Electromagnetic actuator for an electromagnetically actuated non-slip differential, electromagnetically actuated non-slip differential, and vehicle

Abstract

The invention relates to an electromagnetic actuator for an electromagnetically actuated non-slip differential. The electromagnetic actuator comprises an electromagnet, an armature and a sensor target. The armature and the sensor target are arranged such as to lie radially outside the electromagnet.

Description

[0001] Electromagnetic actuator for an electromagnetically actuated limited-slip differential, electromagnetically actuated limited-slip differential and vehicle

[0002] The present invention relates to an electromagnetic actuator for an electromagnetically actuated limited-slip differential, an electromagnetically actuated limited-slip differential and a vehicle.

[0003] A limited-slip differential is a device in a vehicle that allows the wheels to operate at different speeds, for example, to improve maneuverability in corners. A limited-slip differential can improve drive to both wheels in certain situations, such as poor road conditions or off-road driving.

[0004] An electronically controlled limited-slip differential, also known as an "eLocker," allows the driver to electronically engage or disengage the locking function. This can be particularly useful when the vehicle is traveling over difficult terrain and additional grip is required. Electronic control allows the driver to adjust the differential's behavior depending on the current driving conditions.

[0005] A limited-slip differential, for example, can be an electromagnetically actuated locking claw of a differential. For safety reasons, position sensing of the locking claw state may be necessary. For example, the position of the axially movable locking claw can be detected using a sensor. This makes it possible to determine whether the locking claw, and thus the eLocker, is locked or open. Installing a position sensor can be complicated by various structural limitations. Therefore, there is a need to provide an improved electromagnetically actuated limited-slip differential, in particular an improved electromagnetic actuator.

[0006] The object of the invention is achieved by an electromagnetic actuator for an electromagnetically actuated limited-slip differential, an electromagnetically actuated limited-slip differential, and a vehicle according to the independent claims. According to a first aspect, an electromagnetic actuator for an electromagnetically actuated limited-slip differential is proposed. The electromagnetic actuator comprises an electromagnet, an armature, and a sensor target. The armature and the sensor target are arranged radially outwardly of the electromagnet. This allows the radially required installation space to be reduced. In particular, it is possible to dispense with extending the armature for arranging the sensor target along the electromagnet. This allows a dimension of the armature and thus of the electromagnetic actuator to be reduced in both the radial and axial directions.

[0007] In one embodiment, the electromagnet, the armature, and the sensor target can be arranged in an axially overlapping manner. The axial overlap of the armature, sensor target, and electromagnet can reduce the axial expansion of the limited-slip differential.

[0008] In one embodiment, the sensor target can be at least partially circumferential. In particular, the sensor target can be completely circumferential. Due to the at least partially circumferential design of the sensor target, a position sensor mounted so as to rotate relative to the differential housing can detect the sensor target at different angles of rotation of the sensor target relative to the position sensor. This can improve position determination using the sensor target.

[0009] In one embodiment, the electromagnetic actuator can further comprise a locking claw. The locking claw can be frictionally connected to the armature, so that a torque can be transmitted from the armature to the locking claw. This means that the locking claw can absorb a rotation from the armature. Rotation of the armature can thus be reduced or stopped by transmitting force to the locking claw. A force transmission for changing the torque of the armature can thus take place via the fastening area with the locking claw.

[0010] In one embodiment, the locking claw can have a raised portion on a radial end face. The raised portion can have a through-opening for arranging a fastening means. The armature can have a fastening region. The fastening region can be designed to receive the fastening means, so that the armature can be fastened to the locking claw by the fastening means, which can extend through the raised portion of the locking claw. This advantageously creates a force-fit connection between the armature and the locking claw.

[0011] In one embodiment, the electromagnetic actuator may further comprise a position sensor. The position sensor may be decoupled from the rotation of the sensor target. By decoupling the rotation of the sensor target from the position sensor, the design or arrangement of the position sensor can be simplified.

[0012] According to a second aspect of the invention, an electromagnetically actuated limited-slip differential is proposed. The limited-slip differential comprises a differential housing and an electromagnetic actuator as described above. The sensor target is connected to the differential housing in a rotationally fixed manner. Because the sensor target is connected to the differential housing in a rotationally fixed manner, the design of the limited-slip differential can be simplified. For example, decoupling between the sensor target and the differential housing, so that the sensor target is rotationally fixed relative to the differential housing, can be omitted. Furthermore, the rotationally fixed arrangement of the sensor target increases the freedom of arrangement of the sensor target. For example, the sensor target can be designed to form a positive fit with the armature.

