Elephant Fluid Power Co., Ltd.
Elephant Fluid Power Co., Ltd.

Knowledge Related to Hydraulic Gear Pumps

Hydraulic gear pumps are an ideal choice for mobile hydraulic system applications, such as agricultural equipment, construction equipment, and more. The name gear pump comes from the fact that two rotating gears within the pump body mesh together. While we may not often consider how this type of hydraulic pump works, you may be interested in some fun facts.

Little knowledge of hydraulic gear pumps

  • Hydraulic gear pumps are highly efficient power converters. While they may not be as powerful as hydraulic piston pumps, gear pumps deliver the power required for mobile hydraulic equipment applications within a compact frame. Even in extreme temperatures, working environments, or with degraded oil quality, mobile gears can still produce the necessary pressure.

  • Hydraulic gear pumps are very flexible. These pumps can be equipped with relief valves, flow control valves, accumulator charging valves, check valves, and load-sensing valves to provide very compact devices. They are an ideal solution for mobile equipment with limited space, such as forklifts or tractors.

  • There are two types of hydraulic gear pumps. The most common type uses two identically sized gears placed side by side within the pump housing. The other type has one large outer gear, which is larger than the second. In this configuration, the larger gear is located on the outside with its teeth inward, meshing with the smaller second gear located on the inside of the larger gear.

Due to their unique and compact design, hydraulic gear pumps are an ideal choice for mobile equipment applications. However, you need to pay close attention to system monitoring to avoid and prevent performance issues such as oil contamination, which is the leading cause of gear pump failure.

Precautions for hydraulic gear pumps

When installing hydraulic gear pumps, the base or bracket should have sufficient rigidity to support the pump without being subjected to forces other than the twisting force produced by the pump shaft rotation; the different axiality between the connecting shafts should not exceed 0.05mm; hydraulic gear pumps should run in the direction of rotation specified on the pump label, taking note of the position of the inlet and outlet ports, with the larger port serving as the inlet.

Safety valves and pressure gauges must be installed in the hydraulic system, and the oil tank must be dustproof to prevent sand and other debris from entering the oil and must be regularly cleaned. The suction pipeline should be as short as possible, generally not exceeding 500mm, and fittings should be used as little as possible. There should be no air leaks in the oil pipeline.

The prescribed working fluid is HC-8# diesel engine oil for winter and HC-11# diesel engine oil for summer, with a working temperature range of -10 to 70 degrees Celsius.