Spindle driver

Abstract

The invention relates to a spindle drive (10). The spindle driver comprises a driving unit (12), a spindle (34), a shell unit (20) fixedly connected with the driving unit (12), a bearing retainer (28) which is accommodated in the shell unit (20) and can rotate in a preset angle range relative to a rotating shaft, and a spindle nut (30) which is supported in the bearing retainer (28) at a fixed angle and is in threaded connection with the spindle (34), the spindle nut (30) can be driven in rotation by the drive unit (12) via a transmission means (18).

Description

Technical Field

[0001] The present invention relates to a spindle drive having a drive unit, a spindle and a spindle nut threadedly engaged with the spindle, and to a door device for a motor vehicle including such a spindle drive. Background Technology

[0002] Spindle drives are commonly used in various fields to electrically displace one element relative to another. A typical application of spindle drives is operating the doors or hatches of motor vehicles. Because these elements rotate relative to the vehicle body, such automatically operated doors and hatches, especially tailgates, require a spindle drive design capable of handling this rotational motion. For this purpose, sometimes rather complex spindle drives are used, supported on one side of the door or hatch and on the other side of the vehicle body, to follow all movements of the hatch or door. However, this complex support system for spindle drives requires considerable installation space and can be costly and require significant maintenance.

[0003] Although the following description will primarily focus on the possible applications of the spindle drive according to the invention in motor vehicles, it should be understood that the corresponding spindle drive can also be used in various other fields and scenarios with similar motion as a premise.

[0004] For example, in the prior art, DE 10 2017 204 914 A1 discloses a spindle driver that drives a spindle, wherein a connecting element is rotatably supported on a spindle nut that is threaded into the spindle, the connecting element being adapted, for example, to connect a hatch cover. However, a disadvantage of the device described therein is that it requires an additional connecting element with a relatively complex structure between the spindle nut and the driven element, resulting in increased installation space.

[0005] Also refer to DE 10 2018 212 959 A1, which describes a spindle drive in which a corresponding spindle nut is universally supported on the drive element. A similar approach is followed in US 10 655 378 B2, in which the spindle nut is also supported in a complex manner relative to the drive device to create a degree of motion freedom between the drive unit and the spindle.

[0006] However, all of the aforementioned existing technical solutions require a relatively large number of components, resulting in higher costs and complex maintenance. Therefore, the object of the present invention is to provide a spindle drive with a simplified structure that allows its spindle to rotate relative to its drive unit, thereby reducing installation space requirements and being more cost-effective. Summary of the Invention

[0007] To achieve this objective and eliminate the disadvantages of the prior art, the present invention proposes a spindle drive, comprising a drive unit, a spindle, a housing unit fixedly connected to the drive unit, a bearing cage housed in the housing unit and rotatable relative to a rotation axis within a predetermined angular range, and a spindle nut supported at a fixed angle in the bearing cage, the spindle nut being threadedly engaged with the spindle, wherein the spindle nut can be driven to rotate by the drive unit via a transmission device.

[0008] Therefore, in the spindle drive proposed in this invention, the spindle can rotate relative to the drive unit, thereby housing the spindle nut corresponding to the spindle in a bearing cage that can rotate relative to the housing, wherein the housing unit is securely connected to the drive. Thus, the rotation of the bearing cage relative to the housing unit causes the spindle to rotate relative to the drive unit, eliminating the need for complex joints or universal joint arrangements. This invention further separates the kinematically defined rotational motion of the spindle from the drive itself, since the joint realizing the rotational motion is arranged between the spindle and the drive.

[0009] Preferably, a deep groove ball bearing can be provided to support the spindle nut in the bearing cage. This deep groove ball bearing can absorb all forces in a suitable manner, and is therefore particularly suitable for this application.