[0013] In one embodiment, the limited-slip differential may further comprise a fastening means. The fastening means may establish a frictional connection between the armature and the locking claw. This allows torque to be appropriately transmitted from the armature to the locking claw.

[0014] According to a third aspect of the invention, a vehicle is proposed. The vehicle comprises an electric machine configured to drive the vehicle, wherein the electric machine comprises an electromagnetically actuated limited-slip differential as described above. In one embodiment, the vehicle may further comprise a disconnect system. The electromagnetic actuator or the electromagnetically actuated limited-slip differential, in combination with the disconnect system, may be configured to decouple the electromagnetic machine from a drivetrain, such that a connection between the electromagnetic machine and the axle is completely decoupled. As a result, a mass moment of inertia acting on the electromagnetic machine from the drivetrain can be reduced or avoided.

[0015] The present invention will be described below by way of example only, with reference to the accompanying figures. They show:

[0016] Figs. 1a and 1b show different views of an electromagnetic actuator 100 for an electromagnetically actuated limited-slip differential;

[0017] Figs. 2a and 2b show different views of an electromagnetically actuated limited-slip differential;

[0018] Figs. 3a -3b show longitudinal sectional views of a limited-slip differential according to Fig. 2 with open locking claw and closed locking claw;

[0019] Figs. 4a-4c show different views of a limited-slip differential according to the invention;

[0020] Figs. 5a-5f show a limited-slip differential according to the invention in comparison with a limited-slip differential from the prior art;

[0021] Figs. 6a and 6b show the limited-slip differential according to the invention in comparison with a limited-slip differential from the prior art analogous to Fig. 5;

[0022] Fig. 7 shows an embodiment of a vehicle; and Fig. 8 shows a schematic representation of a combination of an electromagnetic actuator with a disconnect.

[0023] Figs. 1a and 1b show various views of an electromagnetic actuator 100 for an electromagnetically actuated limited-slip differential. Fig. 1 shows a longitudinal sectional view of the electromagnetic actuator 100. Fig. 1B shows a partial longitudinal sectional view of the electromagnetic actuator 100. The actuator 104 comprises an electromagnet 130, an armature 110, and a sensor target 120. The armature 110 and the sensor target 120 are arranged radially outwardly of the electromagnet 130.

[0024] This allows the required radial installation space to be reduced.

[0025] Furthermore, by arranging the armature 110 and the sensor target 120 on a radial outer side, the armature 110 and the sensor target 120 can be integrated. This allows the functions of the armature 110 and the sensor target 120 to be combined in a single subcomponent. For example, the actuation function (e.g., by means of the mechanically movable armature 110) and the sensing function (e.g., by means of movable sensor targets) can be implemented in a single subcomponent.

[0026] The radially outer arrangement of the armature 110 allows for further advantages in addition to the possible functional integration of the armature 110 and the sensor target 120. For example, the functional integration can enable a smaller axial installation space requirement. For example, as shown in Fig. 1, the sensor target 120 can be arranged in a recess or cutout of the armature 110.

[0027] Furthermore, positioning the armature 110 radially outside the electromagnet 130 can enable a smaller radial installation space requirement (see also Fig. 6). Furthermore, a reduction in the installation space requirement can enable the integration of a larger electromagnet or coil in the same overall installation space (see also Fig. 6). This allows for higher actuating forces and faster switching times.

[0028] In particular, a simplified and / or more compact design can be achieved compared to the prior art, in which an actuator armature is positioned radially inward and guided on the differential carrier or cover. In the prior art, the position sensor is always positioned radially outward. Since the position of the locking claw is to be sensed directly, it is necessary to establish a positive or non-positive connection between the locking claw, armature, and sensor target. A radially inward arrangement requires an "L-shaped" system architecture. This can require more space.

[0029] In one embodiment, the electromagnet 130, the armature 110, and the sensor target 120 can be arranged in an axially overlapping manner. The axial overlap of the armature, sensor target, and electromagnet can reduce the axial expansion of the limited-slip differential. This allows for a gain in installation space in the axial direction (see also Fig. 6).

[0030] In one embodiment, the sensor target 120 can be at least partially circumferential. In particular, the sensor target 120 can be completely circumferential. Because the sensor target 120 can be at least partially circumferential, the sensor target 120 can be detected in various positions of the sensor target 120 by a position sensor 122, which is decoupled from rotation by the sensor target 120. In particular, the sensor target 120 can be configured such that it can be detected by the position sensor 122 regardless of the position of the sensor target 120 relative to the position sensor 122. For example, the sensor target 120 can be annular.

