Multifunctional shaft adapter, locking device, electric motor drive unit and vehicle

Description

[0001] The invention relates to a multifunctional shaft adapter for a locking device, a locking device with such a multifunctional shaft adapter, an electric motor drive unit with such a locking device, and a vehicle with such an electric motor drive unit.

[0002] The locking device proposed in this disclosure represents a further development of the locking devices described in the German patent applications DE 10 2021 213 737 A1 and DE 10 2021 213 739 A1.

[0003] One of the problems underlying the invention is to provide an improved locking device, in particular for a vehicle.

[0004] This problem is solved by a multifunctional shaft adapter proposed and protected according to claim 1.

[0005] A multifunctional shaft adapter for a locking device is proposed, which is intended for attachment to an electric motor drive unit.

[0006] The shaft adapter can be connected to a lockable shaft of the electric motor drive unit and is essentially made of a plastic in which contacting means for external excitation of a rotor of a synchronous machine of the electric motor drive unit connected to the shaft are embedded and which is also materially connected to a positive locking element for connection to the shaft and locking of the shaft.

[0007] The proposed shaft adapter enables, on the one hand, a locking or locking function of the locking device, since it is part of the locking mechanism of the locking device, and on the other hand, the aforementioned external excitation of the synchronous machine.

[0008] In one embodiment, the contacting means comprise at least two slip rings for contacting an associated grinding brush and at least one conductor track associated with the respective slip ring, which extends from the associated slip ring through the plastic of the shaft adapter.

[0009] In another embodiment, the shaft adapter accommodates a sensor component, at least partially made of metal, for interaction with a signal transmitter fixed to a housing of the locking device, for position detection of the rotor of the synchronous machine. Thus, the proposed shaft adapter also enables the aforementioned position detection of the rotor of the synchronous machine.

[0010] Furthermore, a locking device for an electric motor drive unit according to claim 4 is proposed. The locking device comprises a locking mechanism for locking a lockable shaft of the electric motor drive unit and an electric drive for actuating the locking mechanism, which is housed in a casing of the locking device alongside the locking mechanism.

[0011] In a use position of the locking device, the housing of the locking device also accommodates a multifunctional shaft adapter of the type described above, against whose positive locking element another positive locking element of the locking mechanism can be actuated in an axial stroke movement and along the shaft adapter and the shaft to lock the shaft.

[0012] Such a locking device advantageously contributes to a reduction in components and thus installation space. This also advantageously simplifies assembly.

[0013] The locking mechanism comprises a positive locking element that can be actuated in an axial stroke movement and along the shaft, which can be positively engaged with a shaft-side complement within a positive locking area, at least partially, in order to lock the shaft.

[0014] This actuable positive locking element is in a state, in contact with the shaft-side complement at its end face, and is defined as being able to be pre-tensioned or clamped against the shaft-side complement by means of at least one elastic force transmission means.

[0015] In this case, the actuable positive locking element, in a locking state of the shaft in which the actuable positive locking element and the shaft-side complement interlock in the positive locking area of ​​the locking mechanism, is supported against a housing section of an electric motor drive unit on which the locking actuator or the locking device is attached.

[0016] The locking mechanism exhibits a play in the positive locking area and in the circumferential direction of the shaft between the actuable positive locking element and the shaft-side complement, which, in conjunction with the aforementioned preload / tensioning of the actuable positive locking element against the shaft-side complement, enables the actuable positive locking element to engage with the shaft-side complement or to join the actuable positive locking element with the shaft-side complement.

[0017] A shaft-side complement is understood to be a shaft-side counterpart to the actuable positive locking element, which is designed or formed in the positive locking area in a manner correspondingly complementary to the actuable positive locking element. This can be a correspondingly shaped section of the shaft itself or a separate, correspondingly shaped element joined to the shaft, which interacts positively with the actuable positive locking element.

[0018] An elastic force transmission means is understood to be a mechanical energy storage device for the elastic preloading / tensioning of the actuable positive locking element against the shaft-side complement, for example in the form of at least one separate spring or spring element and / or in the form of at least one spring element section integrated into the actuable positive locking element.

[0019] This energy storage device pre-tensions the actuable positive locking element against the shaft-side complement until the shaft assumes a suitable orientation for a positive lock relative to the actuable positive locking element. As soon as such an orientation is achieved, this energy storage device presses the actuable positive locking element into the shaft-side complement to engage it, thus locking the shaft.

[0020] Furthermore, the locking mechanism can be actuated in an energy-efficient manner, as neither the aforementioned actuation nor the aforementioned preload / tensioning requires high actuating forces. When the actuable positive locking element engages with its shaft-side complement, only the actuable positive locking element is moved, and not the element of the drive train to be locked.

