Gravity balancing device for rehabilitation robot arm

Patent metadata

Field	Value
Publication number	US-11241354-B2
Application number	US-201816156605-A
Country	US
Kind code	B2
Filing date	Oct 10, 2018
Priority date	Jun 29, 2018
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

The present invention discloses a gravity balancing device for a rehabilitation robot arm, and belongs to the field of rehabilitation robots. The gravity balancing device includes a shoulder joint connecting member, an upper arm connecting member and a gravity balancing assembly; the shoulder joint connecting member and the upper arm connecting member are pivotally connected according to the human body bionic structure to simulate the rotational movement of the upper arm of the human body around the shoulder joint; the gravity balancing assembly includes a plurality of springs, wire ropes and guide pulleys, the wire ropes connect the springs to the shoulder joint connecting member and the upper arm connecting member, the spring tension is used to balance the gravity of the arm, and the guide pulleys are used to change the force directions of the wire ropes, thereby saving space and making the device structure more compact. Further, by locking different guide pulleys, the arm gravity can be still balanced by the spring tension after switching of the rehabilitation robot between the left and right hand training modes, thereby ensuring that the robot can still work normally after the training mode is switched.

First claim

What is claimed is:

1. A gravity balancing device for a rehabilitation robot arm, comprising: a shoulder joint connecting member, an upper arm connecting member and a gravity balancing assembly;
the shoulder joint connecting member and the upper arm connecting member are pivotally connected according to a human body bionic structure to simulate rotational movement of the upper arm of a human body around the shoulder joint;
the gravity balancing assembly includes a first tension unit, a second tension unit and a locking mechanism;
the first tension unit includes a first guide pulley as well as a first wire rope, a first spring, a second wire rope, a second guide pulley, a third wire rope, a second spring, a fourth wire rope, a third spring and a fifth wire rope that are fixedly connected in sequence; the second wire rope and the third wire rope are respectively connected to two ends of the second guide pulley in a radial direction;
the second tension unit includes a third guide pulley as well as a sixth wire rope, a fourth spring, a seventh wire rope, a fourth guide pulley, an eighth wire rope, a fifth spring, a ninth wire rope, a sixth spring and a tenth wire rope that are fixedly connected in sequence, the respective members of the second tension unit and the respective members of the first tension unit are arranged in one-to-one correspondence, have a same specification and are symmetrically distributed; the seventh wire rope and the eighth wire rope are respectively connected to two ends of the fourth guide pulley in the radial direction;
head ends of the first wire rope and the sixth wire rope are fixed on the shoulder joint connecting member; tail ends of the fifth wire rope and the tenth wire rope are fixed on the upper arm connecting member and are symmetrically mirroring each other from either side of a rotation axis of the upper arm connecting member; the first guide pulley and the third guide pulley are fixed pulleys, and the fourth wire rope is connected to the second spring and the third spring after passing by the first guide pulley; the ninth wire rope is connected to the fifth spring and the sixth spring after passing by the third guide pulley; the first, second, third, and fourth guide pulleys are all disposed on the shoulder joint connecting member;
the locking mechanism is used to independently lock one of the second guide pulley and the fourth guide pulley when the robot arm is switched between a right hand training mode and a left hand training mode,
and wherein the first and fourth springs have a same stiffness, which is set to K 1 , and the second, third, fifth, and sixth springs have a same stiffness, which is set to K 2 , K 1 is smaller than K 2 .

2. The gravity balancing device for the rehabilitation robot arm of claim 1 , wherein the first tension unit further includes a fifth guide pulley, and the second tension unit further includes a sixth guide pulley; the fifth guide pulley and the sixth guide pulley are both fixed on the upper arm connecting member, the tail end of the fifth wire rope and the tail end of the tenth wire rope are fixedly connected to the fifth guide pulley and the sixth guide pulley, respectively.

3. The gravity balancing device for the rehabilitation robot arm of claim 1 , wherein the second guide pulley includes a seventh guide pulley and an eighth guide pulley that are symmetrically and coaxially distributed on front and back sides of the shoulder joint connecting member to rotate synchronously; the first wire rope, the first spring and the second wire rope are located on a same side of the eighth guide pulley, and the third wire rope, the second spring, the fourth wire rope, the third spring and the fifth wire rope are located on a same side of the seventh guide pulley; the second wire rope is connected to the eighth guide pulley, and the third wire rope is connected to the seventh guide pulley;
the fourth guide pulley includes a ninth guide pulley and a tenth guide pulley that are symmetrically and coaxially distributed on front and back sides of the shoulder joint connecting member to rotate synchronously; the sixth wire rope, the fourth spring and the seventh wire rope are located on a same side of the ninth guide pulley, and the eighth wire rope, the fifth spring, the ninth wire rope, the sixth spring and the tenth wire rope are located on a same side of the tenth guide pulley; the seventh wire rope is connected to the sixth guide pulley, and the sixth wire rope is connected to the ninth guide pulley.

4. The gravity balancing device for the rehabilitation robot arm of claim 1 , wherein the first tension unit further includes an eleventh guide pulley, a twelfth guide pulley and a thirteenth guide pulley; the twelfth guide pulley and the thirteenth guide pulley are located in a same plane and cooperate to clamp the fifth wire rope, an axis of the eleventh guide pulley is perpendicular to the fifth wire rope and an axis of the thirteenth guide pulley; the fifth wire rope is connected to the upper arm connecting member after being guided by the eleventh guide pulley, the twelfth guide pulley and the thirteenth guide pulley;
the second tension unit further includes a fourteenth guide pulley, a fifteenth guide pulley and a sixteenth guide pulley that are arranged in one-to-one correspondence with the eleventh guide pulley, the twelfth guide pulley and the thirteenth guide pulley of the first tension unit in a same manner; the eleventh, twelfth, thirteenth, fourteenth, fifteenth, and sixteenth guide pulleys are all fixed pulleys.

5. The gravity balancing device for the rehabilitation robot arm of claim 1 , wherein sizes of the guide pulleys and the springs are constrained to be:

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Assignees

• Univ Huazhong Science Tech

Inventors

• Xiong Caihua
• Tao Jianbo
• Wu Xuan
• He Chang
• Chen Wenbin
• Wang Chenbo

Classifications

• A61H1/0277

  Elbow · CPC title

• F16H19/06

  comprising {flexible members, e.g. an} endless flexible member · CPC title

• A61H2201/1659

  Free spatial automatic movement of interface within a working area, e.g. Robot · CPC title

• B25J11/008

  Manipulators for service tasks · CPC title

• A61H2205/062

  Shoulders · CPC title