Komatsu PC360 Excavator Rotary Motion Jitter

Whether the excavator is loaded or unloaded, the rotating action is essential. Hundreds of thousands of cycles can be successfully performed every day to ensure the quality and efficiency of the project.

Due to the high frequency of use, faults such as swing, sway, and slow movement often occur during construction.

Today, what I want to share with you is how to effectively handle the first detected swing motion. Save time and stop the machine, accurately eliminate the fault, and leave no hidden dangers.

Fault phenomenon:

This is a typical failure case. During the on-site inspection, the maintenance personnel learned that the Komatsu PC360 excavator had a slight jitter at the beginning of the swinging motion, which was normal after about two or three seconds, and stopped when the handle returned to the neutral position. There was also jitter in the first two seconds.

Excavator swing motion jitter analysis check:

According to the daily maintenance experience, the maintenance personnel first analyzed the problem of the rotary motor, disassembled the motor cover, and found that the contact surface between the distribution plate and the cylinder block was seriously worn. At that time, people thought that the fault had occurred.

However, after replacing the new test machine, the test machine failure still exists. The maintenance personnel disassemble the swing motor again and check it carefully. It was found that the seal gap under the rotary brake cylinder was small. After replacing the seal, the test machine is normal.

process result:

After replacing the seal under the brake cylinder, it works normally. There are a lot of machine friends who have seen some loops here. Why is there a small gap in the seal that can cause such a serious failure?

If there is a gap in the seal, the brake cylinder will not be tightly sealed and the braking time will be longer. When the rotation starts, the brake is not fully released, the spring will shake for a while, and when the rotation stops, the braking time will be shortened. The effect of the valve is not obvious, so it will also shake.