Gear pump common troubleshooting

Gear pump troubleshooting Summary: The processing of automotive hardened steel parts coating PCBN tool CNC WEDM in the spline hole machining applications Sinamics G110 In the need to quickly change the direction of the motor rotation should explore China Machinery Products Innovative design and development of micro-hole machining technology status quo and existing problems Selection and maintenance of cutting fluid can be reasonable choice of indexable milling cutter Key technology trends of the spindle speed Cutting edge strengthening and its latest development CVD diamond dressing tool China CNC machine tool industry will usher in 15 years of golden development Tool manufacturers to process improvement Chengdu Institute of Tool Two research projects through the identification of the door with the loading and unloading system of the machine The first self-bolt six drilling rig Germany Engelhardt (Engelhard Kazakhstan) F33 three-axis CNC system by PDM Health "egg" Anhui forklift successfully developed 4.5t hydraulic pump gearbox low-voltage electrical reliability profile and development of welding teaching reform of thinkers and practitioners [Tag: tag] Currently , CB-B-type gear pump in the dump truck and construction machinery operating mechanism used more now its common And troubleshooting methods are described below for reference. 1, the reasons for the vibration and noise generated and excluded (1) inhaled air â‘  CB-B gear pump body and both sides of the cover for direct contact with the hard seal, if the contact surface flatness does not meet the requirements, the pump Easy to breathe air at work.
At present, CB-B gear pump in the dump truck and construction machinery operating mechanism used more, now its common failures and troubleshooting are described below, for reference.
1, the reasons for the vibration and noise generated and excluded (1) inhaled air ① CB-B gear pump body and both sides of the cover for direct contact with the hard seal, if the contact surface flatness does not meet the requirements, the pump Easy to breathe in the air at work; also, the direct contact between the end cap of the pump and the gland, the air is also easy to invade; if the gland is a plastic product, due to its damage or deformation due to temperature changes, will seal Strictly into the air. The way to get rid of this kind of trouble is: When the flatness of the pump body or pump cover can not meet the stipulated requirements, it can be grinded back and forth on the flat steel with the "8" shaped route with the gold sand, or on the surface grinder , So that its flatness does not exceed 5μm, and the need to ensure that the plane and the hole perpendicularity requirements; For the pump cover and gland at the leak, can be coated with epoxy adhesive sealing.
â‘¡ The shaft is generally sealed with a skeleton oil seal. If the locking lip spring off, or the oil seal installed, or its lips were injured, aging, will make the back end of the seal often in negative pressure and inhale the air, the general can replace the new seal to be resolved.
â‘¢ fuel tank is not enough oil, or the suction nozzle is not inserted below the oil surface, the pump will inhale the air, this time should be added to the fuel tank to the oil line; if the oil return pipe mouth exposed oil, and sometimes because of Negative pressure within the system so that the air back into the system of irrigation, so return pipe mouth generally should be inserted below the oil level.
â‘£ pump installation location is too high from the oil surface, especially in the pump speed is reduced, because the pump can not guarantee the necessary vacuum caused by the suction caused by insufficient suction air. At this point should be adjusted to the relative height of the pump and oil surface to meet the requirements.
⑤ oil filter is clogged with dirt or its capacity is too small, resulting in increased suction resistance and inhalation of air; In addition, into the port of a larger caliber may also be brought into the air. At this point, you can clean the filter, or choose a larger capacity, and out of the appropriate diameter filter. In this way, not only can prevent the inhalation of air, but also to prevent noise.

(2) Mechanical reasons (1) The connection between the pump and the coupling generates vibration and noise due to the non-compliance requirements. Should be required to adjust the coupling.
â‘¡ due to dirt in the oil into the pump gear and other components caused by wear and tear and noise. Should replace the oil, strengthen the filter, open the pump cleaning; serious wear and tear of the gear, to be repaired or replaced.
â‘¢ 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.
â‘£ gear assembly gap is too small; gear end face and front and rear end cover of the sliding surface between the gear assembly before the burr failed to carefully removed, thus running the joint surface injury, so that the internal leakage, resulting in 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); after grinding the front and rear 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 â‘  high oil temperature will make its viscosity decreased, 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.
â‘¡ The viscosity of oil selection is too high or too low, will result in reduced pump output flow, the viscosity should be qualified oil.
â‘¢ 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.
â‘£ engine speed is not enough, resulting in reduced traffic. Reason should be identified and be excluded.

3, poor rotation â‘  axial clearance or radial clearance is too small. Re-adjust and repair.
â‘¡ pump dirt. Disintegrate to remove foreign matter.
â‘¢ 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.
â‘£ 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.
â‘¥ needle sleeve failed quality or needle broken. Repair or replace.
⑦ work oil outlet is blocked. Remove foreign body.

4, fever â‘  cause poor rotation of the gear pump can cause the gear pump fever, the exclusion method can also refer to its implementation.
â‘¡ oil viscosity is too high or too low. Re-election oil.
â‘¢ side panels, bushings and gear face serious friction. Repair or replace.
â‘£ high ambient temperature, small fuel tank, poor cooling, will make the pump heat. Should be handled separately.

5, the main parts of the repair (1) gear â‘  tooth repair: remove or remove with a fine sand cloth or whetstone polygonal area, and then the gear meshing surface replacement orientation and appropriate research, the final clean ; Severe wear parts that can be observed with the naked eye should be replaced.
② end face repair: gear end face due to bearing or front and rear relative rotation of the cover and wear, light from the line, available grinding method to start burr marks grinding and polishing; serious wear, the gear should be placed on a surface grinder Sharpen. It should be noted that the two gears must be grinded on the surface grinder at the same time in order to ensure that the thickness difference between the two gears is within 5μm. At the same time, the perpendicularity of the end surface to the hole and the parallelism of both end surfaces must be 5μm Within the range, and sharp edges with stone will be blunt, but must not be chamfered, so burr-free, flash can be.
â‘¢ When the gear meshing surface wear, the use of whetstone will wear away the burr; the same time, the exchange of gear meshing position, so that the original non-meshing work toothed surface meshing work, so not only to ensure its original working performance , But also extend the working life of gear.

(2) pump body wear and tear, mainly in the cavity and gear round contact that side, and occurred in the suction side. If the pump body is of symmetrical type, the pump body can be overturned by 180 degrees and then reused. If the pump body is asymmetrical, wear the bronze alloy plating or brush plating method to repair the wear parts of the bore in the pump body.
(3) Bearing race Bearing race wear and tear generally in contact with the gear that end face and the needle in contact with the hole. Face wear or pull the hairline, the four bearing rings can be placed on a surface grinder, the gear does not come into contact with the side of the bristle face polished, the accuracy should be guaranteed in the 10μm range. Generally smaller bearing race wear, if serious wear and tear, grinding; or appropriate to increase the aperture and re-election needle; or replace the bearing race.

(4) long, short axis length, short axis failure, mainly in contact with the needle roller bearings wear. If minor wear, use polish repair (and replace the new needle roller bearings); if it is worn out or broken, use chrome plating to repair or rework. Re-processing, to meet the long and short axis of the keyway on the axis of the parallelism and symmetry requirements; installed in the shaft key and the gear keyway with the gap can not be too large; shaft not in the gear bore Produce radial swing; journal and mounting gear part of the mating surface with the coaxiality of not more than 10μm, coaxiality at both ends of the journal shall not exceed 20-30μm.

Chlorinated Polyethylene

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