Rotary Servo Motors

Rotary servo motors are AC or DC motors designed for closed-loop operation with a matched servo drive, delivering precise control of speed, position, and torque in industrial machine applications. PLC Direct supplies rotary servo motors from leading automation manufacturers as surplus sealed, refurbished, and used hardware, supporting replacement and lifecycle maintenance of installed servo systems in manufacturing, packaging, machine tool, and process automation environments. 

Where Are Rotary Servo Motors Used in Industrial Environments?  

Rotary servo motors are used on any machine axis requiring closed-loop control of position, speed, or torque with encoder feedback, from single-axis machine tools to complex multi-axis synchronized motion systems. They are present across virtually every sector of discrete manufacturing and are the standard actuator in packaging, assembly, printing, and CNC machining applications. 

Facilities and operations that depend on rotary servo motors include: 

CNC machining centers and grinding machines using AC servo motors paired with SINAMICS S120 drives on feed and spindle axes, where encoder feedback governs contouring accuracy. 

Packaging and filling lines where synchronous servo motors drive indexing, registration, and filling axes on high-speed equipment requiring repeatable positioning across millions of cycles. 

Automotive assembly and stamping operations using rotary servo motors on transfer, weld, and press axes, where torque control and position repeatability are critical to part quality. 

Food and beverage processing facilities running servo motor and drive systems on mixing, portioning, and conveyor axes requiring precise speed control in washdown-rated environments. 

Plastics and injection molding machines where AC servo motors control clamp, injection, and ejector axes in place of hydraulic actuators on newer or converted installed machines 

When a rotary servo motor fails, sourcing a matched replacement by full part number is the fastest path to restoring the axis and resuming production. 

Which Brands of Rotary Servo Motors Does PLC Direct Stock?  

PLC Direct stocks rotary servo motors from major industrial automation manufacturers. 

Siemens SIMOTICS S 1FK7 and 1FK2 Series: The 1FK7 synchronous servo motors for SINAMICS S120 and the 1FK2 series for SINAMICS S210 are available across multiple frame sizes, power ratings, and encoder configurations, ranging from 0.1 kW to multi-kilowatt. 

Yaskawa Sigma Series Servo Motors: SGM7A, SGMJV, SGMGV, and SGMCS AC servo motors are available across a wide range of power ratings and encoder types, covering the Sigma-7 current generation and earlier Sigma series for legacy system support. 

Schneider Electric BMH and BSH Series: BMH medium-inertia and BSH low-inertia synchronous servo motors for the Lexium 32 drive family are available across flange sizes from 55 mm to 205 mm and speeds up to 8000 RPM. 

Omron 1S Series R88M: The R88M-1 series 1S AC servo motors are available across power ratings from 100 W to 3 kW at 230 V and 400 V, with absolute encoder and optional holding brake configurations for Sysmac-based motion control systems. 

All rotary servo motors at PLC Direct are available as surplus sealed, refurbished, and used, depending on current inventory. 

What Should You Know Before Ordering Rotary Servo Motors?  

Hardware condition options: PLC Direct supplies rotary servo motors as surplus sealed, refurbished, and used hardware. Surplus sealed units are factory-sealed stock in original packaging; refurbished units have been tested and restored to operational condition. Used hardware has been previously installed and carries the same 1-year PLC Direct warranty as all other condition grades.   

Compatibility and part identification: Rotary servo motors are matched to specific drive families by encoder interface type, power rating, and winding voltage, a replacement motor must match the installed unit's full part number, as the encoder type and electrical parameters are encoded in the suffix and are not interchangeable across variants within the same frame size. For motors with integrated holding brakes, the brake voltage and release current must also match the installed drive's brake output specification; confirm both from the machine's electrical documentation before ordering. 

Warranty: All rotary servo motor hardware purchased from PLC Direct carries a standard 1-year warranty covering defects and functionality, applicable to surplus sealed, refurbished, and used products. 

PLC Direct supplies rotary servo motor hardware for replacement and maintenance purposes and does not provide system design, programming, or integration services.