[0031] As can be seen in Fig. 1b, the at least partially rotating sensor target 120 can be sensed by the position sensor 122 independently of a relative rotation of the sensor target 120. Accordingly, by means of the at least partially rotating sensor target 120, detection by a position sensor 122, which is decoupled from a rotation of the sensor target 120, can be improved.

[0032] In one embodiment, the actuator 100 may further comprise a position sensor 122. The position sensor 122 may be decoupled from a rotation of the sensor target 120. By decoupling a rotation of the position sensor 122, an arrangement of the position sensor 122 may be simplified. For example, a Hall sensor or a capacitive sensor may be used as the position sensor 122. In one embodiment, the actuator 100 may further comprise a locking claw 150. The locking claw 150 may be frictionally connected to the armature 110 so that a torque can be transmitted from the armature 110 to the locking claw 150. That is, the locking claw 150 can absorb a rotation from the armature 110. As a result, rotation of the armature 110 and the sensor target 120 can be reduced or stopped by the force-locking connection with the locking claw 150.

[0033] In one embodiment, the locking claw 150 can have a raised portion 152 on a radial end face. The raised portion 152 can have a through-opening 154 for arranging a fastening means. The armature 110 can have a fastening region 156. The fastening region 156 can be configured to receive the fastening means, so that the armature 110 can be fastened to the locking claw 150 by the fastening means, which can extend through the raised portion of the locking claw 150. This advantageously creates a force-fit connection between the armature 110 and the locking claw 150.

[0034] Figs. 2a and 2b show different views of an electromagnetically actuated limited-slip differential 202. Fig. 2a shows a longitudinal sectional view of the electromagnetically actuated limited-slip differential 202. Fig. 1B shows a partial longitudinal sectional view of the electromagnetically actuated limited-slip differential 202. The limited-slip differential 202 includes a differential housing 140 and an electromagnetic actuator 100, e.g., the electromagnetic actuator 100 as described with reference to Fig. 1. The actuator 104 includes an electromagnet 130, an armature 110, and a sensor target 120. The sensor target 120 is rotationally fixedly connected to the differential housing 140.

[0035] The rotationally fixed arrangement of the sensor target 120 simplifies the design of the limited-slip differential 120. In particular, it eliminates the need to decouple rotation of the differential housing 140 from the sensor target 120.

[0036] As can be seen in Fig. 2b, the at least partially rotating sensor target 120 can be sensed by the position sensor 122 independently of a relative rotation of the sensor target 120. Accordingly, the at least partially rotating sensor target 120 can improve detection of a sensor target 120 that is non-rotatably connected to the differential housing 140.

[0037] Furthermore, the limited-slip differential 202 may include further components such as a cable duct 232 for the electromagnet 130, a wave spring 260 for transmitting force to the locking claw 150 and / or an axle bevel gear 270.

[0038] In one embodiment, the limited-slip differential 202 may further include a fastening means 258. The fastening means 258 may establish a frictional connection between the armature 110 and the locking claw 150. The fastening means 258 may, for example, be a screw connection, a press fit, or a retaining ring.

[0039] The limited-slip differential can, for example, be a planetary differential. The number of planets can be selected as appropriate.

[0040] Figs. 3a-3b show longitudinal sectional views of a limited-slip differential 200 according to Fig. 2 with the locking claw 150 open (Fig. 3a) and the locking claw 150 closed (Fig. 3b). The limited-slip differential 200 may be a limited-slip differential, such as that described with Fig. 2. The limited-slip differential 200 may include an actuator as described with reference to Fig. 1. That is, the actuator may include an electromagnet 130, an armature 110, and a sensor target 120. A sleeve 312, in conjunction with a wave spring 260, may adjust the position of the armature 110.

[0041] As can be seen in Fig. 3a, the electromagnet 130 may not be energized. In this case, the electromagnet 130, i.e., the sleeve 312, cannot cause the armature 110 to deflect. The armature 110 may be in position 1, as indicated by 1. In this case, the locking claw 150 may be opened by the wave spring 260. This means that the wave spring 260 can exert a force on the armature 110 such that, for a de-energized actuator, it is positioned in a state that allows the locking claw 150 to open. In Fig. 3b, the electromagnet 130 is energized. Accordingly, the sleeve 312 can lead to a deflection of the armature 110. For example, a longitudinal extent of the sleeve 312 can increase. This allows the armature 110 to be moved from the first position to a second position, indicated by the 2. This allows the locking claw 150 to be moved into a closed position.

[0042] Because the sensor target 120 is arranged radially outward with the armature 110, a movement of the armature 110 can be transmitted to the sensor target 120 without significant structural effort. For example, the sensor target 120 and the armature 110 can be integrally constructed. This means that the sensor target can be arranged in a recess or depression of the armature 110.

