Drive, in particular spindle drive

Abstract

The invention relates to a drive for adjusting an adjusting element (2) of a motor vehicle (3), wherein the drive (1) comprises a drive train (4) with two drive sections adjustable relative to each other along a geometric drive axis (14) between a retracted position and an extended position, the drive sections having several train components coupled to each other in a force- or torque-transmitting manner to transmit a force introduced into the drive connections (8, 9), wherein the drive (1) comprises a feed gear (7) for performing, in particular linear, drive movements along the geometric drive axis (14), wherein one of the two drive sections comprises a drive unit (15) with a drive motor (5) to which the feed gear (7) is connected, wherein the drive motor (5) has a motor shaft (6) having a geometric motor shaft axis (16) which transmits a torque generated by the drive motor (5).and a bearing arrangement (17) with at least one motor shaft bearing (11) having a geometric bearing center axis (18) and configured to radially support the motor shaft (6). It is proposed that the drive (1) has a radial force application unit (19) which radially acts on the rotating motor shaft (6) in the assembled state, so that the motor shaft (6) bears against one side of the motor shaft bearing (11) in a defined manner.

Description

[0001] The present invention relates to a drive, in particular a spindle drive, according to the preamble of claim 1.

[0002] The drive in question can be used for all possible adjusting elements of a motor vehicle. Examples include a tailgate, a trunk lid, a door, especially a side door, a hood, or the like.

[0003] The prior art (DE 10 2020 113 958 A1), from which the invention is based, relates to a drive in the form of a spindle drive. This drive has a drive train with several train components through which torque can be transmitted. In this way, the torque is transmitted in the drive train from the motor shaft of a drive motor to an input-side feed gear component of a feed gearbox. The feed gearbox is designed here as a spindle-spindle nut gearbox with a spindle and a meshing spindle nut, wherein the input-side feed gear component of the feed gearbox is formed by the spindle. The spindle-spindle nut gearbox converts rotary movements into linear drive movements between two drive terminals of the drive. Furthermore, a reduction gearbox designed as a planetary gearbox is connected between the drive motor and the feed gearbox.The drive motor has a bearing arrangement with at least one motor shaft bearing for supporting the motor shaft. Such a drive is also known from DE 10 2023 101 903 A1 and DE 10 2023 101 560 A1.

[0004] The motor shaft is typically mounted with radial play (bearing clearance), meaning that the motor shaft, albeit only to a small extent, is radially movable relative to the drive motor and, in particular, relative to the motor housing. A challenge here is the tendency of the motor shaft to oscillate freely, accompanied by modulating noise.

[0005] The invention is based on the problem of designing and further developing the known drive in such a way that an optimization is achieved with regard to noise development in the drive.

[0006] The above problem is solved by the features of the characterizing part of claim 1.

[0007] The fundamental principle is to press the motor shaft, which is particularly prone to radial play, radially against its associated bearing to prevent free vibration and suppress corresponding modulating noise. This is achieved by applying a targeted, one-sided load to the motor shaft, which clamps it in the bearing, or, in the case of multiple bearings, in one or two of them. This ensures that the motor shaft assumes a defined position within the bearing, thus improving smooth running.

[0008] Specifically, it is proposed that the drive has a radial force introduction unit designed to radially actuate the rotating motor shaft in the assembled state, so that the motor shaft bears against one side of the motor shaft bearing in a defined manner.

[0009] Claims 2 and 3 define a force application means that enables a targeted and controlled application of a radial force to the motor shaft and ensures a defined contact of the motor shaft with one side of the motor shaft bearing.

[0010] Claims 4 and 5 specify the preferred location of the radial force application unit and the force-applying means within the drive. The motor shaft is often particularly susceptible to vibration on the axial side of the drive motor facing the feed gearbox. However, an arrangement at a different location within the drive may also be advantageous, for example, for reasons of simpler assembly and maintenance, such as on the side of the drive motor facing away from the feed gearbox. This arrangement can be located inside or outside the motor housing.

[0011] According to the particularly preferred embodiment of claim 6, the force-actuating means that causes the radial actuation or deflection of the motor shaft is a bracket, preferably elastic, in particular made of metal and / or a spring sheet. Such a component can be installed radially between existing drive components and / or transmission components, one of which is a drive element coupled to the motor shaft for torque transmission or is formed by the motor shaft itself, in a particularly simple and space-saving manner.

