Electrically driven spindle actuator and method for operating an electrically driven spindle actuator

Abstract

The invention relates to an electrically driven spindle actuator (30) with a driven pump which serves to supply cooling and / or lubrication with a suitable medium, and with a first spindle element which interacts via a spindle geometry with a translationally displaceable second spindle element which serves to represent an axial actuating force. In order to improve the functionality and / or manufacturing of the electrically driven spindle actuator (30), the spindle actuator is combined with a drive unit comprising a drive groove geometry with at least one axial groove and at least one circumferential groove having at least one circumferentially effective ramp, wherein the drive unit comprises at least one drive body that engages in the drive groove geometry.

Description

[0001] The invention relates to an electric motor-driven spindle actuator with a driven pump that serves to supply cooling and / or lubrication with a suitable medium, and with a first spindle element that interacts via a spindle geometry with a translationally displaceable second spindle element that serves to generate an axial actuating force. The invention further relates to a method for operating such a spindle actuator.

[0002] German patent application DE 10 2018 112 213 A1 discloses a gear actuator with at least one electric motor that drives a pump. The electric motor causes a linear displacement of a selector shaft by means of a gear that converts a rotary drive of a rotor of the electric motor into a linear movement. A drive shaft of the pump is connected to the gear and is rotationally driven by the gear when the selector shaft is switched to a central position along the shift gates, or preferably by a further electric motor. German patent application DE 10 2018 114 902 A1 discloses a spindle actuator with a spindle drive. The spindle nut can be set in rotation by an electric motor and interacts with a spindle rod such that the spindle rod executes a linear movement when the spindle nut rotates.

[0003] Further prior art is known from DE 20 2022 002 768 U1, DE 10 2022 101 840 A1 and DE 10 2021 125 611 A1.

[0004] The object of the invention is to improve an electric motor-driven spindle actuator according to the preamble of patent claim 1 functionally and / or in terms of manufacturing technology.

[0005] The object is achieved in an electric motor-driven spindle actuator with a driven pump that serves to supply cooling and / or lubrication with a suitable medium, and with a first spindle element that interacts via a spindle geometry with a translationally displaceable second spindle element that serves to represent an axial actuating force, in that the spindle actuator is combined with a driver device that comprises a driver groove geometry with at least one axial groove and at least one circumferential groove that has at least one ramp effective in the circumferential direction, wherein the driver device comprises at least one driver body that engages in the driver groove geometry. The first spindle element is, for example, a nut or a spindle. The second spindle element is then a spindle or a nut.The spindle geometry can convert a rotary motion provided by a drive motor into a translatory motion. The drive groove geometry is formed, for example, on the second spindle element, which is preferably designed as a nut. The circumferential groove enables rotation to drive the pump. The axial groove enables axial relative movement between the two spindle elements to provide the axial actuating force with the spindle actuator. The axial groove maintains a rotationally fixed connection for driving the pump even when the direction of rotation is reversed. This ensures torque transmission to drive the pump even if an actuation request changes during operation of the electric motor-driven spindle actuator. The actuating force is used, for example, to actuate a parking lock. The claimed electric motor-driven spindle actuator provides a change-of-mind capability.In this context, this means in particular that a sufficient supply of cooling and / or lubrication is ensured even if an actuation request changes and the change is implemented directly without the actuation being carried out to the end.

[0006] A preferred embodiment of the electric motor-driven spindle actuator is characterized in that the ramp has a sliding flank and a driver flank aligned with the axial groove. The sliding flank enables rotation of the two spindle elements relative to one another without providing an axial actuating force. This is useful, for example, if only the cooling and / or lubrication is to be supplied via the electric motor-driven spindle actuator. In an opposite direction of rotation, the driver flank, in the interaction of the spindle elements via the spindle geometry, enables the provision of the axial actuating force via the translationally displaceable second spindle element. For this purpose, the driver flank is advantageously aligned with the axial groove such that a driver body, which engages in the axial groove, ensures the desired translational displacement of the second spindle element.

