Addtime： 2020-07-18 Browse times： 1973
Vacuum pump is a kind of rotary variable volume vacuum pump, which can only be used with the cooperation of the front stage pump. It has a large pumping speed in a wide pressure range, and is insensitive to dust and steam in the extracted gas. It is widely used in metallurgy, chemical industry, food, electronic coating and other industries. Today, I'd like to share with you the most comprehensive maintenance method of piston vacuum pump. I'm sure it can be used in the future. Please collect it quickly!
1、 What are the intact standards of piston vacuum pump?
(1) The machine body is clean, the parts are complete, and the quality meets the requirements.
(2) Vacuum meter, ammeter and other instruments are complete, sensitive and accurate, and have regular inspection marks.
(3) The foundation is stable and reliable, the anchor bolts and bolts of each part are connected tightly and neatly, and the exposed length of screw thread meets the requirements.
(4) The installation of pipelines and valves is reasonable, and the marks are clear and meet the requirements.
(5) The installation clearance of each component shall meet the specified requirements.
2、 What are the performance requirements of piston vacuum pump?
(1) The lubrication of the equipment is good, and the oil quality meets the requirements;
The equipment runs smoothly without noise, and its vibration and noise shall not exceed relevant regulations;
When the equipment is running under load, the temperature, pressure, flow, current and other parameters shall meet the requirements.
3、 What are the intact standards for the technical data of piston vacuum pump?
1. The equipment files are complete and the data are accurate and reliable.
2. The maintenance and acceptance records of the equipment are accurate.
3. The equipment resume card is complete.
4. The accident record of the equipment is complete.
5. The equipment operation records are complete.
5. The operation and maintenance procedures are complete.
6. The drawing of vulnerable parts of the equipment is complete.
7. There are general assembly drawings or structural drawings of the equipment.
4、 What are the requirements of piston vacuum pump equipment and environment?
1. The pump body is clean and free of dust and oil dirt.
2. There is no water, waste liquid and other sundries on and around the foundation base surface.
3. There shall be no leakage at the joints of valves and pipe fittings.
4. The leakage at the packing seal shall not exceed the specified value.
5、 How to do well in daily maintenance of piston vacuum pump?
1. The environment around the equipment should be kept clean, dry and well ventilated. Check whether the cooling water circuit is unblocked.
2. Check whether the lubricating oil of each lubricating part meets the requirements.
3. Each shift must check each part of the fastening bolts, there is no loosening phenomenon, often check whether the liquid level in the vacuum tank is normal and effective, and make necessary tightening
4. Check whether the readings of vacuum meter and ammeter are normal at any time. Pay attention to observe whether there is abnormal sound or vibration at any time,
5. If necessary, report the status to relevant departments.
6. Operators must operate in strict accordance with the "operating procedures" and timely handle problems found in patrol inspection.
6、 What is the cause of motor overload of piston vacuum pump? What are the treatment methods?
The reasons are as follows:
1. The eccentric clearance is too small.
2. The connecting rod bush is burnt out.
3. Poor exhaust.
The treatment methods are as follows:
1. Adjust the eccentric ring clearance.
2. Repair or replace connecting rod bush.
3. Check and dredge the exhaust valve.
7、 What is the reason for the impact sound in the operation of piston vacuum pump? What are the treatment methods?
The reasons are as follows:
(1) The piston rod nut is loose.
(2) The connecting rod bushing and crosshead pin are worn.
(3) The clearance of connecting rod ring bearing bush is too large.
(4) The eccentric ring is worn.
(5) There are foreign matters in the cylinder.
The treatment methods are as follows:
(l) Tighten the piston rod nut.
(2) Repair and replace connecting rod bushing and crosshead.
(3) Regrind or replace connecting rod bearing bush.
(4) Adjust the gasket.
(5) Clean the impurities in the cylinder.
8、 Under what circumstances does the piston vacuum pump stop in emergency?