[0012] According to claim 7, the bracket can be secured against rotation by one or more outwardly directed end edges to ensure that the motor shaft maintains its defined position in the motor shaft bearing. For a rotationally fixed connection, the bracket is anchored with its respective edge, particularly radially outward, to one of the drive components and / or transmission components.

[0013] Claim 8 relates to a reduction gear connected downstream of the drive motor, which, according to claim 9, particularly preferably comprises a planetary gear. In this case, the bracket is installed, in particular, between two gear components, one of which is the drive element coupled to the motor shaft for torque transmission. The drive element, which is acted upon or deflected radially by the force-applying means, is preferably the sun gear of the planetary gear. Claim 10 specifies the arrangement of the bracket radially between the sun gear and the ring gear of the planetary gear.

[0014] According to the particularly preferred embodiment according to claim 11, the force-actuating means that causes the radial actuation or deflection of the motor shaft is a preferably rigid, annular additional part, in particular made of metal and / or cast material, which extends around the motor shaft.

[0015] Claim 12 specifies the arrangement of the annular additional part radially between the motor shaft and the motor shaft bearing or one of the motor shaft bearings radially supporting the motor shaft.

[0016] Claim 13 specifies preferred variants of the motor shaft axis in the radially actuated state by the radial force introduction unit or the force application means.

[0017] Claim 14 relates to a particularly preferred embodiment in which the feed mechanism is designed as a spindle-spindle nut mechanism.

[0018] According to the particularly preferred embodiment according to claim 15, the drive has a drive housing with an inner housing tube and an outer housing tube that radially surrounds the radial force introduction unit or the force application means in order to protect these components from the environment of the drive.

[0019] The invention will now be explained in more detail with reference to a drawing that merely illustrates exemplary embodiments. The drawing shows Fig. 1. In perspective view, the rear area of ​​a motor vehicle with at least one proposed drive, as well as the drive in a partially cutaway side view in the retracted state and, quite schematically, the motor shaft of a drive motor of the drive in various load states, Fig. 2 for a first embodiment of the proposed drive a) sectional views of an axial section of the drive and b) exploded views of the axial section of the drive and Fig. 3 for a second embodiment of the proposed drive a) sectional views of an axial section of the drive and b) exploded views of the axial section of the drive.

[0020] The drive 1 shown in the drawing, here and preferably a spindle drive, serves for the motorized adjustment of a [device / structure] according to [a specific regulation / method]. Fig. 1. An example of an adjustment element 2 of a motor vehicle 3 designed as a tailgate. This is advantageous, but not to be understood as limiting. Rather, the proposed drive 1 can be used for all possible adjustment elements 2 of a motor vehicle 3, for example also for a tailgate, a door, in particular a side door, a hood or the like of a motor vehicle 3.

[0021] Fig. Figure 1 shows that the drive 1 has a drive train 4 with several train components. Train components, in this sense, are components that can transmit forces and / or, as in this case, torques in the drive 1, which are necessary for adjusting the adjusting element 2.

[0022] The drive train 4 comprises a drive motor 5, which has a motor shaft 6 extending in an axial direction, and a feed gear 7 comprising an input-side feed gear component and an output-side feed gear component for generating, in particular linear, drive movements between two drive connections 8, 9. A "feed gear component" is a gear component necessary for generating a feed movement, for example, a threaded rod ("spindle"), rack and pinion, or the like. The two drive connections 8, 9 are in Fig. 1 are provided at the end of the drive 1 and serve to transmit the drive movements to the motor vehicle 3, namely the first drive connection 8 to the adjusting element 2 and the second drive connection 9 to the motor vehicle 3 in the remainder.

[0023] The motor shaft 6 is supported radially and axially by at least one motor shaft bearing 11, preferably within a motor housing 10 of the drive motor 5. The motor shaft 6 is supported with a radial clearance, known as bearing clearance, between the motor shaft bearing 11 and the motor shaft 6, allowing the motor shaft 6 to move radially, albeit only slightly, relative to the drive motor 5 and, in particular, relative to the motor housing 10.

[0024] In this context, a motor housing 10 of the drive motor 5 must be distinguished from an optional drive housing 12 of the proposed drive 1, which will be described in more detail below and which, in addition to the drive motor 5, also at least partially surrounds a reduction gear 13 and / or the feed gear 7 radially. The motor housing 10 primarily supports and protects the electrical and mechanical components of the drive motor 5 (e.g., the stator, the rotor, the commutator, the windings, or the like), but does not surround either the reduction gear 13 or the feed gear 7.

