Working principle of gearbox

A reducer is a device used to reduce the output speed of a motor or other power source while increasing the output torque. Its working principle is mainly based on the basic laws of gear transmission. The following is its detailed working principle:

(1)  Gear transmission principle

The reducer mainly transmits power and changes speed through the meshing between gears. The key principle of gear transmission is that, while keeping the number of teeth and the modulus of the gear constant, the diameter of the gear is proportional to the number of teeth. Therefore, when the small gear (input gear) drives the large gear (output gear), due to the large number of teeth on the large gear, its speed is relatively low, but the output torque is large.

(2)  Deceleration process

Input end: The input end of the gearbox is usually connected to a motor or other power source. The input gear (small gear) is directly driven by the power source and rotates at a higher speed.

Gear meshing: The input gear meshes with one or more gears (which can be regular gears, planetary gears, etc.). These gears are fixed on different shafts and transmit power through the meshing between the gears.

Deceleration: Due to the different number of teeth on the gears, when power is transmitted from the input gear to the output gear, the speed decreases while the torque increases. The reduction ratio is the ratio of the number of teeth between the input gear and the output gear, which determines the degree of reduction.

(3)  The working principle of different types of reducers

1. Ordinary gear reducer: Reduction is achieved by meshing gears with different numbers of teeth.

2. Planetary gearbox: Utilizing planetary gears to rotate around the central wheel (sun gear) while also rotating on their own, and outputting power through the planetary carrier to achieve efficient deceleration. The planetary gearbox has a compact structure, small return clearance, high precision, long service life, and a high rated output torque, but it is slightly more expensive.

3. Worm gear reducer: The meshing between the worm gear and the worm wheel utilizes the large helix angle of the worm gear to achieve deceleration. Worm gear reducers are usually used in situations that require a large reduction ratio and have reverse self-locking function. However, they are generally larger in size, have lower transmission efficiency, and are not as accurate as planetary reducers.

4. Harmonic reducer: Utilizing the meshing between flexible gears and rigid gears, the flexible gears are deformed through a wave generator to achieve deceleration. Harmonic reducer has a small volume and high accuracy, but the flexible wheel has limited lifespan, is not resistant to impact, has poor rigidity compared to metal parts, and the input speed cannot be too high.

In summary, the working principle of a reducer is to transmit power and change speed through the meshing between gears, thereby achieving the effect of reducing speed and increasing torque. Different types of reducers have different characteristics and applicable scenarios. In practical applications, the appropriate type of reducer should be selected according to specific needs.