Product Description:

The PMB31B-00200-01 is a brushless servomotor engineered by Pacific Scientific for the PMB Brushless Servomotors series. It converts electrical energy into controlled rotary motion for indexing tables, pick-and-place heads, and other closed-loop automation axes. In motion systems, this allows the motor to respond quickly to changing speed and position commands during repetitive machine cycles. Its compact format is suited to equipment that needs accurate servo control without using a large frame.

This motor is built on a NEMA Size 34 frame, so it shares mounting dimensions with other 3.4-inch square motors commonly used in packaging and material-handling machinery. Power conductors exit as flying leads with MS connectors, eliminating the need for an onboard junction box and allowing direct connection to standard servo cable sets. Under locked-rotor conditions, the winding draws a nominal stall current of 2.7 ARMS when operated from a 240 VAC bus, which helps match drive amplifier current limits to motor thermal capacity. Rotor position feedback is provided by a resolver, allowing reliable feedback signals even with high electrical noise or extended cable runs. The motor relies on permanent-magnet excitation and requires a three-phase drive for commutation.

A shaft with a flat simplifies torque transmission with hub clamps or set-screw couplings while helping prevent unwanted rotation between the shaft and mating part. Environmental protection is enhanced by the optional shaft seal, which limits lubricant loss and particulate ingress at the bearing seat. This arrangement can be useful where light contamination is present around the drive end of the motor. The motor uses a stack length multiple of 1, giving it a single-stack layout that balances inertia and thermal mass for moderate load inertias without oversizing the frame.