Actuator for providing fluid flow and other actuation function

Abstract

The invention relates to an actuator (1) with a separate actuation function, said actuator comprising: an electric drive (5) housed in an actuator housing (2), the electric drive (5) comprising a stator (6) and a drive rotor (7) rotatable about an axis of rotation (23); and a fluid transfer device (18), the transfer rotor (19) of which is connected to the drive rotor (7) for co-rotation therewith, the eccentric (32) being positioned on a drive shaft (30) via a first freewheel (31), which is connected to the transfer rotor (19) coaxially to the axis of rotation (23), the freewheel lever (34) being mounted indirectly on the output shaft (36) via a second freewheel (35), the eccentric (32) moves the freewheel lever (34) at least indirectly in an oscillating manner in the circumferential direction of the output shaft (36), and linear and / or rotationally driven actuating elements driven by the oscillating movement are guided out of the actuator housing (2).

Description

Technical Field

[0001] The invention relates to an actuator for providing a fluid flow for cooling and / or lubrication and an additional actuating function, which actuator has only one electric drive and no further active switching elements. Background Art

[0002] From European patent specification EP 3 126 696 B1, an actuator for clutch actuation is known, which has a motor module and an actuation module, which can be a mechanical module or a hydraulic module. From German patent specification DE 10 2016 218 118 B4, an electric pump actuator for actuating a parking lock with a hydraulic double-acting cylinder-piston unit is known. Both patents have in common that the actuators used are designed only for providing a fluid flow. Therefore, the actuators known in the prior art only provide cooling, lubrication or hydraulic pressure.

[0003] On the basis of this, the present invention is based on the object of at least partially overcoming the disadvantages known from the prior art and in particular providing an actuator which, in addition to providing a fluid flow, also provides an actuation function in a purely mechanical way in order to avoid hydraulic losses and for reasons of robustness and which can be adapted to the requirements of different tasks by varying the characteristics of the actuation function of simple components. Summary of the invention

[0004] This object is achieved by the features of the independent claim 1. Further advantageous embodiments of the invention are described in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technically meaningful manner and can define further embodiments of the invention. In addition, the features indicated in the claims are described and explained in more detail in the description, wherein further preferred embodiments of the invention are shown.

[0005] According to the present invention, an actuator with another actuation function includes an electric drive accommodated in an actuator housing, the electric drive including a stator and a drive rotor rotatable around a rotation axis, and the actuator has a fluid conveying device, the transfer rotor of the fluid conveying device is connected to the drive rotor to rotate together with the drive rotor, wherein an eccentric wheel is positioned on a drive shaft via a first free wheel, the drive shaft is connected to the transfer rotor coaxially with the rotation axis, a free wheel lever is indirectly mounted on an output shaft via a second free wheel, the eccentric wheel at least indirectly causes the free wheel lever to move in an oscillating manner along the circumferential direction of the output shaft, and a linear actuating element and / or a rotationally driven actuating element driven by the oscillating motion is guided out of the actuator housing.

[0006] As a precaution, it should be noted that the numerals used herein ("first", "second", etc.) are primarily (only) used to distinguish between several similar objects, dimensions or processes, and in particular do not necessarily indicate any dependency and / or order of these objects, dimensions or processes relative to each other. If a dependency and / or order is necessary, it will be explicitly stated herein or will be followed in a manner obvious to a person skilled in the art when studying the specifically described embodiments.

[0007] A freewheel, also known as an overrunning clutch, is a clutch that only works in one direction of rotation. A freewheel can only transmit torque in one direction of rotation. If the direction of rotation is reversed or if the speed of the driven part is greater than the speed of the driving part, the connection automatically releases.

[0008] Preferably, the linearly driven actuating element is an actuating tappet and the rotationally driven actuating element is an output shaft. Furthermore, the output shaft can be indirectly mounted on the actuator housing via a third free wheel.

