Actuator with transport lock

Abstract

The invention relates to an actuator 1 comprising an electric motor 2 with a current-carrying stator 3 and a rotor 4 for driving an output element 5. The actuator 1 further comprises an actuator housing 11 and at least one housing-fixed component in the vicinity of the rotor 4, the output element 5 or a component non-rotatably connected to the rotor 4. The rotor 4, the output element 5, or the component non-rotatably connected to the rotor 4 fill an operating volume 6 during operation, in which the rotor 4, the output element 5, or the component non-rotatably connected to the rotor 4 rotates, wherein a locking element 7, which is connected to the housing-fixed component, projects into the operating volume 6 in such a way that rotation of the rotor 4 is prevented when the stator 3 is de-energized, and when the stator 3 is energized, the rotor 4 can be set into rotation in such a way that the locking element 7 is preferably permanently moved out of the operating volume 6 by the movement of the rotor 4 caused by the stator 3.

Description

[0001] The present invention relates to an actuator comprising an electric motor with a stator to which current can be applied and a rotor for driving an output element, an actuator housing and at least one component fixed to the housing in the vicinity of the rotor or a component connected to the rotor in a rotationally fixed manner.

[0002] Actuators are known from the prior art, such as those described in WO 2015 / 117612 A2. A planetary gear train is used to transmit torque from the rotor of an electric motor to a spindle that is fixedly mounted on a housing in a rotationally fixed manner, allowing the spindle to move linearly, i.e. axially. A potential problem with this design is that no preload is applied to the spindle during transport, and any movement of the spindle is transmitted to the rotor by the planetary gear train, causing the rotor to rotate without energizing the stator. For various reasons, it may be desirable to prevent such rotation of the rotor.

[0003] Further relevant prior art is known from DE 10 2014 015 938 A1, DE 10 2009 047 502 A1, DE 10 2016 212 925 A1, DE 10 2010 024 962 A1 and DE 10 2006 054 845 A1.

[0004] The present invention is intended to at least alleviate the problem described above.

[0005] This object of the invention is achieved by a generic actuator according to the features of claim 1.

[0006] Further advantageous embodiments of the actuator are described in the subclaims.

[0007] During operation, i.e. when the stator is energized, the rotor or a component connected to the rotor, such as an output element or a component connected to the rotor in a rotationally fixed manner, fills an operating volume in which the rotor, the output element or the component connected to the rotor in a rotationally fixed manner rotates. The invention provides a securing element which is connected to a component fixed to the housing. This can be a pin or a formation, for example. Furthermore, the securing element projects into the operating volume in such a way that rotation of the rotor is prevented when the stator is de-energized. According to the invention it is further provided that when the stator is energized the rotor can be set in rotation in such a way that the securing element is moved out of the operating volume by the movement of the rotor caused by the stator.This permanently removes the locking element from the rotor's operating volume. This advantageously secures the rotor against unintentional rotation during transport prior to initial commissioning.

[0008] The component fixed to the housing can, on the one hand, be an integral part of the housing itself, on the other hand it can be a cover, in particular a plastic cover of the actuator housing, or it can be a bridging element that is positively, non-positively or materially connected to the actuator housing.

[0009] The actuator can be a non-self-locking actuator. This allows for greater efficiency during operation than self-locking actuators. The safety element described above can enable safe transport of the actuator despite the lack of, or only limited, self-locking.

[0010] To ensure that the safety element can be permanently removed from the operating volume, it can be elastically connected to a component fixed to the housing in such a way that after the stator is first energized, i.e., after the electric motor or rotor is started up, the safety element is relocated to a location outside the operating volume but still remains connected to the component fixed to the housing. This prevents a moving part from remaining inside the actuator, which could interfere with other parts of the actuator. This avoids a potential source of error.

[0011] Alternatively, it can be provided that the securing element is broken off or sheared off from the housing-fixed component by a rotation of the rotor caused by energization of the stator. In order to avoid sources of error in this case as well, a collecting basin can be provided outside the operating volume to collect the broken or sheared-off securing element.

