1. Core Function: Speed Reduction and Torque Increase
This is the most essential function of a DC gear motor.
Reduce Speed: DC motors themselves usually have high speeds (for example, several thousand to over ten thousand rotations per minute), but many applications (such as wheels, robotic arm joints, conveyor belts) only require tens or hundreds of rotations per minute. The gearbox reduces the speed to the required range through a specific reduction ratio (such as 10:1, 100:1).
Increase Torque: According to the principle of energy conservation (ignoring efficiency losses), at constant power, a reduction in speed means an increase in torque on the output shaft. This allows a small-power motor to drive heavier loads.
2. Precise Speed Control
Since the core component is a DC motor, it inherits the excellent speed regulation performance of DC motors:
Voltage Control: By changing the input voltage, the motor speed can be linearly adjusted.
PWM Control: Pulse width modulation (PWM) technology is often used in modern controls to achieve more precise and efficient stepless speed control.
Forward and Reverse Control: By simply changing the polarity of the power supply (or using an H-bridge driver circuit), the motor can easily rotate forward or backward.
3. Self-Locking Function (Specific Types)
If the gearbox contains a worm gear structure, the DC gear motor usually has a self-locking function.
When the motor power is cut off, the load cannot drive the motor shaft in reverse. This is very important in scenarios requiring position safety, such as hoists, electric curtains, and automatic doors.
4. Matching Load Inertia
The gearbox not only changes torque and speed but also changes the rotational inertia of the load as referred to the motor shaft.
With a proper reduction ratio, the inertia of a large load can be reduced (reduced by the square of the reduction ratio), making the motor easier to start, stop, and respond to control signals, thereby improving the dynamic response performance of the system.