[0007] Another preferred embodiment of the electric motor-driven spindle actuator is characterized in that the driver groove geometry comprises two circumferential grooves that are connected to each other via the axial groove. This allows for a simple, desired relative movement in the axial direction, which is particularly advantageous when the desired actuation changes.

[0008] A further preferred embodiment of the electric motor-driven spindle actuator is characterized in that the driver body is connected in a rotationally fixed manner to a rotor of a drive motor, wherein the driver body is radially displaceable relative to the rotor. The driver body is designed, for example, as a pin. However, the driver body can also be designed, for example, cuboid-shaped. The radial displacement in the rotor enables the driver body to move out of the driver groove geometry. This is particularly advantageous when the driver body engages in one of the circumferential grooves without actuation being requested. The rotor then rotates with the driver bodies to drive the pump. In this case, the driver bodies may strike the ramps in the corresponding circumferential groove, which can lead to rattling noises.These unwanted noises are avoided when the driver body is moved out of the driver groove geometry.

[0009] Another preferred embodiment of the electric motor-driven spindle actuator is characterized in that the driver body, under the influence of centrifugal force, is movable out of the driver groove geometry against the preload of a spring device. This reliably prevents the previously described undesirable noise generation. At the same time, the spring device ensures engagement in the driver groove when necessary.

[0010] Another preferred embodiment of the electric motor-driven spindle actuator is characterized in that the driver device comprises two diametrically arranged driver bodies. This makes it easy to prevent unwanted imbalance.

[0011] A further preferred embodiment of the electric motor-driven spindle actuator is characterized in that each driver body is assigned an axial groove. This ensures, particularly in conjunction with a correspondingly aligned driver flank, a stable interaction between the two spindle elements in order to provide the axial actuation force when actuating the spindle.

[0012] A further preferred embodiment of the electric motor-driven spindle actuator is characterized in that the first spindle element is designed as a spindle fixed to the housing, and the second spindle element is designed as a nut. The rotor of the drive motor is drive-connected to the pump. This ensures sufficient supply to the pump in both directions of rotation of the rotor. Via the driver device, the second spindle element, preferably the nut, can be set in translational motion in cooperation with the first spindle element, preferably the spindle, in order to provide the axial actuation force when a corresponding actuation request is present.If this actuation request is changed, i.e. in particular if it is withdrawn, then the spindle actuator can be retracted by directly reversing the direction of rotation, whereby the supply of the pump is also ensured in this direction of rotation via the rotor.

[0013] A further preferred embodiment of the electric motor-driven spindle actuator is characterized in that the driver body is designed as a contour pin which interacts with a holding geometry of the driver groove geometry in such a way that the contour pin cannot move radially outwards when passing through the axial groove. The optional holding geometry for the contour pin advantageously enables high travel speeds of the contour pin in the longitudinal groove without the contour pin(s) being able to lift off due to centrifugal force when passing through the respective axial groove. The axial groove is also referred to as a longitudinal groove. The holding geometry can, for example, comprise a collar at the end of the contour pin which is guided axially in the axial groove but held radially.

[0014] The invention further relates to a spindle element, in particular a spindle or a nut, a driver device, in particular a driver body or a spring device, and / or a rotor for an electromotor-driven spindle actuator as described above. These parts are sold separately.

[0015] In a method for operating a previously described electric motor-driven spindle actuator, the above-mentioned object is achieved alternatively or additionally in that the driver device with the driver groove geometry maintains a sufficient supply of cooling and / or lubrication by the driven pump even when a changed actuation request is directly implemented. The pump is preferably driven rotationally via the rotor, specifically in both directions of rotation of the drive motor. An actuation request is complied with as required via the driver device. For this purpose, at least one driver body engages in an axial groove of the driver groove geometry. The preloaded spring device ensures that the driver body engages in the driver groove geometry.Only with increasing speeds does the driver body move out of the driver groove geometry due to centrifugal force, so that unwanted noises in the interaction of the driver body with the ramp geometry are avoided.