[0010] Furthermore, according to the present invention, the transmission device between the spindle nut and the drive unit can be constituted by a worm gear transmission device with a worm and a worm wheel, wherein the worm can be connected to the drive unit and the worm wheel can be connected to the spindle nut. In particular, in this case, the worm wheel can be configured to be integrally connected to the spindle nut via a thread on the radially outer side of the spindle nut, so that the transmission torque of the transmission device can be applied directly to the worm nut through the worm without any other intermediate components. This design directly reduces the number of required components and saves installation space in the spindle drive area.

[0011] Furthermore, in this arrangement, the axis of rotation of the bearing cage can be aligned with the extension direction of the worm, provided that there are no additional components at that location between the worm and the spindle nut.

[0012] In addition, the transmission components can be completely housed within the housing unit, which protects the components that make up the transmission components from dirt and damage, without requiring additional installation space for the corresponding protective plate.

[0013] For a similar purpose, the housing unit can be enclosed with a housing cover on the side of the housing unit away from the drive unit, which also helps protect the spindle nut, bearing cage and other components that may be housed within the housing unit from external influences.

[0014] Furthermore, the rotation plane of the spindle can be perpendicular to the longitudinal direction of the drive unit. Particularly in the embodiment described above where the worm gear and spindle nut are integrated, the worm can be directly formed in or integrated with the extension of the drive unit's motor shaft, thus allowing the worm to run along the longitudinal direction of the drive unit. Alternatively, an embodiment can be adopted where the drive unit and the spindle rotation plane are at a certain angle, provided that a suitable gearbox or a drive rotation deflection device with angular offset is arranged in the middle for this purpose.

[0015] To determine the range of rotational angles of the bearing cage within the housing unit, the housing unit may, in particular, include an inner contour with an arcuate cross-section, along which the bearing cage moves within the housing unit by means of its outer contour. Thus, in this design, the bearing cage has an external shape corresponding to the inner contour of the housing unit, allowing rotational movement between the end positions of the arcuate cross-section. Alternatively, other methods can be employed to determine and limit the rotational movement of the bearing cage within the housing unit, particularly devices such as stops that limit the range of motion of the bearing cage.

[0016] Regarding the design of the bearing cage, it can be divided into two parts, in which a spindle nut and the aforementioned bearing (if applicable) are used, and these two parts can be connected to each other. In this case, the two parts can be detachably and indirectly connected, for example by snap-fit ​​or bolt connection, or directly and non-detachably connected, for example by laser welding or ultrasonic welding.

[0017] In order to enable the spindle drive according to the invention to be connected to a higher structure to achieve relative movement between the two components, the spindle and the drive unit may each be equipped with a connecting device for mounting the spindle drive on the higher component. In this case, it may primarily be a simple hinge device that itself allows the spindle drive to rotate about a corresponding hinge axis.

[0018] In addition, either end of the spindle, such as the end opposite to the connecting device mentioned above, can be housed in a funnel-shaped sleeve element. This sleeve element can realize the rotational movement of the spindle on the one hand, and protect the spindle from foreign objects, thereby preventing dirt and other contaminants from entering.

[0019] Furthermore, it should be noted that the drive unit of the spindle drive according to the invention is generally composed of an electric motor with a rotary electric motor shaft whose structural form is known. In addition, as an option, it may also include a gearbox, especially a planetary gearbox, and / or a braking device, especially a friction brake.

[0020] As described above, the present invention also relates to a door or hatch device for a motor vehicle, comprising a door or hatch rotatably hinged to the body of the motor vehicle about a hinge axis, and a spindle drive of the type described above arranged between the body and the door or hatch. In this case, the longitudinal direction of the drive unit, for example, which may be defined by its motor shaft, can be parallel to the hinge axis of the door, thereby enabling a particularly space-saving installation. Attached Figure Description

[0021] Other features and advantages of the invention will become clearer when considering one embodiment of the invention in conjunction with the accompanying drawings. In the drawings:

[0022] Figure 1A and Figure 1B An exploded view of the spindle drive according to the present invention and its enlarged cut cross-section are shown;

[0023] Figures 2A to 2C It shows Figure 1A and Figure 1B The diagram shows cross-sectional views of the spindle drive along the spindle rotation plane in three different rotational states; and

[0024] Figure 3 It shows Figures 1A to 2C The spindle driver shown is in its assembled state (side view). Detailed Implementation

[0025] Figures 1A to 3 The spindle drive according to the invention is shown in various views, generally indicated by reference numeral 10. This spindle drive 10 may, for example, be part of a door or hatch device of a motor vehicle (not shown further), and is arranged in the motor vehicle between the door or hatch and the vehicle body.

