Drive system

Abstract

The present invention relates to a drive system comprising an input shaft, an output shaft, and at least two coupling elements coupled to the input shaft and the output shaft, respectively. To accommodate assembly and manufacturing tolerances of the shafts, the coupling elements, and their attachment to the shafts, and thereby prevent the drive system from seizing, at least one coupling element has an elastically deformable section having a different material or a different cross-section than an adjacent section of the coupling element.

Description

Technical Field

[0001] The invention relates to a drive system according to the preamble of claim 1 . Background Art

[0002] Due to installation space requirements and installation reasons, as well as to reduce thermal effects, the energy converter (eg motor) can be arranged partially separated from the actuator axis. However, this requirement requires energy transmission from the input side to the output side.

[0003] It is known from the prior art to transmit torque from an input shaft to an output shaft arranged parallel thereto by means of a coupling element (e.g., a connecting rod). In this respect, for example, drive systems disclosed in DE 10 2007 035 309 A1, WO 2009 / 123551 A1, and US 8 925 406 B1 provide more than one coupling element between the input shaft and the output shaft. Summary of the Invention

[0004] However, due to assembly and manufacturing tolerances of the shaft, the coupling element and the attachment of the coupling element to the shaft, such drives are prone to jamming. It is therefore an object of the present invention to provide a drive system having an input shaft and an output shaft and at least two coupling elements connected therebetween, in which jamming is prevented.

[0005] To achieve this object, the present invention provides a drive system according to claim 1, comprising: an input shaft; an output shaft; and at least two connecting elements, respectively connected to the input shaft and the output shaft, wherein at least one connecting element has an elastically deformable section having a material or cross-section different from that of an adjacent section of the connecting element.

[0006] Due to the elastically deformable section of the coupling element, there is a flexible distance between the two connecting sections of the coupling element, through which the coupling element is connected to the shaft. Because at least one coupling element has an elastically deformable section, the deviation of the alignment of the axis of the shaft and the difference in the length of the coupling element can be compensated by the elastic deformation of the elastically deformable section during operation. Through this configuration, it is still possible to ensure that the torque is free of side play and accurate transmission. In addition, the drive system according to the present invention is also suitable for use in low temperature ranges (up to cryogenic levels) and ultra-high vacuum. Due to the parallel installation of the motors, the drive system remains compact. In addition, the components of the drive system according to the present invention are advantageous compared to gears or friction wheels, which must be accurately manufactured and require accurate adjustment of the axis of the shaft.

[0007] Preferred embodiments are subject matter of the dependent claims.

[0008] Advantageously, the elastically deformable section is configured such that, due to the elastic deformation of the elastically deformable section, at least part of the drive force is absorbed during operation and the efficiency of the drive system is in the range of between 50% and 100%, preferably in the range of between 90% and 95%, preferably in the range of between 95% and 99%, and / or the torque variation between the input shaft and the output shaft is in the range of between 0% and 50%, preferably in the range of between 1% and 25%, preferably in the range of between 1% and 10%. A drive system according to the invention with high efficiency and low torque variation preferably meets the requirements of continuously and relatively rapidly rotating output shafts, while a drive system with relatively low efficiency and high torque variation can be used in positioning systems in which the output shaft generally performs only a partial rotation function.

[0009] It may be useful if the elastically deformable section is located exactly or substantially centrally between the input shaft and the output shaft.Due to the symmetrical arrangement of the elastically deformable section, the elasticity or flexibility of the coupling element may act evenly in both directions along the longitudinal extent of the coupling element.

[0010] It may be advantageous if the elastically deformable section comprises an elastic element, preferably in the form of a spring or an elastomer. By appropriately selecting the elastic element, the elasticity of the elastically deformable section may be selectively adjusted.

[0011] According to the invention, the elastically deformable section has a different material or a different cross-section than adjacent sections of the coupling element. Thus, the elastically deformable section can be integrated into the coupling element by material bonding and / or the entire coupling element can be formed as a single piece.

[0012] It can be advantageous if both the input shaft and the output shaft have one or more eccentric sections, each coupling element being coupled to a respective eccentric section. A simple and reliable connection of the coupling elements can be achieved via the eccentric sections, for example by means of a connecting section at the end of the coupling element that receives the eccentric section.

