High Pressure Gear Driven Hydraulic Pump HD1430 Kato Excavator Parts K3V180

The oil seal is flushed out

(1) The rotation direction of the gear pump is incorrect. When the rotation direction of the pump is incorrect, high-pressure oil will directly flow to the oil seal. As the general low-pressure framework oil seal can only withstand a maximum pressure of 0.5MPa, it will cause the oil seal to be flushed out.

(2) The gear pump bearing is subjected to axial force. The generation of axial force is often related to the tight fit between the extended end of the gear pump shaft and the coupling sleeve, that is, when the pump is installed, the pump shaft is subjected to a backward axial force by hitting it with a hammer or pulling it hard through the installation screws. When the pump shaft rotates, this backward axial force will force the wear inside the pump to intensify. Due to the fact that the internal sealing of the gear pump relies on the fitting of the gear end face and the shaft sleeve end face, when the axial sealing end face is severely worn, a certain gap will be generated in the internal axial sealing of the pump, resulting in communiion between the high and low pressure oil chambers and causing the oil seal to rush out. This situation is common in the dump truck industry, mainly due to the non-standard size of the coupling sleeve on the main engine.

(3) The gear pump is subjected to excessive radial force. If the coaxiality of the gear pump during installation is not good, it will cause the radial force on the pump to exceed the bearing limit of the oil seal, which will cause oil leakage from the oil seal. At the same time, it can also cause damage to the floating bearings inside the pump.

(4) Long term suction or semi suction of the gear pump exacerbates the wear of the gear end face and shaft sleeve inside the pump. Due to the sealing between the gear end face and shaft sleeve end face inside the gear pump, when the axial sealing end face is severely worn, a certain gap will be generated in the axial seal inside the pump, resulting in communiion between the high and low pressure oil chambers, causing the oil seal to burst out.