Should replace the oil, strengthen the filter, open the pump cleaning; serious wear and tear of the gear, to be repaired or replaced. ③ parts pump damage or serious wear and tear will have vibration and noise: such as the tooth or the pitch error of large errors, poor contact between the two gears, tooth surface roughness, overhang length of the common law, the tooth backlash is too small, two meshing gear The contact area is not in the sub-round position. At this point, you can change the gear or the gear on the ground. At the same time, the bearing needle cage damage, the length of the shaft journal and needle wear, etc., can lead to poor bearing rotation and mechanical noise, this need to disassemble the gear pump, needle roller bearings replacement. ④ gear assembly gap is too small; gear end face and the front and rear end cover between the sliding surface due to the gear before the burr can not be carefully removed, thus running the joint surface injury, so that the internal leakage, leading to reduced output flow; The dirt enters the pump and wedges into the gap between the end face of the gear and the front and back end caps to strain the mating face, resulting in the communication of the high and low pressure cavities due to the radial tensioned groove, so that the output flow rate is reduced. The above measures should be used to repair the following measures. Disassemble the gear pump, appropriately increase the axial gap that is grinding the end face of the gear; with a surface grinder polished front and rear cover end face and the gear end face and remove gear on the burr (can not be chamfered); The depth of the unloading trough on the end face of the end cap will vary, and the width should be appropriately increased. (3) Other reasons High viscosity oil will also have noise, we must choose the right viscosity of the oil. 2, the lack of output flow ①high temperature will make it lower viscosity, increased internal leakage, reducing the pump output flow. Should identify the reasons for taking measures; for medium and high pressure gear pump, the seal to be checked for damage. ② the viscosity of oil selection is too high or too low, will result in reduced pump output flow, the viscosity should be qualified oil. ③ CB-B gear pump generally can not be reversed, such as the pump body mounted anti-pressure pump will cause the cavity and the local short circuit to reduce or reduce the flow to the oil to. At this point, should check the pump steering. ④ engine speed is not enough, resulting in reduced traffic. Reason should be identified and be excluded. 3, poor rotation ①axial clearance or radial clearance is too small. Re-adjust and repair. ② pump dirt. Disintegrate to remove foreign matter. ③ assembly error. Gear pump two pin hole machining reference plane is not assembly datum, such as the first pin into, and then tighten the screw, the pump will not move. The correct way is to turn the gear pump while tightening the screws, and finally with the pin hole and into the pin. ④ pump and engine coupling coaxial poor. Coaxiality should be guaranteed within 0.1mm. ⑤ Pump parts are not demagnetized. All parts must be demagnetized before assembly. ⑥ needle sleeve failed quality or needle broken. Repair or replace. ⑦ work oil outlet is blocked. Remove foreign body. 4, fever ①cause poor rotation of the gear pump can cause the gear pump fever, the exclusion method can also refer to its implementation. ② oil viscosity is too high or too low. Re-election oil. ③ side panels, bushings and gear face serious friction. Repair or replace.