What are the specific operation methods for maintenance of screw compressors in cold storage

What are the specific operation methods for maintenance of screw compressors in cold storage 1. Disassembly method of cold storage screw compressor

　　 Before the cold storage screw compressor must be overhauled, if possible, unload the slide valve to the "0" position, shut down normally, and cut off the power supply. Cut off the pipeline connected to the compressor and discharge the refrigerant and lubricating oil in the compressor before disassembling the compressor. Pay attention to develop a good habit when disassembling, place the parts of different parts separately, and make the necessary assembly marks.

　　 1. After removing the pipes, couplings and anchor bolts connected to the compressor, lift the compressor to the workplace. There is an operating platform.

　　2. Remove the suction filter and suction check valve.

　　 3. Remove the energy indicator.

　　4. Take off the positioning pin, take off the suction end cap in parallel, and take out the oil piston and balance piston. Note that the positioning pin can only be pulled out, but not smashed out. Be sure to remove the positioning pin first, and then remove all bolts to prevent the weight of the suction end cover from all acting on the positioning pin and bend the positioning pin.

　　 5. Remove the shaft seal cover and take out the shaft seal. Be careful not to damage the moving and static rings.

　　 6. Take off the positioning pin and remove the exhaust end cover.

　　7. Remove the bearing gland, locknut, gasket, thrust bearing, adjustment pad, etc. To remove the locknut, use the special tools provided and first open the lock plate of the lock washer. Mark them at any time and place them separately.

　　 8. After taking out the positioning pin, remove the exhaust end seat.

　　9. Take out the active rotor slowly and steadily with special eye bolts, and do not collide with the body. At this time, the driven rotor rotates accordingly.

　　 10. Take out the driven rotor.

　　11. Take out the slide valve.

　　 2. Inspection items of screw compressors in cold storage

　　 1. Check the body surface and slide valve surface for abnormal wear marks, and measure the inner surface size and roundness with an inner diameter dial gauge.

　　2. Check the end faces of the main and driven rotors and the suction and exhaust end seats for wear marks.

　　3. Check the outer diameter of the main and driven rotors and the wear of the tooth surface, and measure the outer diameter of the rotor with an outer diameter dial gauge.

　　4. Measure the diameter of the rotor spindle and the inner diameter of the main bearing hole, and check the wear of the main bearing.

　　 5. Check the wear of the shaft seal.

　　 6. Check the deformation and damage of all "o" rings and springs.

　　 7. Check all the internal oil circuits of the compressor.

　　 8. Check whether the energy indicator is damaged or jammed.

　　 9. Check the oil piston and balance piston for abnormal wear.

　　10. Check whether the transmission core or diaphragm of the coupling is damaged.

　　 Three, the repair method of cold storage screw compressor

　　 After inspection, repair or replace damaged parts. The details are as follows:

　　 1. For less serious wear and fuzzing, it can be smoothed by a fitter with oilstone. The surface of the rotor journal and the static and dynamic rings of the shaft seal shall not have any defects such as corrosion or cracks. After the surface of the main journal is polished, its dimensions should be carefully measured, and the main bearing should be adjusted based on this.

　　2. If the main bearing is severely worn and exceeds the clearance limit for the shaft, it should be replaced. If the bearing alloy is cast, the coaxiality of the inner surface and the bearing hole must be ensured.

　　 3. If the thrust bearing is damaged or the clearance increases, it must be replaced with a new one. And the size of the vacuum clearance should be measured, and the bearing adjustment pad should be equipped on this basis.

　　 4. All gaskets and "O" rings must be replaced if they are damaged. The gasket can be processed by yourself, but be careful not to break or crack near the bolt hole to avoid leakage. The gasket should be made of high-quality materials. The "O" ring should be made of materials suitable for the refrigerant.

　　 5. Clean the sealant on both ends of the body and the flat surface of the suction and exhaust end seat. Be careful not to scratch the surface.

　　 Fourth, the assembly rules of the cold storage screw compressor

　　After inspecting each part, repairing or replacing the damaged part, assembly work can be carried out. When assembling, pay attention to the marks written down during disassembly, and don't confuse the parts. When assembling, it is necessary to measure the assembly gap of each part at any time, and adjust the gap or replace the parts for the parts where the gap exceeds the standard. Assembly clearance see clearance table

　　 1. Clean all parts and dry them with compressed air.

　　2. Prepare all the tools needed and clean them.

　　3. Put the main bearing into the bearing hole in the original position, and measure the inner diameter of the bearing to make the inner diameter meet the clearance requirement of the rotor journal.

　　4. Apply sealant evenly on the bonding surface of the suction end seat and the body.

　　5. Place the suction end seat against the suction end of the body, and string in some bolts to bear the weight. After pressing in the positioning pin, tighten the bolt.

　　6. ​​Install the slide valve and its guide pallet. The guide pallet can be fixed with bolts after it is positioned by positioning pins.

　　7. Apply clean lubricating oil of the same type as the one used during operation on the main bearing hole of the suction end and the inner hole of the machine, and install the male rotor and the female rotor. The rear-mounted rotor should be screwed in slowly, and not forced into the body.

　　 8. Place the female and male rotors against the suction end seat, and measure the size difference between the exhaust end surface of the rotor and the exhaust end surface of the body. This value is the sum of the suction and exhaust gaps.

　　 9. Apply sealant evenly on the bonding surface of the exhaust end seat and the body.

　　 10. Place the exhaust end seat against the discharge end of the body, press in the positioning pin, and tighten the bolt. Pay attention to the inner hole of the main bearing when installing the exhaust end block, and do not damage the main bearing.

　　11. Install the adjusting washer and thrust bearing, and fix the inner spacer of the thrust bearing on the journal of the rotor with a round nut and lock washer. Thrust bearings are installed in pairs and pay attention to the installation direction.

　　12. Install the rotor bearing gland and press the outer spacer of the thrust bearing on the body. Remove the connecting bolts between the exhaust end seat and the body, drag the exhaust end seat together with the rotor, and measure the gap between the exhaust end face of the rotor and the exhaust end seat. This gap is the exhaust end gap. If the gap is unreasonable, the thickness of the adjustment pad should be changed. After adjusting the clearance at the exhaust end, assemble. After installation, move the active rotor according to the actual operation of the steering wheel, and the rotation should be flexible without jamming.

　　13. Install the positioning pin on the exhaust end cover, add gaskets and fix it with bolts.

　　 14. Install the shaft seal moving ring, and apply refrigerant oil on the surface of the moving ring and the rubber ring.

　　 15. Put the static ring into the shaft seal gland, add gaskets and fix it on the exhaust end seat with bolts. Adjust the pre-tightening force of the shaft seal spring through the thickness of the gasket. The surface of the stationary ring and the stationary ring apron are also coated with refrigerant oil.

　　 16. Install oil piston and balance piston. Apply refrigerant oil when assembling.

　　17. Install the positioning pin on the suction end seat, add gaskets and fix it with bolts.

　　 18. Install an energy indicator, pay attention to the pointer corresponding to the position of the slide valve.

　　19. Install the overhauled suction filter and check valve on the suction end seat. Transport the installed compressor to the unit. After finding the coaxiality, fix the compressor and the motor, and connect them with a coupling.