Cam-based integrated safety joint unit with torque sensing and reduction functions

Cam-based integrated safety joint unit with non-linear stiffness and torque sensing

This technology is a cam-based integrated safety joint unit that transmits input torque through a hollow shaft to a harmonic gear reducer. A spring-supported roller block contacts a slanted cam to maintain stiffness below a threshold, while deforming non-linearly to absorb shock when an impact exceeds that threshold.

Conventional active control methods struggle to respond to instantaneous impacts due to sensor and control system latency, while passive control methods are limited by the linear characteristics of springs, which can cause unnecessary deflection or restrict design flexibility.

This technology proposes a method that achieves mechanical safety through non-linear stiffness implemented via the contact structure between rollers and a slanted cam, combined with a cam buckling structure and precise torque sensing using torque sensor spokes. It can be applied to the joints of collaborative robots, providing ideal safety characteristics that remain rigid during normal operation and become instantly flexible upon collision.

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Key Features:

• Harmonic gear reduction unit including a hollow shaft connected to the input section to transmit input torque
• Base plate connected to the reduction unit to receive reduced torque and transmit it to the passive safety device unit
• Passive safety device unit with non-linear stiffness that transmits output below a set magnitude and limits it when exceeded
• Torque sensor unit connected to the passive safety device unit to detect output torque applied to the joint through spoke deformation