[0009] Preferably, the actuator housing comprises a base body, a first cover-shaped housing body and a second cover-shaped housing body. The base body of the actuator housing is pot-shaped and comprises a receiving space for the electric drive. The first cover-shaped base body and the second cover-shaped base body are each attached to the pot-shaped end of the base body opposite to each other. Preferably, the first cover-shaped housing base body has a first hydraulic connection and the second cover-shaped housing base body has a second hydraulic connection.

[0010] The fluid delivery device may be a continuous flow machine or a positive displacement machine (pump). In order to achieve an additional actuation function in addition to the fluid delivery function, the delivery rotor of the fluid delivery device is connected to a drive shaft coaxially positioned with the axis of rotation for co-rotation with the drive shaft. The drive shaft is thus at least indirectly connected to the drive rotor for co-rotation with the drive rotor. In order to provide the additional actuation function, an eccentric wheel or a cam is connected to the drive shaft via a first free wheel.

[0011] Preferably, the axially displaceable and oscillating push rod rests with a first end on the peripheral surface of the eccentric and is positioned on the freewheel lever with the other end. The push rod can preferably be positioned orthogonal to the axis of rotation, wherein, alternatively, it is also preferred that the push rod is oriented obliquely relative to the axis of rotation. The eccentric transmits the linear oscillation stroke to the freewheel lever positioned indirectly and coaxially on the output shaft via the push rod extending radially thereon and mounted so as to be axially displaceable. The first freewheel drives the output shaft only in the first rotation direction of the drive shaft or the electric drive via the push rod and the freewheel lever. In the second rotation direction, the first freewheel is overtaken so that only the fluid conveying device is driven, thereby only realizing the cooling or lubrication function.

[0012] The second freewheel is positioned between the freewheel lever and the output shaft in the rotation center of the freewheel lever. Thus, by means of the freewheel lever and the second freewheel, the freewheel lever performs an oscillating rotational movement about the output shaft, wherein this rotational movement is only intermittently transmitted to the output shaft in the first actuation direction due to the second freewheel. The output shaft is in turn supported on the actuator housing, in particular on the second cover-shaped housing body, via preferably a third freewheel. This means that during the return stroke of the second freewheel, which is triggered by the return stroke of the push rod, the output shaft is secured by the third freewheel against rotation in a direction opposite to the actuation direction.

[0013] In order to utilize the intermittent rotational movement of the output shaft, the output shaft is preferably guided out of the actuator housing at least at one end. In order to prevent the hydraulic fluid from escaping through the circumferential gap between the actuator housing and the output shaft, a seal is provided between the actuator housing and the output shaft.

[0014] Preferably, the rotation angle of the output shaft is detected directly or indirectly by a sensor, further preferably, wherein the sensor controls the electric drive via the electronic component so that the electric drive can be activated or deactivated depending on the rotation of the output shaft. The sensor preferably detects the rotation angle of the output shaft directly. Alternatively, the rotation angle of the output shaft can also be detected indirectly by a sensor that determines the adjustment of other components connected to the output shaft, wherein these values ​​are converted into the rotation angle of the output shaft by the electronic component.

[0015] Preferably, a fourth free wheel is positioned between the transfer rotor and the drive shaft, wherein the fourth free wheel is mounted in the opposite direction of action to the first free wheel. Thus, during the actuation function of the output shaft, the fluid transfer device is not driven.

[0016] Preferably, the radial surface of the eccentric and the contact surface of the end of the push rod adjacent to the eccentric are designed to be particularly low-friction. The particularly low-friction surface is characterized by a high level of smoothness, i.e. a surface with fewer protrusions. Preferably, the term low friction is understood to mean that the material pair of the radial surface of the eccentric and the contact surface of the end of the push rod adjacent to the end has a sliding friction coefficient of less than 0.12. The friction reduction of the contact area between the push rod and the eccentric leads to reduced friction losses and increases the life expectancy of the two components. Preferably, the eccentric has a higher hardness than the push rod, because the material contraction can be better compensated by moving the push rod forward without impairing the function of the device or reducing the axial displacement of the push rod. In order to reduce manufacturing and production costs, the first free wheel and / or the second free wheel and / or the third free wheel and / or the fourth free wheel are preferably identical. Standardization of the free wheel leads to reduced procurement costs or manufacturing costs, which means that the actuator can be manufactured more cost-effectively.

