Cause and elimination of running deviation of Komatsu PC200 excavator (1)

1, the dirt into the machine side of the parking brake line in the balance valve

When the machine walks, if the dirt has blocked the balance valve small hole, causes the parking brake to be unable to be relieved, thus causes the traveling deviation. Because the machine when walking, if not spring chamber pressure oil through the hole on the balance valve into the balance valve to promote balanced valve spool movement, the pressure oil can not pass through the balance valve on the tank into the hydraulic system, leading to the parking brake force can not be lifted, the walking motor does not rotate, so walking deviation. Elimination method: cleaning the balance valve; when dismantling, to avoid dirt access; regularly replace the required hydraulic oil and filter.

2 、 the central rotary joint sealing ring is damaged

The center swivel joint is composed of a shell and a mandrel, and the shell is mounted on the upper body. The core shaft is provided with an annular groove and an equal number of tubing, hydraulic oil from the oil tank through the shell from the vertical hole core shaft flow to walking motor, so even if the upper body shell with constant rotation, the grooves on the mandrel and the shell can maintain the smooth flow of the oil port, the liquid pressure oil free in and out. If the filter is not timely replacement of hydraulic oil, can cause the filter on the bypass valve is opened, hydraulic oil due to the sliding surface without filtering the impurities in the oil directly into the center of the rotary joint, damage to the seals, the machine when walking to walking on both sides of the motor speed is not the same because of the pressure of oil leakage on one side, resulting in machine walking deviation. The elimination method is: replace the central rotary joint oil seal; replace the hydraulic oil and filter core.