Rotational driving mechanism in a robot

Patent metadata

Field	Value
Publication number	US-10022860-B2
Application number	US-201515512290-A
Country	US
Kind code	B2
Filing date	Sep 18, 2015
Priority date	Sep 19, 2014
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A rotational driving mechanism for driving a rotary member mounted on a rotatable base member includes: a first link unit that has a first link body and is mounted through a first support part on the base member, the first link unit further having an input part to which an output of the linear motion actuator is inputted at one side of the first link body, and an output part located in the first link body at an opposite side of the input part across the first support part; and a second link unit that has a second link body and is mounted through a second support part on the output part of the first link unit, the second link unit being further mounted through a third support unit on the rotary member or a connecting member joined thereto in such a manner as to be free to rotate.

First claim

The invention claimed is:

1. A rotational driving mechanism in a robot, which drives a rotary member, which is a part of the robot and which is mounted on a base member at the side of a main body of the robot so as to extend from its mounting position in a predetermined extension direction, to rotate in a prescribed direction including a gravity component by means of a linear motion actuator having a linear motion output shaft, said rotational driving mechanism comprising:
a first link unit that has a first link body and is mounted through a first support part on said base member in such a manner as to be free to rotate, said first link unit further having an input part to which an output of said linear motion actuator is inputted at one side of said first link body based on said first support part, and an output part located in said first link body at an opposite side of said input part across said first support part; and
a second link unit that has a second link body and is mounted through a second support part on said output part of said first link unit in such a manner as to be free to rotate, said second link unit being further mounted through a third support unit on said rotary member or a connecting member joined thereto in such a manner as to be free to rotate;
wherein said first link unit and said second link unit are formed in such a manner that in the case where said rotary member is in a horizontal raised position in which it becomes the closest to a horizontal state in a rotational movement range in said prescribed direction of said rotary member and in which a gravity load of said rotary member with respect to said linear motion actuator becomes a maximum, an interlink angle formed by a first straight line connecting between a support point of said first support part and a support point of said second support part, and a second straight line connecting between the support point of said second support part and a support point of said third support part is larger, and the support point of said third support part is more away in an upward direction from the support point of said first support member, in comparison with the case where said rotary member is in a lowermost position in which it comes close to a state of extending in the most downward direction from a mounting position thereof with said base member in said rotational movement range and in which the gravity load of said rotary member with respect to said linear motion actuator becomes a minimum.

2. The rotational driving mechanism in a robot as set forth in claim 1 , wherein
said first link unit is formed in such a manner that when said input part is moved in a downward direction by said linear motion actuator, said output part is moved in au upward direction by rotation thereof through said first support part of said first link body; and
in said first link unit, the support point of said second support part is not arranged on a straight line passing through said input part and the support point of and said first support part, but is arranged at the side of said third support part from said straight line.

3. The rotational driving mechanism in a robot as set forth in claim 1 , wherein
when said rotary member is in a horizontal raised position, said interlink angle becomes an angle of 180 degrees or an angle in the vicinity of 180 degrees.

4. The rotational driving mechanism in a robot as set forth in claim 1 , wherein
said first link unit and said second link unit are formed in such a manner that in the case where said rotary member is located in a predetermined upper position including said horizontal raised position, a ratio of an amount of rotation of said rotary member with respect to an amount of output of said linear motion actuator becomes smaller, in comparison with the case where said rotary member is located in a predetermined downward position including said lowermost position.

5. The rotational driving mechanism in a robot as set forth in claim 1 , further comprising:
a spring member arranged between a main body side of said robot and a rotary member side for applying an urging force to cause said rotary member to rotate upwardly in said prescribed direction.

6. The rotational driving mechanism in a robot as set forth in claim 1 , wherein
said rotary member is an arm unit of said robot; and
said prescribed direction is a pitch direction of said robot.

7. A rotational driving mechanism in a robot, which drives a rotary member, which is a part of the robot and which is mounted on a base member at the side of a main body of the robot, to rotate in a prescribed direction including a gravity component by means of a linear motion actuator having a linear motion output shaft, said rotational driving mechanism, comprising:
a first link unit that has a first link body and is mounted through a first support part on said base member in such a manner as to be free to rotate, said first link unit further having an input part to which an output of said linear motion actuator is inputted at one side of said first link, body based on said first support part, and an output part located in said first link body at an opposite side of said input pan across said first support part; and
a second link unit that has a second link body and is mounted through a second support part on said output part of said first link unit in such a manner as to be free to rotate, said second link unit being further mounted through a third support unit on said rotary member or a connecting member joined thereto in such a manner as to be free to rotate;
wherein said first link unit and said second link unit are formed in such a manner that in the case where said rotary member is in a horizontal raised position in which it becomes the closest to a horizontal state in a rotational movement range in said prescribed direction of said rotary member, an interlink angle formed by a first straight line connecting between a support point of said first support part and a support point of said second support part, and a second straight line connecting between the support point of said second support part and a support point of said third support part is larger, and the support point of said third support part is more away in an upward direction from the support point of said first support member, in comparison with the case where said rotary member is in a lowermost position in which it comes close to a state of extending in the most downward direction from a mounting position thereof with said base member in said rotational movement range;
wherein said first link unit is formed in such a manner that when said input part is moved in a downward direction by said linear motion actuator, said output part is moved in an upward direction by rotation thereof through said first support part of said first link body; and
wherein in said first link unit, the support point of said second support part is not arranged on a straight line passing through said input part and the support point of and said first support part, but is arranged at the side of said third support part from said straight line.

8. The rotational driving mechanism in a robot as set forth in claim 7 , wherein when said rotary member is in a horizontal raised position, said interlink angle becomes an angle of 180 degrees or an angle in the vicinity of 180 degrees.

Assignees

• Thk Co Ltd

Inventors

• Nagatsuka Masaki

Classifications

• B25J9/0015

  Flexure members, i.e. parts of manipulators having a narrowed section allowing articulation by flexion · CPC title

• B25J9/0006

  Exoskeletons, i.e. resembling a human figure · CPC title

• B25J9/123 Primary

  Linear actuators · CPC title

• B25J17/0283

  Three-dimensional joints · CPC title

• B25J17/00 Primary

  Joints · CPC title