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Failure analysis of vane pump

• Posted by Cassidy vanepump September 10, 2020 - Filed in Other - #Fixed Vane Pumps  - 489 views
  1. The inner surface of the Vane Pumps stator and the blade head are severely worn.
  2. The rotor of the vane pump is broken. Rotor fracture often occurs at the root of the blade groove of the oil pump. The reasons for the fracture are: the rotor adopts 40Cr material, which has good hardenability. The surface and core of the rotor are hardened during quenching, and it is easy to break when subjected to impact load. ; The dangerous section between the small holes at the root of the blade is subject to greater stress, and stress is often concentrated due to poor processing. In particular, some manufacturers use the process of milling the blade slot first and drilling the round hole at the root of the blade slot, and the situation is even worse; Foreign matter is sucked into the pump and the rotor is disconnected. Sometimes (YB type vane pump) the pressure ring at the end of the needle roller bearing at the left end of the pump shaft is disconnected, and the bearing needle is often sucked into the pump, causing the rotor to break.
  3. The vane pump has poor operating conditions. For example, the vane pump is prone to abnormal wear and cavitation wear if it works under conditions such as overload, high temperature, corrosive gas, oil leakage, water leakage, and oxidation and deterioration of hydraulic oil.
  4. The vane pump is poorly assembled after disassembly. If the difference between the axial thickness of the rotor and the pump body is too small, the compression screw is forcibly assembled, and the pump can be installed on the main engine when the pump cannot be flexibly rotated by hand. The vane pump will burn out in a short time.
  5. The shaft of the vane pump is broken and damaged. Dirt enters the pump and gets stuck between the relative moving sliding surfaces of the rotor and the stator, the rotor and the oil distribution plate, causing the pump shaft to transmit excessive torque and break, so it is necessary to strictly prevent the dirt from entering the pump; the wrong pump shaft material is selected , The heat treatment is not good, causing the pump shaft to break; other valve components in the system, such as the overflow valve, fail to operate, and the system generates abnormal high pressure. If there is no other safety protection measures, the Fixed Vane Pumps will be overloaded and the shaft will be broken.