Engine exhaust, running, sounds all unusual, difficult to start, accelerate slowly; oil contaminated hydraulic system, hydraulic components and piping, external and internal joints are a serious drain, the hydraulic cylinder does not lock automatically retract; whole Machine loose drive chain of the manipulation of the handle, maneuver block effort. The reason resulting the detections includes overload of work is mainly a long time and do not meet the requirements in the operating environment; routine maintenance is not timely, large, medium and minor repairs not up to standard requirements.
Adjustment and repair methods
(1) the adjustment of the engine throttle
For example, crane equipped with diesel engines in the car, after a long-term use, sometimes in the manipulation of the throttle the car will appear when the slow growth rate, reach maximum speed and maximum power of the situation. At this point need to check and adjust the throttle pedal on the car the entire driveline. This would take two people, one person in the car control the accelerator pedal and the other was observed in the fuel pump speed control lever at the movement. The crane used for many years, the operator in the cab of the accelerator pedal Although extreme position, but in fact the speed diesel engine fuel pump rod and sometimes can not reach the limit position. Speed control lever in the Machine because of the position in the operator's position is not easily observed, the air travel is often overlooked, should be to observe for a while, try several times. Reasons for this situation, one size chain drive engine throttle changes, among which is too large due to the accumulation of air travel; Second, some fasteners on the gear, such as caused by loosening set screws. At this point the throttle should be gradual to check the drive size chain, when the throttle on the train ride in the end, the speed control lever must reach the limit. Throttle drive chain shall be required on the process sacrificing the space should be based on the specific situation of each device fastening and adjustment.
(2) gear pump repair
Gear pump wear, pump shell is mainly the surface of tooth wear on top and tooth thickness. Repair methods are: wear in the pump shell surface layer of metal coating solution at the brush, so to restore the original size; the top of the gear tooth and the tooth may be its thickest plating, restoring the top of the tooth thickness and tooth size; axis sets are generally not only for repair and replacement bushings must pay attention to its axial length, do not leave space. Several of the same model can be used on the gear pump for accurate measurements, and then use lighter gear and wear re-combined with the pump installed and a test in the test rig.
(3) piston pump repair
Wear surface of the plunger piston and the rotor is mainly compatible with the plunger hole. Repair Methods: According to the wear measured by the size of the plunger hole reconstituted plunger, the plunger of the new materials, heat treatment technology and outer dimensions and surface roughness must comply with the relevant technical requirements; Assembly may, before the new plunger with the hole and grind it. In addition, it can be used in the selection of some of the same model worn piston plunger and rotor to a lesser extent plunger hole re-combination equipped. Generally speaking, the old with the gap between the plunger and the hole should not exceed 35mm, 45mm when the wear reached should be rejected.
(4) control valve repair
Should be measured in accordance with the valve stem hole the size of the wear re-formulated the new stem, new stem material, heat treatment, size and surface roughness departments must ensure compliance with relevant technical requirements; the new valve assembly before the best rod and the valve stem hole on the ground look, (preferably a car manufacturing process used to grind the spindle), can also be used if the conditions are not met milling about the same time a new stem, but also on the control valve positioning and pressure adjustment spring Unit elasticity of the return spring testing to see if it meets requirements. Can also be based on the valve stem of each hole to determine the degree of wear and tear repair methods, if the same model more than the old valve can be detected between several and deployment. After repair the valve should be tested in the pilot stage, the valve can also be flat, two holes in the above to fill kerosene, with a stopwatch to measure the speed of the oil spill to determine the extent of the valve seal.