Actuating device

Abstract

The invention relates to an actuating device (10) for an upper movable assembly, i.e. Not belonging to the actuating device (10), in particular for a vehicle part that can be moved relative to a body of a vehicle, comprising at least a drive arrangement (12) having a drive unit (14), a transmission unit (20) arranged in a housing (16), and an actuating element (22), the drive arrangement (12) has an actuating element (14) which can be displaced relative to the drive arrangement (12) by means of a drive unit (14), the drive unit (14) having an output shaft (24) which is mounted in a housing (16) at least by means of an axial bearing (32) for backlash compensation and / or tolerance compensation, a curved shaft end (30) of the output shaft (24) resting on a thrust washer (36) by means of a convex running surface (31), the thrust washer (36) is supported on an elastomeric element (34) arranged in the housing (16), and wherein the thrust washer (36) has a concave thrust surface (42) for contacting a curved shaft end (30) of the output shaft (24), which is designed to be complementary to a convex running surface (31) of the shaft end (30) at least on an end face (38) facing the output shaft (24).

Description

Technical Field

[0001] The present invention relates to an actuation device for a superior movable component, i.e., not an actuation device itself, particularly for a vehicle component movable relative to the vehicle body. The actuation device includes at least a drive arrangement structure having a drive unit, a transmission unit arranged in a housing, and an actuating element displaceable relative to the drive arrangement structure by means of the drive unit. The actuating element is displaceable relative to the drive arrangement structure by means of the drive unit, wherein the drive unit has an output shaft mounted in the housing at least by means of an axial bearing to compensate for clearances and / or tolerances. Background Technology

[0002] Such actuation devices are known, for example, by DE 10 2016 218 226 A1, and are particularly used for automatically opening and closing doors and / or hatches of motor vehicles. The transmission unit can apply significant axial forces to the output shaft of the electric motor. Therefore, the prior art provides a zero-clearance axial bearing for the output shaft, consisting of an elastic element and a flat thrust washer attached thereto. However, a disadvantage of this approach is the lack of radial support for the free-cantilevered end of the output shaft, as the output shaft may bend due to the radially generated transmission forces, potentially altering the shaft spacing of the transmission mechanism. This, in turn, can lead to deterioration of acoustic performance and, on the other hand, increased wear and tear.

[0003] Therefore, other methods have proposed additional radial supports for the shaft end. For example, DE 195 13 970 A1 discloses arranging the shaft end in a spring-loaded can-shaped support that prevents lateral deflection of the shaft. However, such bearing mechanisms result in excessive mechanical constraint on the bearing mechanism, which in turn may lead to unwanted noise generation, increased wear, and potential damage to the actuator.

[0004] Therefore, the object of the present invention is to provide an actuation device with an improved axial bearing and dynamic radial support. Summary of the Invention

[0005] According to the invention, this objective is achieved by an actuation device of the type described at the beginning, wherein the bent shaft end of the output shaft rests on a thrust washer by means of a convex running surface, the thrust washer being supported on an elastomeric element arranged in a housing, wherein, in order to contact the bent shaft end of the output shaft, the thrust washer has a concave thrust surface, the concave thrust surface being designed to be complementary to the convex running surface of the shaft end, at least on the end face facing the output shaft.

[0006] The running surface and thrust surface are synchronized to achieve a self-centering effect and a more uniform load distribution. This helps to increase bearing life.

[0007] Preferably, in the unloaded state, the convex running surface of the shaft end is arranged at least almost centrally on the concave thrust surface of the thrust washer.

[0008] The at least nearly centered arrangement of the convex running surface at the shaft end relative to the concave thrust surface ensures the optimal starting position for bearing loads under no-load conditions and contributes to uniform load distribution.

[0009] This implementation scheme enables precise guidance of the motor shaft even under dynamic loads, thereby improving the operational reliability and performance of the actuator.

[0010] According to an advantageous improvement of the invention, the thrust surface of the thrust washer and the running surface of the shaft end are designed to be complementary to each other, such that when the shaft end is radially deflected from the center of the concave thrust surface, a force that counteracts the deflection can be generated on the shaft end by the elastic deformation of the elastomeric element.

