locking differential. Fig. 1, wherein the components are separated from each other outwards. Fig. Figure 3 is a second perspective view of the locking differential. Fig. 1, where the components exploded away from each other. Fig. 4 is a cross-section through the locking differential made of Fig. 1. Fig. Figure 5 is a perspective view of a first embodiment of a locking arrangement which is axially movable relative to a gearbox housing of the locking differential, while being rotationally fixed relative to the gearbox housing. Fig. Figure 6 is a cross-sectional view of the locking arrangement. Fig. 5. Fig. Figure 7 is a perspective view of the cross-section from Fig. 4. Fig. Figure 8 is an enlarged view of part of Fig. 7. Fig. Figure 9 is another perspective view of the cross-section from Fig. 4. Fig. 10 is an enlarged view of part of Fig. 9. Fig. Figure 11 is a cross-sectional view of a second example embodiment of a locking arrangement in which the pins are attached to a positioning collar. Fig. Figure 12 shows the second end of an example pin of the locking arrangement. Fig. 11, which is attached to the positioning collar by a clamp that engages in a frame of the locking arrangement. Fig. Figure 13 is an enlarged view of part of Fig. 4. Fig. Figure 14 shows a weld seam that forms the second end of the pin. Fig. 13 additionally attached to the positioning collar. Fig. 15 shows the pen Fig. 13, which is held by a first-type fastening on the positioning collar. Fig. 16 shows the pen Fig. 13, which is held on the positioning collar by a fastening element of a second type. Fig. 17 shows the pen Fig. 13, which is held on the positioning collar by a third-type fastening element. Fig. Figure 18 shows an alternative design of the locking arrangement in which the preloading element is located inside the gearbox housing. DETAILED DESCRIPTION
[0018] Detailed reference will now be made to exemplary aspects of the present disclosure, which are illustrated in the accompanying drawings. Where possible, the same reference numerals are used in the drawings to refer to identical or similar parts.
[0019] Fig. Figure 1 shows a limited-slip differential 100 for a vehicle. The limited-slip differential 100 has a gearbox housing 102 (e.g., a gearbox sleeve 104 and an end cap 106) configured to rotate about a longitudinal axis L of the gearbox housing 102. The torque for the limited-slip differential 100 can be transmitted through an input ring (not shown) to a flange 105 of the gearbox housing 102. The gearbox housing 102 defines annular hub sections 108 and 110 to which the left and right axles are coupled. A pair of bearing sets (not shown) arranged on the annular hub sections 108 and 110 provides rotational support for the rotating differential device 100 relative to an outer differential housing or "carrier" (also not shown). The rotatable housing 102 defines a gear chamber 112 in which a differential gear set 114 is arranged.
[0020] The locking differential 100 can be operated in a locked mode or an unlocked mode. In locked mode, one or both side gears 126, 128 of the differential gear set 114 are locked against rotation relative to the gearbox housing 102. In unlocked mode, the side gears 126, 128 can rotate freely relative to the gearbox housing 102. For example, the side gears 126, 128 can be configured to rotate independently of each other about the longitudinal axis L of the gearbox housing 102. In some embodiments, the locking differential 100 is manually switched between locked and unlocked modes by a user. In other embodiments, the locking differential 100 is automatically switched between locked and unlocked modes (e.g., by a vehicle microprocessor based on a detected operating state of the vehicle).
[0021] The locking differential 100 has a locking arrangement 118 that can be switched between a locking configuration and a non-locking configuration. In the locking configuration, the locking arrangement 118 prevents independent rotation of the side gear 126 relative to the gearbox housing 102. In the non-locking configuration, the locking arrangement 118 allows independent rotation of the side gear 126 relative to the gearbox housing 102.
[0022] In certain embodiments, the locking assembly 118 comprises an armature assembly 119 and a locking collar 122, which are spaced apart from each other by one or more pins 124. The pins 124 are configured to maintain a constant distance between the armature assembly 119 and the locking collar 122. The locking collar 122 engages with the gear housing 102, so that the locking collar 122 rotates together with the gear housing 102. The locking collar 122 is configured to engage with a locking gear 130 when the locking assembly 118 is in the locked configuration. The locking collar 122 is disengaged from the locking gear 130 when the locking assembly 118 is in the non-locked configuration.
