Locking device, motor driving unit and vehicle

Abstract

The invention relates to a locking device (SV) for a motor drive unit (EM-AE), comprising: a locking mechanism for locking a lockable shaft (W) of the motor drive unit (EM-AE); an electric drive (EA) for actuating the locking mechanism, the electric drive being housed together with the locking mechanism by a housing (SV-G) of the locking device (SV). The locking mechanism has: a first form-locking element (4) having an internal toothing (IV); a shaft-side second form-locking element (6) having an external toothing (AV), against which the first form-locking element (4) can be actuated in an axial reciprocating movement (X-X) and in a form-locking manner along the shaft (W). According to the invention, a centring conical section (7) is formed on the shaft-side form-fitting element (6) on the end side and facing the first form-fitting element (4), against which conical section the internal toothing (IV) can be placed in order to align the two form-fitting elements (4, 6) with each other. The invention also relates to: a motor drive unit (EM-AE), in particular for driving a vehicle having such a locking device (SV); the invention further relates to a vehicle having such a motor drive unit (EM-AE).

Description

Technical Field

[0001] The invention relates to a locking device, a motor drive unit having such a locking device and a vehicle having such a motor drive unit. Background Art

[0002] The locking device proposed in the context of the present disclosure is a development of the locking device described in the German patent applications with application numbers DE 10 2021 213 737.7 and DE 10 2021 213 739.3. Summary of the invention

[0003] The object of the present invention is to provide an improved locking device, in particular for vehicles.

[0004] This object is achieved by a locking device as set forth and claimed in accordance with claim 1 .

[0005] A locking device for a motor drive unit is proposed, wherein the locking device comprises a locking mechanism for locking a lockable shaft of the motor drive unit and an electric drive for actuating the locking mechanism, the electric drive being accommodated together with the locking mechanism by a housing of the locking device.

[0006] The locking mechanism comprises a positive locking element which is axially reciprocatable and actuatable along the shaft and which can engage at least partially in a positive locking region with a shaft-side complementary portion in order to lock the shaft.

[0007] In this case, the actuatable form-fitting element can be preloaded or clamped in a defined manner, latchably against the axial complement, along the shaft by means of at least elastic force transmission means when the end face is in contact with the axial complement.

[0008] Here, in the locked state of the shaft, in which the actuatable form-fitting element and the complementary part on the shaft side engage with each other in the form-fitting area / form-fitting area of ​​the locking mechanism, the actuatable form-fitting element is supported against a housing section of the motor drive unit, on which the locking actuator is arranged.

[0009] Here, the locking mechanism has an active gap between the actuatable form-locking element and the complementary part on the shaft side in the form-locking area and in the circumferential direction of the shaft, which, together with the or the above-mentioned complementary part on the opposite shaft side, preloads / clamps the actuatable form-locking element to achieve the locking of the actuatable form-locking element into the complementary part on the shaft side or the engagement of the actuatable form-locking element with the complementary part on the shaft side.

[0010] In this context, a shaft-side complement is to be understood as a shaft-side counterpart of the actuatable form-fitting element, which is correspondingly designed or shaped complementary to the actuatable form-fitting element in the form-fitting region. This may be a correspondingly shaped section of the shaft itself or of a separate and correspondingly shaped element engaging with the shaft, which interacts in a form-fitting manner with the actuatable form-fitting element.

[0011] Here, an elastic force transmission device can be understood as a mechanical energy storage device for elastically preloading / clamping an actuatable form-fitting element relative to a complementary part on the shaft side, which is, for example, in the form of at least one separate spring or a separate spring element and / or in the form of at least one spring element section integrated into the actuatable form-fitting element.

[0012] The energy storage device preloads the activatable form-locking element against the shaft-side supplementary portion until the shaft assumes or moves into a suitable orientation for form fit relative to the activatable form-locking element. Once such an orientation is achieved, the energy storage device presses the activatable form-locking element into the shaft-side supplementary portion for latching, thereby locking or latching the shaft.