[0017] Preferably, a return spring is provided, which serves to counteract the axial and oscillating movement of the push rod and the freewheel lever in the direction away from the axis of rotation. The return spring acts directly on the freewheel lever, so that the return stroke of the freewheel lever takes place safely in the freewheel direction, i.e. opposite to the actuation direction of the second freewheel, and the push rod always remains in contact with the eccentric or cam. For this purpose, the return spring is supported with one end on the actuator housing, more precisely on the second cover-shaped housing base body, and with the other end on the freewheel lever. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Both the invention and the technical field are explained in more detail below with reference to the accompanying drawings. It should be noted that the invention is not intended to be limited to the exemplary embodiments shown. In particular, unless explicitly stated otherwise, sub-aspects of the subject matter explained in the drawings may also be extracted and combined with other components and knowledge from the present specification and / or the drawings. In particular, it should be noted that the drawings and in particular the scales shown are only schematic in nature. The same reference numerals indicate the same objects, so that descriptions from other drawings may also be used where applicable. In the drawings:

[0019] FIG1 : shows a longitudinal section through an actuator known from the prior art;

[0020] Figure 2 : A schematic diagram showing an example of a modular actuator;

[0021] Figure 3 : A schematic diagram showing an example of an actuator for additional actuation of a parking brake; and

[0022] Figure 4 :shows the Figure 3 Schematic cross-sectional view of an example of a modular actuator for additional actuation of a parking brake. DETAILED DESCRIPTION

[0023] According to Fig. 1 , a modular actuator 1 having an actuator housing 2 is known from the prior art. The actuator housing 2 comprises a pot-shaped housing base body 3. The pot-shaped housing base body 3 comprises a receiving space for an electric drive 5.

[0024] The electric drive 5 comprises a stator 6 in which a drive rotor 7 is rotatably positioned. The electric drive 5 is controlled via an electronic module 8 .

[0025] The electronic module 8 comprises a printed circuit board 9 with various electronic components 10. The printed circuit board 9 is positioned in the first cover-like housing body 4 of the electrical connector 13. The first cover-like housing body 4 with the printed circuit board 9 and the electronic components 10 is attached to the pot-like housing base body 3 from the left side in FIG.

[0026] Furthermore, the modular actuator 1 comprises a hydraulic module 25 having a fluid conveying device 18. The fluid conveying device 18 comprises a propeller-shaped or screw-shaped conveying rotor 19. In this exemplary embodiment, the fluid conveying device 18 is designed as a continuous flow machine. The conveying rotor 19 is positioned substantially within the driving rotor 7, which can also be referred to as a pump wheel when a pump is used as a fluid conveying device. The conveying rotor 19 is connected to the driving rotor 7 for common rotation. The conveying rotor 19 is driven via the driving rotor 7. The existing bearings of the driving rotor 7 are used for the conveying rotor 19. A separate bearing is not required for the conveying rotor 19.

[0027] The electric drive 5 further comprises an annular magnet 20. In FIG1 , the annular magnet 20 is positioned in the axial direction between the printed circuit board 9 and the transfer rotor 19 of the fluid transfer device 18. The stator 6 of the electric drive 5 comprises a stator overmolding 21. The stator overmolding 21 comprises a tubular attachment portion 22 which, in FIG1 , extends to the left from the stator 6 through a corresponding through hole in the guide plate 9. The term “axial” refers to the rotation axis 23 of the drive rotor 7 of the electric drive 5.

[0028] The rotation axis 23 of the drive rotor 7 advantageously coincides with the flow direction 27 of the flow channel 26. In Fig. 1 , the flow channel 26 extends in a straight line from left to right through the actuator housing 2 between the first hydraulic connection 11 and the second hydraulic connection 12.

[0029] The first hydraulic connector 11 is provided on a second cover-like housing body 14 located opposite to the first cover-like housing body 4 on the other side of the housing base body 3. The second cover-like housing base body 14 comprises a tubular connection body 15 surrounded by an annular connection space 16.

