JPS5834678B2 - Lubrication system for vane type rotary compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lubricating system for a vane-type rotary compressor in which the number of revolutions used changes over a wide range, such as in an automobile air conditioner. One of the purposes is to stop oil supply to sliding friction points and prevent damage to the compressor due to compression of lubricating oil when restarting.

The compressor oil supply system in conventional automobile air conditioners is
(1) Lubrication by a pump from the oil storage chamber on the low pressure side, (2) Oil supply by the pump from the oil storage chamber on the discharge high pressure side, and (2) Through an oil passage that communicates the oil storage chamber on the high pressure side with the low pressure side or the intermediate pressure side between high pressure and low pressure. There are oil supply systems that utilize differential pressure based on the refrigerant pressure difference that exists in this oil path.

However, in the above-mentioned example and the example in item 0, not only an expensive pump is required, but also troubles related to the pump occur, impairing the original function of the ° compressor.

In addition, in the example in item (1) above, the energy for oil supply is made use of the discharge pressure of the compressor applied to the supply oil on the high pressure side, so the rotation range of the compressor is wide (approximately 500 to 650
0 R, P, M), the amount of oil supplied is unrelated to the rotation speed.

In other words, if the oil supply path is sufficient during high-speed rotation, over-lubrication occurs during low-speed rotation, and the excess oil enters the refrigerant and increases the amount of oil contained in the refrigerant, which reduces the amount of refrigerant discharged and reduces the efficiency of the compressor. decreases.

On the other hand, if the oil passages are set so that the required amount of oil can be supplied during low-speed rotation, there will be a shortage of lubricating oil during high-speed rotation, causing accidents such as abnormal wear and seizure.

Furthermore, as shown in Japanese Patent Publication No. 50-86281, a technique is known that automatically controls the amount of lubricating oil supplied according to the load condition or rotational speed fluctuation of the compressor.
In such a structure, when the compressor stops, the lubricating oil is pressed by high residual pressure and accumulates in the compression space, causing oil compression when restarted, causing damage to the compressor, so some kind of countermeasure is desired. .

The present invention eliminates the drawbacks of the above-mentioned conventional examples.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, 1 is a cylinder formed by front and rear side walls 2 and 3, 4 is a rotor in which a rotary shaft 6 is supported on the front and rear side walls 2 and 3 via a bearing 5, and a vane 8 is provided in a slot 7 so as to be freely retractable. There is.

9 is a compression chamber, 10 is a discharge port provided in the cylinder 1, and 11
is its discharge valve.

Reference numeral 12 denotes an outer cylinder attached with bolts 13 between the front and rear side walls 2 and 3, and forms a high-pressure oil separation chamber 14 on the outer periphery of the cylinder 1.

15 is an oil reservoir formed at the lower part of the oil separation chamber 14; 16 is an annular oil groove for supplying lubricating oil provided in the rear wall 3 facing the rotating side surface of the rotor 4; 17 is an oil groove in the oil groove 16; One end,
The oil supply passages are provided in the rear wall 3 and communicate with the oil reservoir 15 at their other ends, and the oil is pushed up and supplied to the oil groove 16 using refrigerant discharge pressure.

18 is a valve chamber provided in the rear wall 3 in the middle of the supply oil passage 17, and 19 is an on-off valve provided in this valve chamber 18, which is attached to the rotating shaft 6, rotates with this shaft, and rotates in the axial direction / sliding direction. It is movably mounted.

Reference numeral 20 denotes an oil passage provided in the on-off valve 19, which communicates with a through hole 21 also provided on the rotating shaft 6 by the sliding movement of the on-off valve 19.
Opening the supply oil path 17 1. Or, it closes with a deviation from the through hole 21.

22 is a first pressure detection path that communicates the discharge port 10 in front of the discharge valve 11 with the valve chamber 18;
Derived to one side.

23 is a second pressure detection path that communicates the oil separation chamber 14 after the discharge valve 10 with the valve chamber 18;
9 to the other.

24 presses the on-off valve 19 to connect the passage 20 to the supply oil passage 17
25 is an outlet of the oil separation chamber, and 26 is a retainer that restricts the opening of the discharge valve 11.