[0026] In this configuration, the spindle drive 10 primarily comprises a drive unit 12 in the form of an electric motor with a motor shaft 14. This drive unit may also include other components, such as a gearbox or brake (not shown further). Furthermore, it should be noted that the drive unit 12 corresponds to a connecting device 12a through which the spindle drive 10 can be mounted on a higher-level component, specifically in the aforementioned application case using a motor vehicle, particularly mounted on the vehicle body, door, or hood.

[0027] In addition, especially Figure 1A As can be seen, the worm 16 is located directly on the motor shaft 14 with anti-torsional force, and the worm forms part of the transmission device 18, which is further described below, especially in Figures 2A to 2C The transmission components can be clearly seen in the image. For example... Figures 2A to 2CAs can be seen most clearly in these cases, the motor shaft 14, together with the worm gear 16 thereon, extends into the housing unit 20. Figure 1A When the spindle unit 10 shown in the exploded view is in the installed state, the housing unit is securely connected to the drive unit 12, for example, by bolts.

[0028] On the other hand, the upper housing cover 22 and the side housing covers 24 can be bolted to the housing unit 20, and they are located on the upper side of the housing unit and Figures 2A to 2C The right side of the housing unit 20 is shown as a closed housing unit. On the side of the housing unit 20 opposite to the side housing cover 24, there is also a funnel-shaped sealing element 26, which protects the spindle 34, described below, from external influences in this area while allowing it to rotate relative to the housing unit 20.

[0029] Furthermore, it should be noted that the outer casing unit 20 has an interior with an inner contour 20a, the inner contour being configured with an arcuate cross-sectional shape, which can... Figure 1A and Figures 2A to 2C It can be clearly seen in the middle. The bearing cage 28 is located in the inner contour 20a. The bearing cage is composed of two parts, the first and second cage portions 28a and 28b, which are firmly or detachably connected to each other in the assembled state.

[0030] The bearing cage 28 is configured in terms of its outer contour such that the bearing cage can rotate within the inner contour 20a of the housing unit 20 about an axis corresponding to the extension direction of the motor shaft 14 at a predetermined angle value. In the embodiment shown here, this rotation angle is, for example, about ±12 degrees.

[0031] Within the bearing cage 28, a spindle nut 30, along with a deep groove ball bearing 32, is also housed. The spindle nut is housed in a manner that allows it to rotate relative to the bearing cage 28, but it remains fixed in the axial direction. In this case, it can also be seen that the spindle nut 30 has a thread 30a on its outer side, which serves as a worm gear connected to the worm 16 on the motor shaft 14 of the drive unit 12. Therefore, the spindle nut 30 can be directly rotated within the bearing cage 28 by operating the motor of the drive unit 12 and thereby rotating the worm 16. This actuation of the spindle nut 30 can be achieved in all rotational positions of the bearing cage 28 relative to the housing unit 20.

[0032] The diagram shows the various end positions and the center position of the rotational movement of the bearing cage 28 within the housing unit 20. Figures 2A to 2C This can be seen from the text. In this case, it can also be seen that... Figures 2A to 2CThese three states also correspond to different stroke states of the spindle 34. The spindle is guided to move within the spindle nut 30 and is threadedly engaged with it by a pair of mating threads 36.

[0033] therefore, Figures 2A to 2C The rotary motion shown can be used to compensate for the motion defined by two upper-level components and their connection. These two upper-level components are connected to the drive unit 12 via the aforementioned connecting device 12a, and are also connected to... Figures 2A to 2C The second connecting device 34a is shown on the end of the main shaft 34 on the right side.