[0030] Figure 2 An actuator 1 is shown, the basic structure of which is based on the actuator according to FIG. 1 known from the prior art. With reference to the description of FIG. 1 , in the following, only the differences with respect to the actuator known from the prior art will be described. Figure 2The actuator 1 of the embodiment of the invention differs from the actuator 1 according to FIG. 1 known from the prior art in that, among other things, in addition to the fluid conveying function by means of a continuous flow machine or a displacement machine (pump), an additional actuation function is provided. For this purpose, the conveying rotor 19 of the fluid conveying device 18 is connected to a drive shaft 30 coaxially positioned with the axis of rotation 23 for co-rotation. The drive shaft 30 is thus indirectly connected to the drive rotor 7 (see FIG. 1 ) for co-rotation and extends out of the space surrounding the fluid conveying device 18. In order to provide the additional actuation function, an eccentric 32 or cam is connected to the drive shaft 30 via a first freewheel 31. The eccentric 32 transmits the linear alternating or oscillating stroke to a freewheel lever 34 indirectly and coaxially positioned on an output shaft 36 via a push rod 33 extending radially thereon and mounted so as to be axially displaceable. The output shaft 36 represents a rotationally driven actuating element, which is guided out of the actuator housing. The output shaft 36 is positioned parallel to the drive shaft 30. However, other alignments are also preferred, such as an inclined arrangement of the output shaft 36 relative to the drive shaft 30. The first freewheel 31 drives the output shaft 36 only in a first rotational direction of the electric drive 5. In a second rotational direction of the drive shaft 30, the first freewheel 31 is overrun, so that only the fluid conveying device 18 is driven, thereby achieving a cooling function and / or a lubrication function.

[0031] like Figure 4 As shown in FIG. 1 , a second freewheel 35 is positioned between the freewheel lever 34 and the output shaft 36 in the rotation center of the freewheel lever 34 . Thus, an oscillating rotational movement of the freewheel lever 34 is performed by means of the freewheel lever 34 and the second freewheel 35 , wherein the rotational movement is only intermittently transmitted to the output shaft 36 in the first actuation direction A due to the second freewheel 35 . Figure 4 As shown in FIG, the output shaft 36 is in turn supported on the actuator housing 2, in particular on the second cover-shaped housing body 14, via a preferred third freewheel 38. This means that during the return stroke of the second freewheel 35 triggered by the return stroke of the push rod 33, the output shaft 36 is fixed to prevent rotation in the direction opposite to the actuation direction A. In addition, the return spring 37 (see Figure 3 ) acts on the freewheel lever 34 so that the return stroke in the freewheel direction B, i.e. the freewheel direction opposite to the actuation direction A of the second freewheel 35, is safely performed and the push rod 33 remains in contact with the eccentric 32 or the cam. For this purpose, although not shown, the return spring 37 is supported at one end on the actuator housing 2 or the second cover-shaped housing base body 14 and at the other end on the freewheel lever 34.

[0032] The output shaft 36 is guided out of the actuator housing 2 through a seal (not shown). Therefore, the output shaft can perform a rotary actuation function in an external area, wherein torque is intermittently transmitted via the output shaft 36 at least in the actuation direction A. A sensor 39 is provided on the housing side to detect the rotation angle or average rotation speed of the output shaft 36.

[0033] Preferably, the fluid conveying device 18 or the conveying rotor 19 of the fluid conveying device 18 is driven via a fourth intermediate freewheel 40 between the conveying rotor 19 and the drive shaft 30, wherein the fourth freewheel 40 is mounted in the opposite direction to the action of the first freewheel 31. Thus, during the actuating function of the output shaft 36, the fluid conveying device 18 is not driven.

[0034] Figure 3 and Figure 4 A schematic diagram of an actuator 1 according to the invention is shown for providing a fluid flow and for providing an additional actuation of another element (not shown), such as a parking brake, by means of a linear actuation element. In order to perform an actuation function, such as an actuation function of a parking brake, the electric drive 5 is driven in a first rotational direction, in which the first freewheel 31 transmits a torque to the eccentric 32. As a result, the push rod 33 is pushed away from the rotation axis 23 of the eccentric 32 by the rising eccentric 32, and the second freewheel 35 rotates in the torque-transmitting actuation direction A, whereby the output shaft 36 also rotates by a corresponding rotational angle.