In case of any of the following circumstances, stop the vehicle immediately
(1) Abnormal vibration and sound appear.
(2) When the current of the ammeter exceeds the rated value and does not drop continuously.
(3) When liquid materials enter the pump body or there is danger of entering the pump body.
(4) When it is found that the cooling water is cut off.
9、 What is the minor repair content of piston vacuum pump?
(l) Check and tighten the bolts of each part.
(2) Clean the dirt on cylinder water jacket and valve chamber.
(3) Check and replace piston rod packing, air valve rod packing, valve plate and spring, and adjust the position of air valve.
(4) Adjust the clearance between eccentric ring and eccentric wheel, connecting rod bush and crank neck.
(5) Check the piston, tighten the nut, and adjust the clearance of the front and rear dead center of the piston.
10、 What is the content of piston vacuum pump intermediate repair?
(1) Including minor repairs.
(2) Check, repair and replace crosshead pin and connecting rod bushing.
(3) Check and replace the valve rod, neck bushing, neck pin and valve seat.
(4) Check and replace piston ring and piston rod.
(5) Measure and adjust the clearance of each part.
(6) Repair the motor.
11、 What is the overhaul content of piston vacuum pump?
Including the contents of medium maintenance
(2) Disassembly inspection, measurement of cylinder wear, repair or replacement.
(3) Repair or replace eccentric wheel and eccentric ring.
(4) Repair or replace crankshaft and connecting rod.
(5) Check, repair or replace crosshead, piston and piston rod.
12、 What are the maintenance quality standards of piston vacuum pump cylinder?
Measure the roundness and cylindricity of cylinder, and determine the roundness and cylindricity of boring cylinder or replacing cylinder according to its wear degree, which shall meet the specified requirements. The inner surface of the cylinder shall be free of cracks, sand holes, scars, grooves and other defects. After boring, the diameter of the cylinder shall not increase by more than 2% of the original size, the wall thinning shall not exceed 1 / 12 of the original wall thickness, and the water jacket of the cylinder shall not have cracks or leakage.
13、 What are the maintenance standards for crankshaft of piston vacuum pump?
(1) Measure the wear degree of crankshaft main journal and crank neck to determine whether to repair or replace. The main journal can be repaired by metal brush plating or spraying.
(2) The wear value of main journal and crankshaft journal shall meet the requirements of Table 1 to table 5.
(3) The maximum reduction of the crankshaft journal shall not exceed 3 lines of the original diameter.
(4) For the scuffing between the crankshaft main journal and the crank neck, the dent area shall not be greater than 2% of the journal area, and the groove depth shall be up to. When it is 10 mm, it should be ground and repaired.
(5) The crankshaft should be replaced if cracks are found in NDT or magnifying glass inspection.
(6) The parallelism of crankshaft axis to crankshaft reference axis is 0.20-0.30mm
(7) The straightness of crankshaft is 0.05mm
14、 What are the maintenance standards for bearing bush of piston vacuum pump?
The bearing alloy should fit well and firmly with the shell, and there should be no cracks, pores, delamination and other defects
The contact area between the bearing shell back and the bearing seat shall not be less than 40% - 50%, and no gasket shall be placed between them
The bearing bush and the journal shall be in point uniform contact, the contact angle shall be 60% - 90%, and the contact point shall not be less than 2-3 points per square centimeter
The radial clearance between bearing bush and journal should be one thousandth of journal diameter
15、 What are the maintenance standards for piston and piston ring of piston vacuum pump?
(l) The surface of piston and piston ring should be smooth without crack, sand hole, scar and other defects.
(2) The installation clearance and relative allowable wear value of piston and cylinder are specified in.
(3) The piston ring shall have enough elastic force, and the total length of the contact surface with the cylinder wall shall not be less than 60% of the circumference.
(4) The piston rings should be staggered with each other in the grooves of 1200.
(5) The clearance of the piston ring in the cylinder, the side clearance in the ring groove and the maximum wear value.
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