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EP-4737076-A1 - DRIVE DEVICE AND WORK MACHINE

EP4737076A1EP 4737076 A1EP4737076 A1EP 4737076A1EP-4737076-A1

Abstract

[Problem] A technique is provided capable of simplifying a structure and accurately detecting torque acting on an elastic body. [Solution] The drive device includes a drive source that generates a rotary drive force, and an elastic body that connects the drive source and a load. The elastic body includes a torsion bar.

Inventors

  • SAIKI, Miyuki
  • UEBAYASHI, YUICHI
  • HIRAMATSU, Toshifumi

Assignees

  • Yanmar Holdings Co., Ltd.

Dates

Publication Date
20260506
Application Date
20251014

Claims (16)

  1. A drive device comprising: a drive source that generates a rotary drive force; and an elastic body that connects the drive source and a load, wherein the elastic body includes a torsion bar.
  2. The drive device according to claim 1, wherein the torsion bar constitutes an outputting shaft that drives the load.
  3. The drive device according to claim 1, wherein the torsion bar has flange portions on one side and the other side.
  4. The drive device according to claim 3, wherein the flange portion on the other side is provided to be rotatable with respect to the flange portion on the one side.
  5. The drive device according to claim 4, wherein the drive source is connected to the other side of the torsion bar in the axial direction, and the load is connected to the one side of the torsion bar in the axial direction.
  6. The drive device according to claim 1, further comprising a detecting portion that detects displacement of the torsion bar.
  7. The drive device according to claim 6, wherein the torsion bar has a penetration portion penetrating in an axial direction of the torsion bar, and the detecting portion is provided in the penetration portion.
  8. The drive device according to claim 7, wherein the detecting portion comprises a detecting shaft extending in the axial direction and a detector detecting displacement of the detecting shaft, wherein the detector is fixed to one side of the torsion bar in the axial direction, and the detecting shaft is connected to the other side of the torsion bar in the axial direction.
  9. The drive device according to claim 8, wherein the detector is fixed to one end portion of the torsion bar on one side in the axial direction, and the detecting shaft is connected to the other end portion of the torsion bar on the other side in the axial direction.
  10. The drive device according to claim 8, wherein the drive source is connected to the other side of the torsion bar in the axial direction, and the load is connected to the one side of the torsion bar in the axial direction.
  11. The drive device according to claim 8, wherein the detector includes an encoder.
  12. The drive device according to claim 8, further comprising a gearbox that changes a speed of a rotary drive force of the drive source and outputs the rotary drive force to the torsion bar, wherein the gearbox is disposed on at least one of one side in the axial direction and the other side in the axial direction with respect to the torsion bar.
  13. The drive device according to claim 12, wherein the gearbox is disposed on a side opposite to the detector with respect to the torsion bar in the axial direction.
  14. The drive device according to claim 1, wherein the drive source includes an electric motor driven by electric power.
  15. A work machine comprising: the drive device according to any one of claims 1 to 14; and the load driven by the drive device.
  16. A drive device comprising: a drive source that generates a rotary drive force; and an elastic body that connects the drive source and a load, wherein the elastic body constitutes an outputting shaft that drives the load.

Description

TECHNICAL FIELD The present invention relates to a drive device and a work machine. BACKGROUND ART A series elastic actuator in which a motor is incorporated is known as a prior art (for example, see Patent Document 1). PRIOR ART DOCUMENT PATENT DOCUMENT Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-513568 SUMMARY OF INVENTION TECHNICAL PROBLEM In a drive device constituted by a series elastic actuator, for example, when a coil spring constitutes an elastic body, a member for connecting a motor as a drive source and the coil spring, a support member for the coil spring, a member for connecting the coil spring and an external load, and the like are required. Therefore, a structure of the drive device tends to be complicated. Further, in order to improve controllability, it is desirable to accurately detect a torque acting on the elastic body in the drive device constituted by the series elastic actuator. The present invention has been made to solve the above problems, and an object of the present invention is to provide a technique capable of simplifying a structure and accurately detecting a torque acting on an elastic body. SOLUTION TO PROBLEM A drive device according to an aspect of the present invention includes: a drive source that generates a rotary drive force; and an elastic body for connecting the drive source and a load, wherein the elastic body includes a torsion bar. A work machine according to another aspect of the present invention includes the above drive device and the load driven by the drive device. ADVANTAGEOUS EFFECTS OF INVENTION The above configuration can simplify a structure and accurately detect a torque acting on an elastic body. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a side view illustrating a schematic configuration of an electric shovel that is an example of a work machine according to an embodiment of the present invention;FIG. 2 is a left rear perspective view illustrating a schematic configuration of a drive device provided in the electric shovel;FIG. 3 is a right front perspective view illustrating a schematic configuration of the above drive device;FIG. 4 is a horizontal cross-sectional view illustrating a configuration of the above drive device;FIG. 5 is a left rear perspective view illustrating a schematic configuration of a modification of the above drive device; andFIG. 6 is a horizontal cross-sectional view illustrating a configuration of a modification of the above drive device. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1. Schematic Configuration of Work Machine FIG. 1 is a side view illustrating a schematic configuration of an electric shovel 1 that is an example of a work machine according to an embodiment of the present invention. The electric shovel 1 includes a machine body 2 and a work machine portion 3. The machine body 2 is configured to be capable of traveling. However, the machine body 2 may be configured to be incapable of traveling. That is, for example, the machine body 2 may be fixed to the ground. Here, directions in this specification are defined as follows. A direction in which the machine body 2 travels straight ahead is defined as a front-rear direction, one side in the front-rear direction is defined as "front", and another side in the front-rear direction is defined as "rear". In this specification, a side on which the work machine portion 3 is positioned with respect to the machine body 2 is referred to as "front". Moreover, a lateral direction perpendicular to the front-rear direction is defined as a left-right direction, and one side thereof is defined as "left" and the other side thereof is defined as "right". In this specification, a left side and a right side when viewed from the rear to the front are referred to as "left" and "right", respectively. A gravity direction perpendicular to the front-rear direction and the right-left direction is defined as an up-down direction, an upstream side in the gravity direction is defined as "up", and a downstream side is defined as "down". In the drawings, when necessary, forward is denoted by a symbol "F", backward by "B", leftward by "L", rightward by "R", upward by "U", and downward by "D". These directions are names used merely for the description and are not intended to limit actual positional relationships or directions. The machine body 2 includes a battery unit 21. The battery unit 21 is configured by, for example, a lithium ion battery, and stores electric power to be supplied to each drive device 100 described later. Further, the machine body 2 rotatably supports the work machine portion 3. The work machine portion 3 includes a boom 31, an arm 32, and an attachment 33. Each of the boom 31, the arm 32, and the attachment 33 is an example of a load 4. That is, the electric shovel 1 includes the load 4. The load 4 is not limited to the boom 31, the arm 32, and the attachment 33. For ex