How many kinds of automobile transmission systems are there? What are their characteristics? There are four types of automobile transmission systems.

Hydromechanical transmission system

Hydrostatic (positive displacement hydraulic) transmission system.

Electric drive system.

2) Features, advantages and disadvantages:

Mechanical transmission system:

Composition-It consists of clutch, transmission, universal drive, drive axle (main reducer, differential, half shaft) and so on.

Advantages-high transmission efficiency, reliable operation, simple structure and wide application.

Disadvantages-heavy weight, many parts, not suitable for super heavy vehicles.

Hydromechanical transmission system:

Composition-hydraulic coupler+mechanical transmission system or hydraulic torque converter+mechanical transmission system

Features-The kinetic energy of liquid circulating flow is used to transmit torque. The hydraulic coupler can only transmit the torque of the engine, but can't change the torque; Hydraulic torque converter can not only transmit engine torque, but also change torque. Because of the small torque range, it must cooperate with the mechanical transmission system to achieve the purpose of reducing speed and increasing torque.

Advantages-auto start is stable, which can reduce the dynamic load, eliminate the torsional vibration of the transmission system, and is easy to operate.

Disadvantages-low mechanical efficiency, complex structure, heavy weight and high cost.

Application-Used in super-heavy dump trucks, loading machinery, luxury cars and city buses.

Hydraulic transmission system (positive displacement hydraulic type):

Composition-the engine drives the oil pump, the oil pump drives the hydraulic motor, and the hydraulic motor drives the drive axle or is directly installed on the wheel.

Features-stepless speed change can be realized, all parts of mechanical transmission system can be cancelled, the ground clearance is large and the passing capacity is strong.

Disadvantages-low transmission efficiency, high precision and poor reliability.

Electric drive train

Features-Engine-driven alternator, after full-wave rectification, DC power is supplied to DC series motors connected with wheels.

Advantages-stepless speed change, wide speed range, simple transmission system (no clutch, no transmission and no transmission shaft), stable operation, small impact, long service life, low efficiency and heavy weight.

Application-super heavy dump truck.