JPH02558B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an oil supply device for a compressor, particularly a refrigerant compressor.

Conventional configurations and their problems Most open horizontal rolling piston type rotary refrigerant compressors that have an internal shaft sealing device are used as oil supply devices from the viewpoint of sealing performance of the shaft sealing device and miniaturization of the refrigerant compressor. Oil is often supplied using the pressure difference between the oil sump, which communicates with the discharge side pressure, and the suction side. In refrigerant compressors equipped with this type of differential pressure oil supply system, lubricating oil in the oil sump continues to flow into the suction side even after operation is stopped until the pressure difference between the discharge side and suction side inside the compressor disappears. . For this reason, lubricating oil in the oil reservoir flows into the cylinder on the suction side when the refrigerant compressor is stopped, causing oil compression when the refrigerant compressor is restarted, causing damage to the refrigerant compressor. Also, when the refrigerant compressor is stopped, the lubricating oil in the oil sump decreases, so
When restarting the refrigerant compressor, differential pressure lubrication is no longer possible.
It also causes seizure of various parts of the sliding surfaces. Furthermore, there are drawbacks such as an increase in lubricating oil mixed into the refrigerant when the refrigerant compressor restarts compression, and an increase in the amount of circulating oil to the refrigeration cycle, resulting in a decrease in heat exchange performance. In addition, in order to improve this drawback, some systems have installed a solenoid valve device in the oil supply passage to stop differential pressure oil supply when the refrigerant compressor is stopped, but this method has the disadvantage of a complicated structure and high cost. It was hot.

OBJECTS OF THE INVENTION In view of the above-mentioned conventional drawbacks, an object of the present invention is to use a simple structure to prevent lubricating oil in an oil sump from flowing into the suction side after a refrigerant compressor is stopped.

Composition of the Invention In order to achieve this object, the present invention provides a suction valve that opens the passage only when the differential pressure is above a certain level and does not allow reverse flow, in the middle of the passage on the downstream side of the sliding surface of the shaft of the differential pressure oil supply passage. When the refrigerant compressor is in operation, the suction valve device opens due to the differential pressure generated in the differential pressure oil supply passage, and lubricating oil flows into the suction side. Immediately after the compressor stops, the suction valve device closes the differential pressure oil supply passage due to the instantaneous reverse flow of the fluid in the compression chamber, preventing lubricant oil from flowing out in the differential pressure oil supply passage, and after the compressor stops, the pressure balance of the refrigeration cycle is maintained. To provide a rotary refrigerant compressor in which the pressure difference is reduced, the suction valve device is closed, and the inflow of lubricating oil is blocked.

DESCRIPTION OF EMBODIMENTS An embodiment in which the present invention is applied to an open horizontal rolling piston type rotary refrigerant compressor will be described below with reference to the drawings. 1 is the cylinder block,
A first side plate 2 and a second side plate 3 are arranged on both sides thereof. A needle bearing 4 and a thrust bearing 5 are mounted on the second side plate 3, and an oil case 7 having an oil suction passage 6 on its end face and whose lower end penetrates into an oil reservoir 8 is arranged. Further, a needle bearing 9 is attached to the first side plate 2. A piston 12 is loosely fitted into the eccentric shaft 10 supported by the needle bearings 4 and 9 within the cylinder interior space 11, and reciprocates in a vane groove (not shown) of the cylinder block 1. A partition vane (not shown) is connected to this piston 1.
2, and is biased by a spring (not shown) so as to be in constant contact with 2. In addition, the first side plate 2
A front plate 14 is attached to the front plate 14, and the inside of the front plate 14 is on the discharge pressure side.
An outer cylinder 15 whose bottom becomes the oil reservoir 8 is fixed by welding. A discharge valve device (not shown) is attached to the first side plate 2, and the outer cylinder 1 is supplied through a discharge gas passage 13 provided in the front plate 14.
It communicates within 5. Also, the front plate 14
A shaft sealing device 16 is attached to the power drive side end of the shaft. A minute gap 18 serving as a lubricating oil passage is provided between the first side plate 2 and the end surface of the eccentric portion of the eccentric shaft 10. 19 is a lubricating oil passage formed in the shaft portion of the eccentric shaft 10;
20 is a lubricating oil passage formed in the eccentric portion 17. 21 is a device space of the shaft sealing device 16 formed in the front plate 14;
A discharge chamber 22 formed between the first side plate and the first side plate is sealed with an O-ring 23.
On the other hand, the suction side passage 24 to the mounting space 21 and the cylinder inner space 11 includes a passage 25 provided in the front plate 14, a passage 20 provided in the first side plate 2, and a passage provided in the cylinder block 1. 27, and the throttle passage 26 is
It is closed by a suction valve device 28 attached to the first side plate 2 and constantly biased in a direction to close the end of the throttle passage 26.

