The hottest way to prolong the service life of hyd

2022-08-22
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Methods to prolong the service life of hydraulic piston pump

the efficiency of the hydraulic system mainly depends on the volumetric efficiency of the hydraulic pump. When the volumetric efficiency drops to 72%, it is necessary to carry out routine maintenance, replace the bearings and aging seals, and replace or repair the friction pairs that exceed the matching clearance, so that their performance can be restored

1. Hydraulic pump: straight shaft swashplate piston pump is divided into pressure oil supply type and self suction type. Most of the pressure oil supply hydraulic pumps use oil tanks with air pressure, and some hydraulic pumps have oil replenishment sub pumps to provide pressure oil to the oil inlet of the hydraulic pump. The self sucking hydraulic pump has strong self sucking ability and does not need external oil supply. After starting the machine every time, the hydraulic oil tank supplied by air pressure must wait until the hydraulic oil tank reaches the use air pressure before operating the machine. If the hydraulic oil tank acts as the machine when the air pressure is insufficient, it will pull off the whip in the hydraulic pump and cause abnormal wear of the return plate and pressing plate in the pump. After using the plunger pump supplied by the makeup oil pump for 3000h, the operator needs to check the plunger pump once a day to check whether the hydraulic pump operates normally. If the speed of the hydraulic cylinder decreases or the vehicle is blocked, the makeup oil pump should be disassembled and inspected to check whether there is scratch on the edge of the impeller and whether the clearance of the internal gear pump is too large

2. For self-priming piston pump, the oil in the hydraulic oil tank shall not be lower than the lower limit of the oil standard, and a sufficient amount of hydraulic oil shall be maintained. The higher the cleanliness of the hydraulic oil, the longer the service life of the hydraulic pump

3. Bearing for hydraulic pump the most important component of plunger pump is the bearing. If the bearing has clearance, the normal clearance of the three pairs of friction pairs in the hydraulic pump cannot be guaranteed. At the same time, the hydrostatic support oil film thickness of each friction pair will be damaged and the service life of the plunger pump bearing will be reduced. According to the information provided by the hydraulic pump manufacturer, the average service life of the bearing is 10000h. If it exceeds this value, it needs to be replaced with a new port. The clearance of the removed bearing cannot be detected without professional testing instruments. It can only be visually inspected. If there are scratches or discoloration on the surface of the roller, it must be replaced. When replacing bearings, attention should be paid to the English letters and models of the original bearings. Most plunger pump bearings use bearings with large load capacity. It is best to buy products of the original manufacturer and original specifications. If you replace another brand, you should consult the experienced personnel who adopt electro-hydraulic loading, sensor force measurement, digital display force value, printer print force value data, and automatically convert the compressive strength to check the table for replacement, The purpose is to maintain the accuracy level and load capacity of the bearing

4. Inspection and repair of three pairs of friction pairs: according to the replacement standard of piston pump parts, when the various clearances of parts are out of tolerance, they can be repaired according to the following methods:

(1) if the cylinder body is embedded with a copper sleeve, it can be repaired by replacing the copper sleeve. First, trim the diameter of a group of plunger rods to a unified size, and then polish the outer diameter with more than 1000 # sandpaper. Three methods of adjusting the stiffness sleeve of the lifting angle relaxation punch at the same time are required for the installation of copper in the cylinder: (a) heating and hot assembly of the cylinder or low-temperature freezing and extrusion of the copper sleeve, interference assembly; (b) Adopt loctite adhesive assembly, this method requires that the outer diameter surface of the copper jacket has grooves; (c) Tap the cylinder hole, process the thread on the outer diameter of the copper sleeve, apply loctite, and screw it in for assembly

(2) the repair methods of the cylinder block and the copper sleeve in the fusion firing mode are as follows: (a) use the grinding rod to grind and repair the cylinder hole manually or mechanically; (b) Use coordinate boring machine to re bore the cylinder block hole; (c) Repair the cylinder block hole with reamer

(3) using "surface engineering technology", the methods are as follows: (a) electroplating technology: plating a layer of hard chromium on the surface of the plunger; (b) Brush plating technology: Brush Plating wear-resistant materials on the surface of the plunger; (c) Thermal spraying, arc spraying or electric spraying: spraying high carbon martensite wear-resistant materials; (d) Laser deposition: deposit high hardness wear-resistant alloy powder on the surface of the plunger

(4) the cylinder block material without copper sleeve in the cylinder block hole is mostly nodular cast iron, and amorphous films or coatings are prepared on the inner wall of the cylinder block. Because of this special material on the inner wall of the cylinder block hole, a hard hard friction pair can be formed. If you blindly grind the cylinder block hole and grind off the surface material of the inner wall of the cylinder block hole, the structural performance of the friction will change. If the friction pair with the coating removed is forcibly used, the temperature of the friction surface will rise sharply, and the plunger rod and the cylinder hole will be glued

