Which jacks require a brake motor?
May 21 , 2015
Firstly, let’s see self-locking. Self-locking is a term used to describe jacks that require power to move in either direction. They hold their position when power to the system is off.
Machine Acme Screw Jacks having gear ratios between 20:1 and 32:1, are self-locking and, in the absence of vibration, will hold loads without backdriving. In the case of large shocks, the self-locking function of the lift may be invalidated.
All machine acme screw jacks of other ratios may require a brake to prevent backdriving. All Ball Screw Jacks and Bevel ball screw jacks can backdrive and require some means of holding the load, such as a brake on the motor.
Besides back driving, system inertia usually results in some over travel when the motor is switched off. The inertia of the system should be considered when determining the brake size required to stop a dynamic load. Because mechanical stops can cause damage to the jacks,a limit switch and a brake should be used to stop the motor.
