Series Elastic Actuator

Series Elastic Actuator

This technology is a Series Elastic Actuator (SEA) structure that measures torque and controls rotation angle without changes to the moment arm by utilizing wire tension during relative rotation between a first body (including a motor) and a second body. The wire's center is wound around a pulley seat, with both extended ends connected to preloaded first and second springs and adjustment devices.

Conventional series elastic actuators suffer from difficulties in accurate torque measurement and control because the spring is positioned between the output stage and the link, causing the spring to bend or rotate during deformation, which alters the moment arm.

This technology maintains a constant moment arm by securing the center of the wire to the outer circumference of the pulley and supporting the extended ends through a preloaded spring system within the second body. It establishes a structure that allows for precise control and measurement of wire tension via adjustment devices and a housing design. Applicable to robotic gripping, precision measurement, and automation equipment, it improves torque measurement accuracy and facilitates torque measurement based on external forces.

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Key Features:

• A wire comprising a central portion curved around a seating area, and first and second straight extension portions extending from both ends of the central portion.
• A pulley configured to rotate about a first rotation axis when the rotor rotates, equipped with a seating area that forms an arc around the first rotation axis.
• A first adjustment housing accommodating a first spring, a first neck portion, and a first adjustment nut.
• A first adjustment device coupled to the first extension portion to move in tandem with it.

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This invention was developed with support from the Ministry of Science and ICT for the commercialization of immersive human-robot multi-sensory interaction technology.