In the above configuration, when the low-pressure refrigerant returned from the evaporator (not shown) in the refrigeration cycle is compressed by the rotating rotor 4 and vane 8 in the compression chamber 9, it becomes high-pressure refrigerant gas, and the discharge valve 11 is opened from the discharge port 10. oil separation chamber 1
Enter 4.

When the direction is changed, the refrigerating machine oil with a heavy specific gravity is separated from the refrigerant gas by its inertia and collected in the oil sump 15, and only the refrigerant gas is discharged from the outlet 25 or S to the condenser (
(not shown) and is circulated again to the compressor via the evaporator.

Now, assuming that the compressor has been stopped for a long time and the refrigerant pressure is uniform and stable, there is no differential pressure between the first and second pressure detection paths 22 and 23, so the spring 24, the on-off valve 19 has moved to the left as shown in FIG. 3, and the supply oil passage 17 is closed.

Subsequently, when the compressor starts operating, the pressure at the discharge port 10 first increases.

The pressure of this refrigerant gas is applied to the left side of the on-off valve 19 through the first pressure detection path 22, and moves the on-off valve 19 to the right in FIG. 3 against the spring 24, as shown in FIG. Thus, the passage 20 coincides with the supply passage 17.

After a while, the pressure in the oil separation chamber 14 also rises, but the pressure at the discharge port 10 is higher than the pressure in the oil separation chamber 14 by the force of opening the discharge valve 10, so the state shown in FIG. 4 is maintained.

The on-off valve 19 rotating together with the rotating shaft 6 is
It communicates with the supply oil path 17 intermittently according to changes in rotational speed.

In other words, at an interval corresponding to the rotation speed of the rotating shaft 6,
Oil under pressure flows from the oil reservoir 15 to the supply oil path 17 and is sent from the oil groove 16 to both rotational sides of the rotor 4, the slot 7, etc.

Then, an appropriate amount of oil is supplied according to each rotational speed, such as a large amount at high speed rotation and a small amount at low speed rotation.

Subsequently, when the operation of the compressor is stopped, the discharge port 10 is immediately opened.
Not only does high pressure not occur at
pressure drops rapidly.

On the other hand, since the discharge valve 11 is closed, the pressure in the oil separation chamber 14, the oil reservoir section 15 side of the supply oil path 17, and the pressure detection path 23 are still maintained at high pressure, and the on-off valve 19 in FIG. Due to the differential pressure between the second pressure detection paths 22 and 23, it moves to the left, resulting in the state shown in FIG.

Therefore, the supply oil path 17 is shut off by the on-off valve 19, and the excess pressure in the oil separation chamber 14 causes the lubricating oil and high-temperature, high-pressure refrigerant gas remaining on the oil reservoir 15 side to flow through the oil groove 16, slot 7, etc. It will no longer flow into the compression chamber 9.

As a result, when the compressor is restarted, the lubricating oil is compressed in the compression chamber 9, and the phenomenon of liquid compression does not occur.

Further, the high temperature and high pressure refrigerant gas remaining in the oil reservoir 15 does not flow into the cylinder 1 and impede natural cooling of the compressor.

Of course, if the compressor is stopped for a long time, the high-pressure refrigerant and low-pressure refrigerant will be balanced by the small gap in the expansion valve (not shown) installed near the evaporator inlet, and the entire refrigeration cycle will be at a uniform pressure. Needless to say, it will fall off.

In this embodiment, the on-off valve 19 is rotated to intermittently communicate the passage 20 with the supply oil passage 1γ and the through hole 21 to adjust the oil amount.

However, the on-off valve 19 is provided on the rotating shaft 6 so that it slides only in the axial direction without rotating, and the on-off valve 19 slides due to the differential pressure between the first and second pressure detection paths 22 and 23. The amount of oil supplied can also be adjusted by overlapping the oil supply passage 20 with the supply oil passage 17 and the through hole 21.

However, in this case, the above-mentioned differential pressure cannot be obtained even in response to slight changes in the rotational speed of the compressor, so there is a drawback that the oil amount cannot be adjusted more sensitively depending on the rotational speed than in the above embodiment.

