Product Description:

The 8MSA4M.E1-31 is a three-phase synchronous motor engineered by B&R Automation as part of the 8MS Three Phase Synchronous Motors series. It serves as a drive element in automated packaging lines, indexing tables, and conveyor axes where constant torque and repeatable positioning are required. The unit is suited to mid-range machinery, and its housing supports direct connection to pulleys or gearboxes when a compact servo axis is needed. This layout helps keep the drive train short and limits extra overhang at the machine interface.

At its nominal operating point, the rotor turns at 3000 rpm, a speed that works with common servo drives without requiring large reduction ratios. Rated torque is in the medium range, placing this motor between lighter and heavier 8MS variants for general automation duty. Heat leaves the frame through a self-cooling design, so no external blower or liquid circuit is required, and power and feedback cables exit on the A-side of the housing for straightforward routing. The integrated encoder supports carrier frequencies of ≥ 100 kHz at −3 dB, delivers 512 lines of incremental data, and holds an angular accuracy of ±60″ for reliable closed-loop positioning. The motor is supplied without a holding brake and without an oil seal, so load retention and sealing must be handled by the application.

The encoder uses the EnDat digital format, and its multi-turn design records up to 4096 revolutions so the controller can recover absolute position after power loss without a homing move. The shaft end uses a keyed shaft, which helps resist slip when cyclic torque is applied during indexing motion. The motor uses size 4 with the M length code, allowing it to fit mid-range frames while keeping inertia suitable for responsive axis control. Because the unit has no internal oil seal, it is better suited to clean environments where external sealing is not required.