Hydraulic machines are used in many industrial applications to accomplish significant work requiring high amount of mechanical energy in a single stroke. Hydraulic machines perform this work through the use of the high pressure fluid method. The fluid which is typically oil is pumped from a reservoir to the cylinder with the help of hydraulic pump to actuate the piston. Thus, a hydraulic pump needs to generate enough pressure to overcome the pressure induced by the piston load. The pump creates a vacuum at the inlet which draws the fluid from the reservoir to the hydraulic system. Hydraulic gear pump is fixed displacement pump which has a set flow rate.
Hydraulic gear pump moves a high amount of fluid with a constant flow rate at relatively low pressure. They are best suited for mobile equipment as most of the hydraulic machines need a constant flow rate for their operation. Thus, hydraulic gear pump finds its applications in many agricultural and construction machines which require less pressure up to 3000 psi. On the basis of design, hydraulic gear pump can be classified as external and internal gear pump. The internal gear pump is majorly used in mobile applications due to its capability in handling thick fluids and providing high efficiency compared to external gear pumps. Hydraulic gear pumps are cheaper as compared to vane pump, axial piston and radial piston pump due to simplicity in construction. Further, the maintenance required and number of breakdowns in gear pump is lesser as compared to other types of hydraulic pump. This is due the gradual wear down of the main bushing due to the less stress exerted on gears.