Hydraulics and Hydraulic Tools


The article gives you an insight into the working of hydraulic pumps, where they can be put to use, and what precautions you need to take to make sure that the pumps keep on working for a long time.


The Heart of Hydraulic Systems – Hydraulic Pumps

The hydraulic pumps are the heart of any system that operates on hydraulic force. Be it a hydraulic lift, or a garage car lifter, or a dump truck, it cannot operate without hydraulic pump or an air compressor.


 Use of air compressors is rare because of engineering problems of air leakages and the attendant safety related problems. Hence only the oil pumps are discussed here.

Two Types of Hydraulic Pumps

Primarily there are two types of hydraulic pumps Wiz reciprocating and rotary. Both the types are used but the reciprocating pumps are used for smaller systems whereas rotary pumps are used for larger systems. There is another category of pumps that is called the positive displacement pumps or centrifugal pumps. In the hydraulic systems most of the positive displacement type pumps are used as they can generate higher pressure required for the hydraulic systems without any difficulty.

Components of Hydraulic Pumps

In the system here we will discuss two types of pumps here, one will be reciprocating pump and the other will be a gear pump.

Reciprocating pump: Here the rotating action of electric motor is converted in to reciprocating motion of the piston with help of piston head and crank shaft. The crank shaft is similar to the crank shafts in your cars & trucks. Only here the action is reversed. The pump sucks in oil from a reservoir and pumps it into hydraulic system. To ensure that the oil does not flow back in to the reservoir, valves are so placed so that they allow flow only in one direction. Once the oil comes into pump, it can go only to the system and once it goes into the system, it go back to reservoir only after it has done its work and the pressure has been reduced back to atmospheric.

 Gear Pumps or lobe pumps: This type of is also a positive displacement pump but it does not have non-return valves like the reciprocation pumps. Here the action of motor is directly converted into pumping action by the gears and the oil is pumped into the hydraulic system.

Oil seals: In order to ensure that oil does not leak out of the hydraulic system, oil seals seal placed wherever the parts of pumps are brought out for connection to motor or shaft. These seals are designed to take on the system pressure and prevent leakage of oil. These are made of butyl rubber or viton rubber and can be damaged by the dirt in oil. When this happens all the oil in the system can come out making the system inoperative.

Care of Hydraulic System & Pumps

The ingress of dirt & water in the system can damage pumps and seals therefore make sure that the hydraulic systems are closed systems without any possibility of water or dirt intrusion in the system. If water or dirt enters in the system it can be removed by oil purifiers that can filter out the oil and remove water from system. Independent contractors who have purification equipment can assist you in keeping the oil in the system clean and water free. It would be better to have some one on your call list if you operate a hydraulic system.