A tractor is a self-propelled power machine used for pulling and driving working machinery to complete various mobile operations1. It consists of four major components: the engine, chassis, working equipment, and electrical system1. The following is an introduction to its structure and operating principle:
Structure of Tractors1
Engine
Function：The power source for the tractor, converting the thermal energy from the combustion of diesel and air into mechanical energy.
Composition：Comprises the crankshaft-connecting rod mechanism, ventilation system, fuel supply system, lubrication system, cooling system, starting system, and preheating device.
Chassis
Function：Connects the engine to various systems and components, transforming the engine's power into the driving force and traction needed for the tractor to operate.
Composition：Includes the transmission system, steering system, braking system, and walking system.
Working Equipment
Function：Mainly used for towing, suspending, and driving agricultural machinery to perform various farming tasks.
Composition：Includes the towing device, power take-off, and hydraulic suspension system.
Electrical System
Function：Ensures the tractor has a reliable source of electricity, facilitating lighting, starting the engine, and other electrical operations.
Composition：Consists of a generator, battery, lighting system, and other components.
Principle of Tractors
Driving Principle1：The engine's power is transmitted to the driving wheels via the transmission system, causing the driving wheels to rotate. The tires then exert a horizontal force on the ground, and the ground in turn applies an equal and opposite horizontal reaction force, which propels the tractor forward.
Working Principle1：The tractor can be equipped with agricultural machinery such as plows, seeders, and harvesters through its working equipment. The engine's power is transferred to these agricultural machines through the power take-off or hydraulic system, enabling them to perform various farming tasks.
Engine: It is the power source of a tractor. Common types include diesel engines, which feature high torque and good fuel economy. Its working principle is that the fuel burns in the cylinder to generate high-temperature and high-pressure gas, which drives the piston to move and then drives the crankshaft to rotate, outputting power.
Transmission system: It includes components such as clutch, gearbox, drive shaft, differential, etc. The clutch is used to cut off and transmit the power of the engine. The gearbox achieves different vehicle speeds and torque outputs through different gear combinations. The drive shaft transmits the power of the gearbox to the drive wheels. The differential enables the left and right drive wheels to rotate at different speeds when turning, ensuring a smooth turn for the vehicle.
The traveling system: The traveling system of a wheeled tractor mainly consists of wheels, axles, suspension devices, etc. The type and size of wheels vary according to different operation requirements. For instance, narrow tires are commonly used in dry land operations, while wide tires or high-tread tires are needed in paddy field operations. The suspension device is used to connect the tractor and farm tools, and at the same time serves as a buffer and shock absorber, ensuring the stability of the tractor's driving and operation.