[0021] In one embodiment, the electric drive is arranged transversely to the shaft. Such a transverse arrangement advantageously creates installation space for accommodating the aforementioned contact elements through the housing of the locking device.

[0022] "Transverse" in this context refers either to an orthogonal arrangement of the electric drive to the shaft or to an arrangement in which a longitudinal axis of the electric drive forms an acute or obtuse angle with a longitudinal axis of the lockable shaft.

[0023] The housing of the locking device also accommodates at least two grinding brushes for the external excitation of the rotor of the synchronous machine of the electric motor drive unit, which is connected to the shaft.

[0024] In another embodiment, the grinding brushes are arranged radially to the shaft. Such a radial arrangement also facilitates a compact design of the locking device.

[0025] It is proposed that the grinding brushes be spring-loaded against a corresponding slip ring of the contacting means. This ensures that the grinding brushes, which wear down over time, are continuously guided against the corresponding slip rings.

[0026] Furthermore, an electric motor drive unit according to claim 5 is proposed.

[0027] Furthermore, a vehicle according to claim 6 is proposed.

[0028] The term "vehicle" refers to any type of vehicle or motor vehicle that is electrically powered, but especially passenger cars and / or commercial vehicles. These are preferably semi-autonomous and especially fully autonomous vehicles.

[0029] The invention will now be explained in detail with reference to the figures. Further advantageous embodiments of the invention will become apparent from the dependent claims and the subsequent description of preferred embodiments, the invention being defined by the claims. The following are shown: Fig. 1 a perspective view of an electric motor drive unit with a proposed locking device (left) and additionally a separate, perspective and enlarged view of part of the locking device (right); Fig. 2 the in Fig. 1 The locking device shown is in a planar sectional view; Fig. 3 shows a locking mechanism of the locking device together with an arrangement of contacting means; Fig. 4 shows the in Fig. 3 The arrangement of the locking mechanism and the contacting means shown in a perspective view; Fig. 5 a multifunctional shaft adapter of the locking device according to the invention; Fig. 6 a positive locking area between a lockable shaft and the locking device in a sectional view; Fig. 7 a perspective and enlarged view of the Fig. 6 The form-locking area shown, as well as Fig. 8, a perspective sectional view of the locking device.

[0030] The proposed locking device SV is attached to 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 machine and a reduction gearbox RG connected to it. The locking device SV is arranged on a housing EM-G of the synchronous machine.

[0031] The locking device SV has a locking mechanism and an electric drive EA for actuating the locking mechanism, which, along with the drive EA, is housed in a casing SV-G of the locking device. Fig. 2 For example, it nicely illustrates that a housing section EM-G of the synchronous machine also forms the housing SV-G of the locking device.

[0032] The drive EA is arranged transversely and orthogonally to the shaft W or shaft axis X-X. In an embodiment not shown here, the drive EA can also be arranged to the shaft such that a longitudinal axis of the drive EA forms an acute or obtuse angle with the longitudinal axis X-X of the shaft W.

[0033] The drive EA drives a helical gear shaft 8, which in turn interacts with a gear segment 10 of a spindle nut SM with an internal thread. This spindle nut SM is longitudinally displaceable from a spindle S with a corresponding external thread, which together with the spindle nut SM forms a so-called screw drive or helical gear drive. This drive converts a rotational movement of the spindle nut SM (clockwise or counterclockwise) into a translational movement of the spindle nut SM along the spindle S and in the longitudinal direction X - X or along the shaft W. The spindle S is fixed to the housing SV-G and is supported against the housing SV-G. Fig. 2 ).

[0034] On the shaft side, the spindle nut SM is elastically pre-tensioned via a ring element RE, which is supported by the spindle nut SM itself via a rolling bearing with low friction, and individual springs, for example in the form of helical springs SF, against a positive locking element 4 that can be actuated in the longitudinal direction X - X or along the shaft W ( Fig. 3, Fig. 4 ).

[0035] This positive locking element 4 is thus elastically connected via these - approximately three coil springs SF arranged around the circumference of the ring element RE - to a movement mechanism of the locking device SV which causes the axial stroke movement of the positive locking element 4.

[0036] This positive locking element 4 is metallic and high-strength, and is designed as a closed, circumferential, ring-shaped element with an internal toothing IV and an external toothing 5. While the internal toothing IV can be positively engaged with an external toothing AV of a shaft-side, high-strength metallic complement 6 to lock the shaft W, the external toothing 5 always positively engages with a complementary section of the electric motor housing EM-G. This positive locking ensures guidance and support of the positive locking element 4 against the electric motor housing EM-G. This external toothing 5 enables a favorable and uniform force distribution over the circumference of the positive locking element 4 and simultaneously a favorable and uniform force transmission into the electric motor housing EM-G. Fig. 7 This illustrates the section on the electric motor housing EM-G that is shaped complementarily to the external toothing 5, with its internal toothing. For the sake of simplicity, the positive locking element 4 is not shown, hidden, or omitted.

