Product Description:

The SS242LEG4 is a gearmotor from Danaher produced within the Slo-Syn Synchronous Motors series. It pairs a permanent-magnet synchronous stator with an integral reduction gearbox to deliver low-speed, high-torque rotation directly at the shaft. In industrial automation, it is used for constant-speed indexing or conveyor duties where mechanical simplicity is favored over electronic speed control. The motor operates from a single-phase AC supply and includes a rear auxiliary shaft that can accommodate encoders, power takeoffs, or manual handwheels.

Rated for 240 VAC, the winding draws 0.20 A at 60 Hz, allowing direct connection to standard control transformers without a separate inverter. The integral gearbox uses a 4:1 ratio, so the synchronous internal rotor speed of 72 rpm at 60 Hz is reduced to a shaft output of 18 rpm, while the same ratio provides 15 rpm on a 50 Hz supply. Under these conditions, the motor produces a minimum static torque of 845 oz-in, helping it maintain motion when the applied load changes. Mechanical losses in the gear train are limited by its measured efficiency of 88%, which minimizes heat buildup and keeps the delivered torque close to the electrical rating.

The motor supports up to 150 lb of radial force and 100 lb of axial force, so pulleys or spur gears can be mounted without exceeding the bearing load limits. Positioning repeatability is influenced by the drivetrain: the input shaft exhibits 7° of lost motion caused by magnetic detent and torsional compliance, while the geared output limits backlash to 2°, which is suitable for many unidirectional feed systems. A 2 µF run capacitor is required for 60 Hz operation to establish the quadrature phase needed for synchronous locking. The permissible load inertia is 35 lb-in² at 60 Hz, providing a limit for selecting compatible couplings and flywheels while reducing the risk of pullout.