[0035] After reaching the highest point of the eccentric 32, the freewheel lever 34 and the push rod 33 follow the rear edge of the eccentric 32 by means of the return spring 37. Figure 2 As already described, this return movement of the push rod 33 and the freewheel lever 34 does not lead to any rotation of the output shaft 36 opposite to the actuation direction A, ie in the freewheel direction B, since the second freewheel 35 is overtaken in the process.

[0036] At the housing-side end of the output shaft 36, an output lever 41 is provided for co-rotation, on which a roller 42 is mounted in a coaxially rotatable manner. The axis of rotation of the roller 42 is stacked horizontally with the axis of rotation of the output shaft 36. The roller 42 is in turn mounted in a guide 43, which enables the roller 42 to be displaced vertically in the guide 43. The guide 43 itself is connected on one side in a non-form-fitting manner to an actuating tappet 44 representing a linear actuating element, wherein the actuating tappet 44 is mounted orthogonally to the output shaft 36 in the actuator housing 2 so as to be able to be displaced axially. If the output shaft 36 is rotated in the actuation direction A, so that the output lever 41 rotates counterclockwise, and the roller 42 is thus displaced downward in the guide 43, the end of the actuating tappet 44 facing away from the guide 43 moves out of the actuator housing 2. In this disengaged position of the actuating tappet 42, the operating load of the parking brake generates a torque on the output shaft 36 in the direction opposite to the actuating direction A, which, however, is maintained by the third freewheel 38. In addition, a return spring (not shown) can also counteract the movement of the actuating tappet 44 away from the actuator housing 2. After the output shaft 36 rotates further in the actuating direction A, the radially rising section of the eccentric 32 follows again, so that the output shaft 36 rotates intermittently in the actuating direction A. Figure 2 Differently, the sensor 39 detects the displacement of the actuating tappet 44 rather than the rotation of the output shaft 36. Figure 3 and Figure 4 In this embodiment, direct sensing of the output shaft 36 is preferred. The sensor 39 detects when the parking brake is almost fully applied, thereby reaching a state in which the output lever 41 is maximally rotated in the direction of the actuating tappet 44. Figure 3 Compared to the illustration in FIG. , this corresponds to a rotation of 180°. In this state, the electric drive 5 is stopped, so that the maximum compressed return spring (not shown) between the actuating tappet 44 and the actuator housing 2 exerts a maximum reaction force on the actuating tappet 44, wherein the output shaft 36 is still held by the third freewheel 38. In this exemplary embodiment, if the output shaft 36 is used for other actuations in addition to the actuating tappet, it is only necessary to guide the output shaft out of the actuator housing.

[0037] In this state, the electric drive 5 can remain stationary or be driven in the second rotational direction to perform cooling and / or lubrication functions. The parking brake is not affected due to the first freewheel 31. This position represents the open state of the parking brake.

[0038] However, if the parking brake is to be closed, the electric drive 5 is driven again in the first rotational direction so that the parking brake exceeds the above-mentioned dead point, wherein a restoring torque is caused to act on the output shaft 36 via a return spring (not shown) in the freewheel direction B. Since this restoring torque acts in the actuation direction A after exceeding the dead point and thus in the freewheel direction of the second freewheel 35 and the third freewheel 38, the output shaft 36 can be freely rotated by the return spring, so that the parking brake can be quickly closed until the parking brake reaches its position in the example. Figure 3 The dead center in the closed position shown in FIG. 1 and remains stable there. In order to close the parking lock, it is only necessary to exceed the opening dead center of the parking lock.

[0039] However, the opposite is also possible, in which the pre-tensioned state represents the closed state and according to Figure 3 The state of represents the opening state of the parking brake. In this respect, the device is not fixed.

