Hydraulic pumps convert mechanical energy and motion into hydraulic fluid power and are usually powered by gas or electricity. However, hand and air driven pumps are also utilized. There are three main types of hydraulic pumps used in the fluid power industry, namely vane pumps, gear pumps, and piston pumps. These are all positive displacement pumps, meaning that they transfer a calculated quantity of pressurized hydraulic fluid into a hydraulic system. This fluid progresses to the necessary component and its pressure is reconverted to mechanical force.
A general hydraulic pump design can be further categorized into specific groups. For example, piston pumps can be radial, axial, in-line reciprocating, or axial bent-axis piston pumps. Vane pumps are either cam or sliding vane pumps. Pumps can be further subcategorized according to the modifications made for special applications. These pumps show a great variety in design. Irrespective of the design, all hydraulic pumps are to be used with fluids of definite viscosity. Changes in fluid viscosity will cause altered performance, often lowering the efficiency. Most pumps get damaged by any solid particles in hydraulic fluid, and, hence, require a filtration system.
A hydraulic pump is a very important component of construction, manufacturing, and machining equipment. It is responsible for a machine’s precision, its efficiency, and overall performance of an entire system. Various materials are used in hydraulic pumps to minimize wear and provide consistent performance. The type of material used varies according to pressures and temperatures that a hydraulic system will undergo. A number of plastics, synthetic rubbers, and steel alloys are used in the manufacturing of hydraulic pumps. High-strength alloys and polymers are used in high-pressure systems.
When choosing a pump, it is recommended to consider factors like operating pressure, temperature, and frequency. For applications requiring minimal pressures, less expensive, low-pressure pumps are available. Some examples of hydraulic pump manufacturers are Lifco Hydraulics, Inc., Flint Hydraulics, Inc., HYSECO, Inc., and Craft Fluid Systems.