[0023] The armature assembly 119 has an armature frame 138 that is rotationally fixed relative to a stator 134. The armature frame 138 is axially movable relative to the stator 134 between a first and a second position. The stator 134 is located outside the gearbox housing 102. For example, the stator 134 can form a ring that surrounds the annular hub section 110. The gearbox housing 102 rotates relative to the stator 134. A snap ring 136 holds the stator 134 axially to the gearbox housing 102 (e.g., to the annular hub section 110). The locking collar 122 is located inside the gearbox housing 102. The pins 124 extend through the gear housing 102 between the locking collar 122 and the armature assembly 119. In some examples, the pins 124 are guided through narrow passages defined by the gear housing 102.In other examples, the pins 124 are defined by the gearbox housing 102, which defines through-channels 103 in which the pins 124 slide without touching the inner surfaces of the through-channels 103. The armature assembly 119 also has a positioning collar 120 on which the pins 124 are received. The positioning collar 120 is configured to rotate relative to the armature frame 138 while remaining axially fixed relative to the armature frame 138.
[0024] In certain embodiments, the locking assembly 118 is biased into the non-locking configuration by a preload element 140 (e.g., a wave spring). In certain embodiments, the locking assembly 118 is moved from the unlocked configuration to the locked configuration using an electromagnet 132 against the preload of the spring 140. In certain examples, the armature frame 138 is formed from a ferrous material. When the electromagnet 132 is energized, it attracts the armature frame 138, causing it to move axially along the axis L relative to the gearbox housing 102. The armature frame 138 moves axially with a portion of the locking assembly 118 as a unit, thereby moving the locking collar 122 axially into the locked configuration.
[0025] In certain embodiments, the electromagnet 132 is arranged on the stator 134. The stator 134 is located outside the gearbox housing 102. The armature assembly 119 is also located outside the gearbox housing 102. For example, the armature frame 138 and the positioning collar 120 can be annular elements surrounding the annular hub section 110. In some embodiments, the preload element 140 is located outside the gearbox housing 102. In certain such examples, the preload element 140 is located between the stator 134 and the armature frame 138. For example, an axial end of the preload element 140 can contact the armature frame 138 (e.g., a catch surface 156), while an opposite axial end of the preload element 140 contacts the stator 134 (see, for example, [reference]). Fig. 4) In other embodiments, the preload element 140 is arranged inside the gearbox housing 102. For example, the preload element 140 can be arranged between the locking collar 122 and an inner shoulder 141 of the gearbox housing 102. In such examples, the preload element 140 pushes the locking collar 122 away from the inner shoulder 141 and thereby pulls the pins 124, which pull the positioning collar 120 against the armature frame 138 to pull the armature frame 138 away from the electromagnet 132.
[0026] With reference to the Fig. 5-6 The locking arrangement 118 is mounted such that it moves uniformly relative to the gear set and the gearbox housing 102. In certain embodiments, the locking collar 122 has an outer circumference configured to engage an inner surface of the gearbox housing 102 in order to connect the locking collar 122 to the gearbox housing 102 in a rotationally fixed manner, while the locking collar 122 can move axially relative to the gearbox housing 102. In certain embodiments, the locking collar 122 has one or more tabs 142 that slide along corresponding grooves 144 defined by the gearbox housing 102 (e.g., by the gearbox casing 104). The engagement between the tabs 142 and the grooves 144 prevents rotation between the locking collar 122 and the gearbox housing 102. The grooves 144 are sufficiently long to accommodate the movement of the locking collar 122 between the locked and non-locked configurations.