[0040] Reference numerals list

[0041] 1 Modular Actuator

[0042] 2 Actuator housing

[0043] 3 Shell base body

[0044] 4. First cover-shaped housing body

[0045] 5 Electric drive

[0046] 6 Stator

[0047] 7 Driving rotor

[0048] 8 Electronic modules

[0049] 9. Printed Circuit Board

[0050] 10 Electronic components

[0051] 11 First hydraulic connection

[0052] 12 Second hydraulic connection

[0053] 13 Electronic connectors

[0054] 14 Second cover-shaped housing body

[0055] 15 Tubular connection body

[0056] 16 Ring connection space

[0057] 18 Fluid delivery device

[0058] 19 Transfer rotor

[0059] 20 Ring magnet

[0060] 21 Stator overmolding

[0061] 22 Tubular attachment portion

[0062] 23 Rotation axis

[0063] 24 Motor Module

[0064] 25 Hydraulic Module

[0065] 26 Flow Channel

[0066] 27 Flow direction

[0067] 30 Drive shaft

[0068] 31 First Liberty Ship

[0069] 32 eccentric wheel / cam

[0070] 33 Putter

[0071] 34 Freewheel lever

[0072] 35 Second Liberty Ship

[0073] 36 Output shaft

[0074] 37 Return spring

[0075] 38 Third Liberty Ship

[0076] 39 Sensors

[0077] 40 Fourth Freedom Ship

[0078] 41 Output lever

[0079] 42 Roller

[0080] 43 Guide

[0081] 44 Actuating tappet

[0082] A Actuation direction

[0083] B Freewheel direction

Claims

1. An actuator (1) having another actuation function, the actuator comprising: an electric drive (5) which is accommodated in an actuator housing (2), the electric drive (5) comprising a stator (6) and a drive rotor (7) which can rotate about a rotation axis (23); and a fluid conveying device (18), a conveying rotor (19) of the fluid conveying device (18) being connected to the drive rotor (7) for co-rotation with the drive rotor, characterized in that An eccentric (32) is positioned via a first freewheel (31) on a drive shaft (30), which is connected coaxially to the transmission rotor (19) with respect to the rotation axis (23), a freewheel lever (34) is indirectly mounted on an output shaft (36) via a second freewheel (35), the eccentric (32) at least indirectly causing the freewheel lever (34) to move in an oscillating manner in the peripheral direction of the output shaft (36), and a linear actuating element and / or a rotationally driven actuating element driven by the oscillating movement is guided out of the actuator housing (2).

2. The actuator (1) according to claim 1, characterized in that The linear drive type actuating element is an actuating tappet (44), and the rotary drive type actuating element is the output shaft (36).

3. The actuator (1) according to claim 1 or 2, characterized in that The output shaft (36) is indirectly mounted to the actuator housing (2) via a third free wheel (38).

4. Actuator (1) according to any one of the preceding claims, characterized in that The sensor (39) directly or indirectly detects the rotation angle of the output shaft (36).

5. Actuator (1) according to any one of the preceding claims, characterized in that A push rod (33) which is axially displaceable and oscillating rests with a first end on the peripheral surface of the eccentric (32) and is positioned with the other end on the freewheel lever (34).

6. Actuator (1) according to claim 5, characterized in that A return spring (37) counteracts axial and oscillating movements of the push rod (33) and the freewheel lever (33) in a direction facing away from the axis of rotation (23).

7. Actuator (1) according to any one of the preceding claims, characterized in that A fourth free wheel (40) is positioned between the transfer rotor (19) and the drive shaft (30).

8. Actuator (1) according to any one of the preceding claims, characterized in that The first free wheel (31) and / or the second free wheel (35) and / or the third free wheel (38) and / or the fourth free wheel (40) are identical in structure.

9. Actuator (1) according to any one of the preceding claims, characterized in that The actuator housing (2) comprises a base body (3), a first cover-shaped housing body (4) and a second cover-shaped housing body (14).

10. The actuator (1) according to claim 8, characterized in that The first cover-shaped housing body (4) has a first hydraulic connection (11), and the second cover-shaped housing body (14) has a second hydraulic connection (12).

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