Type APM-GSM-60 Series AC Geared Servo Motors are permanent split capacitor induction motors. No brushes or starting switches are employed. The low inertia servo-type motor is specifically designed for servo applications requiring relatively fast response. Its two windings are referred to as the fixed or reference phase (red leads) and the control phase (black leads). In the normal mode of operation a fixed voltage is impressed on the reference phase and a variable voltage, in quadrature to reference voltage is given to the control phase. The speed and direction of rotation then depend on the magnitude and phase (±90⁰) of control voltage. However, by using a phase splitting capacitor it is also possible to operate the motor (reversibly) from single phase supply.

Special Features:

• Compact size                          

• Low output speeds

• Quick reversibility                                       

• High starting torque

• Dynamic braking

• Easy speed control

• Ability to withstand for continuous stalled rotor condition

Specifications:

• Gear Ratio: Motors are available with any one of the following standard gear reduction ratios of 10, 30, 100, 300, 1000, 3000. (Basic rotor speed is 2500 rpm).

• Windings: Motor windings are designated by means of two letter. First letter refers to the voltage to the reference phase, and the second letter  to the voltage on the control phase. The letter code for voltages is as follows: A = 230V, B = 115V, C = 115V, D = 23V, E = 11.5

Mechanical & Electrical Ratings:

Note: For other gear ratios of 300, 1000, and 3000, the corresponding no-load speeds are 7, 2, 0.75 rpm and the torque is limited to maximum 35Kg-cm.

General Engineering information:

• Special Features: Motor and gear box are built in separate units to facilitate the customer in changing the gear box according to the requirement.

• Winding Temperature Rise & Limits: Under continuous stall with rated voltages on both phases, the temperature rise (due winding resistance) will not exceed 45⁰C. The windings can safely operate at temperatures up to 105⁰C. Therefore, at normal ambient temperature, the motor will withstand continuous stall, provided of course, that the load torque on the output shaft does not exceed the limit of 35Kg-cm, set by the gear train.

• Dynamic Braking: For positive holding after stopping, the motor can be dynamically braked by shunting the capacitor with the energized winding.

• Non-single Phasing: A free running motor will stop by itself if its control phase circuit is opened.

• Color Coding Leads: Leads are color coded as follows: Reference phase is Red, Control phase is Black. In case of center-tapped control windings, the lead corresponding to the center tap is distinguished by a small piece of yellow sleeve near the spade terminal.

• Ordering Instructions: When ordering, please specify the Motor Type, required Gear Ratio, and Winding Connection. For single phase operation from 230V mains, please specify the winding connection AA along with the phase splitting capacitor of required value as an extra in your order. On request, different gear ratios can also be provided.

• Easy Maintenance: Any major part can be replaced in two minutes without removing the leads. No special tools are needed for component replacement. Most sub-assemblies can be replaced with a screw driver. Since most minor parts are also replaceable, individual sections can be repaired in the field.

• Gearing: The speed reducing spur gears are enclosed in a separate box. All gears are hardened steel and fit together only one way and cannot be assembled incorrectly after servicing.

• Shock Absorber: A built-in shock absorber permits the motor, driving at full speed to be stopped mechanically without the danger of gear-tooth failure from impact fatigue.

• Bearings: The ball bearings will operate for approximately 3 years under continuous small amplitude vibration or approximately one year under continuous oscillatory use. These bearings reduce friction at the point where friction effects are most critical.

The mounting specifications along with the motor physical dimensions can be seen in the picture below. The normalized torque-speed characteristic plot is also shown.