Drive system

Abstract

A drive system as disclosed includes an input shaft, an output shaft, and at least two coupling elements respectively coupled to the input shaft and the output shaft. In order to absorb assembly and manufacturing tolerances with respect to the shafts, the coupling elements and their attachment to the shafts and thereby prevent jamming of the drive system, at least one coupling element has an elastically deformable section, the elastically deformable section having a different material or a different cross-section than an adjacent section of the coupling element.

Claims

1. Drive system comprising: an input shaft; an output shaft arranged in parallel to the input shaft; at least two coupling elements coupled to the input shaft and the output shaft, respectively, and extending in a direction perpendicular to the input shaft and the output shaft, wherein: at least one coupling element of the at least two coupling elements has an elastically deformable section, the elastically deformable section having a different material than an adjacent section of the coupling element, wherein the elastically deformable section is integrated into the coupling element by material bond, or the elastically deformable section having a different cross section than an adjacent section of the coupling element, wherein an entirety of the coupling element is formed as one piece.

2. Drive system according to claim 1, wherein the elastically deformable section is arranged exactly or substantially centrally between the input shaft and the output shaft.

3. Drive system according to claim 1, wherein the elastically deformable section has an elastic element, formed as a spring or an elastomer.

4. Drive system according to claim 1, wherein each of the input shaft and the output shaft comprises: one or more eccentric sections, and each coupling element is coupled to a corresponding eccentric section.

5. Drive system according to claim 1, wherein each coupling element is coupled to an end face of the input shaft and/or an end face of the output shaft.

6. Drive system according to claim 1, wherein the coupling elements are arranged on the input shaft and the output shaft so as to be out of phase with one another.

7. Drive system according to claim 1, wherein the input shaft and the output shaft are mounted in a common housing which is elastically deformable.

8. Drive system according to claim 1, wherein the output shaft has a longitudinal slot extending along an axis of output shaft rotation.

9. Drive system according to claim 1, wherein the at least one coupling element is U-shaped.

10. Drive system according to claim 8, wherein the output shaft is adjustable by a rotation angle of +/135 about the axis of output shaft rotation.

11. Drive system according to claim 1, wherein the coupling elements are arranged on the input shaft and the output shaft so as to be out of phase with one another by 60 or 90.

12. Drive system according to claim 1, wherein the elastically deformable section is arranged exactly or substantially centrally between the input shaft and the output shaft.

13. Drive system according to claim 12, wherein the elastically deformable section has an elastic element, formed as a spring or an elastomer.

14. Drive system according to claim 13, wherein each of the input shaft and output shaft comprises: one or more eccentric sections, and each coupling element is coupled to a corresponding eccentric section.

15. Drive system according to claim 14, wherein each coupling element is coupled to an end face of the input shaft and/or an end face of the output shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic sectional view of a first embodiment of the drive system according to the invention.

(2) FIG. 2 shows a perspective view of the first embodiment of the drive system.

(3) FIG. 3 shows a longitudinal section of the first embodiment of the drive system.

(4) FIG. 4 shows a perspective view of a second embodiment of the drive system according to the invention.

(5) FIG. 5 shows a front view of the second embodiment of the drive system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) FIG. 1 schematically shows a first embodiment of the drive system. The drive system 1a includes a drive shaft 2 and an output shaft 3 arranged parallel thereto. Both shafts 2, 3 are mounted via rolling bearings. The bearing arrangement and the type of rolling bearing are not specified in more 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 specific applications. In addition to rolling bearings, the use of plain bearings is also possible.

(7) Furthermore, 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 may also include more than two coupling elements 4. In the present embodiment, each coupling element 4 is connected to an eccentric section 2a, 3a of the input and output shafts 2, 3 via a connecting section 4b, 4c. In this case, the connection is preferably made via rolling bearings, with an outer ring of the corresponding rolling bearing being connected to the connecting section 4b, 4c of the coupling element 4 and an inner ring being connected to the eccentric section 2a, 3a of the input or output shaft 2, 3. In addition to other types of connection, plain bearings may be used instead of rolling bearings. The eccentric sections 2a, 3a or the coupling elements 4 are preferably arranged 60 or 90 out of phase with one another with respect to the axes of rotation of the input or output shafts 2, 3.

