The danger of excessive pressure of the hydraulic pump housing

The danger of excessive pressure of the Hydraulic Pump housing: oil seal leakage + sliding shoe eccentric wear + swash plate wear + return disc breakage

Requirements for housing drain pressure on Rexroth piston pump A10VSO sample: the maximum allowable pressure is 0.5 bar above the inlet pressure of the oil port S (i.e. oil suction port), but not higher than 2 bar.

Requirements for housing drain pressure on Rexroth piston pump A11VO sample: The discharge pressure of ports T1 and T2 can be up to 1.2 bar higher than the inlet pressure of port S, but not greater than 2 bar.

For the requirements of Vickers,  Parker and other brands of Hydraulic Pumps for oil discharge pressure, you can obtain a sample manual from online customer service for free or download the sample on the product introduction page of this site.

Let the hydraulic pump run beyond the range of housing pressure requirements, your hydraulic pump is not just an oil seal leakage, it is very likely to lead to fatal hazards of the hydraulic oil pump at any time.

Hazard 1: slippery shoe eccentricity

The overturning of the hydraulic pump shoe leads to wear around the shoe, that is, the sliding shoe in the hydraulic pump picture is eccentric. Eccentric abrasion will destroy the oil film pressure distribution of the sliding shoe, resulting in the imbalance of the force of the hydraulic oil pump sliding shoe, which will further aggravate its wear and cause a vicious circle.

Hazard 2: swash plate wear

Due to the eccentric wear caused by the overturning of the hydraulic oil pump sliding shoe, when the sliding shoe runs to the high pressure area, the oil film pressure field of the sliding shoe can not effectively support the high pressure from the plunger cavity, which will lead to the abnormal increase of the direct contact force between the sliding shoe and the swash plate, which will cause irreversible wear on the surface of the swash plate of the hydraulic pump.

If this happens early and is not detected in time, it can quickly develop to the following severity: the swash plate of the hydraulic oil pump is deeply damaged.

Hazard 3:the fracture of the retainer plate

At the same time as the shoe overturned, the hydraulic pump return disc was not spared. When the shoe runs to the low pressure area, the contact force between the shoe and the return disc will also be abnormally high, resulting in increased wear between the two, the most obvious sign is that there is obvious wear around the shoe hole of the return disc, and even small pits. More serious is the rupture of the return disc of the hydraulic pump.