Product Description:

The 40PA59-55-TEFC-S permanent-magnet DC motor is manufactured by Pacific Scientific and belongs to the Permanent Magnet DC Motors series. Within automated equipment, this unit supplies steady torque and speed when driven from a DC source, allowing motion tasks such as feed rolls, small conveyors, or positioning tables to be executed under closed-loop control with consistent response. Its magnet field is fixed, so response remains linear and predictable, which simplifies drive tuning and supports stable low-speed regulation in industrial automation cells.

The motor’s identification code lists a type designation of SRF55. This designation indicates the internal winding style and magnetic circuit used to produce the required torque constant for low-voltage drives. A totally enclosed fan-cooled enclosure rated as TEFC prevents airborne contaminants from reaching the internal laminations, while an external blower moves heat away from the frame. Mechanical integration is eased by a Small adapter, which indicates that the mounting face matches compact gearheads or pump brackets that cannot accept larger NEMA footprints. The primary shaft diameter is 0.187 in, providing enough surface for standard clamp couplings, while an alternate machining option reduces that journal to 0.120 in so lighter load elements with smaller bores can be fitted without additional bushings.

Drive-train alignment is controlled through the specified coupling ST-9502-1, and this flexible element limits axial load transfer back into the armature bearings. When the motor is ordered, suffix -84 is appended so the exact winding, enclosure, and shaft combination listed here is supplied. For speed feedback, the design accepts tachometers identified as SA-757A/SA-7103A/SA-7360-F-1. Each model delivers a linear output proportional to rotor speed, and the gradient is fixed at 7 V/KRPM, allowing a simple voltage follower circuit to close the speed loop without additional scaling hardware in basic analog control circuits.