5. In addition, a unique thin-film coating is prepared on the surface of the plunger rod, which has the functions of wear reduction + wear resistance + lubrication. This group of friction pairs is actually a hard soft pair. Once the coating is changed manually, the friction pair with the best matching material will be destroyed, and these special plunger pumps will be repaired, It will be sent to a professional repair shop

the efficiency of the hydraulic system mainly depends on the volumetric efficiency of the hydraulic pump. When the volumetric efficiency drops to 72%, it is necessary to carry out routine maintenance, replace the bearings and aging seals, and replace or repair the friction pairs that exceed the matching clearance, so that their performance can be restored

1. Hydraulic pump: straight shaft swashplate piston pump is divided into pressure oil supply type and self suction type. Most of the pressure oil supply hydraulic pumps use oil tanks with air pressure, and some hydraulic pumps have oil replenishment sub pumps to provide pressure oil to the oil inlet of the hydraulic pump. The self sucking hydraulic pump has strong self sucking ability and does not need external oil supply. After starting the machine every time, the hydraulic oil tank supplied by air pressure must wait until the hydraulic oil tank reaches the use air pressure before operating the machine. If the hydraulic oil tank acts as the machine when the air pressure is insufficient, it will pull off the whip in the hydraulic pump and cause abnormal wear of the return plate and pressing plate in the pump. After using the plunger pump supplied by the makeup oil pump for 3000h, the operator needs to check the plunger pump once a day to check whether the hydraulic pump operates normally. If the speed of the hydraulic cylinder decreases or the vehicle is blocked, the makeup oil pump should be disassembled and inspected to check whether there is scratch on the edge of the impeller and whether the clearance of the internal gear pump is too large

2. For self-priming piston pump, the oil in the hydraulic oil tank shall not be lower than (1) the lower limit of the oil standard, and a sufficient amount of hydraulic oil shall be maintained. The higher the cleanliness of the hydraulic oil, the longer the service life of the hydraulic pump

3. Bearing for hydraulic pump the most important component of plunger pump is the bearing. If the bearing has clearance, the normal clearance of the three pairs of friction pairs in the hydraulic pump cannot be guaranteed. At the same time, the hydrostatic support oil film thickness of each friction pair will be damaged and the service life of the plunger pump bearing will be reduced. According to the information provided by the hydraulic pump manufacturer, the average service life of the bearing is 10000h. If it exceeds this value, it needs to be replaced with a new port. The clearance of the removed bearing cannot be detected without professional testing instruments. It can only be visually inspected. If there are scratches or discoloration on the surface of the roller, it must be replaced. When replacing bearings, attention should be paid to the English letters and models of the original bearings. Most plunger pump bearings use bearings with large load capacity. It is best to buy products of the original manufacturer and original specifications. If you replace another brand, you should consult the personnel with experience in bearings to check the table and exchange, in order to maintain the accuracy grade and load capacity of the bearings

4. Inspection and repair of three pairs of friction pairs: according to the replacement standard of piston pump parts, when the various clearances of parts are out of tolerance, they can be repaired according to the following methods:

(1) if the cylinder body is embedded with a copper sleeve, it can be repaired by replacing the copper sleeve. First, trim the diameter of a group of plunger rods to a unified size, and then polish the outer diameter with more than 1000 # sandpaper. There are three methods to install the copper sleeve on the cylinder block: (a) heating and hot assembly of the cylinder block or low-temperature freezing and extrusion of the copper sleeve, interference assembly; (5) according to whether the sample has prefabricated cracks, it can be divided into: routine fatigue test and fatigue crack expansion test B) loctite adhesive assembly is adopted, which requires that there are grooves on the outer diameter surface of the copper jacket; (c) Tap the cylinder hole, process the thread on the outer diameter of the copper sleeve, apply loctite, and screw it in for assembly

(2) the repair methods of the cylinder block and the copper sleeve in the fusion firing mode are as follows: (a) use the grinding rod to grind and repair the cylinder hole manually or mechanically; (b) Use coordinate boring machine to re bore the cylinder block hole; (c) Repair the cylinder block hole with reamer

(3) using "surface engineering technology", the methods are as follows: (a) electroplating technology: plating a layer of hard chromium on the surface of the plunger; (b) Brush plating technology: Brush Plating wear-resistant materials on the surface of the plunger; (c) Thermal spraying, arc spraying or electric spraying: spraying high carbon martensite wear-resistant materials; (d) Laser deposition: deposit high hardness wear-resistant alloy powder on the surface of the plunger

(4) the cylinder block material without copper sleeve in the cylinder block hole is mostly nodular cast iron, and amorphous films or coatings are prepared on the inner wall of the cylinder block. Because of this special material on the inner wall of the cylinder block hole, a hard hard friction pair can be formed. If you blindly grind the cylinder block hole and grind off the surface material of the inner wall of the cylinder block hole, the structural performance of the friction will change. If the friction pair with the coating removed is forcibly used, the temperature of the friction surface will rise sharply, and the plunger rod and the cylinder hole will be glued

5. In addition, a unique thin-film coating is prepared on the surface of the plunger rod, which has the functions of wear reduction + wear resistance + lubrication. This group of friction pairs is actually a hard soft pair. Once the coating is changed manually, the friction pair with the best matching material will be destroyed, and these special plunger pumps will be repaired, It will be sent to a professional repair shop

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