[0027] In certain embodiments, the locking collar 122 is also configured to engage with the locking gear 130 in the locking configuration. In certain examples, the locking collar 122 has an inner circumference that defines teeth 146 or other projections that engage with the teeth of the locking gear 130. In certain examples, the locking gear 130 is formed around an outer circumference of the lateral gear 126. In the locking configuration, the locking collar 122 is axially positioned so that it is radially aligned sufficiently with the locking gear 130 to engage the teeth 146 with the locking gear 130. The interaction between the teeth 146 and the locking gear 130, as well as the interaction between the lugs 142 and the grooves 144, causes the locking gear 130, and thus the lateral gear 126, to rotate together with the gear housing 102. In the non-locking configuration (see e.g. Fig. 4) The locking collar 122 is axially displaced from its radial alignment with the locking gear 130, so that the teeth 146 of the locking collar 122 are not engaged with the locking gear 130. Accordingly, the locking gear 130 and thus the side gear 126 can rotate independently of the gearbox housing 102 and the locking collar 142.
[0028] In certain embodiments, the anchor frame 138 of the locking arrangement 118 has a first axial end oriented towards the gear set and an opposing second axial end oriented away from the gear set. The anchor frame 138 defines an annular groove 150 at the first axial end. For example, the anchor frame 138 may have an axial extension 155 in which the annular groove 150 is defined (see, for example, Figure 1). Fig. 6) An annular open surface of the groove 150 is oriented radially outwards from the longitudinal axis of the differential 100. The second axial end of the anchor frame 138 defines the catch surface 156 for the preload element 140 (see e.g. Fig. 6).
[0029] Fig. Figures 5-10 illustrate one possible way in which the locking assembly 118 can be assembled. The positioning collar 120 has a radially inwardly directed flange 152 which is configured to extend into the groove 150 of the anchor frame 138 when the locking assembly 118 is assembled (see, for example, Figure 5-10). Fig. 6) The engagement between the flange 152 and the groove 150 axially fixes the positioning collar 120 and the armature frame 138 relative to each other. When the frame 138 is attracted to the stator 134 by the electromagnet 132, the armature frame 138 pulls the positioning collar 120 with it. In certain embodiments, the positioning collar 120 can be formed from several parts (e.g., see Figure 1). Fig. 5) to facilitate the mounting of the positioning collar 120 to the anchor frame 138. In the example shown, the positioning collar 120 is formed from a first part 120a and a second part 120b.
[0030] The pins 124 extend between opposing first and second ends 124a, 124b. The first ends 124a are axially attached to the locking collar 122. In the Fig. In the example shown in Figures 5-10, the first ends 124a of the pins 124 are held on the locking collar 122 by means of clamps 160 (e.g., snap rings). For example, the first end 124a of a pin 124 can extend through one of the eyelets 142 of the locking collar 122 and through a snap ring 160 (see, for example, Figure 5-10). Fig. 8) In certain embodiments, the tabs 142 that hold the pins 122 are larger than the other tabs 142. In other embodiments, the first ends 124a of the pins 124 can be held on the locking collar 122 by press fits, threads, adhesive, welds, etc.
[0031] The second ends 124b are axially attached to the positioning collar 120. In the Fig. In the examples shown in Figures 5-10 and 13, the second ends 124b of the pins 124 are pressed into the positioning collar 120. In other embodiments, the second ends 124b of the pins 124 can be welded to the positioning collar 120 (see weld W) (see e.g. Fig. 14). For example, the pins 124 can be pressed into the positioning collar 120 with welds W. In other examples, the second ends 124b of the pins 124 can be attached to the positioning collar 120 with fasteners. Alternatively, in Fig. Figure 15 shows an example of a screw-like fastener F1 for attaching a pin 124 to the positioning collar 120; an example of a threaded pin fastener F2 is shown in Figure 15. Fig. Figure 16 shows how to attach a pin 124 to the positioning collar 120; and an example of a cotter pin fastening P is shown in Figure 16. Fig. Figure 17 shows how to attach a pin 124 to the positioning collar 120. A threaded connection between the pin 124 and the positioning collar 120 is shown in Fig. 18 shown.