[0011] Therefore, if the radial force from the transmission unit causes the free shaft end of the output shaft to bend, the shaft end will shift out of the center of the thrust washer and its concave running surface. This lateral displacement of the shaft end causes compression, i.e., elastic deformation, of the elastomeric element, which generates a reaction force on the shaft end against deflection, thereby reducing deflection and centering the shaft end. Thus, the centering of the shaft end is achieved solely by resisting the deflection force, without the excessive constraints associated with forced guidance.

[0012] Bearing systems under load can be affected by the geometry of thrust washers and the design (geometrically and in terms of material properties) of elastomeric elements.

[0013] Preferably, the elastomeric element has a progressive force-displacement characteristic curve. This results in a non-constant spring characteristic curve for the elastomeric element, wherein, in the first characteristic curve region of the force-displacement characteristic curve, the elastomeric element applies a small bias force to the output shaft. Advantageously, friction is lower in this region.

[0014] By giving the elastomer element a cross-section that decreases towards the housing, a flat first characteristic curve region of the force-displacement characteristic curve can be easily achieved. This creates a tilt angle on the outer surface of the elastomer element, which has a significant impact on the orientation of the first characteristic curve region because the elastomer element first undergoes elastic deformation under compression, causing the outer surface to rest on the limiting side surface of the housing.

[0015] According to an advantageous improvement of the invention, the elastomeric element has a non-uniform structure with recesses on its end face facing the housing. When the elastomeric element is compressed, the material surrounding the recesses can elastically deform into them. The material surrounding the recesses forms tooth-like protrusions that can move into the free space created by the recesses. After filling the free space, the characteristic curve of the elastomeric element rises sharply and changes to a second characteristic curve region where the elastomeric element has ideal stiffness.

[0016] Within the scope of this invention, other structures that generate free space can be conceived.

[0017] According to an advantageous embodiment of the invention, if the thrust washer is arranged in the recess of the elastomeric element, the thrust washer can be decoupled from the housing noise.

[0018] Preferred radial support for the thrust washer can be achieved, for example, by having at least one end face of the thrust washer facing the elastomeric element with a central protrusion, which serves to provide radial support on a recess of the elastomeric element that is complementary to the protrusion. This eliminates the possibility of radial displacement of the thrust washer due to forces acting upon it.

[0019] If, according to an advantageous improvement, the thrust washer has concave running surfaces on both end faces, assembly can be significantly simplified because the identical design of the end faces reliably prevents misalignment. Preferably, the thrust washer has a central protrusion on both end faces.

[0020] According to an advantageous embodiment, the drive arrangement may be provided with a connection unit for connecting to another upper component, while the actuating element is provided with another connection unit for connecting the actuating element to the upper component. The actuating element may, for example, be an axially displaceable spindle, the linear motion of which is generated by a transmission element of a transmission unit. Alternatively, it is conceivable to transmit the rotational motion of the transmission unit to an axially fixed spindle having an axially displaceable spindle nut, wherein the actuating element connected to the upper component is hinged to the spindle nut.

[0021] Preferably, the actuating element is designed as a spindle that can be displaced relative to the drive arrangement structure by means of a drive unit.

[0022] The present invention also relates to a motor vehicle having a movable vehicle component as a higher-level component and a body as another higher-level component, wherein the movable vehicle component is equipped with an actuation device according to the present invention. Attached Figure Description

[0023] The invention will now be explained in more detail based on exemplary embodiments with reference to the accompanying drawings, in which: Figure 1 A partial cross-sectional side view of the actuation device according to the present invention is shown; Figure 2 It shows Figure 1 Enlarged section A: Figure 3 It shows Figure 1 and Figure 2 An enlarged schematic diagram of the axial bearing of the actuator; and Figure 4 It shows Figure 1 and Figure 2 An exploded view of the axial bearing of the actuator. Detailed Implementation

[0024] Figure 1 A partial sectional side view illustrates an actuation device according to the invention. For example, this actuation device is used to move a movable vehicle component (not shown) relative to a vehicle body, which represents another superior component. The movable vehicle component may be, for example, a door or a vehicle hood. The actuation device 10 includes a drive arrangement 12 having a drive unit 14 (e.g., an electric motor) and an optional motion state sensor (not shown) (e.g., a Hall sensor) for detecting the motion state of the drive unit 14.