[0037] In the locked state of shaft W, both static and dynamic torque loads of the drive train are thus introduced into the electric motor housing EM-G via this external toothing 5.

[0038] As an alternative to external toothing 5, the positive locking element 4 can also be provided with an external profile in the form of individual, radial, claw-like projections. In this regard, reference is made to the German patent applications DE 10 2021 213 737 A1 and DE 10 2021 213 739 A1 mentioned above, which describe and illustrate this.

[0039] The locking device SV further comprises a multifunctional shaft adapter 12, which extends through the spindle S and into a region of the hollow shaft W. This shaft adapter 12 is essentially made of a plastic material in which two metallic slip rings 14a, 14b and a metallic conductor or contact track 16 associated with each slip ring 14a, 14b are embedded. The conductor track 16 extends from the associated slip ring 14a, 14b towards the hollow shaft W through the plastic of the shaft adapter 12.

[0040] Furthermore, the plastic of the shaft adapter 12 is injection molded or bonded to the shaft-side complement 6, which is designed in the form of a metallic adapter ring. Fig. 6 This illustrates, by way of example, an annular projection of the adapter ring or positive locking element 6, which is formed in a dovetail shape on the end face of the adapter ring 6 and the positive locking element 4 and is enclosed by a plastic flange of the shaft adapter 12. This adapter ring 6 has an external toothing AV complementary to the internal toothing IV and also an internal profile or toothing via which the adapter ring 6, and thus the shaft adapter 12, is pressed onto a correspondingly complementary external profile or toothing of the hollow shaft W.

[0041] The adapter ring 6 makes it advantageous to adapt the proposed locking device SV to different shaft diameters.

[0042] Radially arranged to the shaft adapter 12 are two grinding brushes 2a, 2b, 3a, 3b each assigned to the two slip rings 14a, 14b and received by the housing SV-G. The grinding brushes 2a, 2b, 3a, 3b are spring-loaded against the assigned slip rings 14a, 14b and thus in contact with them. The grinding brushes 2a, 2b, 3a, 3b assigned to a slip ring 14a, 14b and forming a pair are arranged relative to each other such that they lie at the same height and form an angle ( Fig. 3, Fig. 4 ).

[0043] For the purpose of aligning the two interlocking elements 4, 6 with each other, a centering tapered section 7 is formed on the end face of the interlocking element 6 and facing the interlocking element 4 ( Fig. 6 , Fig. 7 In the event of an axial misalignment between the positive locking element 4 and the positive locking element 6 or the hollow shaft W, the internal toothing IV can, during a longitudinal displacement of the positive locking element 4 in the direction X - X, abut against this tapered section or centering section 7 in order to be aligned with the external toothing AV and thus with the hollow shaft W. The positive locking element 6 therefore has, in addition to a locking function, a centering function, which ensures a coaxial alignment of the two positive locking elements 4, 6 with respect to each other. This ensures a uniform force distribution over the circumference of the two positive locking elements 4, 6 in the joined state.

[0044] The locking device SV further includes, for example, an inductively acting position sensor arrangement for detecting the position of the rotor of the synchronous machine connected to the shaft W, in order to enable efficient electronic commutation of the synchronous machine. Fig. 8 This illustrates, by way of example, a position sensor arrangement in the area of ​​the outer end of the shaft adapter 12 or the end of the shaft adapter 12 which is facing away from the shaft end.

[0045] A signal transmitter with a coil arrangement is provided, stationary to the housing SV-G and integrated into a circuit board 20. This transmitter interacts with a sensor component in the form of a metallic, disc-like element 18, which is stationary to the hollow shaft W. This element 18, which is arranged opposite the circuit board, is held in place by the plastic of the shaft adapter 12 and is also fixed to the shaft adapter 12. This element 18 has individual radial, claw-like projections around its circumference, which, as such, cause a detuning of an applied magnetic field. At least these radial, claw-like projections can be magnetic, e.g., ferromagnetic. In a simple embodiment, this disc-like element 18 is made entirely of a non-magnetic metal, such as aluminum.

[0046] Alternatively, such a position sensor arrangement can also be provided in the area of ​​the aforementioned positive locking elements 4, 6 or on the shaft side.

[0047] The circuit board 20 integrates not only the aforementioned signal transmitter but also sensor electronics for the position sensor arrangement and motor electronics for controlling the electric drive EA.

