1, piston freezer
Piston freezer require lubrication friction parts: the piston and the cylinder wall; connecting rod bearing and crank pin; rod small end bearing and piston pin; piston pin and piston pin seat; slide back and forth bearing bush spindle neck as well as the spindle shaft seal static and dynamic friction sealing surface.
The most simple means of lubrication is a splash lubrication in a small low-speed in the freezer, i.e., in the refrigerating machine of the crankcase, the oil surface of the rotary agitator of the connecting rod by means of the crankshaft, lubricating oil flung friction surface so that lubrication, but difficult to achieve some friction surface of lubricating oil, the lubrication is not sufficient, easy to cause large friction and wear, and therefore such lubrication poor reliability, has been rarely used alone.
Compulsory circulation lubrication is mostly used in the freezer, the old and new series, namely the use of pump forcing oil transported to the lubrication points. Lubrication of the piston-type refrigerating machine is mostly within the transmission system, i.e. the lubrication system does not set up a separate oil tank and the pump station, instead of using refrigerating machine crankcase doubles as a lubricating oil tank, connected to one end of a dedicated lubrication pump crankshaft, lubrication means and frozen bodies into a whole.
Pump 0.28-0.154mm mesh strainer Suction from the crankcase through the holes, and then by a filtration accuracy of 10-20μm, fine paper or powder metallurgy oil filter of the refrigerating machine oil is pressed out of the way lubricating oil is sent to the front end of the crankshaft, lubricate the shaft seal, front main bearing, crank pin and rod small end, another way to pressure oil into the rear end of the crankshaft, the bearing lubrication emperor, crank pin and rod small end, in addition to the the pressure oil is also supplied to the oil distribution valve for controlling the energy regulator structure. Lubrication system should be with the essential element of the pressure gauge, pressure regulator, the regulator for regulating the pressure of the lubricant and allows the excess the lubricant flow back into the crankcase. The cylinder surface in the system is the use of the connecting rod small end the extruded oil thrown off by the oil and the connecting rod to achieve lubrication of the friction surfaces.
Lubrication pumps are usually used in the freezer outer meshing gear type oil pump, internal gear gear-type oil pump (commonly known as the crescent pump) and cycloid rotor pump (commonly known as the Plum pump) 3. For external gear pump suction pressure port location is determined, the direction of rotation of the pump is certain, irreversible, fully enclosed and semi-enclosed freezer, due to the chassis and motor of the freezer cabinet fused from external difficult to discern steering pump, easily lead to error by the steering gear pump lubrication failure, external gear pump it is rarely used in the freezer. Inward gear pump, crescent body (separate suction, pressure oil chamber, to ensure that the internal and external gears top sealing member) can be made with the automatic positioning of the structure, regardless of the direction of rotation of the gear does not change suction, pressure oil port position, it is turning on the pump unlimited, so widely used in the new series of enclosed and semi-enclosed freezer. Cycloid rotor pump and inner gear pump is similar to the direction of rotation of the pump can also be done unlimited addition cycloid rotor pump toothed simple, easy processing, compact structure, has a broad application prospects in the freezer.
2, screw chillers
Lubricating parts of the screw-type refrigerating machine: the rotation of the engagement portion serrated screw (aka yin rotor); the relative sliding surfaces of the rotating screw and the shell; screw around a sliding bearing; the active screw of the balance piston and the axial end of the mechanical seal friction surface. Open ports communicating with the pressure of the oil in the lubricating parts. In the energy adjusting the size of the opening in the valve or the housing hole spaced lubricating pressure oil can be injected directly into the rotor, to cooling and lubrication of the rotor and the casing, but also to seal the gap of the moving parts, is compressed in order to reduce the leakage of the gas, and reducing the running noise.
Regulator adjustable oil pressure is usually higher than the condensing pressure 0.2-0.3MPa, the amount of lubricating oil equivalent to 1% -2% of the gas transmission capacity of the freezer. The lubrication pump can be directly driven by the rotor itself can also be made outside the transmission type. Usually the oil separator to the tank of the lubrication system. Wider application of centrifugal - gravity type and filler - a gravity-type oil separator. In addition, in the screw-type refrigerating machine also use more secondary oil separator, two oil separator the separated lubricating oil can be used for suction, and the exhaust pressure difference without a pump is pressed directly sent to the suction chamber on the bearing, balance piston etc. lubrication. The column tube type oil coolers are commonly used in the lubrication system, the oil temperature was maintained at 20-50 ° C, the cooling medium may be water or a refrigerant of the refrigerating machine itself to evaporative cooling lubricants. Fine filter lubrication system pressure drop should not exceed 0.1MPa, otherwise clean or replace the filter.
3, centrifugal chillers
The main lubricating parts of the centrifugal chiller is an overdrive gear, the mechanical seal of the main bearing and the shaft end. Gearbox usually cater to the lubricating oil tank, which can be equipped with an electric heater preheating of lubricants, oil pump for pumping the oil to a dedicated high fuel tank, lubricating oil lead to the desired parts by high fuel tank the ways to prevent a sudden failure of the fuel supply system or freezer to a sudden power failure shut down the oil pump oil supply while the freezer remains running by inertia to continue high-speed rotary friction lubrication equipment parts "burn" or "bite" accident.
4, the refrigerating machine oil
Also made some specific requirements in view of the special nature of the work in the freezer, lubricant medium, developed a dedicated freezer lubricants. In the selection of lubricants should be in accordance with the type of the refrigerating machine, the type of refrigerant used and the evaporation temperature, and the refrigerating machine specific working conditions (such as the level of speed, load size, work environment, etc.) to be a comprehensive analysis and comparison, in order to determine the frozen engine oil specifications or grades. Optional two-cylinder piston-type refrigerating machine for small low-speed (average linear velocity is less than 2m / s) No. N15 or N22, refrigerating machine oil, the large, medium, high-speed (average speed greater than 3m / s) can be selected a multicylinder piston type refrigerating machine N32 or N46 of the refrigerating machine oil, the exhaust gas temperature is high, the load weight, the harsh use conditions, particularly the piston-type refrigerating machine can be used refrigerating machine oil of the N68; N32, N46 refrigerating machine oil injector lubricated screw-type refrigerating machine can be used; small dry (non-injection lubrication) screw chillers and centrifugal chillers, due to the lubricating oil from time to contact with the refrigerant, according to the load of the gearbox and main bearing selection N32 or N46 frozen oil can also be used viscosity extremely equivalent of L-TSA32 or of L-TSA46 the gasoline engine oil.