Proportional solenoid valve SV90-G39 24V loader hydraulic pump

   CAT excavator pump distribution gear box into the hydraulic oil

(1) The fault phenomenon that may occur in the maintenance of Carter excavator The hydraulic oil is trapped in the pump split gear box and overflows from its respirator.

(2) Carter excavator maintenance reason analysis Because the three main pumps are installed on the pump split gear box, according to the working principle of the system analysis, there may be two parts of the oil channeling: one is the pump split gear box
There is hydraulic oil intrusion at the lubrication pump, that is, due to long-term work, the skeleton oil seal of the lubricating oil pump is damaged or aging, resulting in the hydraulic oil in the main pump 1 invading the lubricating oil pump and entering the pump through circulation
A moving gear box that overflows from its respirator over time; The second is oil pumping at the connection between the main pump and the pump split gear box, that is, due to damage or aging of the skeleton oil seal of the main pump, the high-pressure hydraulic oil in the main pump directly invades the pump split gear box and spills from the breathing apparatus. Transmission or axial movement of the main pump oil seal can also cause hydraulic oil to invade the lubrication system. The reasons are: the oil seal installation clearance is large, and the rotating action is generated under the drive of the pump shaft; Splines connected to the pump The bearing wear at the top causes the radial runout of the pump shaft, deforms the inner ring of the oil seal, and increases the clearance of the outer ring, resulting in the transmission and axial movement of the oil seal. The long-term action of oil pressure causes the oil seal to move axially. The hardening of the oil seal causes the wear of the shaft diameter with it to intensify, resulting in the increase of the fit clearance.

(3) Carter excavator maintenance troubleshooting first remove and disassemble the oil seal of the lubrication pump of the pump split gear box, check whether the oil seal is well matched with the shaft, and whether there is damage or aging; Check whether there is obvious wear at the shaft diameter of the oil seal, and then determine whether it is the fault location; Then check the main pump oil seal. Disassemble the 3 main pumps, remove the oil seals and check whether their inner edges are aging or damaged; Whether the oil seal spring fails, whether the axial and radial of the shaft at the installation of the oil seal have wear marks, so as to determine whether it is the fault part. The solution to the problem is: replace the oil seal regularly; Regularly clean and maintain the heat dissipation device of the hydraulic system, and regularly test the system pressure to ensure the normal heat dissipation of the system; Repair by replacing the pump shaft or chroming the radial worn parts of the shaft.