[0032] Fig. Figures 11-12 illustrate another possible way in which the locking arrangement 118 can be assembled. The positioning collar 120 has a radially inwardly directed flange 152 that does not extend into the groove 150 of the frame 138. Rather, the flange 152 is formed by an annular groove defined on the side of the positioning collar 120 facing the stator 134. The axial extension 155 of the armature frame 138 runs in the groove 166, while the positioning collar 120 and the pins 124 rotate relative to the armature frame 138 (see, for example, Figure 11-12). Fig. 12). The second ends 124b of the pins 124 are held axially on the positioning collar 120 by means of clamps 162 (e.g. snap rings).
[0033] In certain embodiments, the clamps 162 extend parallel to the flange 152. In certain embodiments, the clamps 162 are dimensioned such that they extend radially outward from the pin ends 124b and into the groove 150 of the armature frame 138. Accordingly, a portion of the armature frame 138 is clamped between the radial flange 152 of the positioning collar 120 and the clamp 162. When the frame 138 is moved axially toward the electromagnet 132, the armature frame 138 pulls the clamps 162, which in turn pull the pins 124, which in turn pull the locking collar 122. In other embodiments, the second ends 124b of the pins 124 can be held on the positioning collar 120 by clamps, threads, adhesive, welds, etc.
[0034] The first ends 124a of the pins 124 are pressed into the locking collar 122. For example, the first ends 124a can terminate halfway through the locking collar 122. In certain embodiments, the first ends 124a are pressed into the eyelets 142 of the locking collar 122. In other embodiments, the first ends 124a of the pins 124 can be held to the locking collar 122 by clips, threads, adhesive, welds, etc.
[0035] Examples of revelation can be described using the following aspects.
[0036] Aspect 1. A differential assembly comprising the following: a stator with an electromagnet; a gearbox housing configured to rotate relative to the stator; a differential gear set arranged inside the gearbox housing, wherein the differential gear set has a locking gear; a locking arrangement attached to the gearbox housing, wherein the locking arrangement comprises the following: a locking collar arranged inside the gearbox housing, wherein the locking collar is movable relative to the locking gear between a locking position and a non-locking position; an armature arrangement arranged outside the gearbox housing, wherein the armature arrangement has an armature frame which is rotationally fixed relative to the stator, wherein the armature frame is axially movable relative to the stator between a first and a second position, wherein the armature frame is configured to move into the second position when the electromagnet is excited; a preloading element arranged between the stator and the armature frame to preload the armature frame into the first position; and a pin extending between the locking collar and the anchor assembly, wherein the pin is configured to maintain a distance between the locking collar and the anchor frame such that the locking collar is in the non-locking position when the anchor frame is in the first position, and the locking collar is in the locking position when the anchor frame is in the second position.
[0037] Aspect 2. The differential assembly according to Aspect 1, wherein the preload element is arranged outside the gearbox housing.
[0038] Aspect 3. The differential assembly according to Aspect 1, wherein the preload element has a first axial end that engages with the stator and a second axial end that engages with the armature frame.
[0039] Aspect 4. The differential assembly according to aspect 1, wherein the preload element comprises a wave spring.
[0040] Aspect 5. The differential assembly according to one of aspects 1 to 4, wherein the armature assembly has a positioning collar arranged outside the gearbox housing, wherein the pin is fixed axially relative to the positioning collar and the positioning collar is fixed axially relative to the armature frame.
[0041] Aspect 6. The differential assembly according to aspect 5, wherein either the anchor frame or the positioning collar has a protruding flange and the other part, i.e. either the anchor frame or the positioning collar, defines a groove that accommodates the protruding flange.
[0042] Aspect 7. The differential assembly according to aspect 6, wherein the anchor frame has the protruding flange and wherein the protruding flange is axially fixed between the groove defined by the collar and a snap ring which axially fixes the pin to the positioning collar.
[0043] Aspect 8. The differential assembly according to aspect 6, wherein the positioning collar has the protruding flange; and wherein the protruding flange extends into the groove defined by the anchor frame to axially fix the collar to the anchor frame.
