A gear motor is a combination of a gear reducer and a motor. Either DC or AC motors can be deployed to make a gear motor. Coupling a motor with gears allows us to control the output speed or horsepower without changing the torque of the motor. This design removes the need for a gearbox, and hence reduces the overall cost. Such a combination allows even small motors to generate low-speed output. Gear motors are classified based on the types of gears it uses, planetary, parallel shaft & worm drive.
How do they work?
The lower the speed of the motor, the larger the design has to be. This problem is efficiently resolved by using a gear drive with small motors. A DC or AC motor is combined with a gear train to control the output speed without changing the rpm of the motor. A gear motor is further classified based on the type of gear train used.
A motor converts electrical energy into mechanical energy. When a current is applied to a motor, the powerful magnets inside the motor forces a rotary motion on the shaft. In a gear motor, the shaft is further coupled with a gear train. A secondary shaft is connected to this gear train. The gear train is designed to output the required speed at the secondary shaft.
Types of Gear Speed Reducers
Based on the gear speed reducers, there are planetary speed reducers, worm drive & parallel shaft gear motor. These are the most common types of gear motors.
Planetary Speed Reducer
A planetary speed reducer has 3 stages, sun or the central gear, carrier (which can hold 3 gears) & a ring gear. They are highly reliable and have a high level of precision. They also have better rotational stability which makes them the most widely used gear motor in industries.
A worm drive gear motor has a worm drive coupled to the primary shaft. The worm drive has a screw and a wheel. They are arranged in such a way that they mesh together to drive the screw. They offer a high speed-reduction with few stages.
Parallel Shaft Gear Motor
They are composed of spur gears, helical gears, and double helical gears. They have a very compact design and can withstand high torque as well. They are the least noisy among gear motors, even at high power.