1. The role of the drive system
The function of the transmission system is to transmit the power output from the engine via the flywheel to the driving wheels, and change the magnitude of the torque to meet the needs of the driving conditions and ensure the normal driving of the car. In addition, it also has functions such as changing the vehicle speed, driving backward, cutting off power, and differential speed.
2. Classification of transmission system
(1) Classification by structure and transmission medium
1) Mechanical transmission system
Mechanical transmission systems are classified into gear type and friction type according to their transmission methods. The gear type has a simple structure and high transmission efficiency, so it is widely used in cars with manual transmissions.
2) Hydraulic mechanical transmission system
The hydraulic system is installed on the basis of the mechanical drive train to make it easy to operate. At present, it is mainly used in middle and high-end cars.
3) Hydrostatic transmission system
The high pressure oil pump is driven by the engine, so that the pressurized liquid enters the hydraulic motor through the control valve and pipeline, thereby driving the wheels. Currently only used in military vehicles.
4) Electric drive system
The generator is driven by the engine, and then driven by a motor mounted on the drive axle or drive wheels. There are currently few applications.
(2) Classification by transmission ratio change
1) Stepped transmission system
A stepped transmission system refers to a transmission system with several fixed value transmission ratios, such as a geared mechanical transmission system. 2) Stepless transmission system
Continuously variable transmission system refers to a transmission system whose transmission ratio can be changed in an infinite number of stages within a certain range, such as a hydraulic transmission system and an electric transmission system.
3.The composition of the drive system
The mechanical transmission system is generally composed of clutches, transmissions, universal transmissions (universal joints and drive shafts), drive axles (main reducers, differentials, and half shafts). Take a car as an example, as shown in the figure
The power from the engine is transmitted to the driving wheels through the clutch, transmission, drive axle, and universal transmission.
