8MSA4S.R0-31 B & R Automation
Wake Industrial LLC is not an authorized distributor of this product.
No Tariffs On US Orders- Straightforward Pricing: No Rush Fees, No Credit Card Fees
The B & R Automation 8MSA4S.R0-31 is part of the 8MS Three Phase Synchronous Motors series and has a nominal rated speed of 3000 rpm. This self-cooled motor features a keyed shaft end and uses BRX resolver technology with ±1 angular minute non-linearity. The motor is size 4 and does not include a holding brake or oil seal.
To contact sales for pricing and lead time:
Payment Methods
Shipping Methods
Our Credentials
Product Description:
The 8MSA4S.R0-31 is a three-phase synchronous motor manufactured by B&R Automation and assigned to the 8MS Three Phase Synchronous Motors series. Designed for precision positioning and speed regulation in automated machinery, the unit converts drive current into controlled torque for axes that require a compact motor. Its size-4 frame and short S length suit installations where available mounting space is limited but dynamic response must be maintained. Typical applications include conveyor sections, pick-and-place heads, and compact tooling stations. The synchronous design supports controlled acceleration and repeatable movement when paired with a compatible servo drive.
The motor has a nominal speed of 3000 rpm, allowing the connected drive to regulate shaft velocity across the intended operating range. Heat is expelled through the housing by the self-cooling design, eliminating the need for an external blower and simplifying machine ventilation. Power and feedback connectors are oriented on the A-side, allowing cables to remain clear of moving machine components. The motor is supplied without a holding brake, so vertical axes must rely on an external lock or drive-applied torque when power is removed. The motor has a size of 4, a length code of S, and a small relative rated torque, favoring responsive acceleration over high continuous torque. A BRX resolver provides analog sine-cosine feedback that the drive uses to monitor rotor position and regulate motion.
The mechanical interface uses a keyed shaft to transmit torque through positive engagement with a coupling or pulley. The resolver has a nonlinearity of ±1 angular minute, supporting consistent position feedback during closed-loop operation. Its absolute precision is ±10 angular minutes, making it suitable for moderate-accuracy servo applications. The motor has no oil seal, so it should not be installed where pressurized lubricant could migrate along the shaft and enter the housing. The coupling area should remain clean and dry to protect the shaft opening from oil and other contaminants. Proper alignment of the keyed connection also helps prevent unnecessary radial loading on the shaft and resolver assembly.
