When it comes to safety, sometimes it is best to be both precise and accurate. Power-off brakes are commonplace on robotic applications. They mount on the motors located in the robotic joints, mostly for safety reasons. When the power is disconnected (or interrupted), the brake engages. This keeps the load from falling due to gravity.

Typical power off brakes are made to deliver a minimum static torque for holding. Because of traditional manufacturing methods and cost concerns, the actual torque could have a wide range above the minimum torque spec. It would still meet the minimum torque, but it could be very inaccurate.

For cobots that need to interact with humans, pets, or other delicate beings or products, it can be important that brake torque is both precise and accurate. In other words, if the cobot arm bumps into a person, it will need to break free like a torque limiter to prevent damage or injury. One way to do this is to have precise torque that meets an important level of accuracy, thus leading to controlled slipping when overloaded.

Ogura offers the MCNB-Tsp brake for cobot applications. It is a spring applied brake and mechanical torque limiter in one. Due to specialized materials and manufacturing technology used by Ogura, the brake can slip if overloaded temporarily without causing damage. While extended sizes are available, standard torque ranges from 0.2 lb-ft (0.32 Nm) to 3 lb-ft (4 Nm).

Benefits of Ogura cobot brakes:

• Critical safety device
• Electromagnetic brake with mechanical torque limiter
• Prevents unwanted injury or damage
• Surrounding parts can be made less robust
• Lighter system allows for quicker throughput

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