[0044] Aspect 9. The differential assembly according to aspect 5, wherein the positioning collar is configured to engage directly with the anchor frame when the anchor frame is moved into the second position.
[0045] Aspect 10. The differential assembly of Aspect 1, wherein the pin engages directly in the anchor frame when the anchor frame is moved into the second position.
[0046] Aspect 11. The differential assembly according to aspect 1, wherein the pin is pressed into the locking collar.
[0047] Aspect 12. The differential assembly according to one of aspects 1 to 11, wherein the pin is one of several pins extending between the locking collar and the anchor assembly.
[0048] Aspect 13. A locking arrangement for a locking differential, wherein the locking arrangement comprises the following: a locking collar which is movable relative to a ratchet wheel of a locking differential between a locking position and a non-locking position, wherein the locking collar engages with the ratchet wheel to jointly connect the locking collar and the ratchet wheel in a rotationally fixed manner in the locking position, wherein the locking collar is rotatable relative to the ratchet wheel in the non-locking position; an anchor arrangement with an anchor frame that is axially movable between a first and a second position, wherein the anchor frame is prestressed in the first position and is made of an ferrous material; and a pin extending between a first and a second end, wherein the first end of the pin is axially attached to the locking collar and the second end of the pin is axially attached to the anchor arrangement.
[0049] Aspect 14. The locking arrangement according to aspect 13, wherein the anchor arrangement has a positioning collar which is axially attached to the anchor frame, wherein the positioning collar is rotatable relative to the anchor frame; and wherein the second end of the pin is axially attached to the positioning collar.
[0050] Aspect 15. The locking arrangement according to aspect 14, wherein the second end of the pin is pressed into the positioning collar.
[0051] Aspect 16. The locking arrangement of Aspect 14, wherein the second end of the pin is held by a snap ring on the positioning collar.
[0052] Aspect 17. The locking arrangement according to one of aspects 13-16, wherein the pin is one of several pins, each of the pins extending between a respective first end and a respective second end, the first end of each pin being axially attached to the locking collar and the second end of each pin being axially attached to the anchor arrangement.
[0053] Aspect 18. The locking arrangement according to one of aspects 13-17, wherein the anchor frame is pre-tensioned into the first position by a pre-tensioning element located on a side of the anchor frame opposite the pin.
[0054] Aspect 19. The locking arrangement according to one of Aspects 13-18, further comprising a stator holding an electromagnet, the electromagnet being configured to move the armature arrangement into the second position when the electromagnet is excited.
[0055] Aspect 20. Method for operating a locking differential that has the following features: the excitation of an electromagnet to attract an iron-containing armature assembly against a preload force from a first position to a second position; and Moving a locking collar in accordance with the anchor arrangement by pulling on a pin that connects the locking collar to the anchor arrangement, so that the locking collar moves from a non-locking position to a locking position.
[0056] Aspect 21. The method according to aspect 20, which further includes switching off the electromagnet to allow the preload force to move the armature arrangement back to the first position.
[0057] Having described the preferred aspects and embodiments of the present disclosure, a person skilled in the art could easily conceive of modifications and equivalents of the disclosed concepts. However, it is intended that such modifications and equivalents be included within the scope of the claims set forth herein.