[0025] exist Figure 1 In the actuation device shown, the motor 14 is directly flange-connected to the housing 16. Other embodiments in which the motor 14 is housed within the housing 16 are also possible. The housing 16 surrounds the transmission unit 20, which includes at least one worm gear 18 as a first transmission element and a gear (not visible) as a second transmission element.

[0026] In addition, the actuation device 10 includes an actuation element 22, which is designed as a main shaft in an exemplary embodiment and is capable of being displaced relative to the drive arrangement structure 12, i.e. relative to the housing 16, by means of the drive unit 14.

[0027] The actuating element 22 is hinged to a movable vehicle component by means of a bracket, while the housing 16 of the actuating device 10 is connected to the vehicle body via a universal joint 26. The degree of freedom of movement provided by the universal joint 24 reliably prevents the actuating device 10 from jamming.

[0028] Figure 2 An enlarged cross-section A of the actuation device 10 shown in Figure 10 is illustrated; as can be seen in... Figure 1 and Figure 2As seen in the diagram, the output shaft 24 of the drive unit 14 carries a worm gear 18, which meshes with a gear. In this exemplary embodiment, the gear, serving as a second transmission element, surrounds the main shaft 22. In this arrangement, the gear is radially inwardly connected to a main shaft nut, which engages with the external thread of the main shaft 22, such that the rotational motion of the drive unit 14 is converted into linear motion of the main shaft 22 in the longitudinal direction of the main shaft.

[0029] To control the operation of the drive unit 14, a control unit (not shown) is also assigned to the drive arrangement structure 12. Output signals from the motion state sensor can be provided to the control unit via a signal input terminal. Additionally, output signals from the obstacle detection sensor can be provided to the control unit via a signal input terminal.

[0030] If the control unit determines, based on signals from the motion state sensor, that a movable vehicle component is being manually moved, the control unit controls the drive unit 14 to support the desired movement, i.e., in the manner of the power steering system. The magnitude of the force required by the drive unit 14 to move the movable vehicle component can be adjusted as needed, but is advantageously selected so that the vehicle component can operate with a small force on the order of 5 to 10 N, even when the vehicle is traveling on a slope or tilting.

[0031] The worm 18 is directly mounted on the output shaft 28 of the motor 14, i.e., there is no flexible coupling arranged between the worm 18 and the output shaft 24 connected to the rotor of the motor 14. Alternatively, the worm 18 may be formed as a single piece or integrally with the output shaft 24.

[0032] The output shaft 24 of the drive unit 14 is also rotatably supported by two rotary bearings (not shown). Figure 1 In this configuration, the downward-facing shaft end (not shown) of the output shaft 24 can axially contact a ball, which is supported within a housing formed by the drive housing 28. In this way, an axial bearing is provided for the output shaft 24, allowing it to still rotate relative to this axial bearing with minimal loss. Figure 1 At the top of the diagram, at the bent shaft end 30 of the output shaft 24, the output shaft 24 contacts an axial bearing 32, which is configured to accommodate, for example, temperature-dependent changes in the length of the output shaft 24 in the axial direction or to compensate for clearance and tolerances.

[0033] exist Figure 3 and Figure 4The axial bearing 32, shown in the enlarged view, includes an elastically deformable elastomer element 34 disposed within a housing 16 and a thrust washer 36 supported thereon. The bent shaft end 30 abuts against the thrust washer under preload, and the thrust washer is disposed within a recess 46 of the elastomer element 34, the recess being adapted to the shape of the thrust washer 36. The recess 46 is designed such that the side surfaces 47, 49 of the thrust washer 36 are covered by the elastomer element 34, thereby decoupling the thrust washer 36 from the housing 16. The elastomer element 34 and the thrust washer 36 are substantially rectangular in shape. However, other forms, such as a disc-shaped design, are conceivable.

