Torque sensor and robot

Patent metadata

Field	Value
Publication number	US-10444098-B2
Application number	US-201815919557-A
Country	US
Kind code	B2
Filing date	Mar 13, 2018
Priority date	Apr 10, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

Provided is a torque sensor that includes: a bearing that is provided with an inner ring and an outer ring that are supported so as to be relatively movable only in the direction of rotation about a predetermined axis; a connecting member that is provided with fixing sections that are respectively fixed to the inner ring and the outer ring and a strain generation section that connects between the fixing sections; and a strain sensor that is disposed on the connecting member so as to be capable of detecting a strain at least in the circumferential direction.

First claim

The invention claimed is:

1. A torque sensor comprising:
a bearing that is provided with an inner ring and an outer ring that are supported so as to be relatively movable only in the direction of rotation about a predetermined axis;
a connecting member that is provided with fixing sections that are fixed on respective side surfaces of the inner ring and the outer ring and a strain generation section that connects between the fixing sections, the respective side surfaces being substantially perpendicular to the predetermined axis; and
a strain sensor that is disposed on the connecting member so as to be capable of detecting a strain at least in the circumferential direction.

2. The torque sensor according to claim 1 , wherein the transverse-sectional area of the strain generation section is smaller than the transverse-sectional areas of the fixing sections.

3. The torque sensor according to claim 1 , wherein the inner ring and the outer ring are provided with fixing means that fix the inner ring and the outer ring to a detection target.

4. The torque sensor according to claim 1 , wherein the connecting member is formed in a plate-like shape extending along the respective side surfaces.

5. The torque sensor according to claim 1 , wherein the strain sensor is provided with a correction means that corrects a strain-amount variation caused by an ambient-temperature change.

6. The torque sensor according to claim 1 , wherein the strain sensor is fixed to the connecting member with screws.

7. The torque sensor according to claim 1 , wherein a plurality of strain sensors that are each the same as the strain sensor are disposed side by side on the strain generation section.

8. The torque sensor according to claim 1 , wherein the bearing is a cross roller bearing.

9. The torque sensor according to claim 1 , wherein the bearing is a compound ball bearing.

10. The torque sensor according to claim 1 , wherein the bearing is a sliding bearing.

11. The torque sensor according to claim 1 , wherein:
a plurality of connecting members that are each the same as the connecting member are provided at intervals in the circumferential direction around the axis; and
the strain sensor is disposed on the strain generation section of each of the connecting members.

12. The torque sensor according to claim 1 , comprising at least one reinforcing member that is fixed to each of the inner ring and the outer ring and that couples the inner ring and the outer ring.

13. A robot to which a torque sensor according to claim 1 is attached while making the axis of the bearing match with the rotation axis of each joint.

Assignees

• Fanuc Corp

Inventors

• Nakayama Kazutaka

Classifications

• G01L5/0076

  Force sensors associated with manufacturing machines (G01L5/0066, G01L5/0071 and B23Q17/09 take precedence; for the specific machine or operation involved see relevant class, e.g. B21 - B42) · CPC title

• G01L5/0009

  Force sensors associated with a bearing (testing of bearings G01M13/04) · CPC title

• G01L3/1428

  using electrical transducers · CPC title

• F16C19/362

  the rollers being crossed within the single row · CPC title

• B25J13/085

  Force or torque sensors (B25J13/082, B25J13/084 take precedence) · CPC title