The Function of a Reduction Gear

The main reduction gear has two main functions: first, it changes the direction of power transmission; second, it acts as an extension of the transmission, providing a common gear ratio for all gears. The transmission output is a torque rotating around its longitudinal axis, while the wheels must rotate around the vehicle's lateral axis. This necessitates a device to change the direction of power transmission. It's called a main reduction gear because, regardless of the gear in which the transmission is in, the gear ratio of this device is always a factor of the overall gear ratio. This gear ratio effectively reduces the requirements for the transmission's deceleration capacity. This design allows for a reduction in the size of the transmission, resulting in a more rational overall vehicle layout.

The primary function of a car's main reduction gear is to reduce speed and increase torque. We know that the engine's output power is constant. According to the power calculation formula P=M*ω (power = torque * angular velocity), by reducing the transmission speed through the main reduction gear, a higher output torque can be obtained, thus providing greater driving force. In addition, the car's main reduction gear also functions to change the direction of power output and to achieve differential speeds between the left and right wheels or between the middle and rear axles.