Claims
[1] A differential assembly comprising the following: a stator with an electromagnet; a gearbox housing configured to rotate relative to the stator; a differential gear set arranged inside the gearbox housing, wherein the differential gear set has a locking gear; a locking device attached to the gearbox housing, wherein the locking device comprises the following: a locking collar arranged inside the gearbox housing, wherein the locking collar is movable relative to the locking gear between a locking position and a non-locking position; an armature arrangement arranged outside the gearbox housing, wherein the armature arrangement has an armature frame which is rotationally fixed relative to the stator, wherein the armature frame is axially movable relative to the stator between a first and a second position, wherein the armature frame is configured to move into the second position when the electromagnet is excited; a prestressing element configured to prestress the anchor frame into the first position; and a pin extending between the locking collar and the anchor assembly, wherein the pin is configured to maintain a distance between the locking collar and the anchor frame such that the locking collar is in the non-locking position when the anchor frame is in the first position, and the locking collar is in the locking position when the anchor frame is in the second position. [2] Differential assembly according to claim 1, wherein the preload element is arranged outside the gearbox housing. [3] Differential assembly according to claim 2, wherein the preload element has a first axial end that engages with the stator and a second axial end that engages with the armature frame. [4] Differential assembly according to claim 1, wherein the preload element is arranged inside the gearbox housing. [5] Differential assembly according to one of claims 1 to 4, wherein the armature arrangement has a positioning collar arranged outside the gearbox housing, wherein the pin is fixed axially relative to the positioning collar and the positioning collar is fixed axially relative to the armature frame. [6] Differential assembly according to claim 5, wherein either the anchor frame or the positioning collar has a projecting flange and the other part, i.e. either the anchor frame or the positioning collar, defines a groove that accommodates the projecting flange. [7] Differential assembly according to claim 6, wherein the anchor frame has the protruding flange; and wherein the protruding flange is axially fixed between the groove defined by the collar and a snap ring which axially fixes the pin to the positioning collar. [8] Differential assembly according to claim 6, wherein the positioning collar has the protruding flange; and wherein the protruding flange extends into the groove defined by the anchor frame to axially fix the collar to the anchor frame. [9] Differential assembly according to claim 5, wherein the positioning collar is configured to engage directly with the anchor frame when the anchor frame is moved into the second position. [10] Differential assembly according to claim 1, wherein the pin engages directly in the anchor frame when the anchor frame is moved into the second position. [11] The differential assembly according to claim 1, wherein the pin is pressed into the locking collar. [12] Differential assembly according to one of claims 1 to 11, wherein the pin is one of several pins extending between the locking collar and the anchor arrangement. [13] A method for operating a locking differential, comprising the following: the excitation of an electromagnet to attract an iron-containing armature assembly against a preload force from a first position to a second position; and Moving a locking collar in accordance with the anchor arrangement by pulling on a pin that connects the locking collar to the anchor arrangement, so that the locking collar moves from a non-locking position to a locking position. [14] Method according to claim 13, further comprising switching off the electromagnet to allow the preload force to move the armature arrangement back to the first position. [15] A locking arrangement for a locking differential, wherein the locking arrangement comprises: a locking collar which is movable relative to a ratchet wheel of a locking differential between a locking position and a non-locking position, wherein the locking collar engages in the ratchet wheel to jointly connect the locking collar and the ratchet wheel in a rotationally fixed manner in the locking position, wherein the locking collar is rotatable relative to the ratchet wheel in the non-locking position; an anchor arrangement with an anchor frame that is axially movable between a first and a second position, wherein the anchor frame is prestressed in the first position and is made of an ferrous material; and a pin extending between a first and a second end, wherein the first end of the pin is axially attached to the locking collar and the second end of the pin is axially attached to the anchor arrangement. [16] Locking arrangement according to claim 15, wherein the anchor arrangement has a positioning collar which is axially attached to the anchor frame, wherein the positioning collar is rotatable relative to the anchor frame; and wherein the second end of the pin is axially attached to the positioning collar. [17] Locking arrangement according to claim 16, wherein the second end of the pin is pressed into the positioning collar. [18] Locking arrangement according to claim 16, wherein the second end of the pin is held on the positioning collar by a snap ring. [19] Locking arrangement according to one of claims 15 to 18, wherein the pin is one of several pins, each of the pins extending between a respective first end and a respective second end, the first end of each pin being axially attached to the locking collar and the second end of each pin being axially attached to the anchor arrangement. [20] Locking arrangement according to one of claims 15 to 19, further comprising a stator holding an electromagnet, wherein the electromagnet is configured to move the armature arrangement into the second position when the electromagnet is excited, wherein the armature frame is biased into the first position by a biasing element arranged on a side of the armature frame opposite the pin.