[0016] Further advantages, features, and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawings. They show: Fig. 1 a perspective view of an electric motor driven spindle actuator; the Fig. 2 and Fig. 3 two perspective sectional views of the spindle actuator from Fig. 1; the Fig. 4 and Fig. 5 the spindle actuator Fig. 1 from a different perspective in two different operating states; and the Fig. 6 to 8 each show a perspective view of two spindle elements of the spindle actuator, which are combined with a driver device, in different operating states.

[0017] In the Fig. 1 to 5, an electric motor-driven spindle actuator 30 is shown in perspective and partially in section. A pump 9, which is driven by a drive motor 11, is integrated into the spindle actuator 30. The drive motor 11 is designed as an electric motor with a rotor 26 arranged radially within a stator 27 for rotation about a rotational axis. The drive motor 11 is controlled via an electronic component 10. The electronic component 10 is, for example, a printed circuit board.

[0018] The pump 9 is designed as a gear pump and is driven by the rotor 26 of the drive motor 11. For this purpose, the rotor 26 of the drive motor 11 is connected to a driven gear of the pump 9 via a compensating coupling. The pump 9 is integrated into a pump housing 1. The pump housing 1 comprises two hydraulic connections 2, 3.

[0019] The drive motor 11 is arranged in a motor housing 4. The motor housing 4 is combined with the pump housing 1 in a common housing of the spindle actuator 30. The drive motor 11 is supplied with power and controlled via a connector 5. The common housing of the electric motor-driven spindle actuator 30 also includes a gear housing 6.

[0020] The motor housing 4 is arranged axially between the pump housing 1 and the gear housing 6. The term "axial" refers to the rotational axis of the rotor 26 of the drive motor 11. "Axial" means in the direction of or parallel to this rotational axis. "Analog" means radially perpendicular to this rotational axis. The term "circumference" or "circumferential direction" also refers to the rotational axis of the rotor 26.

[0021] The common housing of the spindle actuator 30 is equipped with a mounting flange 7. Using the mounting flange 7, the spindle actuator 30 can preferably be mounted in a drive train of a motor vehicle. A desired actuating function can be performed in the drive train via an actuating shaft 8. The pump 9 serves to supply a cooling and / or lubrication system with a suitable medium in the drive train. The suitable medium is, for example, a hydraulic medium, such as oil.

[0022] The spindle actuator 30 comprises a first spindle element 31 and a second spindle element 32. The two spindle elements 31, 32 interact with each other in a conventional manner via a spindle geometry 33. The first spindle element 31 is designed as a spindle 12. The second spindle element 32 is designed as a nut 13.

[0023] The first spindle element 31, i.e., the spindle 12, is fixed to the housing, i.e., rotationally and translationally fixed, in the common housing of the spindle actuator 30. The second spindle element 32, designed as a nut 13, is equipped with a driver groove geometry 34 on its outer surfaces. The driver groove geometry 34 serves to represent a driver device 35 in the spindle actuator 30.

[0024] The driver device 35 comprises two driver bodies 36, 37, which are designed as contour pins 16, 29. The driver bodies 36, 37 are, as can be seen in the Fig. 6 to 8 are arranged diametrically or oppositely relative to the rotational axis of the rotor 26. In Fig. 2 shows that the two carrier bodies 36, 37 are arranged radially movable in the rotor 26. In conjunction with the Fig. 6 to 8 it can be seen that the driver bodies 36, 37 are each preloaded radially inwards in the direction of the driver groove geometry 34 by a spring device 38, 39.

[0025] The spring devices 38, 39, for example, are springs 17 designed as helical compression springs. The driving groove geometry 34 comprises two axial grooves 22, 28 formed on the outside of the nut 13, also referred to as the spindle nut, between two circumferential grooves 20, 24. The axial grooves 22, 28 are also referred to as driving grooves for functional reasons. The circumferential grooves 20, 24 are also referred to as circumferential grooves for functional reasons.

[0026] The circumferential grooves 20, 24 or circumferential grooves are each equipped with a ramp geometry in the circumferential or circumferential direction. The axial grooves or driving grooves 22, 28 are equipped with a geometric undercut 23, which serves to hold the respective driving body 36, 37 radially in the respective axial groove 22, 28. The ramp geometries each comprise at least two ramps 21, 25. The ramps 21 and 25 are, as can be seen in Fig. 7, aligned with the axial groove 22.

