Gear pump TROUBLESHOOTING

Posted by：admin  date：2009-9-29  click：3703

Currently, CB-B-type gear pump dump truck and construction machinery in the steering mechanism in the use of more, now its Common Faults and exclusion method described below for your reference. 1, vibration and noise causes and remedy 1) inhalation of air ① CB-B-type gear cover both sides of the pump and the pump is in direct contact with hard seal, if contact surface flatness do not meet requirements, the pump at work easily inhaled air; Similarly, between the pump cover and gland also direct contact, air is easily penetrated; if gland of plastics, because it is damaged or deformed due to temperature changes, but also make Mifengbuyan into the air. Excluded from this failure is: When the pump or the pump cover to reach the flatness requirements, you can use emery on the plate press "8" shaped route back and forth grinding, you can also surface grinder grinding , so that flatness of not more than 5μm, and the need to ensure the vertical plane of the hole required; gland at the pump cover and the leakage, can be coated with adhesive such as epoxy resin for sealing. ② generally use the skeleton on the shaft seal for sealing. If the garter spring off the lip, or anti-oil package, or lips were strained, aging, are often in a negative pressure will seal the backend state inhalation of air, and can be replaced with new seals to be addressed. ③ enough fuel tank or suction nozzle is not plugged in to the oil below the surface, the pump will draw air time should be added to the oil to the oil tank marking ; when exposed oil return pipe mouth, and sometimes because of the negative pressure within the system instantly leaving air anti-irrigation into the system, so the return pipe should generally also be inserted into the mouth of the oil below the surface. ④ pump is installed from the oil is too high, especially when the pump speed is reduced, because the pump can not guarantee the necessary suction vacuum chamber caused by the inhalation of airborne oil shortage. You should adjust the oil pump and the relative height, so as to satisfy the requirements. ⑤ suction filter clogged by dirt or capacity is too small, resulting in increased resistance to the inhalation of airborne oil; addition, into and out of the mouth of the oil is also possible with a larger diameter into the air. At this point, washable filter, or select a larger capacity, and import and export tracks of appropriate filters. So, not only to prevent the inhalation of air, but also to prevent the generation of noise. (2) mechanical reasons ① Connect the pump and coupling requirements due to irregularities in vibration and noise. Requirements should be required to adjust the couplings. ② because of dirt into the oil pump gears and other parts wear resulting strain generated noise. Oil should be changed to strengthen the filter, open the pump cleaning; gear for serious wear and tear, shall be repaired or replaced. ③ pump damaged or badly worn parts will produce vibration and noise: If the tooth pitch error or error, two bad gear tooth surface roughness is high, normal line length of the ultra-poor, the backlash is too small, the contact area of ​​two meshing gears not pitch circle location. In this case, replace the gear or the gear on the research. Meanwhile, needle roller bearing cage damaged, the length of shaft journal and roller wear, can lead to poor bearing rotation produces mechanical noise, this time to overhaul the gear pump, replacement needle roller bearings. ④ gear assembly axial gap is too small; gear end and sliding joints between the front and rear cover before assembly glitches due to gear failure carefully removed, thus running injury joints, the inner large leak, causing the output flow is reduced; dirt from entering the pump and the front and rear wedging face gear cover the gap between the strain with the surface, resulting in high pressure chamber because of a groove radial strain and communicating the output flow rate decreases. Were used for the above situation the following measures should be repaired. Dismantling gear pumps, axial gap that is appropriate to increase the grinding gears of the face; polished surface grinding machine with front and rear covers face and gear end, and clear the glitch on teeth (not chamfered); by plane before and after grinding Unloading cover its end face groove depth dimension will change, should be increased width. (3) other reasons high viscosity fluid will produce noise, you must use the appropriate viscosity fluids. 2, the output flow shortage ① high oil viscosity will make it drop, internal leakage increases, the pump output flow reduction small. Measures should be taken to identify the reasons; For high pressure gear pumps, seals should be checked for damage. ② choose oil viscosity is too high or too low will cause the pump output flow is reduced, you should use a qualified oil viscosity. ③ CB-B-type gear pump is generally not reversed, such as pump installed backwards, it will cause the pressure chamber and the suction chamber partially shorted to flow to reduce or even do not suck Oiling come. At this point, you should check the steering pump. ④ engine speed is not enough, causing the flow rate decreases. Should identify and eliminate the cause. 3, poor ① rotating axial or radial clearance gap is too small. To be re-adjusted replacement. ② pump dirt. Disintegration to remove foreign matter. ③ assembled incorrectly. Gear pumps two pin hole machining plane was not equipped planes, such as the pin into the first, and then tighten the screws, the pump will not turn. The correct way is, side rotary gear pump side tighten the screws, and finally with and into the dowel pin hole drilled. ④ pump and the engine is poor coaxial coupling. Concentricity should ensure that within 0.1mm. ⑤ pump parts are not demagnetization. All parts must be assembled prior to demagnetization. ⑥ needle or needle breakage sets of substandard quality. Repair or replacement. ⑦ working oil output port is blocked. Remove foreign bodies. 4, fever ① rotary gear pump caused various reasons can lead to poor gear pump heating, exclusion method may also refer to its execution. ② oil viscosity is too high or too low. Oil re-election. ③ side panels, sleeve and the gear face serious friction. Repair or replacement. ④ high ambient temperature, fuel tank capacity is small, poor heat dissipation, will cause the pump heat. Should be treated separately. 5, main parts repair (1) toothed gear ① Repair: with a fine emery cloth or stone ground to remove strain or more prismatic parts, and then swap gear surface orientation and appropriately on the research, and finally cleaned; pairs can be observed with the naked eye badly worn parts should be be replaced. ② face repair: gear end bearing due to the relative rotation of the front and rear cover or wear light up when the line will be available starting line burr polishing method to study traces and polished; badly worn, should gear on a flat surface grinding machine for grinding. It should be noted: two gears must be on a flat surface grinder for grinding, the purpose is to ensure the two gears in 5μm thickness difference within; also must ensure that the face and the vertical hole and parallel end surfaces were 5μm range, and poured oil stone will blunt sharp edges, but must not chamfered, so that no burrs can be. ③ When the gear meshing surface wear, the application will wear the stone burrs removed; Meanwhile, replacement gears meshing position, so that the original does not work tooth surface meshing engagement work This will not only ensure their original performance, but also to extend the working life of the gear. 2) pump pump wear, mainly round the cavity and in contact with the gear term side, and mostly occurs in the suction side. If the pump is symmetric, the pump can be rotated 180 degrees and then use; if the pump is non-symmetrical, you need to use electroplating bronze alloy plating process or method of repairing electrical pump cavity hole wear parts. (3) bearing ring bearing ring gear wear in general and in contact with the needle end which contact with the inner hole. Picking up face wear or lines, can be four bearing race on a flat surface grinder so as not to contact with the gear side of Jizhunjiangla hair face polished, its accuracy should ensure 10μm range. Bearing races generally less wear, if badly worn, can grind; or appropriate to increase aperture and re-matching needle; or replace the bearing race. (4) long and short axis length , minor failure, primarily in contact with the roller bearing at the frayed. If minor wear, can be polished repair (and replace with new needle bearings); if badly worn or broken, you need to use chrome plating repair, or re-processing. Re-processing, the requirement of long keyways on the minor axis parallel to the axis line and the symmetry requirements; mounted on the shaft of the gear keyway flat key with the gap can not be too large; not the gear shaft bore produce radial wobble; journal and install the gear portion of the coaxial mating surface not more than 10μm, both ends of the journal concentricity shall not exceed 20-30μm.

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