[0034] Finally, it should be noted that the spindle driver 10 also includes a flexible sleeve element 38, through which the spindle 34 is... Figures 2A to 2C The outer side shown on the right is guided out of the housing unit 20, and the enclosure element can also prevent dirt and the like from entering the housing unit 20 in this position.

[0035] Therefore, the spindle drive 10 according to the invention shown here allows the spindle 34 to rotate relative to the drive unit 12 in a simple and compact manner, thereby allowing a rotational trajectory curve that is directly related to the current travel position of the spindle 34 and is determined by the movement of external components.

Claims

1. A spindle drive (10), the spindle drive comprising: -Drive unit (12); - Main spindle (34); - The housing unit (20) is fixedly connected to the drive unit (12); - A bearing cage (28) housed in the housing unit (20) and rotatable relative to the rotation axis within a predetermined angular range; and - A spindle nut (30) supported at a fixed angle in the bearing cage (28), the spindle nut being threaded into the spindle (34), wherein the spindle nut (30) can be rotated by the drive unit (12) via a transmission device (18).

2. The spindle drive (10) according to claim 1. in, A deep groove ball bearing (32) is provided in the bearing cage (28) to support the spindle nut (30).

3. The spindle drive (10) according to claim 1 or 2. in, The transmission device (18) is composed of a worm gear transmission device with a worm (16) and a worm wheel (30a), wherein the worm (16) is connected to the drive unit (12) and the worm wheel (30a) is connected to the spindle nut (30).

4. The spindle drive (10) according to claim 3. in, The worm gear (30a) is configured to be integrated with the spindle nut (30) via a thread on the radially outer side of the spindle nut.

5. The spindle drive (10) according to claim 3 or 4. in, The rotation axis of the bearing cage (28) is aligned with the extension direction of the worm (16).

6. The spindle drive (10) according to any one of claims 3 to 5. in, The extension direction of the worm (16) is consistent with the longitudinal direction of the drive unit (12).

7. The spindle drive (10) according to any one of the preceding claims. in, The transmission device (18) is completely housed within the housing unit (20).

8. The spindle drive (10) according to any one of the preceding claims. in, The housing unit (20) is closed by a housing cover (22) on the side of it away from the drive unit (12).

9. The spindle drive (10) according to any one of the preceding claims. in, The rotation plane of the main shaft (34) is perpendicular to the longitudinal direction of the drive unit (12).

10. The spindle drive (10) according to any one of the preceding claims. The range of rotation angles of the bearing cage (28) within the housing unit (20) is determined by the inner contour (20a) of the housing unit (20) having an arcuate cross-sectional shape, and the bearing cage (28) runs along the inner contour by means of its outer contour.

11. The spindle drive (10) according to any one of the preceding claims. in, The bearing cage (28) is divided into two parts, which (28a, 28b) can be connected to each other when the spindle nut (30) is used in it.

12. The spindle drive (10) according to any one of the preceding claims. in, The spindle (34) and the drive unit (12) can also each be equipped with a connecting device (34a, 12a) for mounting the spindle driver (10) on a higher component.

13. The spindle drive (10) according to any one of the preceding claims. in, Either end of the spindle (32) can be accommodated in a funnel-shaped sleeve element (26).

14. The spindle drive (10) according to any one of the preceding claims. in, The drive unit (12) includes a gearbox, particularly a planetary gearbox, and / or a braking device, particularly a friction brake.

15. A door or hatch device for a motor vehicle, said door or hatch device comprising: - A door or hatch that is rotatably hinged to the body of a motor vehicle around a hinge axis. as well as - The spindle drive (10) according to any one of claims 1-14 is arranged between the vehicle body and the door or the hatch.

16. The door or hatch device according to the preceding claims, in, The longitudinal direction of the drive unit (12) is parallel to the hinge axis of the door.

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