[0013] In addition, the locking mechanism can be activated energy-savingly, because neither the activation nor the preloading requires high adjustment forces. Specifically, when the activatable form-locking element is engaged with the supplementary portion on the shaft side, only the activatable form-locking element moves, without moving the element of the drive train to be locked.

[0014] Here, the locking mechanism has a first positive-locking element with internal toothing and a second positive-locking element on the shaft side with external toothing, against which the first positive-locking element can be moved back and forth in the axial direction and can be actuated in a positive-locking manner along the shaft.

[0015] In this case, a centering conical section is formed on the shaft-side form-fitting element at the end and facing the first form-fitting element, against which the internal toothing can abut in order to align the two form-fitting elements with one another.

[0016] This ensures a uniform distribution of the forces in the circumferential direction of the two form-fitting elements in the joined state.

[0017] In one embodiment, the housing of the locking device also accommodates a multifunctional shaft adapter for connecting a lockable shaft, the shaft adapter being essentially made of plastic and having contact devices embedded in the shaft adapter for separately exciting a rotor of a synchronous motor of a motor drive unit connected to the shaft, wherein the plastic of the shaft adapter is materially connected to a positive locking element on the shaft side.

[0018] In this case, the contact means comprises at least two slip rings for contacting associated sliding contact brushes and at least one conductor associated with the respective slip ring, which conductor extends from the associated slip ring through the plastic of the shaft adapter.

[0019] Here, the housing of the locking device further accommodates at least two separately arranged sliding contact brushes for the external excitation.

[0020] The proposed integration of functions advantageously saves on components and thus installation space. The assembly effort can also be advantageously simplified as a result.

[0021] In one embodiment, the electric drive is arranged transversely to the shaft. This transverse arrangement advantageously provides structural space for accommodating the contact means by the housing of the locking device.

[0022] In this context, transverse is to be understood as an orthogonal arrangement of the electric drive relative to the shaft or an arrangement in which the longitudinal axis of the electric drive forms an acute or obtuse angle with the longitudinal axis of the lockable shaft.

[0023] In another embodiment, the sliding contact brush is arranged radially relative to the shaft. This radial arrangement is also conducive to the compact implementation of the locking device.

[0024] It is proposed that the sliding contact brush is placed against the associated slip ring of the contact element with spring preload or is in contact with it. This ensures that the sliding contact brush, which wears over time, is tracked / guided against the associated slip ring.

[0025] Furthermore, a motor drive unit is proposed, in particular for driving a vehicle, having a locking device of the above-mentioned type, which is arranged on the housing of the motor of the motor drive unit (claim 4 ).

[0026] A vehicle is also proposed, which has an electric motor drive unit of the above-mentioned type (claim 5 ).

[0027] A vehicle can be understood here to be any type of vehicle, more precisely a motor vehicle, which is driven by an electric motor, in particular a passenger car and / or a commercial vehicle. Preferably, this is a semi-automatic vehicle and in particular a fully automatic vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention is explained in detail below with reference to the accompanying drawings. Other advantageous developments of the invention are obtained from the dependent claims and the following description of preferred embodiments. Among them:

[0029] Figure 1 A perspective view of a motor drive unit with the proposed locking device is shown (left), and in addition to the motor drive unit, a separate perspective enlarged view of a part of the locking device is shown (right);

[0030] Figure 2 A cross-sectional view cut through a plane shows Figure 1 The locking device shown in;

[0031] Figure 3 The arrangement of the locking mechanism of the locking device together with the contact means is shown;

[0032] Figure 4 The stereoscopic view shows Figure 3 The arrangement of the locking mechanism and the contact device shown in FIG.

[0033] Figure 5 A multifunctional shaft adapter showing a locking device;

[0034] Figure 6 The form-fitting area between the lockable shaft and the locking device is shown in a sectional view;

[0035] Figure 7 Shown in Figure 6 A perspective enlarged view of the form-fitting area shown in FIG.

