Rockwell Automation HPK-Series Asynchronous Servo Motor - Manual (Page 6)

6 HPK-Series Asynchronous Servo Motors
Publication HPK-IN001C-EN-P - June 2010
Cable Orientation for Drip Loop
• Brakes on these servo motors are holding brakes. The brakes are spring-set, and release
when voltage is applied to the brake coil. A separate power source is required to
disengage the brake. This power source may be applied by a servo motor controller, in
addition to manual operator control.
If system main power fails, holding brakes can withstand occasional use as stopping
brakes. However, this creates rotational mechanical backlash that is potentially damaging
to the machine, increases brake wear, and reduces brake life.
Mechanical Connections
Mechanical connections to the motor shaft, such as couplings and pulleys, require a torsionally
rigid coupling or a reinforced timing belt. The high dynamic performance of servo motors can
cause couplings, pulleys, or belts to loosen or slip over time. A loose or slipping connection will
cause system instability and may damage the motor shaft. All connections between the machine
and the motor shaft must be rigid to achieve acceptable system response. Periodically inspect
connections to verify their rigidity.
IMPORTANT Holding brakes are not designed to stop rotation of the motor shaft, nor are
they intended to be used as a safety device. They are designed to hold a motor
shaft at 0 rpm for up to the rated brake holding torque.
The recommended method of preventing motor shaft rotation is a four step
process: first - command the servo drive to 0 rpm; second - verify the motor is at
0 rpm; third - engage the brake; and fourth - disable the drive.
Disabling the drive removes the potential for brake wear caused by a badly
tuned servo system oscillating the shaft.
Cables enter from above.
Drip loops are not formed. Cables enter from below.
A drip loop is formed in each cable.