Further, in the above embodiment, the passage 20 has a structure in which it communicates with the supply oil passage 17 through the through hole 21 of the rotating shaft 6, but the on-off valve 1
It is also possible to provide the passage 20 only in the rotary shaft 9, and in this case, the passage becomes a meandering passage that avoids the rotation shaft 6.

Further, the on-off valve 19 may be installed in the rotating shaft 6, and the spring 24 is not necessarily required.

As is clear from the above embodiments, the oil supply device for a vane rotary compressor according to the present invention includes a cylindrical cylinder, a piston that rotates in contact with the inner wall surface of the cylinder, and a piston that is provided so as to be retractable from the cylinder. A vane, a discharge port formed in the cylinder, a discharge valve provided in the discharge port, an outer cylinder that houses these and forms an oil reservoir at the bottom, openings at both ends of the outer cylinder, and a discharge valve provided in the discharge port. A rotary compressor is constituted by a side wall that closes openings at both ends, and the side wall is further connected to the side wall, one end of which communicates with the inside of the discharge port via a first pressure detection circuit, and the other end of which communicates with the inside of the discharge port via a second pressure detection circuit. and a valve chamber communicating with the inner space of the outer cylinder, and a supply oil passage having one end opening into the oil reservoir and the other end communicating with the rotor and the sliding portion of the side plate through the valve chamber, In addition, in the valve chamber,
A valve body is provided that slides due to the pressure difference between the first pressure detection circuit and the second pressure detection circuit, and the valve body is further provided with a passage that connects or shuts off the supply oil path by the sliding movement. When the compressor is operating, the valve body slides due to the pressure difference before and after the discharge valve and communicates the supply oil path, so lubricating oil is supplied to each sliding part by the pressure inside the outer cylinder. This eliminates the need for an oil pump, simplifying the configuration. In addition, when the compressor stops, the valve body slides back and shuts off the supply oil path, so the residual pressure inside the outer cylinder allows continuous The lubricating oil is pushed out, and the lubricating oil does not flow into the low pressure side of the cylinder and cause liquid compression when restarting.
The compressor is protected.

Furthermore, since the supply oil path is blocked, the high-temperature, high-pressure refrigerant gas remaining in the oil sump will not flow into the cylinder, inhibiting the natural cooling action of the compressor and reducing compressor efficiency. , which has various advantages.

[Brief explanation of drawings]

FIG. 1 is a front cross-sectional view of a vane-type rotary compressor equipped with an oil supply device according to an embodiment of the present invention, and FIG. 2 is an A of FIG. 1.
3 is an enlarged sectional view of section B in FIG. 2 when the compressor is stopped, and FIG. 4 is an enlarged sectional view taken when the compressor is in operation. 1...Cylinder, 2, 3...Side wall, 4
...Rotor, 8...Vane, 10...
...Discharge port, 11...Discharge valve, 12...
... Outer cylinder, 17 ... Supply oil path 0.19 ...
...Opening/closing valve, 20-...Passage, 21...
・Through hole, 22...First pressure detection path, 23...
...Second pressure detection path.

Claims (1)

[Claims] 1. A cylindrical cylinder, a piston that rotates in contact with an inner wall surface of the cylinder, a vane that is removably provided on the piston, and a discharge port formed in the cylinder;
A rotary compressor is composed of a discharge valve provided at the discharge port, an outer cylinder that accommodates these and forms an oil reservoir at the bottom, and side walls that close openings at both ends of the outer cylinder and both ends of the cylinder. and further includes a valve chamber in the side wall, one end of which communicates with the inside of the discharge port via a first pressure detection circuit, and the other end of which communicates with the inner space of the outer cylinder via a second pressure detection circuit; A supply oil passage is provided through the valve chamber, with one end opening into the oil reservoir and the other end communicating with the rotor and the sliding portion of the side plate, and the first pressure detection circuit is provided in the valve chamber. and a second pressure detection circuit, the vane type rotary compressor is provided with a valve body that slides due to the pressure difference between the first pressure detection circuit and the second pressure detection circuit, and further includes a passage provided in the valve body that communicates or cuts off the supply oil path by the sliding movement. refueling device.