Magnetic Brake II

Mankind’s activities in space are constantly increasing. Modern satellites and other spacecraft are equipped with a large number of rotary actuators. Conventional friction-based brakes or brakes with mechanical locking cannot be used to block rotational movements, e.g. when fixing antennas or solar panels in their orientation, due to the risk of cold welding or abrasion. The conventional approach uses stepper motors that have an inherent cogging torque due to magnetic reluctance. However, the size of the stepper motor is sometimes determined not by the required rated torque, but by the required braking torque. This makes these actuators unnecessarily large and heavy.

The MagneticBrake II project has developed a new concept for a magnetic brake that can be switched on and off with a simple current pulse. The special thing about it is that no energy is consumed in any of the stable states – neither in the locked nor in the unlocked state. The functional principle is simple: a permanent magnet generates a magnetic flux that creates a stable latching position through the teeth. This ensures energy-free holding. A special design of the permanent magnet makes it possible to switch the magnetic flux on and off by means of a short current pulse in a coil. If there is no magnetic flux, the rotor can be adjusted without resistance. A second current pulse then switches the magnetic flux of the permanent magnet back on and the brake is locked again.

Requirements

Minimum size and mass
Application temperature: -45°C – +100°C
Service life >15 years
Minimal energy consumption
No wear and tear
Fully redundant system

Your benefit

From the idea to the prototype
Design and optimization of the magnetic system
Wear-free system with 176mNm holding torque
No permanent energy consumption in the locking and release process
Weight reduction from 900g (50mNm holding torque) to 150g (176mNm holding torque)
Unique principle