What are hydraulics?

Hydraulics are a key component of many machines and are used to transfer power using fluid pressure. This fluid is often oil.

How do hydraulics work in tractors?
In a tractor, hydraulics are used to raise and lower attachments, as well as to control their movements. How is this done? Well, by means of a hydraulic pump creating a flow in the hydraulic oil, which is then moved through hoses and pipes. The oil is led to a valve, which can control one or more hydraulic cylinders. This in turn makes it possible for a front loader to be lifted or a plough to be controlled, for example.

Hydraulic systems in tractors vary according to model and age. Older tractors have round pumping systems where the oil circulates continuously, whereas newer models may have pressure-controlled systems that only flow when needed. Larger tractors have more powerful pumps to handle heavier attachments, and the number of hydraulic outlets determines how many attachments or functions can be switched on at the same time. Newer tractors may also have electronic controls for governing the hydraulics.

Hydraulics in construction machinery
Construction machinery uses hydraulics in a more advanced way. Excavators and wheel loaders, for example, use higher pressures and flows in their hydraulics in order to power heavy attachments. A feature known as proportional control allows the operator to adjust the movements precisely using joysticks or electronic controls. Many construction machines also have hydraulic functions, which can be used to turn the excavator or lift a load, making them more versatile and efficient.

Maintenance of hydraulic systems
For the hydraulic systems to work efficiently, it is important to look after them properly. This means always using the right oil, i.e. the one that is recommended for your particular machine. Hoses and connections should also be checked regularly, as leaks can affect the pressure and reduce machine performance. It is extremely important to prevent dirt or contaminants from getting into the system when carrying out repairs or topping up with oil. This is because all the parts of the system have very small tolerances, i.e. they are carefully adjusted and have to be precisely aligned in order to work properly.

NOTE: After carrying out repairs or replacing parts, it is important to purge any air from the system to ensure that the hydraulics work properly.

Hydraulics – a summary
Hydraulics are a technology that transfers power by means of fluid pressure, often oil. In tractors, they are used to raise and control attachments, while construction machines use hydraulics to power heavy attachments with higher pressure and precise control. To keep systems working well, it is important to use the right oil, keep an eye out for leaks and dirt, and make sure that air is purged after carrying out repairs.