Troubleshooting of two faults of the HS205 rock drilling jumper

Fault 1

When the trolley is in full-power impact (drilling position), the operation is unstable, and the impact oil pipe connected to the trolley shows significant jumping. Immediately, the full-power/half-power impact handle was pushed back to the middle position (half-power impact position), but the problem still persisted.

Preliminary speculation suggests that the accumulator diaphragms on both sides of the trolley might have ruptured, causing significant fluctuations in the impact pressure.

The accumulator diaphragm was removed for inspection, and it was found that the accumulator diaphragm on the high-pressure side had cracked. Replace the diaphragm with a new one and restart the machine. As a result, the trolley worked normally.

Fault 2

When an old car is repaired and tested, if the full-power/half-power impact handle is in the half-power impact position (hole opening position) or full-power impact position (drilling position), the entire vehicle will be powered off and the trolley will stop working. At this moment, the indicator light on the trolley distribution box shows that the water pump motor is overloaded. When the switch was reset and the machine was tested again, the fault symptoms persisted.

It is speculated that the possible reasons might be: 1. The relay is damaged. 2. Motor damage. 3. The water pump malfunctioned, causing the motor to overload.

Considering the above reasons, the following exclusion steps were taken: 1. The relay on this trolley was transferred to another trolley, and it worked normally. This ruled out the cause of the relay. 2. Remove the motor from the water pump and check if it is damaged. During the disassembly process, it was found that the bolts used to connect the motor and the water pump were relatively long. As the bolt connection holes on the motor were through holes, if the bolts were too long, they would extend into the interior of the motor and damage it. When the motor was disassembled for inspection, it was indeed found that the coil winding of the motor had been broken by the bolts. After repairing the coil winding, connect the motor and the water pump with bolts of appropriate length, and re-test run. The operation returned to normal.