Joint positioning device

Joint Positioning Device Supporting Multi-Joints with a Single Spring Balancer and Tension Wire

This technology is a joint positioning device that maintains the position of a multi-joint system by redirecting a unidirectional force from a spring balancer via a tension wire to deliver gravity compensation to linear and rotary joints.

In multi-joint robots, installing individual gravity compensation devices for each joint increases the number of components, adds to the overall mass and volume of the system, and leads to structural complexity and inefficiency.

This technology proposes a method where force applied from a single source is transmitted via a tension wire to the connection points of the linear guide rolling unit and the first and second rotary joints. By winding the wire multiple times around the connection and auxiliary connection parts, the required force is efficiently amplified and transmitted. Applicable to industrial robot arms and medical stands, this system supports the entire multi-joint structure with a single compensation device, achieving both weight reduction and structural simplification.

‍

‍

Key Features:

• A force application unit consisting of a spring balancer located on one side of the base frame that provides continuous, unidirectional force.
• A redirection roller positioned on the upper side, opposite the force application unit, to change the direction of the tension wire's force.
• A tension wire connected at one end to the force application unit and routed around the redirection roller to transmit force in a new direction.
• A linear guide and rotary joint assembly that receives force from the tension wire to maintain its position against gravity.

‍

This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of human-centered smart dual-arm transfer assistance robots.