[0013] It may also be beneficial if each coupling element is coupled to an end face of the input shaft and / or an end face of the output shaft.This may allow free access to the input shaft or the output shaft along its axis of rotation.

[0014] It may be useful to arrange the coupling elements on the input and output shafts so that they are preferably 60° or 90° out of phase with each other. This arrangement may provide a more constant or uniform torque transmission between the input and output shafts while avoiding singularities in the motion space.

[0015] It has proven useful if the input shaft and the output shaft are mounted elastically, preferably in a common housing, particularly preferably in an elastically deformable housing. This can further reduce the risk of the drive system seizing.

[0016] It may be advantageous if the output shaft has a longitudinal slot extending along the axis of rotation. The longitudinal slot may accommodate an optical fiber.

[0017] It may be advantageous if the output shaft has a clamping device in the region of the longitudinal slot for clamping the optical fiber arranged in the longitudinal slot. This allows the optical fiber to be positioned and fixed on the axis of rotation of the output shaft.

[0018] It may be useful if one or both of these coupling elements are U-shaped. The specific movement space of the U-shaped coupling element may create a free space in the vicinity of the axis, which free space may be used, for example, to position the optical fiber.

[0019] Conveniently, the output shaft is adjustable around the axis of rotation by an angle of rotation of + / - 135°. This makes it possible to provide a positioning system whose use case requires such a range of angles of rotation.

[0020] Another aspect of the present invention relates to a hexapod comprising a plurality of legs and at least one drive system according to any of the preceding embodiments, wherein an output shaft of one of the drive systems is connected to one of the legs of the hexapod for moving the leg of the hexapod by actuation of the drive system.

[0021] Terms and Definitions

[0022] An elastically deformable section of the coupling element.

[0023] At least in the longitudinal direction of the coupling element (a direction perpendicular to the axis of the shaft), the elastically deformable section of the coupling element has a higher elasticity and thus a lower Young's modulus than other sections of the coupling element. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic cross-sectional view of a first embodiment of a drive system according to the invention is shown.

[0025] Figure 2 A perspective view of a first embodiment of a drive system is shown.

[0026] Figure 3 A first embodiment of a drive system is shown in longitudinal section.

[0027] Figure 4 A perspective view of a second embodiment of a drive system according to the present invention is shown.

[0028] Figure 5 A front view of a second embodiment of a drive system is shown. DETAILED DESCRIPTION

[0029] Figure 1A first embodiment of a drive system is schematically shown. Drive system 1a comprises an input shaft 2 and an output shaft 3 arranged parallel thereto. Both shafts 2 and 3 are mounted via rolling bearings. The bearing arrangement and the type of rolling bearings will not be described in detail here. It goes without saying that various options exist for the bearing arrangement and the choice of rolling bearings to meet the requirements of a specific application. In addition to rolling bearings, the use of plain bearings is also possible.

[0030] In addition, the drive system 1a includes two coupling elements 4. The number of coupling elements is not limited to two. In particular, the drive system 1a can also include more than two coupling elements 4. In the present embodiment, each coupling element 4 is connected to the eccentric sections 2a, 3a of the input shaft 2 and the output shaft 3 via connecting sections 4b, 4c. In this case, the connection is preferably made via rolling bearings, the outer ring of the respective rolling bearing being connected to the connecting sections 4b, 4c of the coupling element 4 and the inner ring being connected to the eccentric sections 2a, 3a of the input shaft 2 or the output shaft 3. In addition to other types of connections, sliding bearings can be used instead of rolling bearings. The eccentric sections 2a, 3a or coupling elements 4 are preferably arranged to be 60° or 90° out of phase with each other relative to the axis of rotation of the input shaft 2 or the output shaft 3.