[0025] The drive motor 5 with its motor shaft 6 on the one hand, and the feed gear components of the feed gearbox 7 on the other hand, each form train components of the drive train 4. A torque can be transmitted from the motor shaft 6 via further train components of the drive train 4 to the input-side feed gear component of the feed gearbox 7.

[0026] The embodiment shown in the figures, which is preferred in this respect, relates to a drive 1, in particular a spindle drive, for adjusting an adjusting element 2, in particular a flap, of a motor vehicle 3, wherein the drive 1 has a first drive connection 8, here the adjusting element-side drive connection 8, and a second drive connection 9, here the body-side drive connection 9, for coupling with the motor vehicle 3, wherein the drive 1 has a drive train 4 with two drive sections, in particular linearly, adjustable to each other along a geometric drive axis 14 between a retracted position and an extended position, which have several train components that are coupled to each other in a force- or torque-transmitting manner in order to transmit a force introduced into the drive connections 8, 9, wherein each of the drive sections is assigned to one of the drive connections 8, 9.wherein the drive 1 comprises a feed gear 7 for performing, in particular linear, drive movements along the geometric drive axis 14, wherein one of the two drive sections comprises a drive unit 15 with a drive motor 5, to which the feed gear 7 is connected, wherein the drive motor 5 comprises a motor shaft 6 having a geometric motor shaft axis 16, which transmits a torque generated by the drive motor 5, and a bearing arrangement 17 for supporting the motor shaft 6, comprising at least one motor shaft bearing 11, in particular a sliding bearing, having a geometric bearing center axis 18, which is configured to radially support the motor shaft 6.

[0027] The bearing center axis 18 is defined as the axis that defines the radial center of the motor shaft bearing 11, both in the unloaded and, in particular, also in the loaded state. Here, and preferably, the bearing arrangement 17 comprises several motor shaft bearings 11, in particular plain bearings, which have a common geometric bearing center axis 18 and are configured to radially support the motor shaft 6.

[0028] It is essential that the drive 1 has a radial force introduction unit 19 which is designed to act radially on the rotating motor shaft 6 in the assembled state, so that the motor shaft 6 bears against one side of the motor shaft bearing 11 in a defined manner.

[0029] In the present context, radial application of the motor shaft 6 means that a force is introduced into the motor shaft 6 with a force direction oriented radially to the geometric motor shaft axis 16.

[0030] The side of the motor shaft bearing 11, against which the motor shaft 6 is defined as proposed, is defined by its position relative to a stationary element of the drive 1, and is therefore always directed towards the same point in the drive 1.

[0031] The radial force application unit 19 exerts a targeted radial force on the rotating motor shaft 6. This force forces the motor shaft 6, within the limits of the bearing clearance (here, for example, a bearing clearance of 0.01 mm to 0.1 mm, preferably 0.01 mm to 0.05 mm), in a specific direction within the respective motor shaft bearing 11, thereby positioning the motor shaft 6 against a radial side of the motor shaft bearing 11 and ensuring a defined bearing contact. The radial force application unit 19 thus forces the motor shaft 6 into a position that deviates from the geometric bearing center axis 18; that is, the geometric motor shaft axis 16 and the geometric bearing center axis 18 are not coaxial. Rather, the geometric motor shaft axis 16 is, in particular, curved or inclined relative to the geometric bearing center axis 18. Specifically, the two geometric axes 16 and 18 intersect at least one point 20.

[0032] The targeted one-sided load clamps the motor shaft 6 in the motor shaft bearing 11, or, in the case of multiple motor shaft bearings 11, in one or at least two of the motor shaft bearings 11. This causes the motor shaft 6 to assume a defined position in the respective motor shaft bearing 11. This, in turn, can prevent free oscillation of the rotating motor shaft 6 and suppress corresponding modulating noise.

[0033] In this context, the terms “axial” and “radial” always refer to the geometric drive axis 14.

[0034] Furthermore, and preferably, the radial force application unit 19 includes a force application means 21. The force application means 21 deflects the motor shaft 6 and / or a drive element 22 coupled to the motor shaft 6 in a torque-transmitting manner, in particular rotationally fixed and preferably axially fixed, radially relative to an unloaded state, thus pushing the motor shaft 6 and / or the drive element 22 in a specific radial direction.

