The PR70 is a power take-off (PTO) unit designed for use in XCMG QY25K truck cranes. It is manufactured by Qijiang (綦江) and is compatible with Qijiang series transmissions .

1. Installation Location
The PR70 PTO is mounted directly onto the transmission housing of the crane carrier . For XCMG QY25K models, the transmission is typically paired with either a Weichai WD615.329 or Shangchai SC8DK280Q3 engine . The PTO connects to the transmission's gear train and is positioned to transfer mechanical power from the engine to the hydraulic pump that powers the crane's superstructure functions.

2. Function
The PR70 transfers engine power from the transmission to the hydraulic pump, which then drives the crane's hydraulic system for lifting, slewing, and boom operations. It features pneumatic control, and its output torque is rated at 700 N·m . Output speed ratio options include 0.92, 1.18, 1.1, and 1.07, with output tooth configurations available as 22/32, 22/36, or 20/26 . The unit uses an externally engaged mesh form with straight tooth, involute tooth curve design .

3. Maintenance and Service
Regular inspection of the PTO includes checking for oil leaks at the mounting interface, verifying pneumatic engagement/disengagement operation, and listening for unusual noise during operation. The pneumatic control system should be checked for proper air supply pressure and clean filters. When replacing a PR70 PTO, ensure the output tooth configuration matches the original specification for the specific crane application. The unit itself contains internal gears that are not user-serviceable; complete replacement is recommended if internal wear or damage occurs.

4. Important Notes
Before installation, verify the part number and specification against the original unit. Ensure the transmission is the correct Qijiang series model for compatibility. After installation, test PTO engagement and disengagement cycles before returning the crane to full operation.