[0031] According to the present invention, at least one of the coupling elements 4 includes an elastically deformable section 4a. In the case where the drive system 1a includes more than two coupling elements 4, at least so many coupling elements 4 include an elastically deformable section 4a that the number of coupling elements 4 having an elastically deformable section 4a is less than one of the total number of coupling elements 4. The elastically deformable section 4a is preferably arranged precisely or substantially centrally between the connecting sections 4b, 4c of each coupling element 4 or, respectively, between the eccentric sections 2a, 3a of the input shaft 2 and the output shaft 3. The intermediate sections 4d, 4e of the coupling element 4 connect each connecting section 4b, 4c to the elastically deformable section 4a. The elastically deformable section 4a can be formed as an elastic element 5, for example, in the form of an elastomer or a spring. The connecting sections 4b, 4c, the intermediate sections 4d, 4e, and the elastic element 5 can be separate parts, each of which can have different materials and are preferably connected by material bonding to form the coupling element 4. Furthermore, in one option, the connecting sections 4b, 4c and the intermediate sections 4d, 4e can be formed as one piece and thus also made of the same material. Furthermore, the entire coupling element 4 can also have a monolithic structure. In this case, the elastically deformable section 4a can be characterized by a smaller cross-section than the intermediate sections 4d, 4e or the connecting sections 4b, 4c of the coupling element 4.

[0032] In all embodiments of coupling element 4, the elastically deformable section provides a variable spacing between connecting sections 4b, 4c, thereby compensating for differences in the length of coupling element 4, deviations from the parallelism of the shaft axes, and overall assembly and manufacturing tolerances of the individual components of drive system 1a, and preventing jamming of drive system 1a. Consequently, a portion of the input power is absorbed by elastically deformable section 4a due to the elastic deformation, which affects the efficiency of drive system 1a and causes torque variations between input shaft 2 and output shaft 3.

[0033] Figure 2 and Figure 3 A perspective view and a longitudinal section, respectively, show a first embodiment of a drive system 1a as part of a hexapod. In particular, an output shaft 3 is connected to an actuator 7, or leg, of the hexapod, which is configured to perform a linear motion based on the rotation of the output shaft 3. The input and output shafts 2 and 3 are mounted in a common housing 6, which also preferably has a resilient design. This allows for a resilient mounting of the shafts 2 and 3, which introduces additional flexibility into the system and further reduces the risk of jamming.

[0034] In the present application, the drive system 1a is designed for continuous and rapid rotation of the output shaft 3. In order to reliably prevent the drive system 1a from getting stuck, the elastically deformable section 4a has a suitable absorption capacity, but preferably, the efficiency of the drive system 1a is at least 95% and / or the torque variation between the input shaft 2 and the output shaft 3 is no more than 20%.

[0035] Figure 4 and Figure 5 A second embodiment of a drive system 1b according to the present invention is shown. The main difference from the first embodiment is that the connecting sections 4b, 4c of the coupling elements 4 are connected to the end faces 2b, 3b of the input and output shafts 2, 3, with the two coupling elements 4 being at different distances from the corresponding end faces 2b, 3b. In particular, the coupling elements 4 are rotatably attached to the end faces 2b, 3b of the shafts 2, 3, such that one coupling element 4 is positioned above the other coupling element 4 relative to a direction perpendicular to the end faces 2b, 3b of the shafts 2, 3. A phase offset of the coupling elements 4, preferably 60°, can also be achieved in this embodiment.

[0036] Various embodiments as the elastic element 5 made of a specific material or a specific shape or as the elastically deformable section 4a having a cross section of reduced cross section have been described with reference to the first embodiment of the drive system 1a.

[0037] Furthermore, to receive the optical fiber, the output shaft 3 is provided with a receiving section 3d that extends from the end face 3b and extends beyond the coupling element 4 in a direction perpendicular to the end face 3b. In this embodiment, the coupling element 4 is formed into a U-shape to allow the output shaft 3 to rotate in both directions to a rotation angle at which the coupling element 4 is blocked by the receiving section 3d. Specifically, in this embodiment, the rotation of the output shaft 3 is limited to a rotation angle of + / - 135° about the rotation axis. The attachment of the coupling element 4 to the end faces 2b, 3b of the input shaft 2 and the output shaft 3, respectively, ensures free access to the input shaft 2 and the output shaft 3 along their respective rotation axes.

[0038] A longitudinal slot 3c is also formed in the output shaft 3 to receive the optical fiber, extending axially into the receiving section 3d and radially to the rotational axis of the output shaft 3. The optical fiber can be clamped to the rotational axis of the output shaft 3 by a clamping device provided in the longitudinal slot 3c and / or the receiving section 3d of the output shaft 3.