[0035] In order to achieve the proposed function, i.e., so that the rotating motor shaft 6, in the assembled state, is pressed radially to one side into the motor shaft bearing 11 and bears against one bearing side of the motor shaft bearing 11 in a defined manner, the force-applying means 21 acts on the motor shaft 6 either directly or via the aforementioned drive part 22, which is coupled to the motor shaft 6 in a torque-transmitting manner. The drive part 22 is, as will be explained further below, in particular a transmission component.

[0036] The force-actuating means 21 is preferably formed by an independent, i.e., separate, component. However, according to another embodiment not shown here, it is alternatively conceivable that the force-actuating means 21 is formed by a component section of a component that is rotationally fixed and, in particular, axially fixed with respect to the drive motor 5, or of a component that is rotatable with respect to the drive motor 5 and, in particular, axially fixed.

[0037] "Independent" or "separate" component refers to a component of the drive 1 that is designed for the proposed function, namely to actuate or deflect the rotating motor shaft 6 radially to one side, and which itself does not, in particular, provide any torque-transmitting function for the purpose of generating the linear drive movements, and preferably no other function at all within the drive 1, as will be explained in more detail below. In contrast, "component section" refers to a section of a component that, in addition to the proposed function of acting upon or deflecting the rotating motor shaft 6 radially to one side, also provides at least one other function within the drive 1, for example, a housing function, thus a protective function, and / or a function as a gear component that is rotationally fixed to the drive motor 5.

[0038] Here, and preferably, the radial force introduction unit 19 or the force application means 21 radially applies force to the motor shaft 6 outside the motor housing 10 of the drive motor 5.

[0039] It can also be provided that the radial force introduction unit 19 or the force application means 21 radially applies force to the motor shaft 6 within the motor housing 10 of the drive motor 5.

[0040] Furthermore, it is preferably provided that the radial force introduction unit 19 or the force application means 21 radially applies force to the motor shaft 6 on the axial side of the drive motor 5 facing the feed gear 7.

[0041] The axial side of the drive motor 5 facing the feed gearbox 7 is the side where the torque generated by the drive motor 5 is transmitted from the drive motor 5 to the feed gearbox 7. On this side, the motor shaft 6 is particularly susceptible to vibration.

[0042] However, it can also be provided that the radial force introduction unit 19 or the force application means 21 radially applies force to the motor shaft 6 on the side of the drive motor 5 facing away from the feed gear 7.

[0043] The side of the drive motor 5 facing away from the feed gear 7 is the axial side (rear of the drive motor) facing the nearest drive connection 8, 9. On this axial side, the drive motor 5 or the motor housing 10 has, as is typical here, an axial end cap 23 ("end cap") and / or carries a commutator (inside the motor housing 10) and / or a rotary encoder, for example a Hall sensor (outside the motor housing 10).

[0044] In the following, particularly preferred embodiments of the force-actuating device 21 will be explained.

[0045] Thus, according to Fig. 2 here and preferably provided that the radial force introduction unit 19 has as force application means 21 a, preferably elastic, bracket 24, in particular made of metal and / or a spring sheet 24.

[0046] In this context, "elastic" means that the bracket 24 deforms elastically during assembly and can return to its original state after disassembly, which it had inside before assembly.

[0047] In its assembled state, the bracket 24 extends around the motor shaft 6 and / or the drive part 22 which is coupled to the motor shaft 6 in a torque-transmitting manner.

[0048] The bracket 24, in particular the spring plate 24, has a thickness (dimension in radial direction) of 0.1 mm to 1 mm, preferably of 0.1 mm to 0.5 mm, more preferably of 0.1 mm to 0.2 mm, over its entire extent circumferential around the geometric bearing center axis 18.

[0049] Furthermore, the bracket 24 has an inner contour 25 running around the drive part 22 in the assembled state, which in a first contour section 26 is arranged radially closer to the geometric bearing center axis 18 than in at least a second contour section 27.

[0050] The first contour section 26 therefore points radially further inwards than the at least one second contour section 27, here the two second contour sections 27, or the inner contour 25 in general. The second contour section(s) 27 form, as Fig. Figure 2 shows, in particular, the largest part of the inner contour 25, here only with the exception of at least one end section 28 of the bracket 24 with a radially outward or inward directed edge, which will be described below.

[0051] Due to the special contour of the inner contour 25 of the bracket 24, the rotating motor shaft 6 is radially acted upon by the bracket 24 in the assembled state, here and preferably indirectly, so that the motor shaft 6 rests in a defined position against one side of the motor shaft bearing 11, which will be described in more detail below.

