learn more about the hydraulic pump!


A hydraulic pump converts mechanical energy into fluid power. Used in hydraulic systems to perform tasks such as lifting heavy loads in excavators or jacks for use in hydraulic splitters. In this article, we discuss how hydraulic pumps work, types of hydraulic pumps and their applications.

How does a hydraulic pump work?

A hydraulic pump operates in positive displacement, where a confined fluid is pressurized using a reciprocating or rotary motion. The pump is powered by a prime mover such as an electric motor, internal combustion engine, human power, or compressed air that drives an impeller, gear, or vane to create fluid flow in the pump housing.

The mechanical operation of the hydraulic pump creates a vacuum at the pump inlet, which allows atmospheric pressure to force fluid into the pump. The drawn fluid creates a vacuum in the inlet chamber, which allows the fluid to then be pushed to the outlet at high pressure.

Different types of pumps (i.e. gear, vane and piston) use different mechanisms to create fluid flow and pressure.

Gear pump: Two mesh gears rotate in opposite directions, creating chambers that expand and contract, creating fluid flow and pressure.

Vane Pump: The vanes are pushed out by centrifugal force and driven back into the rotor as they pass through the inlet and outlet of the pump, creating fluid flow and pressure.

Piston pump: A piston moves back and forth inside a cylinder, creating chambers of various sizes that draw and compress fluid, creating fluid flow and pressure.

The performance of a hydraulic pump is determined by the size and shape of the pump’s internal chambers, the pump’s operating speed, and the power supplied to the pump. Hydraulic pumps use an incompressible fluid, usually petroleum oil or a safe food substitute, as the working fluid. The fluid should have lubricating properties and be able to work at high temperatures. The type of fluid used may depend on safety requirements such as fire resistance or food preparation.

Different types of hydraulic pumps

1) Based on the energy source

The types of pumps based on this feature are: air pump, electric pump, gas pump and manual pump.

2) Based on pump activity

Types of pumps are based on single-action (one-way) and double-action (two-way) performance.

3) Types of positive displacement

Three types of positive displacement mechanisms; They are gears, vanes and pistons.

Pressure: Hydraulic gear pumps and hydraulic vane pumps are suitable for low pressure applications and hydraulic piston pumps are suitable for high pressure applications.

Cost: Gear pumps are less expensive to purchase and maintain, while piston pumps are more expensive.

Efficiency: gear pumps are the least efficient. They are typically 80% efficient, meaning 10 mechanical horsepower is converted to 8 hydraulic horsepower. Vane pumps are more efficient than gear pumps and piston pumps are the most efficient with an efficiency of up to 95%.

Applications of hydraulic pump

Hydraulic pumps have wide applications in various industries.

Automotive Industry: In the automotive industry, hydraulic pumps are combined with engine jacks and hoists to lift vehicles, platforms, heavy loads, and pull engines.

Mechanical workshops: In mechanical workshops, electric tools and hydraulic pumps for applications such as cutting, drilling, pressing and drawing.

Wood workshops: In wood workshops, hydraulic jacks are used in splitters.

Process and construction: Heavy duty hydraulic pumps are used for driving and tapping applications, turning heavy duty valves, tightening and expanding applications.

Heavy machinery: hydraulic pumps are used in heavy machinery such as excavators, cranes, loaders and tractors.

Production possibilities: hydraulic pumps are also used in conveyors, mixers and forklifts.

Selection criteria

·Operating pressure: Consider the maximum operating pressure of the system and the minimum pressure to create the required force against the load.

·Propulsion source: Should it be operated manually (by hand or foot), air from a compressor, electric power or fuel engine as the main drive? Other factors that may affect the type of drive are whether or not it is remotely operated, the speed of operation, and the load required.

Working speed: if the hydraulic pump is manual, should it be single-speed or two-speed? What is the volume of liquid in each stroke of the handle? What is the volume per minute when using an electric hydraulic pump? Air, gas and electric hydraulic pumps are useful for high volume flows.

Portability: Hand hydraulic pumps are usually portable but have a lower output, while fuel pumps have a high output pressure but are fixed for remote operation in locations without electricity. Electric hydraulic pumps can be mobile and fixed as well as air hydraulic pumps. Air hydraulic pumps require compressed air at work.

Operating temperature: The operating temperature of the application can affect the size of the oil reservoir required, the type of fluid and the materials used for the pump components. Oil is the working fluid, but it also acts as a coolant in heavy duty hydraulic pumps.

Load displacement: The amount of travel required by the load affects the size of the oil tank and the number of cylinders of the hydraulic pump.

Operational noise: Consider whether the environment requires noise. A fuel-driven hydraulic pump makes a louder noise than an electric hydraulic pump of the same size.

Non-sparking: Should the hydraulic pump be non-sparking due to the presence of a possible explosive environment? Remember, most working fluids are petroleum oil derivatives, but non-sparking options are also available.

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