[0039] The second embodiment of drive system 1b is particularly suitable as a positioning system for optical fibers. By rotating the optical fiber about its axis of rotation, the polarization angle of the optical fiber can be precisely adjusted for optical coupling. To prevent drive system 1b from becoming stuck, elastically deformable section 4a of drive system 1b also has suitable absorption capacity. The efficiency of drive system 1b is at least 50%, and / or the torque variation between input shaft 2 and output shaft 3 is no greater than 50%.

[0040] Reference Signs List

[0041] 1a, 1b drive system

[0042] 2 Input shaft

[0043] 2a Eccentric section of input shaft

[0044] 2b End face of input shaft

[0045] 3 output shaft

[0046] 3a Eccentric section of output shaft

[0047] 3b End face of output shaft

[0048] 3c Longitudinal slot of output shaft

[0049] Receiving section of 3D output shaft

[0050] 4Connection elements

[0051] 4a elastically deformable section

[0052] 4b, 4c connecting section

[0053] 4d, 4e middle section

[0054] 5 elastic elements

[0055] 6 Shell

[0056] 7Regulator

Claims

1. A drive system (1a, 1b), comprising: Input shaft (2), an output shaft (3), which is arranged parallel to the input shaft (2), At least two coupling elements (4) are respectively coupled to the input shaft (2) and the output shaft (3) and extend in a direction perpendicular to the input shaft (2) and the output shaft (3), wherein: At least one of the coupling elements (4) has an elastically deformable section (4a), wherein The elastically deformable section (4a) comprises a different material than an adjacent section of the coupling element (4), and the elastically deformable section (4a) is integrated into the coupling element (4) by material bonding, or The elastically deformable section (4a) has a cross-section that is different from adjacent sections of the coupling element (4), and the entire coupling element (4) is formed as a single piece.

2. The drive system (1a, 1b) according to claim 1, characterized in that The elastically deformable section (4a) is configured such that due to the elastic deformation of the elastically deformable section (4a) during operation, at least part of the driving force is absorbed and the efficiency of the drive system is in the range between 50% and 100%, and / or the torque fluctuation between the input shaft (2) and the output shaft (3) is in the range between 0% and 50%.

3. The drive system according to claim 1 or 2, characterized in that: The elastically deformable section (4a) is arranged exactly or substantially centrally between the input shaft (2) and the output shaft (3).

4. Drive system according to any one of the preceding claims, characterized in that The elastically deformable section (4a) has an elastic element (5), preferably in the form of a spring or an elastomer.

5. Drive system according to any one of the preceding claims, characterized in that Each of the input shaft (2) and the output shaft (3) includes one or more eccentric sections (2a, 3a), and each coupling element (4) is coupled to a corresponding eccentric section (2a, 3a).

6. The drive system according to any one of claims 1 to 4, characterized in that: Each of the coupling elements (4) is coupled to an end face (2b) of the input shaft (2) and / or an end face (3b) of the output shaft (3).

7. Drive system according to any one of the preceding claims, characterized in that The coupling elements (4) are arranged on the input shaft (2) and the output shaft (3) so as to be out of phase with each other, preferably 60° or 90° out of phase.

8. Drive system according to any one of the preceding claims, characterized in that The input shaft (2) and the output shaft (3) are elastically mounted, preferably in a common housing (6), particularly preferably in an elastically deformable housing (6).

9. Drive system according to any one of the preceding claims, characterized in that The output shaft (3) has a longitudinal slot (3c) extending along the rotation axis.

10. The drive system according to claim 9, characterized in that: The output shaft (3) has a clamping device in the region of the longitudinal slot (3c) for clamping the optical fiber arranged in the longitudinal slot (3c).

11. Drive system according to any one of the preceding claims, characterized in that At least one of the coupling elements (4) is U-shaped.

12. The driving system according to claim 9, characterized in that The output shaft (3) is adjustable around the rotation axis by a rotation angle of + / - 135°.

13. A hexapod comprising a plurality of legs and at least one drive system (1a, 1b) according to any one of the preceding claims, characterized in that The output shaft (3) of one of the drive systems (1a, 1b) is connected to one of the legs of the hexapod so as to move the leg by actuating the drive system (1a, 1b).

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