In the above configuration, after the refrigerant compressor starts operating,
When the discharge pressure in the outer cylinder 15 increases and the suction pressure in the cylinder inner space 11 decreases, a refrigerant gas pressure difference occurs between the oil sump 8 and the suction side passage 24, and the oil sump 8
The lubricating oil is applied to the oil suction passage 6, the passage 19, the gap between the needle bearing 4, the thrust bearing 5,
Passage 20, first side plate 2 and eccentric part 17
It flows into the cylinder interior space 11 through the minute gap 18 between the needle bearing 9, the mounting space 21, the passage 25, the throttle passage 26, and the passage 27. At this time, the supplied lubricating oil is depressurized each time it passes through the minute gap 18 and the throttle passage 26, so that the pressure in the installation space 21 of the shaft sealing device 16 becomes an intermediate pressure between the discharge pressure and the suction pressure, and the pressure in the passage 27 decreases. , the pressure is very close to the suction pressure and slightly higher than the suction pressure. During operation, the suction valve device is opened by the differential pressure between the outlet pressure of the throttle passage 26 and the pressure of the suction side passage 24. Immediately after the refrigerant compressor stops, the refrigerant flows backward from the high pressure side to the low pressure side in the cylinder, and the eccentric shaft 10 also reverses accordingly, and the suction valve device 28 performs differential pressure lubrication due to the biasing force of the refrigerant gas reverse flow. The passage is closed to prevent lubricating oil in the differential pressure oil supply passage from flowing into the oil sump 8 due to refrigerant gas backflow. Further, after the refrigerant compressor stops operating, as refrigerant gas flows into the cylinder interior space 11 from the evaporator side of the refrigeration cycle, the throttle passage 26
As the pressure difference between the outlet and the suction side passage becomes smaller, the throttle passage 26 is closed by the suction valve device 28.

In the above embodiment, an open horizontal rolling piston type rotary compressor has been described, but the present invention can be similarly applied to other rotary compressors such as a slide vane type rotary compressor.

Effects of the Invention As is clear from the above description, the refrigerant compressor of the present invention includes a cylinder block surrounded by an outer cylinder, a first side plate and a second side plate disposed on both sides of the cylinder block. A sealed internal space of the cylinder is formed by the side plate of
A piston member is disposed in the inner space of the cylinder, and the piston member is driven by a shaft supported by the side plates to suck suction refrigerant gas containing lubricating oil through the suction side passage into the cylinder, In a refrigerant compressor configured to discharge into a discharge chamber after compression, an oil sump in the lower part of the outer cylinder is communicated with the discharge chamber, an oil suction passage whose one end penetrates into the oil sump, and a sliding portion of the shaft. A lubricating oil passage passing through the surface, and a communication passage that communicates the lubricating oil passage and the suction side passage are sequentially connected to constitute a differential pressure oil supply passage having a throttle passage, and a constant pressure is provided in the middle of the communication passage. The passage is opened only when the differential pressure is higher than the
It is characterized in that a suction valve device is provided that allows passage only from the communication passage to the suction side passage, and the suction valve device is provided in the middle of the differential pressure oil supply passage from the oil reservoir to the suction side passage. During operation, the valve can be opened continuously due to the pressure difference between the pressure on the upper (discharge) side of the passage and the pressure on the lower (suction) side of the passage, allowing lubricating oil from the oil sump to be supplied to each sliding part, and the compressor can be stopped. Immediately after, the refrigerant flows backward from the high-pressure side to the low-pressure side in the cylinder, and the suction valve device closes the differential pressure oil supply passage due to the back pressure biasing force generated during the reverse flow, allowing differential pressure oil supply due to the refrigerant gas reverse flow. The movement of the lubricating oil in the passage prevents the lubricating oil on the shaft sliding surface from running out, thereby preventing the sliding portion from seizing when the compressor is restarted. Thereafter, the suction side pressure is increased by the refrigerant gas flowing from the evaporator side of the refrigeration cycle, so that the suction valve device is closed, and it is possible to prevent lubricating oil from flowing into the suction side passage. Therefore, by using a simple configuration of the differential pressure oil supply passage having a throttle passage, it is possible to appropriately adjust the amount of lubricating oil flowing into the cylinder interior space from the oil sump while the refrigerant compressor is in operation, and also to stop unnecessary oil supply when the refrigerant compressor is stopped. This reduces oil compression and power loss during restart, improving durability and compression efficiency. In addition, when the refrigerant compressor is stopped, the suction valve device retains the lubricating oil that flows into the upstream oil supply passage due to the differential pressure, so when the refrigerant compressor is restarted, each sliding part rotates and slides smoothly. It has excellent durability when restarting the compressor, such as eliminating the seizure phenomenon.

[Brief explanation of drawings]

The figure is a longitudinal sectional view of an embodiment in which the present invention is applied to an open horizontal rolling piston type rotary compressor. 1... Cylinder block, 2... First side plate, 3... Second side plate, 7...
Oil case, 8...Oil sump, 10...Eccentric shaft, 11...Cylinder inner space, 12...Piston, 14...Front plate, 15...Outer cylinder,
16...Shaft sealing device, 18...Minute gap, 19,2
0, 25, 27... passage, 22... discharge chamber, 24
...Suction side passage, 26... Throttle passage, 28... Suction valve device.

Claims (1)

[Claims] 1. A cylinder block surrounded by an outer cylinder, and a first side plate and a second side plate disposed on both sides of this cylinder block form a sealed cylinder inner space, and this cylinder inner space is A piston member is provided, and the piston member is driven by a shaft supported by both side plates to suck suction refrigerant gas containing lubricating oil into the cylinder via the suction side passage, and after compression, it is transferred to the discharge chamber. In a refrigerant compressor configured to discharge refrigerant, an oil sump in the lower part of the outer cylinder is communicated with the discharge chamber, and lubrication is provided through an oil suction passage whose one end penetrates into the oil sump and a sliding surface of the shaft. An oil passage, a communication passage that communicates the lubricating oil passage and the suction side passage are sequentially connected to form a differential pressure oil supply passage having a throttle passage, and in the middle of the communication passage,
A refrigerant compressor provided with a suction valve device that opens the passage only when the pressure difference is above a certain level and allows passage only from the communication passage to the suction side passage.