[0034] The shaft end 30 is designed as a free cantilever, allowing radial forces from the transmission unit 20 to cause it to deflect. This may alter the shaft spacing of the transmission unit 20, potentially leading to acoustic degradation and, on the other hand, increased wear.

[0035] To avoid these drawbacks, the thrust washer 36 has a concave thrust surface 42 for contacting the convex running surface 31 of the bent shaft end 30, which adapts to the shape of the shaft end 30 at least on the first end face 38 facing the output shaft 24. Therefore, the convex running surface 31 of the shaft end 30 and the concave thrust surface 42 of the thrust washer 36 are designed to complement each other. Figure 3 As can be seen, the thrust surface 42 and the running surface 31 are designed in the form of spherical segments in this paper.

[0036] In the unloaded state, the convex running surface 31 and the concave thrust surface 42 are arranged at least almost centered on each other.

[0037] If the radial force from the transmission unit 20 causes the output shaft 24 to deflect radially, the shaft end 30 moves out of the center of the thrust washer 36 and its concave thrust surface 42. This lateral displacement of the shaft end 30 results in compression, i.e., elastic deformation of the elastomeric element 34, which generates a force on the shaft end 30 that counteracts the deflection and re-centers the shaft end 30 in the thrust surface 42.

[0038] In other words, a reaction force proportional to the deflection or bending of the output shaft 24 is generated, which reduces the deflection itself without supporting the output shaft 24 in a radially over-constrained manner.

[0039] To facilitate the assembly of the thrust washer 36 and avoid assembly errors, an additional thrust surface 42 is formed on the second end face 40 facing away from the output shaft 24. This eliminates the possibility of incorrect assembly based on the Poka-Yoke principle.

[0040] To provide radial support for the thrust washer 36, a central disc-shaped protrusion 44 is provided on at least the second end face 40 of the thrust washer 36 facing the elastomeric element 34, wherein the recess 46 of the elastomeric element 34 has a complementary shape. Advantageously, according to the Poka-Yoke principle, the first end face 38 also has a central protrusion 44.

[0041] The elastomeric element 34 is arranged in the recess 48 of the housing 16. The recess 48 may be formed by the housing body 50 and the housing cover 52 attached to the housing body 50.

[0042] If possible Figure 3 As can be seen, the elastomer element 34 has a cross-section that decreases toward the housing 16, such that an inclination angle α is formed on the outer surface 54 of the elastomer element 34.

[0043] The tilt angle α is provided, for example, on all side surfaces 55, 57 of the elastomer element 34. This is particularly evident in the exploded view showing the axial bearing 32. Figure 4 As can be seen, the tilt angle α can also be formed only in certain areas of the side surface at 55° and 57°.

[0044] exist Figure 3 It can also be seen that the elastomer element 34 has an uneven structure on its end face 56. The elastomer element uses this uneven structure to abut the housing 16. The uneven structure has a groove-shaped recess 60 with a circular segmental cross-section. When the elastomer element 34 is compressed, the material surrounding the recess 60 can elastically deform into the recess. The material surrounding the recess 60 forms tooth-like protrusions 58, which can move into the free space created by the recess 60.

[0045] Within the scope of this invention, other structures that generate free space can be conceived.

[0046] The shape and material of the elastomer element 34 determine its force-displacement characteristic curve. This force-displacement characteristic curve is advantageously asymptotic, resulting in a non-constant spring constant for the elastomer element 34. To obtain a lower bias force and therefore lower friction under low compression of the elastomer element 34, the shape of the elastomer element 34 is designed to produce a very flat first characteristic curve region. Since the elastomer element 34 initially rests with its outer surface 54 against the limiting side surface of the housing 16 during compression, this region can be achieved by an inclination angle α.