[0036] Figure 8 A perspective cross-sectional view of a locking device is shown. DETAILED DESCRIPTION

[0037] The proposed locking device SV is arranged on an electric motor drive unit EM-AE, in particular for driving a vehicle. The electric motor drive unit EM-AE comprises an electric motor EM in the form of a separately excited synchronous motor and a reduction gear mechanism RG coupled to the electric motor. The locking device SV is arranged on the housing EM-G of the synchronous motor.

[0038] The locking device SV has a locking mechanism and an electric drive EA for actuating the locking mechanism, and the locking mechanism and the drive EA are accommodated by a housing SV-G of the locking device. Figure 2 For example, it is very well shown that the housing segment EM-G of the synchronous machine also forms the housing SV-G of the locking device.

[0039] The drive EA is arranged transversely and orthogonally to the shaft W, more precisely to the shaft axis XX. In embodiments not shown here, the drive EA can also be arranged relative to the shaft such that the longitudinal axis of the drive EA forms an acute or obtuse angle with the longitudinal axis XX of the shaft W.

[0040] Here, the drive EA drives the helical gear shaft 8, which in turn interacts with the gear section 10 of the spindle nut SM with an internal thread. Here, the spindle nut SM is longitudinally movable in engagement with a spindle S with a corresponding external thread, which together with the spindle nut SM forms a so-called helical transmission or a so-called helical gear transmission, which converts the rotational movement of the spindle nut SM (counterclockwise or clockwise) into a translational movement of the spindle nut SM along the spindle S and the longitudinal direction XX or along the axis W. Here, the spindle S is arranged in a fixed position relative to the housing SV-G and is supported relative to the housing SV-G ( Figure 2 ).

[0041] On the shaft side, the spindle nut SM is elastically preloaded by means of an annular element RE and a separate spring, for example in the form of a helical spring 18, against a positive locking element 4 which can be actuated in the longitudinal direction XX or along the axis W ( Figure 3 , Figure 4 ), in which the annular element is accommodated by the spindle nut SM itself in a low-friction manner via a rolling bearing.

[0042] The form-fitting element 4 is thus elastically connected to the kinematic mechanism of the locking device SV which brings about the axial reciprocating movement of the form-fitting element 4 via, for example, three helical springs 18 distributed in the circumferential direction of the ring element RE.

[0043] Here, the form-locking element 4 is metallic and high-strength and is designed in the form of a closed circumferential ring element with an inner toothing IV and an outer toothing 5. While the inner toothing IV can be moved in a form-locking manner into the outer toothing AV of the high-strength metal supplementary part 6 on the shaft side for locking the shaft W, the outer toothing 5 always interacts in a form-locking manner with a complementary designed section of the motor housing EM-G. The latter's form fit ensures the guidance and support of the form-locking element 4 relative to the motor housing EM-G. Here, the outer toothing 5 enables an advantageous and uniform distribution of force in the circumferential direction of the form-locking element 4 and at the same time enables an advantageous and uniform introduction of force into the motor housing EM-G. Here, Figure 7 The section formed on the motor housing EM-G and its internal toothing in a manner complementary to the external toothing 5 is shown. For the sake of simplicity, the form-locking element 4 is not shown here or is concealed or omitted.

[0044] In the locked state of the shaft W, the static and dynamic torque loads of the drive train are therefore introduced into the motor housing EM-G via the external toothing 5 .

[0045] Instead of the external toothing 5, the outer contour of the form-fitting element 4 can also be provided in the form of separate radial claw-like projections. In this regard, reference is made to the German patent applications DE 10 2021 213737.7 and DE 10 2021 213739.3 mentioned at the outset, which describe and illustrate this.

[0046] The locking device SV also has a multifunctional shaft adapter 12, which extends through the threaded spindle S and into the region of the hollow shaft W. The shaft adapter 12 is essentially made of plastic, in which two metal slip rings 14a, 14b and metal conductors or contact rails 16 associated with the respective slip rings 14a, 14b are embedded. The conductors 16 extend from the associated slip rings 14a, 14b in the direction of the hollow shaft W through the plastic of the shaft adapter 12.

