Patient transfer robot with gravity compensation

Patient Transfer Robot with Spring-Cam Based Gravity Torque Compensation

This technology is a patient transfer robot that features a gravity compensation function. It uses spring elasticity combined with a cam or gear mechanism to physically reduce the load on the motors and reducers by compensating for the gravity torque acting on the robot's link structure.

Patient transfer robots typically require high-capacity motors and reducers to move heavy patients, which can lead to reduced collision safety, higher energy consumption, and shorter operating times.

This technology proposes a system where gravity torque compensators are installed on the central rotating unit and the first and second rotating arms. A reference plane maintenance unit ensures these components always point in the direction of gravity, allowing the slider and torque compensation spring to generate compensating torque based on varying angles to offset the load on the links. Suitable for nursing homes, hospitals, and home care settings, this system enables safe transfers using lower-capacity motors, thereby reducing both equipment costs and the risk of accidents.

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Key Features:

• A central rotating unit rotatably coupled to the robot body and a central area
• First and second rotating arms rotatably coupled to both ends of the central rotating unit
• Gravity torque compensators that provide compensation torque based on gravity to each of the first and second rotating arms
• Includes a reference plane forming unit that establishes first and second reference planes to generate compensation torque according to angular changes

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