[0047] Upon further compression, the elastomer element 34 deforms, allowing the toothed protrusion 58 to move into the free space formed by the recess 60. After filling the free space, the characteristic curve of the elastomer element rises sharply and changes to the second characteristic curve region of ideal stiffness of the elastomer element.

[0048] According to the exemplary embodiments described above, the axial bearing 32 is described for use in an actuator 10 for use in a vehicle component. However, the present invention is by no means limited to actuators for vehicles.

[0049] It can also be used in actuators for other applications, such as home automation.

Claims

1. An actuation device (10) for a superior movable component, i.e., not belonging to the actuation device (10), particularly for a vehicle component movable relative to the vehicle body, wherein, The actuation device (10) includes at least: A drive arrangement structure (12) is provided, wherein the drive arrangement structure has a drive unit (14). A transmission unit (20), which is arranged in a housing (16), and Actuating element (22), which can be displaced relative to the drive arrangement structure (12) by means of the drive unit (14), The drive unit (14) has an output shaft (24) mounted in the housing (16) at least by means of an axial bearing (32) for clearance compensation and / or tolerance compensation. The bent shaft end (30) of the output shaft (24) rests on a thrust washer (36) by means of a convex running surface (31), the thrust washer being supported on an elastomeric element (34) arranged in the housing (16). The thrust washer (36) has a concave thrust surface (42) for contacting the bent shaft end (30) of the output shaft (24), the concave thrust surface being designed to be complementary to the convex running surface (31) of the shaft end (30) at least on the end face (38) facing the output shaft (24).

2. The actuation device (10) according to claim 1. Its features are, In the unloaded state, the convex running surface (31) of the shaft end (30) is arranged at least almost centrally to the concave thrust surface (42) of the thrust washer (36).

3. The actuation device (10) according to claim 2. Its features are, The thrust surface (42) of the thrust washer (36) and the running surface (31) of the shaft end (30) are designed to be complementary to each other, such that when the shaft end (30) is radially deflected from the center of the concave thrust surface (42), a force that counteracts the deflection can be generated on the shaft end (30) by the elastic deformation of the elastomer element (34).

4. The actuation device (10) according to any one of the preceding claims. Its features are, The elastomeric element (34) has a progressive force-displacement characteristic curve.

5. The actuation device (10) according to any one of the preceding claims. Its features are, The elastomeric element (34) has a cross-section that decreases toward the housing (16).

6. The actuation device (10) according to claim 4 or 5. Its features are, The elastomeric element (34) has an uneven structure on its end face (56) facing the housing (16), the uneven structure having a recess (60) into which the material surrounding the recess (60) can elastically deform when the elastomeric element (34) is compressed.

7. The actuation device (10) according to any one of the preceding claims. Its features are, The thrust washer (36) is arranged in the recess (46) of the elastomer element (34).

8. The actuation device (10) according to any one of the preceding claims. Its features are, At least the thrust washer (36) has a central protrusion (44) on its end face (40) facing the elastomer element (34) for radial support on a recess (46) of the elastomer element (34) that is complementary to the protrusion (44).

9. The actuation device (10) according to any one of the preceding claims. Its features are, The thrust washer (36) has concave thrust surfaces (42) on both end faces (38, 40).

10. The actuation device (10) according to claim 8 or 9. Its features are, The thrust washer (36) has a central protrusion (44) on both end faces (38, 40).

11. The actuation device (10) according to any one of the preceding claims. Its features are, The drive arrangement structure (12) is provided with a connection unit (23) for connecting to another component above, that is, not belonging to the actuation device (10), and the actuation element (22) is provided with another connection unit for connecting the actuation element (22) to another component above, that is, not belonging to the actuation device (10).

12. The actuation device (10) according to any one of the preceding claims. Its features are, The actuating element (22) is designed as a main shaft, which can be displaced relative to the drive arrangement structure (12) by means of the drive unit (14).

13. A motor vehicle having a movable vehicle component as a higher-level component and a body as another higher-level component, characterized in that, The movable vehicle component is equipped with an actuation device (10) according to any one of the preceding claims.

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