(8) According to the invention, at least one of the coupling elements 4 includes an elastically deformable section 4a. In a case where the drive system 1a includes more than two coupling elements 4, at least so many coupling elements 4 include the elastically deformable section 4a that the number of coupling elements 4 having the elastically deformable section 4a is one less than the total number of coupling elements 4. The elastically deformable section 4a is preferably arranged exactly or substantially centrally between the connecting sections 4b, 4c of each coupling element 4 or between the eccentric sections 2a, 3a of the input and output shafts 2, 3, respectively. 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 may 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 may be individual parts, each of which may have different materials and which are preferably joined by material bonding to form the coupling element 4. In addition, in one option the connecting sections 4b, 4c and the intermediate sections 4d, 4e may be formed in one piece and consequently also may be made of the same material. Furthermore, the entire coupling element 4 may also be of integral construction. In this case, the elastically deformable section 4a may be characterized by a smaller cross-section than the intermediate sections 4d, 4e or the connecting sections 4b, 4c of the coupling element 4.

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

(10) FIGS. 2 and 3 show respectively a perspective view and a longitudinal section of the first embodiment of the drive system 1a as part of a hexapod. In particular, the 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. Input and output shafts 2, 3 are mounted in a common housing 6, which is preferably also of elastic design. This enables elastic mounting of the shafts 2, 3, which introduces additional flexibility into the system and further reduces the risk of jamming.

(11) 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 jamming of the drive system 1a, 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 not greater than 20%.

(12) FIGS. 4 and 5 show a second embodiment of the drive system 10 b according to the invention. The main difference from the first embodiment is that the connecting sections 40 b, 40 c of the coupling elements 40 are connected to end faces 20 b, 30 b of the input and output shafts 20, 30, the two coupling elements 40 being at different distances from the respective end faces 20 b, 30 b. In particular, the coupling elements 40 are rotatably attached to the end faces 20 b, 30 b of the shafts 20, 30 such that one coupling element 40 is located above the other coupling element 40, with respect to a direction perpendicular to the end faces 20 b, 30 b of the shafts 20, 30. A phase offset of the coupling elements 4 may also be realized in the present embodiment and is preferably 60.

(13) The various embodiments of the elastically deformable section 40 a as an elastic element 50 made of a specific material or a specific shape or as a section with a reduced cross-section are already described with reference to the first embodiment of the drive system 10 a.

(14) Furthermore, for receiving an optical fiber, the output shaft 30 is provided with a receiving section 30 d, which protrudes from the end face 30 b and projects beyond the coupling elements 40 with respect to a direction perpendicular to the end face 30 b. In the present embodiment, the coupling elements 40 are formed in a U-shape to allow rotation of the output shaft 30 in both directions up to a rotation angle, at which a coupling element 4 is blocked by the receiving section 30 d. In particular, in the present embodiment, the rotation of the output shaft 30 is limited to a rotation angle of +/135 about the rotation axis. The attachment of the coupling elements 4 to the end faces 20 b, 30 b of the input and output shafts 20, 30 ensures free access to the input and output shafts 20, 30, respectively, along their axis of rotation.

(15) A longitudinal slot 30 c is also formed in the output shaft 30 to receive the optical fiber, extending axially into the receiving section 30 d and extending radially to the axis of rotation of the output shaft 30. The optical fiber may be clamped onto the rotational axis of the output shaft 30 by a clamping device provided in the longitudinal slot 30 c of the output shaft 30 and/or the receiving section 30 d.

(16) The second embodiment of the drive system 10 b is particularly suitable as a positioning system for an optical fiber, whose polarization angle may be precisely adjusted for coupling light by rotating the fiber about its rotation axis. In order to prevent jamming of the drive system 10 b, the elastically deformable section 40 a of the drive system 10 b also has a suitable absorbing capacity, wherein the efficiency of the drive system 10 b is at least 50% and/or the torque variation between the input shaft 20 and the output shaft 30 is not greater than 50%.

LIST OF REFERENCE SIGNS

(17) 1 a, 10 b drive system 2, 20 input shaft 2 a eccentric section of the input shaft 2 b, 20 b end face of input shaft 3, 30 output shaft 3 a eccentric section of output shaft 3 b, 30 b end face of output shaft 3 c, 30 c longitudinal slot of output shaft 3 d, 30 d receiving section of output shaft 4, 40 coupling element