[0052] The first contour section 26 of the inner contour 25 has a tangential, i.e., straight, course with respect to the geometric bearing center axis 18, and preferably in the assembled state, but can also have a curved course, in particular radially inwards. Additionally or alternatively, the at least one second contour section 27 of the inner contour 25 has a radially outward curved course with respect to the geometric bearing center axis 18, in particular a circular arc.

[0053] The first contour section 26 is here and preferably delimited by a bending edge 29 to the second contour section(s) 27, which are adjacent to it.

[0054] Furthermore, and preferably, it is provided here that the bracket 24, in the assembled state, has, in particular at one or two circumferential end sections 28, a radially outwardly directed end edge 30 or a radially inwardly directed end edge, by means of which the bracket 24 is secured against rotation in the assembled state. This will be explained in more detail below.

[0055] In drive 1 in the Fig. 1, Fig. 2 to Fig. In section 3, the drive unit 15 has a reduction gear 13 downstream of the drive motor 5, to which the feed gear 7 is connected. According to the previous definition, the reduction gear 13 is arranged on the axial side of the drive motor 5 facing the feed gear 7.

[0056] Here, and preferably, the drive part 22, which is coupled to the motor shaft 6 in a torque-transmitting manner and is radially acted upon or deflected by the force-applying means 21, is a transmission component of the reduction gear 13.

[0057] The bracket 24, or rather its specific contour of the inner contour 25, exerts a radial force on the rotating motor shaft 6 in the assembled state via the drive part 22, in particular the transmission component, so that the motor shaft 6 bears against one side of the motor shaft bearing 11 in a defined manner. The bracket 24 thus introduces a radial force into the drive part 22 or the transmission component, which is fixed to the motor shaft 6 with respect to the radial direction and is consequently subjected to or deflected radially by the bracket 24 and the radial force, together with the motor shaft 6.

[0058] Here, and preferably, the reduction gear 13 comprises a planetary gear 31, which includes a rotatable sun gear 32 and, coaxially thereto, a rotatable planet carrier 33 and a fixed or lockable ring gear 34. The planet carrier 33 carries at least one rotatable planet gear 35, which is in axially parallel engagement with the respective sun gear 32 on the one hand and the respective ring gear 34 on the other.

[0059] “Fixed” here means that the ring gear 34 is rotationally fixed to the drive motor 5 and / or drive housing 12.

[0060] The drive part 22, which is coupled to the motor shaft 6 in a torque-transmitting manner and is radially acted upon or deflected by the force-applying means 21, is preferably, as Fig. Figure 2 shows the sun gear 32 of the planetary gear 31.

[0061] It is also possible to have several, here two, gear stages 36 connected in series, each formed by a planetary gear set 31. The sun gear 32 in question is then the sun gear 32 of the first gear stage 36.

[0062] The bracket 24, or rather its specific contour of the inner contour 25, thus applies a radial force to the rotating motor shaft 6 in the assembled state via the aforementioned sun gear 32, causing the motor shaft 6 to bear against one side of the motor shaft bearing 11 in a defined manner. The bracket 24, in particular the first contour section 26, accordingly introduces a radial force into the sun gear 32, which is fixed to the motor shaft 6 with respect to the radial direction and is therefore radially acted upon or deflected by the bracket 24 and the radial force, together with the motor shaft 6.

[0063] Furthermore, it is preferably provided that the bracket 24, in the assembled state, is arranged radially between the sun gear 32 and the ring gear 34, and in particular clamped in place. "Clamped" here means that the bracket 24 is under permanent radial preload in the assembled state. The bracket 24 bears radially against the inner side of the ring gear 34 and, due to the existing preload, deflects the sun gear 32 radially, thereby acting upon and deflecting the motor shaft 6, to which the sun gear 32 is coupled, to the same extent.

