Use and maintenance method for extending the service life of hydraulic piston pump
The efficiency of the hydraulic system depends mainly on the volumetric efficiency of the hydraulic pump. When the volumetric efficiency drops to 72%, routine maintenance, replacement of bearings and aging seals are required, and friction pairs that exceed the fit clearance are replaced or repaired. Get restored.
1. Hydraulic pump: Straight-axis swash plate type piston pump is divided into two types: self-priming oil type with pressure supply type. Pressure-supply hydraulic pumps mostly use a gas tank with air pressure, and the hydraulic pump itself has a charge pump to supply pressure oil to the hydraulic pump inlet. The self-priming hydraulic pump has a strong self-priming capability and requires no external force to supply oil. The hydraulic fuel tank for pneumatic oil supply must operate the machine after the hydraulic pick-up tank has reached the air pressure after each start of the machine. If the pressure of the hydraulic oil tank is insufficient, it will cause the machine to pull off the slippery whip in the hydraulic pump, which will cause abnormal wear of the returning plate and the pressure plate in the pump body. After using the plunger pump for oil supply by the oil pump, after 3000 hours, the operator needs to check the plunger pump 1-2 times a day to check whether the sound of the hydraulic pump is normal. If the speed of the hydraulic cylinder is found to be degraded or boring, the charge pump should be disassembled to check whether there is any scratch on the edge of the impeller, and whether the clearance of the internal gear pump is too large.
2. For the self-priming oil type plunger pump, the oil in the hydraulic oil tank should not be lower than the lower limit of the oil mark, and a sufficient amount of hydraulic oil should be maintained. The higher the cleanliness of the hydraulic fluid, the longer the service life of the hydraulic pump.
3. The most important component of the bearing piston pump for hydraulic pump is the bearing. If there is play in the bearing, the normal clearance of the three pairs of friction pairs inside the hydraulic pump cannot be guaranteed, and the thickness of the hydrostatic bearing oil film of each friction pair is also destroyed. Reduce the life of the piston pump bearings. According to the information provided by the hydraulic pump manufacturer, the average service life of the bearing is 10000h. If this value is exceeded, a new port needs to be replaced. The disassembled bearing can't detect the clearance of the bearing without professional testing equipment. It can only be visually tested. If it is found that the roller surface has scratches or discoloration, it must be replaced. When replacing the bearing, pay attention to the original letter and type of the original bearing. Most of the piston pump bearings use large load capacity bearings. It is best to buy the original manufacturer and the original specification. If you change another brand, you should consult the bearing. The personnel check the table to change, the purpose is to maintain the bearing's accuracy level and load capacity.
4. Three pairs of friction sub-inspection and repair: According to the replacement standard of the plunger pump parts, the plunger rod and the cylinder hole can be repaired as follows when the various gaps of the parts are out of tolerance:
(1) If the cylinder is fitted with a copper sleeve, it can be repaired by replacing the copper sleeve. First, the diameter of a set of plunger rods is trimmed to a uniform size, and then the outer diameter is polished with a sandpaper of 1000# or more. Three methods for installing the copper sleeve in the cylinder: (a) cylinder heating or copper sleeve low temperature freezing extrusion, interference assembly; (b) mining with Loctite adhesive assembly, this method requires copper jacket There are grooves on the surface of the diameter; (c) tapping of the cylinder bore, the outer diameter of the copper sleeve is machined, and after the coating is applied, the assembly is screwed into the assembly.
(2) The cylinder block and the copper sleeve of the fusion-fired combination method are as follows: (a) grinding or repairing the cylinder bore by a grinding rod by hand or mechanical means; (b) re-clamping the cylinder bore by using a coordinate boring machine; ) Reaming the cylinder bore with a reamer.
(3) Adopt “surface engineering technology” as follows: (a) electroplating technology: plating a layer of hard chrome on the surface of the plunger; (b) brush plating technology: brushing the surface of the plunger with wear-resistant material; (c) Thermal spraying or arc spraying or electro spraying: spraying high carbon martensite wear resistant material; (d) laser welding: welding high hardness wear resistant alloy powder on the surface of the plunger.