Fault Phenomenon: Bauer BG22 rotary drilling rig during operation, actions jitter, pressure gauge needle swings violently.

Troubleshooting Process:
– Checked pump: variable piston pump swashplate mechanism stuck.
– Checked accumulator: system accumulator nitrogen leaked.
– Checked fluid: a large amount of air mixed into the hydraulic oil.
– Checked suction line: suction line leaking air.

Root Cause: A loose suction line connection allowed air to enter the pump, causing cavitation and pressure pulsation.

Required Parts: Repair suction line seal and replace hydraulic oil.