[0043] The sensor target 120 can thus move with the armature 110 from the first position to the second position. Accordingly, the state of the locking claw 150 can be determined based on the position of the sensor target 120. The radially outward arrangement of the armature 110 can simplify the design of the electromagnetic actuator.

[0044] The wave spring 160 shown in Fig. 3 is only one exemplary embodiment of a return spring. Alternatively, a helical spring can be used. Furthermore, the return spring, e.g., the wave spring 160, can be arranged radially flexible. For example, a return spring can be arranged radially inside or outside of the electromagnet 130.

[0045] Figs. 4a-4c show various views of a limited-slip differential 402 according to the invention. The limited-slip differential 402 can be the same limited-slip differential 402 as described with reference to Fig. 2 and / or Fig. 3. As can be seen in Fig. 4, the limited-slip differential 402 comprises a locking claw 450. The locking claw comprises a protrusion 452 comprising a through-opening 454. The through-opening can be designed to pass through a fastening means 458. The fastening means can be arranged in a fastening region 456 of the armature 410. With the fastening means 458, the armature can therefore be non-positively connected to the locking claw 450. Figs. 4b and 4c show an arrangement of the locking claw 450 within a differential housing 440. The elevations 452 of the locking claw 450 are arranged in recesses 442 of the differential housing 440. This can improve the transmission of force from the locking claw 450 to the differential housing 440.In particular, force transmission can be increased. This ensures that the locking claw 450 can also absorb the forces from the armature and transmit them to the differential housing 440.

[0046] The elevation 452 of the locking claw can also be considered a toothing. That is, the elevation 452 or elevations 452 can form a locking claw toothing. As shown in Fig. 4, the elevation 452 can be arranged on a radial end face. In this case, the locking claw 450 can be a radial claw. Alternatively, the elevation 452 can also be arranged on an end face. In this case, the locking claw 450 can be a front claw.

[0047] The differential housing 440 can be designed in one piece or in multiple pieces, e.g., in two pieces.

[0048] Figs. 5a-5f show a limited-slip differential 502 according to the invention compared with a limited-slip differential from the prior art. Fig. 5a shows a longitudinal sectional view of a limited-slip differential 502 according to the invention. The armature and the sensor target are arranged radially outward.

[0049] Fig. 5b shows a longitudinal sectional view of a prior art limited-slip differential. In contrast to the limited-slip differential according to the invention, the armature in Fig. 5b is arranged radially inward. As a result, an axially outward connection must be established between the armature and the sensor target in order to connect the radially inward armature to the radially outward sensor target. This connection has an L-shape and can represent increased design complexity. With the limited-slip differential 502 according to the invention, the design complexity can be reduced.

[0050] Fig. 5c shows the same longitudinal sectional view as Fig. 5a. In Fig. 5c, the rotating and non-rotatable components of the limited-slip differential 502 are highlighted. As can be seen, the sensor target 102 is arranged in a rotating manner. This means that the sensor target 120 is connected in a rotationally fixed manner to the differential housing and rotates with it. In contrast (see Fig. 5d), the sensor target 520 is arranged in a rotationally fixed manner. This means that in the prior art, the sensor target 520 does not rotate with the differential housing. Decoupling the sensor target 520 from a rotation of the differential housing can be structurally complex. The rotating arrangement of the limited-slip differential 502 according to the invention can reduce the structural complexity for the arrangement of the sensor target 120.

[0051] Fig. 5e shows the same longitudinal section as Fig. 5a. In Fig. 5e, the required installation space for the armature is highlighted. The radially outer arrangement of the armature allows for a reduction in the required installation space. In particular, an L-shaped bypass to the sensor target is eliminated.

[0052] In contrast (see Fig. 5f), the armature in the prior art requires significantly more space due to the L-shaped bypass. In particular, the L-shaped bypass must maintain a minimum distance from the electromagnet so that the armature and the sensor target can still move from a first position to a second position. This further increases the required space.

[0053] Figs. 6a and 6b show the limited-slip differential 502 according to the invention in comparison with a limited-slip differential from the prior art analogous to Fig. 5. In contrast to Fig. 5, Fig. 6a shows the installation space gain and Fig. 6b shows a possible enlargement of the coil cross-section.

[0054] As can be seen in Fig. 6a, a limited-slip differential according to the invention can achieve both a radial installation space gain (because the armature no longer has an area for arranging the L-shaped component) and an axial installation space gain (because the L-shaped component is omitted). Alternatively, as shown in Fig. 6b, a cross-section of a coil can be enlarged compared to the prior art with the same installation space. Fig. 7 shows an embodiment of a vehicle 700. The vehicle comprises an electric machine 710 which is designed to drive the vehicle 700. The electric machine 710 comprises an electromagnetic actuator 720, as described, for example, with reference to Fig. 1 or an electromagnetically actuated limited-slip differential, as described, for example, with reference to at least one of Figs. 2-6.