[0047] Furthermore, the plastic of the shaft adapter 12 is connected by injection molding or material bonding to the shaft-side supplementary part 6 designed in the form of a metal adapter ring. Figure 6 By way of example, an annular projection of the adapter ring or form-locking element 6 is shown, which is formed in the form of a dovetail groove on the end face of the adapter ring 6 and faces the form-locking element 4 and is surrounded by the plastic flange of the shaft adapter 12. In this case, the adapter ring 6 has an external toothing AV that is complementary to the internal toothing IV and also has an inner contour or internal toothing, by means of which the adapter ring 6 and therefore the shaft adapter 12 are pressed onto a correspondingly complementary designed outer contour or external toothing of the hollow shaft W.

[0048] The proposed locking device SV can advantageously be adapted to different shaft diameters by means of an adapter ring 6 .

[0049] Arranged radially relative to the shaft adapter 12, two sliding contact brushes 2a, 2b, 3a, 3b are respectively assigned to two slip rings 14a, 14b and are accommodated by the housing SV-G. Here, the sliding contact brushes 2a, 2b, 3a, 3b are spring-preloaded against or in contact with the associated slip rings 14a, 14b. Here, the sliding contact brushes 2a, 2b, 3a, 3b assigned to the slip rings 14a, 14b and in pairs are arranged relative to each other so that they enclose an angle ( Figure 3 , Figure 4 ).

[0050] In order to align the two form-fitting elements 4, 6 relative to one another, a conical section 7 ( ) having a centering effect is formed on the end face of the form-fitting element 6 and facing the form-fitting element 4. Figure 6 , Figure 7 ). In the event of an axial offset between the form-locking element 4 and the form-locking element 6 or the hollow shaft W, the inner toothing IV can abut against the conical section or centering section 7 during the longitudinal displacement of the form-locking element 4 in the direction XX in order to be oriented relative to the outer toothing AV and thus relative to the hollow shaft W. The form-locking element 6 thus has, in addition to the locking function, a centering function which ensures a coaxial orientation of the two form-locking elements 4, 6 relative to one another. In the joined state, a uniform distribution of forces in the circumferential direction of the two form-locking elements 4, 6 is thus ensured.

[0051] The locking device SV also includes, for example, an inductive position sensor assembly for detecting the position of a rotor of the synchronous motor connected to the shaft W in order to achieve efficient electronic commutation of the synchronous motor. Figure 8 By way of example, the position sensor arrangement is described in the outer end region of the shaft adapter 12 , more precisely in the end region of the shaft adapter 12 facing away from the shaft end.

[0052] Here, a signal transmitter is provided which is fixed in position relative to the housing SV-G and integrated into the printed circuit board 20 and which has a coil arrangement and interacts with a sensor component in the form of a metallic disk-shaped element 18 which is fixed in position relative to the hollow shaft W. Here, the element 18 arranged opposite the printed circuit board is accommodated by the plastic of the shaft adapter 12 and is fixed in position relative to the shaft adapter 12. Here, the element 18 has individual radial claw-shaped projections on the circumferential side, which projections themselves cause a detuning of the magnetic field acting on them. Here, at least these radial claw-shaped projections can be embodied magnetically, for example ferromagnetically. In a simple embodiment, the disk-shaped element 18 is made completely of a non-magnetic metal, for example aluminum.

[0053] As an alternative thereto, such a position sensor arrangement can also be arranged in the region of the form-fitting elements 4 , 6 , more precisely on the shaft side.

[0054] In addition to the signal transmitter, sensor electronics for the position sensor assembly and motor electronics for controlling the electric drive EA are integrated into the printed circuit board 20 .

[0055] The proposed locking device is a compact, space-saving and cost-effective concept for a parking lock, or more precisely a locking actuator, in a drive train, in particular a vehicle, according to which the locking mechanism is integrated into the electric motor EM and the locking device is integrated into the motor housing EM-G.

[0056] In vehicles with such a locking device, this means that the vehicle can be locked or latched, for example, upon request of the driver, when the vehicle is stationary and parked.