[0048] The proposed locking device represents a compact, space-saving and cost-effective solution within a powertrain, in particular a vehicle, in the sense of a parking lock or a locking actuator, according to which the locking mechanism is integrated into the electric motor EM and the locking device into the electric motor housing EM-G.

[0049] In a vehicle equipped with such a locking device, this means that the vehicle can be locked or blocked in a parking situation where the vehicle is stationary, for example at the request of the driver.

[0050] If, in this parking position, the orientation of shaft W is not such that it allows locking by the positive locking element 4, the positive locking element 4, in a state where its end face rests against the shaft-side complement or positive locking element 6 or against the external toothing AV, can be pre-tensioned or pre-tensioned to engage the shaft W by means of the aforementioned screw drive – formed by the spindle S and the spindle nut SM – and the aforementioned coil springs SF, along the shaft W, with a definable force against the shaft W. If the shaft W is then rotated slightly further, the positive locking element 4 engages with the positive locking element 6 and thus with the shaft 6 as soon as a corresponding orientation of the shaft W is achieved that enables engagement. Such further rotation of the shaft W in the parking position can be initiated by the vehicle system.

[0051] The aforementioned movement between the two positive locking elements 4, 6 and in the circumferential direction of the shaft W also enables the following emergency scenario in the event of a vehicle failure, in which the electric motor EM of the electric motor drive unit EM-AE fails.

[0052] If the electric motor EM fails during driving and the vehicle is subsequently braked to a standstill on an incline, the proposed locking device SV enables the locking or blocking of the vehicle as it rolls forward from a standstill, up to a maximum rotational speed of the shaft W or maximum speed of the vehicle, which depends on the play in the movement.

[0053] In this process, the positive locking element 4 engages with the positive locking element 6 and thus with the shaft W, utilizing the play in the movement and up to the maximum rotational speed of the shaft W or the maximum speed of the vehicle, which depends on the play in the movement, thus bringing the vehicle to a standstill.

[0054] By pre-tensioning or clamping the positive locking element 4 in a state, in contact with the face of the positive locking element 6 or the external toothing AV, via the screw drive and the helical springs SF and along the shaft W with a definable force against the shaft W until it engages, the engagement finally occurs as soon as the shaft W achieves a corresponding alignment with the positive locking element 4.

[0055] Although the preceding description explains exemplary embodiments, it should be noted that a multitude of variations are possible. Furthermore, it should be emphasized that the exemplary embodiments are merely examples and are not intended to restrict the scope of protection, applications, or structure in any way. Rather, the preceding description provides the skilled person with a guideline for implementing at least one exemplary embodiment, whereby various modifications, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as defined in the claims.

Claims

1. Multifunctional shaft adapter (12) for a locking device (SV) provided for fitting to an electric motor drive unit (EM-AE), wherein the shaft adapter (12) can be connected to a lockable shaft (W) of the electric motor drive unit (EM-AE) and is in this instance substantially produced from a plastics material into which are embedded contacting means for external excitation of a rotor of a synchronous machine of the electric motor drive unit (EM-AE), said rotor being connected to the shaft (W), and which is additionally materially connected to a positive-locking element (6) for connection to the shaft (W) and locking of the shaft (W).

2. Multifunctional shaft adapter (12) according to Claim 1, wherein the contacting means comprise at least two slip rings (14a, 14b) for contacting with an associated brush (2a, 2b, 3a, 3b), and at least one conductor track (16), which is associated with the respective slip ring (14a, 14b) and which extends from the associated slip ring (14a, 14b) through the plastics material of the shaft adapter (12).

3. Multifunctional shaft adapter (12) according to Claim 1 or 2, wherein a sensor component (18) of metallic design, at least in some portion or portions, for interaction with a signal transmitter, fixed relative to a housing (SV-G) of the locking device, for position detection of the rotor of the synchronous machine is received in a fixed location by the shaft adapter (12).

4. 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 electric motor drive unit (EM-AE) and an electric drive (EA) for actuating the locking mechanism which in addition to the locking mechanism is received by a housing (SV-G) of the locking device (SV), wherein the locking device (SV) can be arranged on an electric motor drive unit (EM-AE) and the housing (SV-G) of the locking device (SV) furthermore receives a multifunctional shaft adapter (12) according to one of the preceding claims, with respect to the positive-locking element (6) of which a further positive-locking element (4) of the locking mechanism can be actuated in an axial stroke movement (X - X) and longitudinally with respect to the shaft adapter and the shaft (W) to lock the shaft (W).

5. Electric motor drive unit (EM-AE), in particular for driving a vehicle with a locking device (SV) according to Claim 4, which is attached to a housing (EM-G) of an electric motor (EM) of the electric motor drive unit (EM-AE).

6. Vehicle having an electric motor drive unit (EM-AE) according to Claim 5.