Ball Screw Brake and Coupling

Ball Screw Brake and Coupling

The axial forces created by thermal expansion of the ball screw can be large enough to preload the brake bearing and cause the device to fail prematurely. To solve that problem, Nexen has developed a spring-engaged, air-released servomotor brake made specifically for ball screws. Our device incorporates a backlash-free elastomer coupling that compensates for up to 2 millimeters of axial misalignment. The coupling is fixed into the brake bore with an expanding cone shaft. The other end of the coupling has a clamping hub that attaches to the ball screw.

BD Caliper Brake

Nexen Group's unique BD Air-Spring actuator has two separate air chambers. One is for cycling in the air-engaged mode, and the other air chamber holds a powerful spring in the disengaged mode until a power-off stop or holding mode is needed. The two modes are not used simultaneously to prevent high stress on the brake components.

Cycling (service port) for the air-engaged mode.
Power-off, parking for spring hold-off pressure. Engage the brake with a spring when the air is released.
BD (brute disc) – This caliper brake steps up the clamping force with a design utilizing arms to provide a mechanical advantage for higher clamping force.

BD, Air-actuated
BD, Spring actuated/air released
BD, Spring actuated/hydraulic released

Three models are offered with different caliper widths for various disc thicknesses.