A.C. Synchronous Servo Motor
These motors are operated from single phase source with R-C Phase shifting network. The speed of the motor is proportional to applied frequency of the supply. It attains its full synchronous speed within 5 to 25 ms. We manufacture various models of motors with torque capacities of 2.5, 3, 5, 7,10, 20, 30, 40, 60 kg.cm. We also make as per your requirements.
Our range is manufactured by using high grade copper, stampings, milmex paper, varnish, inner, rods and shafts
Features:
Permanent Magnet AC Motors - No winding on rotor.
Extremely rapid starting, stopping and reversing characteristics.
Basic constant synchronous speed of 60 rpm at 50 Hz.
Torque from 2 kg.cm to 60 kg.cm.
Gearing possible to achieve reduced speeds Built in overload protection -motor stops if overloaded but does not burn.
Starting and operating currents are identical.
Magnetically rotor can be locked by D.C. applying.
Power coated cast aluminium body with steel shaft.
Applications:
These motors are finding applications in servo control applications where precise positioning is required. The Instantaneous starting stopping and reversing characteristics of the motors make them very aptly suited for following applications among many:
Servo Voltage Stabilizers.
Diamond machines.
D.C Drives.
Precise positioning.
Valve Controls.
Automated Welding Equipments.
Medical Equipments.
Conveyor Systems.
Actuators.
Fluid Metering.
Textile edge guide control.
Paper Feed.
Characteristics:
A.C. Operation : Motor can be directly connected to 240 V; 50Hz, supply along with "APPLE" supplied R-C network in series with one of the stator winding. Change of this R-C network from one winding to other results reversal of motor direction. Single pole three position switch can be used for Forward, Reverse and Off control as shown in the following diagram. Metal varistor oxide may be used to minimize the switch contact arcing.
Starting : Motor start within 1 1/2 Cycles of its applied frequency & will reach 60 RPM within 5 to 30 ms at 50 Hz. Since motor has no significant current rise on starting, this motor is ideal to an application which requires six or more starts per minute.
Stalling : Motor will not be overheated if stalled because starting, full load and no load currents are same. However prolonged operation against a solid stop will eventually produce bearing failure due to the resultant shaft vibrations.
Inertia Limitations : Since the motors are having extremely rapid starting, there is a limit to the inertia load at which the motor will start from rest. Addition of resilient coupling with app. 5 degree of rotational freedom or gearing with backlash between motor & load can increase the permissible inertia load handing capability.
Phase Shift Network : The values of R-C network have considerable effect on motor performance. They have been chosen by "APPLE"' in such a manner that no reverse torque is produced when voltage is applied.
R-C values should not be varied more than 5% so as to enhance smoother starting, give quieter operation, maximize torque & improve efficiency.
Other values may be recommended by "APPLE" for the continuous duty specific OEM application.
Stopping & Holding (Braking) : Due to magnetic rotor, these motors decelerate faster than conventional motors and stop within 5 degree after turnoff with no external inertia. Application of D.C. supply to one or both motor windings after removal of A.C. supply results deceleration time 1/10th to 1/20th those available with conventional motor & the motor shaft is electrically locked after the stop. A typical circuit for applying, stopping & or holding current is shown in the following diagram.
Back Driving : These motors act as generators when back driven. Rotating in access of 1400 RPM is not recommended because high voltages can be generated. At 1400 RPM or below suitable precautions for protection of personnel/phase shift capacitor & any other connected circuitry may be necessary when back driving.
60 Hz Operation : These motors may be operated on 60 Hz, but may require a different R-C network, the factory must be consulted. Torque rating should be similar to those shown for 50Hz & speed is 72 RPM @ 60 Hz.