[0012] The rotation of the rotor causes the rotor itself to rotate. Any output element coupled to the rotor or a component connected to the rotor in a rotationally fixed manner is also moved or set in rotation. Only during movement or rotation is the operating volume as a whole swept over by components of the rotor, the output element or the component connected to the rotor in a rotationally fixed manner. This means that when the respective element is at a standstill, the securing element protruding into the operating volume is not affected. Only when the rotor moves does an interaction occur. Depending on the connection between the component fixed to the housing and the securing element, the latter is removed from the operating volume above a predetermined force or a predetermined torque. By appropriately selecting or designing the connection to the securing element, it is achieved that this predetermined force or torque is maintained during active control of the rotor, ieis exceeded during (initial) commissioning of the rotor and otherwise the locking element prevents corresponding movement at smaller forces or torques by supporting them on the housing.

[0013] In an actuator it can be provided that the torque is transferred from the rotor to the output element and the output element is coupled to the input of a gearbox. The electric motor is then connected via this gearbox to an actuating element such as a clutch actuating means or parking lock actuating means, here for example a lever, a pressure pot or a cross member. The gearbox can be used to increase the speed or reduce the speed. It can therefore be provided that a greater torque occurs at the gearbox output than at the gearbox input, i.e. when coupled to the output element. If the rotor is not operated, i.e. the stator is de-energized, the gearbox can still be actuated from the gearbox output. This is particularly relevant during transport of the actuator prior to installation, i.e. before initial commissioning.If a higher torque is applied to the gearbox input of the actuator's gearbox during transport than that provided for by the limit torque of the securing element, it can advantageously be provided that this torque is reduced by the gearbox in such a way that this torque at the position of the securing element in the operating volume is lower than the limit torque and rotation of the rotor is prevented by this introduced torque. Furthermore, it can then also be provided that, at least during the initial commissioning of the electric motor or the actuator, the torque caused by the stator is so much higher than the torques occurring at the gearbox input during transport that a corresponding limit torque is exceeded and the securing element is permanently removed from the operating volume.This removal from the operating volume is preferably achieved by dissolving or deforming the connection between the securing element and the component fixed to the housing.

[0014] In contrast to a locking element in the area of ​​the output of a gearbox behind the electric motor, such as a planetary roller gear, the locking element in the area of ​​the rotor or the operating volume only has to support a lower torque determined by the gear ratio. This leads to a reduced torque required to remove the locking element from the operating volume. Furthermore, manual intervention is not necessary to remove the locking element from the operating volume.

[0015] A simple arrangement can be achieved by providing the securing element on an axial end face of the rotor, the output element or the component connected to the rotor in a rotationally fixed manner. So that the securing element can then protrude into the operating volume, the corresponding component, i.e. the rotor, the output element or the component connected to the rotor in a rotationally fixed manner, has a receptacle corresponding to the securing element on the end face facing the securing element. The interaction between the securing element and the receptacle can be designed in such a way that a corresponding form-fit connection is provided between the securing element and the receptacle. On the other hand, it can also be sufficient if the securing element protrudes into the receptacle in such a way that a slight play is still possible for the corresponding component.

[0016] In one embodiment, the output element is an output sleeve which can be connected in a rotationally fixed manner to an inner diameter of the rotor, in particular via an interference fit. On one axial end face of the output sleeve, the output sleeve has a receptacle for receiving the securing element. For this purpose, the output sleeve can have an axial notch which correlates with the axial extent of the securing element. In particular, the securing element can be a pin which engages in this notch. The width of the pin in the circumferential direction is then less than the tangential extent of the notch, while the pin preferably has a greater extent, i.e. width, than the output sleeve, in the radial direction.

[0017] A preferred embodiment of the invention, from which further features according to the invention can also arise and to which the invention is not limited, is shown in the single figure.

[0018] The single figure shows an actuator 1 with an electric motor 2. The electric motor 2 comprises a stator 3 and a rotor 4. The rotor 4 is connected to an output sleeve 5 via an interference fit. The output sleeve 5 extends axially in the direction of the axis of rotation 12 of the rotor 4. On a first axial end face 15, the output sleeve 15 has a radial collar 16. The collar 16 serves to accommodate a bearing 20, in particular the inner ring 21 of the bearing 20. The stator 3 is completely overmolded. The overmold 22 is designed such that it forms the motor area 23 and plug area 24 of the actuator 1. The motor area 23 of the overmold 22 is designed such that it accommodates the actuator housing 11 in the area of ​​the first axial end face 15 of the output sleeve 5. The actuator housing 11 is made of metal and closes off the motor area 23 to the outside.The actuator housing 11 is pot-shaped and correlates with the shape of the overmolding 22.