[0027] An actuating element 18, which can also be referred to as a driver, is arranged on the second spindle element 32, which is designed as a nut 13. The actuating element 18 is, as can be seen in Fig. 3, it is rotationally decoupled from the second spindle element 32 by a decoupling bearing 15. The decoupling bearing 15 is designed here as a radial ball bearing.

[0028] The actuating element 18, also referred to as the driver, follows a translational movement of the second spindle element 32. The actuating element 18, also referred to as the driver, is rotationally decoupled from the second spindle element 32.

[0029] In Fig. In Figure 7, an arrow indicates an axial actuating force 41, which results from a translational displacement of the second spindle element 32 with the actuating element 18 onto the first spindle element 31. In the illustrated embodiment, the axial actuating force 41 is converted into a rotary movement of the actuating shaft 8 via a coupling device 40. However, this is only an example in the present case. In the claimed spindle actuator 30, the primary concern here is the provision of the axial actuating force 41.

[0030] The coupling device 40 comprises a connecting rod 14 and a lever 19. The connecting rod 14 is articulated to the driver or actuating element 18 in a first end region of the connecting rod 14, which in the present case comprises two symmetrically arranged parts. In a second region, the lever 19 is connected to the connecting rod 14. The lever 19 is connected to the actuating shaft 8, which is mounted in the housing, in a torque-transmitting manner. The driver 18 is also rotationally fixed relative to the housing via the articulated connections.

[0031] If one of the driver bodies 36, 37, which can also be referred to as drivers for short, is located axially at the level of one of the circumferential grooves 20, 24 of the groove geometry, the rotor 26 with the driver bodies 36, 37 can be freely rotated in a first direction of rotation of the rotor 26. The rotor 26 then drives the pump 9 connected to it in a torque-transmitting manner, without also rotating the second spindle element 32. If the rotor 26 is driven slowly, the respective driver body 36, 37 rubs against the bottom surface of the associated circumferential groove 20, 24 and follows the rising ramp geometry applied thereto, or at the end of the respective ramp 21, 25, due to the spring force, falls radially inward onto a minimum base circle of the circumferential groove 20, 24 following the ramp step.In order to avoid the resulting noise and vibrations, the driver mass, spring and the position of the driver bodies 36, 37 are selected such that the driver body 36, 37, when the pump 9 is operating at its full speed, is lifted radially outwards from the base surface of the circumferential groove 20, 24 due to the centrifugal force and can thus rotate silently and frictionlessly relative to the second spindle element 32.

[0032] If the direction of rotation of the drive motor 11 is reversed, the driver bodies 36, 37 are initially pressed radially inward onto the base surface / ramp of the circumferential groove 20, 24 by the respectively associated spring device 38, 39 due to the falling speed. Following the reversal of the direction of rotation, the driver bodies 36, 37 then follow the then descending ramp geometry up to its end or a step in the transition to the radially outer end region of the circumferential groove 20, 24. Due to the stop at the step, the second spindle element 32 is now rotationally driven by the rotor 26 via the driver body 36, 37. The spindle geometry 33 causes an axial feed of the second spindle element 32 and the actuating element 18, which is also referred to as a driver, meshes into the axial groove 22, 28, which is also referred to as a driving groove, of the driving groove geometry 34.The undercut geometry in the driver body 36, 37 and the axial groove 22, 28 geometrically prevents the driver body 36, 37 from being moved out of the respective axial groove 22, 28 even at high speed.

[0033] As an alternative to the only indicated undercut geometry with the undercut 23, the radial groove height in the area of ​​the axial groove 22, 28 can also be designed to be greater than the maximum height of the ramp. This way, the radial outward movement of the driver bodies 36, 37 can be limited such that the driver body 36, 37 is no longer in contact with the respective ramp in the area of ​​the circumferential groove 20, 24, but flies over it. In the area of ​​the axial groove 22, 28, however, there is a radial overlap between the driver and the groove edge. Although this solution is not shown, it is easier to implement in terms of manufacturing technology.