[0055] Fig. 8 shows a schematic representation of a combination of an electromagnetic actuator, e.g., as described with reference to Fig. 1, or an electromagnetically actuated limited-slip differential, e.g., as described with reference to Figs. 2-5, with a disconnect. Fig. 8 shows an exemplary representation of a sideshaft disconnect. A sideshaft disconnect system represents a dog clutch that can be controlled by an actuator. This enables decoupling of the electromagnetic machine from the drive train. An electromagnetic actuator according to the invention or an electromagnetically actuated limited-slip differential can be combined with a disconnect system. The disconnect system can therefore, in particular, comprise an electromagnetic actuator according to the invention or an electromagnetically actuated limited-slip differential.For safety reasons, position sensing of an elocker locking claw may be necessary in such an application to reliably detect the elocker's status. An electromagnetic actuator according to the invention, or an electromagnetically actuated limited-slip differential, can therefore be used for both an electric drive and an axle drive.

[0056] In one embodiment, the electromagnetically actuated limited-slip differential can be used in combination with a disconnect system, which can decouple the electromagnetic machine from a drive train so that a connection between the electromagnetic machine and the axle is completely dissolved. This means that the vehicle can further comprise a disconnect system. The electromagnetic actuator or the electromagnetically actuated limited-slip differential can be designed in combination with the disconnect system to decouple the electromagnetic machine from a drive train so that a connection between the electromagnetic machine and the axle is completely decoupled. For example, a second axle can be disconnected from an electric motor so that the second axle only rotates. This can prevent a transfer of power from the second axle to the electric motor.In particular, this makes it possible to reduce or decouple the moment of inertia acting on the electric motor.

[0057] Reference symbol actuator armature sensor target position sensor electromagnet differential housing locking claw elevation through-hole fastening area limited-slip differential cable duct electromagnet fastening means wave spring axle bevel gear sleeve limited-slip differential armature differential housing locking claw elevation through-hole fastening area fastening means limited-slip differential sensor target vehicle electric machine electromagnetic actuator electromagnetically actuated limited-slip differential

Claims

Patent claims 1. An electromagnetic actuator (100) for an electromagnetically actuated Limited-slip differential, comprising: an electromagnet (130); an armature (110); and a sensor target (120), wherein the armature (110) and the sensor target (120) are arranged radially outwardly of the electromagnet (130) 2. The actuator (100) according to claim 1, wherein the electromagnet (130), the armature (110) and the sensor target (120) are arranged to overlap axially.

3. The actuator (100) according to one of the preceding claims, wherein the sensor target (120) is at least partially circumferential.

4. The actuator (100) according to any one of the preceding claims, further comprising a locking claw (150), wherein the locking claw (150) is non-positively connected to the armature (110) so that a torque can be transmitted from the armature (110) to the locking claw (150).

5. The actuator (100) according to claim 4, wherein the locking claw (150) has a protrusion (152) on a radial end face, wherein the protrusion (152) has a through-opening (154) for arranging a fastening means and wherein the armature (110) has a fastening region (156), wherein the fastening region is designed to receive the fastening means, so that the armature (110) can be connected to the locking claw (150) by the fastening means, which can extend through the through opening (154) of the locking claw (150).

6. The actuator (100) according to any one of the preceding claims, further comprising a position sensor (122), wherein the position sensor (122) is decoupled from a rotation of the sensor target (120).

7. An electromagnetically actuated limited-slip differential, comprising: a differential housing (240); an electromagnetic actuator (100) according to any one of the preceding claims; wherein the sensor target (120) is rotationally fixedly connected to the differential housing (240).

8. The electromagnetically actuated limited-slip differential according to claim 7, further comprising a fastening means, wherein the fastening means establishes a frictional connection between the armature and the locking claw.

9. A vehicle (700) comprising: an electric machine (710) configured to drive the vehicle (700), wherein the electric machine (710) comprises an electromagnetic actuator (720) according to any one of claims 1-6 or an electromagnetically actuated limited-slip differential (730) according to any one of claims 7 or 8.

10. The vehicle (700) of claim 9, further comprising a disconnect system, wherein the electromagnetic actuator (720) or the electromagnetically actuated limited-slip differential (730) in combination with the disconnect system are configured to decouple the electromagnetic machine (710) from a drive train such that a connection between the electromagnetic machine (710) and the axle is completely decoupled.

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