[0019] For axial and radial support of the output sleeve 5, the outer ring 25 of the bearing 20 has a radial nose 26 at its axial end region 27. The nose 26 is circumferentially annular and is axially received between the actuator housing 11 and the overmolding 22, providing axial support for the bearing 20. Furthermore, the outer ring 25 rests with its radial outer surface 28 against a radial inner surface 29 of the overmolding 22, thereby providing radial support.

[0020] Furthermore, the stator 3 is connected to a printed circuit board 31 of the electronics 32 of the actuator 1 via a lead frame 30. The lead frame 30 and the printed circuit board 31 are located on the second axial end face 33 of the output sleeve 5, opposite the first axial end face 15. The connection of the electric motor 2 to a connector 44 of the connector area 24 is also established via the electronics 32 or the printed circuit board 31.

[0021] The output sleeve 5 has a cup-shaped profile on its second axial end face 33, i.e. the output sleeve 5 tapers, here gradually radially inwards towards the axis of rotation 12, and is rotatably received in the overmolding 22. On this second axial end face 33, the base region 34 of the output sleeve has a connecting hole 35 for connection to a connecting shaft 36 of a sun gear 37 of a planetary gear 38. In this region, the circuit board 31 has a hole 39 through which the connecting shaft 36 extends axially, so that the planetary gear 38 and the output sleeve 5 are located on axially different sides of the circuit board 31.

[0022] In the example shown here, the overmolding 22 also projects axially at least into the hole 39 of the printed circuit board 31 and thus creates a rotationally fixed connection between the overmolding 22 and the printed circuit board 31.

[0023] The planetary gear 38 further comprises planets 40, whose planet carrier 41 acts as the output of the planetary gear 38. Via an internal gearing 42, the planet carrier 41 can be connected to suitable mechanical modules of the actuator 1 (not shown here) and drive them.

[0024] During transport of the actuator 1, especially before initial commissioning, the mechanical module is not yet connected to the planetary carrier 41. Therefore, blocking of the planetary gear 38 by this mechanical module cannot occur, and unintentional movements of the planetary gear 38 may occur. These (rotational) movements are then transmitted to the output sleeve 5 via the sun gear 37 and the connecting shaft 36, since the output sleeve 5 is connected to the connecting shaft in a rotationally fixed manner. Via the interference fit between the output sleeve 5 and the rotor 4, the movement can be transmitted to the rotor 4, causing damage there or at least unintentionally adjusting the position of the rotor 4 relative to the stator 3.

[0025] In order to prevent these unwanted movements of the rotor 4, the actuator housing 11 has a component fixed to the housing as an integral part. From this component fixed to the housing, a securing element 7 projects into the output sleeve 5. The output sleeve 5 is constructed from a sheet metal cylinder 43 with a collar 16 on the first axial end face 15 of the output sleeve 5. This sheet metal cylinder 43 has a gap 45 on the first axial end face 15 as a receptacle for the securing element, into which the securing element 7 can project axially. The securing element 7 is then arranged in the circumferential direction directly adjacent to the tangential side surfaces of the gap 45. The securing element 7 is constructed here like a tab 46 that projects into the gap 45. The tab 46 prevents the output sleeve 5 from rotating and prevents the transmission of a torque introduced via the planetary gear 38 to the rotor 4.In particular, several gaps 45 can be provided to accommodate several tabs 46, allowing torque to be supported more effectively. The tab(s) 46 thus provide effective transport security for the actuator 1.

[0026] If the tabs 46 are removed radially outwards or inwards from the area of ​​the gaps 45, the output sleeve 5 and thus the rotor 4 can rotate freely again, for example caused by energizing the stator 3. During this free rotation, the sheet metal cylinder 43 and thus the output sleeve 5 sweeps over the spatial area of ​​the gap 45, the operating volume of the output sleeve 5 here occupies an annular space into which the tabs 46 protrude in the case of transport security.