[0064] The bracket 24 is, and preferably is, secured against rotation relative to the ring gear 34. The sun gear 32 rotates accordingly relative to the bracket 24 when the motor shaft 6 rotates. The anti-rotation feature is formed, in particular, by a frictional engagement, or alternatively or additionally, a positive engagement, of the radially outwardly directed end edges of the bracket 24 with the ring gear 34. The sun gear 32, here and preferably when, as here, the bracket 24 is secured against rotation relative to the ring gear 34, only comes into contact with the first contour section 26, in particular its center, thus touching the bracket 24 only with a single contact area 37, which is, in particular, substantially linear. The sun gear 32 then slides along the bracket 24 over this contact area.According to another embodiment, not shown here, it is also conceivable that the bracket 24 is secured against rotation relative to the sun gear 32 and, when the motor shaft 6 is rotating, rotates with the sun gear 32 relative to the ring gear 34. The anti-rotation device is then formed, in particular, by a frictional engagement, or alternatively or additionally by a positive engagement, of radially inwardly directed end edges of the bracket 24 with the sun gear 32.

[0065] Another variant of a force-applying device 21 further shows Fig. 3.

[0066] It is preferably provided that the radial force introduction unit 19 has a force application means 21, preferably a rigid, ring-shaped additional part 38, in particular made of metal and / or cast material.

[0067] In this context, "rigid" means that the ring-shaped additional part 38 does not deform elastically during assembly, or at least not to a significant extent.

[0068] “Ring-shaped” here means that the additional part 38 is mostly or completely closed all around and in particular has a predominantly circular arc-shaped inner contour 25, preferably also an at least predominantly circular arc-shaped outer contour.

[0069] The ring-shaped additional part 38 extends around the motor shaft 6 when assembled.

[0070] Here, the annular accessory 38 has an inner contour 25 extending around the motor shaft 6 in the assembled state. In a first contour section 26, this contour is arranged radially closer to the geometric bearing center axis 18 than in at least one second contour section 27. Thus, the first contour section 26 also points radially further inwards than the at least one second contour section 27 (here, the only second contour section 27) or the inner contour 25 in general. The second contour section(s) 27 form, as Fig. Figure 3 shows, in particular, the largest part of the inner contour 25.

[0071] Due to the special contour of the inner contour 25 of the annular additional part 38, the rotating motor shaft 6 is radially acted upon by the annular additional part 38 in the assembled state, directly, so that the motor shaft 6 rests against one side of the motor shaft bearing 11 in a defined manner, which will be described in more detail below.

[0072] The first contour section 26 of the inner contour 25 has, here and preferably in the assembled state, a tangential, i.e., straight, course with respect to the geometric bearing center axis 18, but can also have a curved course, in particular radially inwards. Additionally or alternatively, the at least one second contour section 27 of the inner contour 25 has, in the assembled state, a course curved radially outwards with respect to the geometric bearing center axis 18, in particular a circular arc.

[0073] The first contour section 26 is preferably formed by an inner flattening, while the second contour section 27 is arc-shaped. The motor shaft 6 preferably comes into contact only with the first contour section 26, particularly in its center, and the opposite section of the second contour section 27, thus contacting the annular accessory part 38 only with two opposing contact areas 37, which are preferably essentially linear. The motor shaft 6 slides over these contact areas in the annular accessory part 38.

[0074] How Fig. As shown in Figure 3, the annular accessory part 38 is arranged radially between the motor shaft 6 and the motor shaft bearing 11, which radially supports the motor shaft 6, preferably in the assembled state. The motor shaft bearing 11 thus forms a counter-bearing for the annular accessory part 38; that is, the annular accessory part 38 is supported radially on its inner side by the motor shaft bearing 11.

[0075] The annular accessory 38, or rather its specific contour profile of the inner contour 25, directly applies a radial force to the rotating motor shaft 6 in the assembled state, causing the motor shaft 6 to bear firmly against one side of the motor shaft bearing 11. The annular accessory 38, in particular the first contour section 26, thus introduces a radial force into the motor shaft 6 and deflects it radially, or applies a radial force to it.

[0076] Here, and preferably, the ring-shaped additional part 38 is secured against rotation in the motor shaft bearing 11, in particular by a form-fit, force-fit or material-fit, here by a press fit.

[0077] In the embodiments presented here, which are preferred in this respect, the geometric motor shaft axis 16 is generally tilted or bent relative to the geometric bearing center axis 18 when the motor shaft 6 is radially acted upon by the radial force introduction unit 19 or the force application means 21. These two alternatives are described in Fig. 1c) schematically represented by dashed lines.

