The gear pump works by the closed movement of the two meshing gears when they rotate. The gear pump is a gear drive to provide power, and the gear pump is a quantitative pump, which is mostly used for low-precision medium and low-pressure control. Its main features are: simple structure, convenient manufacturing, low cost, low price, small size, light weight, good self-priming performance and reliable work. What should I do when there is a problem with the gear pump? In fact, there are many reasons for gear pump failures. Next, the excavator maintenance technician will pick two of them to explain!
(1) The gear pump has poor sealing and air leakage
① Method to reduce internal leakage: appropriately adjust the movement gap of the pump. For example, when the pump body and the front and rear end covers are assembled due to burrs or poor flatness, use oilstone to trim the burrs, grind with emery stone on a flat plate or repair on a surface grinder. Grind so that the flatness is not greater than 0.05mmo
②There are plastic glands for the pump cover, but the plastic is cold-shrinking, which may cause poor sealing. The solution is to clean the front and rear cover holes and glands with acetone, and then coat and seal with epoxy resin adhesive, and start the pump only after the adhesive is dry.
③The oil suction pipe is not tightly sealed, the gear shaft (drive shaft) is damaged, and air is mixed in. The sealing nut of the oil suction pipe can be tightened to check whether the sealing ring is damaged. If it is damaged, replace it. If the spring in the sealing ring is too loose due to too long time to make the sealing ring and the gear shaft seal, you can remove the spring and grind the other end (non-tapered end) on the grinding wheel for a short period of time.
④The oil level of the fuel tank is too low and air is sucked in. The oil inlet pipe is required to be immersed in the specified height, otherwise the oil inlet pipe shall be replaced and the oil tank shall be filled in time.
(2) Loud noise and severe pressure fluctuation
① Check whether the oil pipe, mounting frame, and frame are loose. If it is loose, tighten it to avoid resonance.
②The tooth profile accuracy is not high or the contact is poor. Changing gears with high profile precision can also be used for refurbishing (after refining, the pump must be disassembled and cleaned and then reassembled).
③Air enters the pump. Air infiltrates from the oil inlet pipe, the seal of the pump shaft or the pump cover. Follow the above method to deal with, you can also replace the oil seal or paper pad.
④ The axial clearance between the gear and the end cover is too small. The gear is removed and placed on a surface grinder to grind away a little, so that the gear is thinner than the pump body 0. 02~0. 04mmO
⑤ The coupling between the pump and the motor is rubbed. The pump and the motor should be connected flexibly, and their positions should be adjusted appropriately so that they no longer collide. If the cylinder and rubber ring in the coupling are damaged, they should be replaced, and the coaxiality error of the two should be within 0.1mm during installation.
⑥Check the liquid level of the oil tank and add enough hydraulic oil.
⑦ The oil viscosity is too high, check the viscosity at working temperature.
⑧Improper layout of the inlet and return pipes. When the liquid level is low, the return flow will produce vortex with bubbles. Enough oil should be added.
⑨The diameter of the oil inlet pipe of the pump is too small. Check that the flow rate does not exceed L 2~1.5m/s.
⑩ The oil is dirty. Dust, sand, and foreign matter enter the gear pump and damage the pump.
Summary: The problem of the gear pump is related to the failure of the hydraulic pump. Owners must pay attention to their gear pumps when they find problems with their gear pumps, and be careful that small troubles may cause major accidents!