[0027] In order to deactivate the transport lock, the stator 3 is energized in such a way that the rotor 4 and thus also the output sleeve 5 are subjected to such a large torque that the tabs 46 are sheared off. This torque lies above a predetermined torque above which the tabs 46 are safely sheared off. This predetermined torque is selected and adjusted by material properties such as material type, thickness and width of the tabs 46 and the sheet metal cylinder so that it lies above the torques to be expected from unwanted movements during transport. Since the planetary gear 38 reduces any introduced unwanted torque, this predetermined torque does not have to be selected to be inappropriately high. In particular, it is sufficient if this torque is only exceeded during initial commissioning.

[0028] To prevent further disruptions, collection areas, such as collecting basins or magnetic holders for the sheared-off tabs 46 can be provided inside or outside the output sleeve 5, i.e., outside the operating volume of the output sleeve 5, either directly on the output sleeve 5, on the overmolding 22, or on the actuator housing 11. If the tabs 46 are made of a magnetizable metal, they can be collected by a suitable magnet. Alternatively, the tabs 46 can also be elastically constructed such that they are deformed by the movement of the output sleeve 5 such that they are permanently outside the operating volume of the output sleeve 5. List of reference symbols 1 actor 2 electric motors 3 Stator 4 Rotor 5 Output sleeve 6 Operating volume 7 Fuse element11 Actuator housing 12 axis of rotation 15 first axial end face 16 fret 20 warehouses 21 inner ring 22 Overmolding 23 Engine area 24 plug area 25 Outer ring 26 Nose 27 End area 28 exterior area 29 inner surface 30 punched grids 31 circuit board 32 Electronics 33 second axial end face 34 Floor area 35 connecting hole 36 Connecting shaft 37 Sun gear 38 planetary gears 39 holes 40 planets 41 planet carrier 42 internal gearing 43 sheet metal cylinders 44 plugs 45 gap 46 tab

Claims

[1] Actuator (1) comprising an electric motor (2) with a stator (3) to which current can be applied and a rotor (4) for driving an output element (5), an actuator housing (11) and at least one housing-fixed component in the vicinity of the rotor (4), the output element (5) or a component connected in a rotationally fixed manner to the rotor (4), wherein the rotor (4), the output element (5) or the component connected in a rotationally fixed manner to the rotor (4) fills an operating volume (6) during operation, in which the rotor (4), the output element (5) or the component connected in a rotationally fixed manner to the rotor (4) rotates, a securing element (7) is connected to the housing-fixed component and the securing element (7) projects into the operating volume (6) in such a way that rotation of the rotor (4) is prevented in a currentless state of the stator (3), in an energized state of the stator (3), the rotor (4) can be set in rotation such that the securing element (7) is permanently moved out of the operating volume (6) by the movement of the rotor (4) caused by the stator (3), and the connection between the securing element (7) and the housing-fixed component is designed in such a way that rotations of the rotor (4) caused by gear parts located outside the electric motor (2) are prevented and the connection is either dissolved or deformed during initial commissioning by a torque caused by energizing the stator (3) in such a way that the securing element (7) is no longer permanently located in the operating volume (6), so that the securing element (7) provides transport security. [2] Actuator according to claim 1, characterized by that it is a non-self-locking actuator (1). [3] Actuator according to one of claims 1 or 2, characterized bythat the securing element (7) is elastically connected to the housing-fixed component in such a way that after the rotor (4) has been put into operation and is moved outside the operating volume (6), it is connected to the housing-fixed component. [4] Actuator according to one of claims 1 or 2, characterized by that the securing element (7) is broken off or sheared off from the housing-fixed component by the rotation of the rotor (4) caused by the energization of the stator (3). [5] Actuator according to claim 4, characterized by that a collecting basin for receiving the broken or sheared-off securing element (7) is provided inside the actuator housing (11) and outside the operating volume (6). [6] Actuator according to one of the preceding claims, characterized bythat the securing element (7) is provided on a first axial end face (15) of the rotor (4), the output element (5) or the component connected in a rotationally fixed manner to the rotor (4), and the rotor (4), the output element (5) or the component connected in a rotationally fixed manner to the rotor (4) has an axial receptacle for receiving the securing element (7) in the operating volume (6). [7] Actuator according to claim 6, characterized by that the output element is a sleeve (5) and the sleeve (5) has a receptacle (16) for receiving the securing element (7) in the operating volume (6) of the sleeve (5).

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