[0078] As previously indicated, the one in the Fig. 1, Fig. 2 to Fig.Figure 3 illustrates a proposed drive 1 around a spindle drive. Accordingly, it is preferably provided that the feed drive 7 is a spindle-spindle nut drive 39 with a spindle 40 and a meshing spindle nut 41, and that one of the two drive sections comprises the spindle 40 and the other comprises the spindle nut 41. Here, the spindle 40 is axially fixed to the first drive connection 8, in this case the drive connection 8 on the adjusting element side, and the spindle nut 41 is axially fixed to the second drive connection 9, in this case the body-side drive connection 9, via a spindle guide tube 42.

[0079] Furthermore, and preferably, the drive 1 comprises a drive housing 12 with an inner housing tube 43 and an outer housing tube 44. The inner housing tube 43 slides telescopically within the outer housing tube 44. The inner housing tube 43 is axially fixed to one of the two drive sections, and the outer housing tube 44 is axially fixed to the other of the two drive sections. Here, and preferably, the radial force introduction unit 19 and / or the force application means 21 are radially surrounded by the drive housing 12, in particular by the outer housing tube 44. Additionally or alternatively, the radial force introduction unit 19 and / or the force application means 21 are arranged axially outside the motor housing 10 of the drive motor 5, as shown here.

[0080] Here, and preferably, a drive spring assembly 45 with at least one helical spring 46 is arranged coaxially to the geometric drive axis 14. The drive spring assembly 45, with the at least one helical spring 46, is arranged within the drive housing 12, in particular within the inner housing tube 43 and / or outer housing tube 44. The drive spring assembly 45 pre-tensions the two drive sections against each other, in particular into the extended position. Furthermore, and preferably, a spring guide tube 47 is provided here that guides the at least one helical spring 46, extending inside or outside the at least one helical spring 46, wherein the spring guide tube 47 is preferably axially fixed at one of its ends to one of the two drive sections, in particular to the drive section that includes the drive unit 15.