[0034] As long as the driver body 36, 37 engages in the respective axial groove 22, 28, the direction of rotation of the actuating shaft 8 can be reversed as desired, whereby the desired change-of-mind capability is ensured.

[0035] If the driver body 36, 37 reaches a circumferential groove 20, 24 at the end of the axial groove 22, 28 on the second spindle element 32, the second spindle element 32 is no longer driven in rotation, and further rotation in the same direction can drive the pump 9. Upon further reversal of the direction of rotation, the driver body 36, 37 re-engages the corresponding axial groove 22, 28, and so on. List of reference symbols 1 pump housing 2 hydraulic connections 3 Hydraulic connection 4 engine housing 5 plugs 6 Gearbox housing 7 Mounting flange 8 Actuating shaft 9 Pump 10 Electronic component 11 Drive motor 12 spindle 13 Mother 14 connecting rods 15 decoupling bearings 16 contour pen 17 spring 18 Actuating element 19 levers 20 circumferential groove 21 Ramp 22 axial groove 23 Undercut 24 circumferential groove 25 Ramp 26 Rotor 27 Stator 28 axial groove 29 contour pen 30 spindle actuator 31 first spindle element 32 second spindle element 33 Spindle geometry 34 Driving groove geometry 35 Carrier device 36 driver bodies 37 Driver body 38 Spring device 39 Spring device 40 Coupling device 41 axial actuating force

Claims

[1] Electric motor-driven spindle actuator (30) with a driven pump (9) which serves to supply cooling and / or lubrication with a suitable medium, and with a first spindle element (31) which cooperates via a spindle geometry (33) with a translationally displaceable second spindle element (32) which serves to represent an axial actuating force (41), characterized by in that the spindle actuator (30) is combined with a driver device (35) which comprises a driver groove geometry (34) with at least one axial groove (22, 28) and with at least one circumferential groove (20, 24) which has at least one ramp (21, 25) acting in the circumferential direction, wherein the driver device (35) comprises at least one driver body (36, 37) which engages in the driver groove geometry (34). [2] Electric motor driven spindle actuator according to claim 1, characterized bythat the ramp (21,25) has a sliding flank and a driving flank which is aligned with the axial groove (22,28). [3] Electric motor driven spindle actuator according to one of the preceding claims, characterized by that the driving groove geometry (34) comprises two circumferential grooves (20,24) which are connected to one another via the axial groove (22,28). [4] Electric motor driven spindle actuator according to one of the preceding claims, characterized by that the driver body (36,37) is connected in a rotationally fixed manner to a rotor (26) of a drive motor (11), wherein the driver body (36,37) is radially displaceable relative to the rotor (26). [5] Electric motor driven spindle actuator according to claim 4, characterized by that the driver body (36,37) is movable out of the driver groove geometry (34) under the action of centrifugal force against the pretensioning force of a spring device (38). [6] Electric motor driven spindle actuator according to claim 4 or 5, characterized by that the driver device (35) comprises two diametrically arranged driver bodies (36,37). [7] Electric motor driven spindle actuator according to claim 6, characterized by that each driver body (36,37) is assigned an axial groove (22,28). [8] Electric motor driven spindle actuator according to one of the preceding claims, characterized by that the first spindle element (31) is designed as a spindle (12) fixed to the housing and the second spindle element (32) is designed as a nut (13). [9] Electric motor driven spindle actuator according to one of the preceding claims, characterized by that the driver body (36,37) is designed as a contour pin (16,29) which interacts with a holding geometry of the driver groove geometry (34) in such a way that the contour pin (16,29) cannot move radially outwards when passing through the axial groove (22,28). [10] Method for operating an electric motor driven spindle actuator (30) according to one of claims 1 to 9, characterized by that the driver device (35) with the driver groove geometry (34) maintains a sufficient supply of cooling and / or lubrication by the driven pump (9) even when a changed actuation request is directly implemented.

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