[0057] If the orientation of the shaft W in the parking situation is not such that it can be locked by the form-locking element 4, the form-locking element 4 can be preloaded or clamped for locking along the shaft W and with a definable force toward the shaft W by the helical transmission formed by the spindle S and the spindle nut SM and the helical spring 18 in its end-side state against the shaft-side complement, more precisely the form-locking element 6, more precisely against the external toothing AV. If the shaft W is then rotated or turned only slightly further, the form-locking element 4 is locked with the form-locking element 6 and thus with the shaft 6 as soon as a corresponding orientation of the shaft W that enables locking is achieved. In this case, such a further rotation / rotation of the shaft W in the parking situation can be caused by the vehicle system.

[0058] The play between the two form-fitting elements 4 , 6 and in the circumferential direction of the axis W also enables an emergency situation in the event of a vehicle malfunction in which the electric motor EM of the electric motor drive unit EM-AE fails.

[0059] If the electric motor EM fails during driving and the vehicle is subsequently braked to a standstill on an inclined road, the proposed locking device SV can lock or latch the vehicle which then rolls from a standstill, i.e. up to the maximum rotation speed of the shaft W or the maximum speed of the vehicle depending on the play.

[0060] In this case, the form-fitting element 4 locks with the form-fitting element 6 and thus with the shaft W with play and up to the maximum rotational speed of the shaft W or the maximum speed of the vehicle, which is dependent on the play, so that the vehicle comes to a standstill.

[0061] The positive locking element 4 is preloaded or clamped along the axis W with a definable force relative to the axis W via the helical gear and the helical spring 18 when the end face of the positive locking element 4 is in contact with the positive locking element 6 or the external toothing AV, and locking is finally achieved as soon as the axis W has undergone a corresponding orientation relative to the positive locking element 4.

[0062] Although exemplary embodiments have been described in the foregoing description, it should be noted that various modifications may be made. It should also be noted that the exemplary statements are merely examples and are not intended to limit the scope of protection, application and structure in any way. On the contrary, the foregoing description provides a person skilled in the art with guidance for implementing at least one exemplary embodiment, wherein various changes may be made without departing from the scope of protection resulting from the claims and equivalent feature combinations, especially changes with respect to the function and arrangement of the described components.

Claims

1. A locking device (SV) for an electric motor drive unit (EM-AE), wherein: The locking device (SV) has: a locking mechanism for locking a lockable shaft (W) of the motor drive unit (EM-AE); and an electric drive (EA) for actuating the locking mechanism, the electric drive together with the locking mechanism being accommodated by a housing (SV-G) of the locking device (SV), wherein the locking mechanism has a first form-locking element (4) with an internal toothing (IV) and a second form-locking element (6) on the shaft side with an external toothing (AV), the first form-locking element (4) being actuable along the shaft (W) for form-locking axial reciprocating motion (XX) against the second form-locking element, wherein a conical section (7) having a centering effect is formed on the shaft side form-locking element (6) at the end side and facing the first form-locking element (4), against which the internal toothing (IV) is abutted so as to align the two form-locking elements (4, 6) with each other.

2. The locking device (SV) according to claim 1, wherein: The housing (SV-G) also accommodates a multifunctional shaft adapter (12) for connecting the lockable shaft (W), which shaft adapter is essentially made of plastic and in which contact devices are embedded for externally exciting the rotor of the synchronous motor of the motor drive unit (EM-AE) connected to the shaft (W), wherein the plastic of the shaft adapter (12) is connected to the form-locking element (6) on the shaft side in a material-locking manner.

3. The locking device (SV) according to claim 2, wherein: The contact device comprises: at least two slip rings (14a, 14b) for contacting the associated sliding contact brushes (2a, 2b, 3a, 3b); and at least one wire (16) associated with the corresponding slip ring (14a, 14b), the wire extending from the associated slip ring (14a, 14b) through the plastic of the shaft adapter (12).

4. An electric motor drive unit (EM-AE), in particular for driving a vehicle, having a locking device (SV) according to any of the preceding claims, which is arranged on a housing (EM-G) of an electric motor (EM) of the electric motor drive unit (EM-AE).

5. A vehicle having an electric motor drive unit (EM-AE) according to claim 4.

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