Claims

[1] Drive, in particular spindle drive, for adjusting an adjusting element (2), in particular a flap, of a motor vehicle (3), wherein the drive (1) has a first drive connection (8) and a second drive connection (9) for coupling with the motor vehicle (3), wherein the drive (1) has a drive train (4) with two drive sections adjustable to each other along a geometric drive axis (14) between a retracted position and an extended position, in particular linearly, with several train components which are coupled to each other in a force- or torque-transmitting manner in order to transmit a force introduced into the drive connections (8, 9), wherein each of the drive sections is assigned to one of the drive connections (8, 9), wherein the drive (1) has a feed gear (7) for performing, in particular linear, drive movements along the geometric drive axis (14),wherein one of the two drive sections comprises a drive unit (15) with a drive motor (5) to which the feed gearbox (7) is connected, wherein the drive motor (5) comprises a motor shaft (6) having a geometric motor shaft axis (16) which transmits a torque generated by the drive motor (5), and a bearing arrangement (17) with at least one motor shaft bearing (11) having a geometric bearing center axis (18) which is configured to radially support the motor shaft (6), . characterized by , that the drive (1) has a radial force introduction unit (19) designed to act radially on the rotating motor shaft (6) in the assembled state, so that the motor shaft (6) bears against one side of the motor shaft bearing (11) in a defined manner. [2] Drive according to claim 1, characterized by, that the radial force introduction unit (19) has a force application means (21) and that the force application means (21) deflects the motor shaft (6) or a drive part (22) coupled to the motor shaft (6) in a torque-transmitting manner, in particular rotationally fixed and preferably axially fixed. [3] Drive according to claim 2, characterized by , that the force-actuating means (21) is formed by a separate component, or that the force-actuating means (21) is formed by a component section of a component that is rotationally fixed and in particular axially fixed to the drive motor (5) or of a component that is rotatable and in particular axially fixed to the drive motor (5). [4] Drive according to claim 2 or 3, characterized by , that the force-applying means (21) applies radial force to the motor shaft (6) outside or inside a motor housing (10) of the drive motor (5). [5] Drive according to claim 4, characterized by, that the radial force introduction unit (19) or the force application means (21) radially acts on the motor shaft (6) on the axial side of the drive motor (5) facing the feed gear (7), or that the radial force introduction unit (19) or the force application means (21) radially acts on the motor shaft (6) on the side of the drive motor (5) facing away from the feed gear (7). [6] Drive according to any one of the preceding claims, characterized by, that the radial force introduction unit (19) as force application means (21) comprises a, preferably elastic, bracket (24), in particular made of metal and / or a spring sheet (24), that the bracket (24) extends around the motor shaft (6) and / or the drive part (22) coupled to the motor shaft (6) in a torque-transmitting manner in the assembled state, and that the bracket (24) has an inner contour (25) extending around the drive part (22) in the assembled state, which in a first contour section (26) is arranged radially closer to the geometric bearing center axis (18) than in at least a second contour section (27), preferably that the first contour section (26) of the inner contour (25) has a tangential course with respect to the geometric bearing center axis (18) or a course that is curved, in particular radially inwards, in the assembled state, and / or,that the at least one second contour section (27) of the inner contour (25) in the assembled state has a radially outward curved, in particular arc-shaped, course with respect to the geometric bearing center axis (18). [7] Drive according to claim 6, characterized by , that the bracket (24) in the assembled state, in particular at one or two circumferential end sections (28), has a radially outward directed end edge (30) or a radially inward directed end edge by which the bracket (24) is secured against rotation in the assembled state. [8] Drive according to any one of the preceding claims, characterized by, that the drive unit (15) has a reduction gear (13) downstream of the drive motor (5), to which the feed gear (7) is downstream, preferably that the drive part (22) coupled to the motor shaft (6) in a torque-transmitting manner, which is radially deflected by the force-applying means (21), is a gear component of the reduction gear (13). [9] Drive according to claim 8, characterized by, that the reduction gear (13) has a planetary gear (31) which has a rotatable sun gear (32) and coaxially thereto a rotatable planet carrier (33) and a fixed or lockable ring gear (34), which planet carrier (33) carries at least one rotatable planet gear (35) which is in axially parallel engagement with the respective sun gear (32) on the one hand and the respective ring gear (34) on the other, preferably that the drive part (22) coupled to the motor shaft (6) in a torque-transmitting manner, which is radially deflected by the force-applying means (21), is the sun gear (32) of the planetary gear (31). [10] Drive according to claim 9, characterized by, that the bracket (24) is arranged radially between the sun gear (32) and the ring gear (34) in the assembled state, in particular clamped, preferably that the bracket (24) is secured against rotation towards the ring gear (34), in particular by the radially outwardly directed end edges, or that the bracket (24) is secured against rotation towards the sun gear (32), in particular by the radially inwardly directed end edges. [11] Drive according to any one of the preceding claims, characterized by, that the radial force introduction unit (19) comprises, as force application means (21), a preferably rigid, annular additional part (38), in particular made of metal and / or cast material, that the annular additional part (38) extends around the motor shaft (6) in the assembled state, and that the annular additional part (38) has an inner contour (25) extending around the motor shaft (6) in the assembled state, which in a first contour section (26) is arranged radially closer to the geometric bearing center axis (18) than in at least a second contour section (27), preferably that the first contour section (26) of the inner contour (25) has, in the assembled state, a tangential course with respect to the geometric bearing center axis (18) or a course that is curved, in particular radially inwards, and / or,that the at least one second contour section (27) of the inner contour (25) in the assembled state has a radially outward curved, in particular arc-shaped, course with respect to the geometric bearing center axis (18). [12] Drive according to claim 11, characterized by , that the annular additional part (38) is arranged radially between the motor shaft (6) and the motor shaft bearing (11) or one of the motor shaft bearings (11) radially supporting the motor shaft (6) in the assembled state, preferably that the annular additional part (38) is secured against rotation in the motor shaft bearing (11), in particular by a form-fit, force-fit or material-fit. [13] Drive according to any one of claims 2 to 12, characterized by , that the geometric motor shaft axis (16) is tilted or bent relative to the geometric bearing center axis (18) in the radially actuated state of the motor shaft (6) by the force-actuating means (21). [14] Drive according to any of the preceding claims, characterized by , that the feed mechanism (7) is a spindle-spindle nut mechanism (39) with a spindle (40) and a meshing spindle nut (41) and that one of the two drive sections has the spindle (40) and the other of the two drive sections has the spindle nut (41). [15] Drive according to any one of the preceding claims, characterized by, that the drive (1) has a drive housing (12) with an inner housing tube (43) and an outer housing tube (44), that the inner housing tube (43) runs telescopically in the outer housing tube (44), and that the inner housing tube (43) is axially fixed to one of the two drive sections and the outer housing tube (44) is axially fixed to the other of the two drive sections, preferably that the radial force introduction unit (19) and / or the force application means (21) is radially surrounded by the drive housing (12), in particular the outer housing tube (44), and / or is arranged axially outside the motor housing (10) of the drive motor (5).

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