Use and maintenance of piston pumps


Use of plunger pump

The plunger pump cylinder body is inlaid with a copper sleeve, which can be installed by replacing the copper sleeve. First trim the diameter of a group of plunger rods to a uniform size, and then polish the outer diameter with sandpaper of 1000 # or more.

的 Three methods of installing copper sleeve on cylinder block:

A (a) The cylinder body is heated and heated or the copper sleeve is cryogenically frozen and extruded, and the interference is assembled;

(B) Adopt Loctite adhesive assembly, this method requires grooves on the outer surface of the copper jacket;

(C) Tapping the cylinder bore, machining the outer diameter of the copper sleeve, applying Loctite, and screwing in the assembly.

Cylinder block and copper sleeve with fusion method, the installation method is as follows:

A (a) Grinding and repairing the cylinder bore with a grinding rod, manually or mechanically;

B (b) Re-boring the cylinder bore with a coordinate boring machine;

(C) Use a reamer to repair the cylinder bore.

(3) Adopt "surface engineering technology" as follows:

(A) Electroplating technology: a layer of hard chromium is plated on the surface of the plunger;

(B) Brush plating technology: Brush plating of wear-resistant materials on the surface of the plunger;

C (c) Thermal spraying or arc spraying or electrospraying: spraying high-carbon martensite wear-resistant materials;

(D) Laser cladding: cladding high-hardness wear-resistant alloy powder on the plunger surface.

(4) Most of the cylinder block materials without copper sleeves are made of ductile cast iron. An amorphous film or coating is prepared on the inner wall of the cylinder. Because the inner wall of the cylinder bore has this special substance, it can form a hard-hard paired friction pair.

Maintenance of piston pumps

The plunger pump supplied by the charge pump is used. After 3000 hours of use, the operator needs to check the plunger pump 1-2 times a day to check whether the hydraulic pump is operating normally. If it is found that the speed of the hydraulic cylinder drops or the vehicle is stuffy, the charge pump should be disassembled and inspected to check whether the edges of the impeller are scratched and whether the internal gear pump clearance is too large. For self-priming plunger pumps, the oil in the hydraulic oil tank must not be lower than the lower limit of the oil standard, and a sufficient amount of hydraulic oil must be maintained. The higher the cleanliness of the hydraulic oil, the longer the service life of the hydraulic pump.

The most important part of the plunger 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. At the same time, the thickness of the hydrostatic supporting oil film of each friction pair will be destroyed. Service life. According to the information provided by the hydraulic pump manufacturer, the average service life of the bearing is 10,000 hours. If it exceeds this value, it needs to be replaced with a new one. The disassembled bearing can not detect the bearing clearance without professional inspection equipment. Only visual inspection can be used. If scratches or discoloration of the roller surface are found, it must be replaced.

When replacing bearings, you should pay attention to the English letters and models of the original bearings. Most of the plunger pump bearings use high-load capacity bearings. It is best to buy products from the original manufacturer and the original specifications. If you replace another brand, you should consult the bearing experience The personnel look up the table and swap, the purpose is to maintain the accuracy grade and load capacity of the bearing.

The life of the plunger pump is related to the usual maintenance, the quantity and quality of hydraulic oil, and the cleanliness of the oil. Avoiding particles in the oil from causing wear on the friction pairs of the plunger pump is also an effective way to extend the life of the plunger pump. Replacement parts in repair should try to use original factory parts. These parts are sometimes more expensive than other counterfeit parts, but the quality and stability are better. If you buy cheap counterfeit parts, it seems to save costs in the short term. However, this has brought hidden dangers and may cause greater harm to the use of plunger pumps.

Flow distribution plate has two types of plane distribution and spherical distribution. The friction pair of spherical flow distribution is repaired by grinding when the scratches on the cylinder flow surface are relatively shallow; when the grooves on the cylinder flow surface are deep, the grooves should be filled with "surface engineering technology" before grinding. , Do not blindly grind to prevent the copper layer from thinning or oil leaking out of the steel base.