JPS5944515B2 - vane rotary compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in vane rotary compressors used in automobile air conditioners and the like.

More specifically, when the vane rotary compressor is stopped,
This prevents lubricating oil from flowing into the cylinder and prevents the liquid compression that occurs when the compressor is restarted, and also makes the operating mechanism more reliable by preventing reversal that occurs immediately after the compressor is stopped.

Conventionally, in this type of rotary compressor, lubricating oil is pressurized by high pressure generated on the discharge side as a force that presses the vane against the cylinder wall and introduced into the bottom of the vane groove, and the high-pressure lubricating oil pushes the vane against the cylinder inner wall. At the same time, it was used to lubricate both sides of the rotor and the tips of the vanes.

However, in this structure, once the compressor stops, the lubricating oil continues to flow to the bottom of the vane groove due to the high pressure remaining on the discharge side, and some of the lubricating oil enters the cylinder through the gap between the vanes and the vane groove.

After a certain period of time, the residual pressure balances with the low pressure side through the expansion valve or the gap inside the compressor, and the lubricating oil stops flowing into the cylinder, but even if it is a small amount of lubricating oil, When the compressor is rotated again, a severe oil compression phenomenon occurs, causing major problems such as damage to vanes and deformation of valves.

In addition to the inflow of lubricating oil during stoppage, this type of compressor performs reverse rotation by applying the high pressure remaining immediately after stoppage to the bottom of the vane groove.

When the compressor is reversed when stopped, not only does high-pressure gas flow back to the low-pressure side, but also a large amount of lubricating oil returns into the cylinder or suction pipe.

The negative effects of restarting are as described above.

The disadvantages of oil compression in the method of introducing high-pressure lubricating oil into the bottom of the vane groove are as described above, but in the method of introducing high-pressure discharge gas into the bottom of the vane groove, there is a problem with the discharge gas due to reversal of the compressor when the compressor is stopped. Backflow to the low pressure suction side is a major problem.

In other words, the intake gas is superheated by the backflow of high-pressure gas,
This results in an increase in the discharge gas temperature when restarting the operation.

As a method for preventing such oil compression or reversal, (1
) Installing a check valve on the suction side of the compressor is a well-known method of eliminating oil inflow and reverse flow by directly preventing the back flow of high-pressure gas when the compressor is stopped.

(2) A method in which an oil passage opening/closing member that rotates in synchronization with the rotor is provided at the end of the loaf shaft, and when the rotor stops rotating, the oil passage is blocked by the oil passage to prevent oil from flowing in and reversing, for example, JP-A No. 5
1-133811.

and so on.

The former increases the passage resistance of the suction gas, leading to a decline in compressor performance, while the latter increases the passage resistance of the oil passage as the rotor rotation speed increases, reducing the supply of lubricating oil to the bottom of the vane groove, which reduces the durability of the compressor. It has the disadvantage of reduced performance.

The present invention focuses on two points where a significant pressure change occurs when the compressor is rotating and when it is stopped, for example, the pressure difference before and after the discharge valve, and the present invention operates based on the pressure difference and is capable of responding to instantaneous pressure changes. The purpose of this invention is to solve the above-mentioned drawbacks by providing an on-off valve mechanism that does not vibrate in the oil passage, and by making the operating mechanism more reliable, which opens the oil passage when the compressor is rotating and closes the oil passage when the compressor is stopped.

To achieve this object, the present invention includes a cylinder having a cylindrical wall, a rotor located eccentrically within the cylinder and having a plurality of vane grooves, and a rotor slidably inserted into each of the vane grooves and having a tip end. It consists of a vane that slides on the cylindrical wall of the cylinder, the cylinder and the rotor, and front and rear walls that close the vane from both sides, and is connected to the bottom space of the vane groove and the discharge high pressure area in the compressor body. The located oil separation chamber is communicated with an oil passage, and when the rotor is rotating, there is a pressure difference between the pressure before passing through the discharge valve and the oil separation chamber, and when the rotor is stopped, there is almost no pressure difference. A plunger valve mechanism is provided for opening and closing each of the oil passages, and a vibration prevention means is provided for preventing the plunger from vibrating when the pressure difference is almost eliminated, and the vibration prevention means guides the reciprocating movement of the plunger. The plunger is provided with a seal ring that has frictional resistance against the plunger hole.

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

FIG. 1 shows a cross section of a vane rotary compressor in the rotor axial direction, and FIG. 2 shows a cross section taken along line AA in FIG. 1.

In the figure, 1 is the rotor, 2 is the cylinder, 3 is the front wall,
4 is a rear side wall, 5 is a vane, 6 is a refrigerant inlet provided in the cylinder 2, 1 is a discharge port, 8 is a discharge valve, 9 is a cylinder head, 10 is an oil separation chamber, 11 is a refrigerant from the oil separation chamber 10 A refrigerant outlet, 12 a roller bearing, and 13 a shaft sealing device form the basic structure of the vane rotary compressor.

Reference numeral 15 denotes a circumferential groove that supplies high-pressure lubricating oil 16 to the bottom of the vane groove 14, and is provided on the rear side wall 4.

Reference numeral 17 denotes an outlet for the pressure before passing through the discharge valve, which is formed in the rear side wall 4.

18 is a pressure passage that transmits the pressure of the outlet 17, 19 is an oil passage that sends lubricating oil 16 to the circumferential groove 15, which is located downstream of the plunger valve mechanism described later, and 20 is a similar oil passage, which is described later. It is located upstream of the jar valve mechanism, and the other end is opened below the oil level of the lubricating oil 16 in the oil separation chamber 10.

21 is a flancier hole, 22 is a plunger with a protrusion on its upper part, and 28 is an elastic seal ring (for example, a rubber
- ring), 23 is an oil passage connecting the oil passage 19 and the oil passage 20, surrounds the protrusion 22a of the plunger 22, and 23 is an oil passage that connects the oil passage 19 and the oil passage 20.
3, there is a passage 31 whose lower end is in the shape of a circular vertebra.
is formed, into which a steel ball 25 of a size that can block the oil passage 23 is inserted in a floating state, and the plunger 2
The steel ball 25 opens and closes the oil passage 23 by vertical movement of the steel ball 2.

The other end of the pressure passage 18 opens at the lower end of the plunger hole 21.

Next, the effect will be explained.

When the rotor 1 starts rotating in the direction of the arrow shown in FIG. is pushed open and reaches the oil separation chamber 10, where the refrigerating machine oil is separated from the refrigerant gas due to the difference in specific gravity, and the lubricating oil 1
6 is stored at the bottom of the oil separation chamber 10, while the refrigerant gas is delivered into the refrigeration cycle through the refrigerant outlet 11.

Focusing on the pressure across the discharge valve 8 in the flow of refrigerant gas as described above, during compressor operation, the pressure before the discharge valve, that is, the pressure generated at the bottom of the pressure passage 18 and the plunger hole 21, and A pressure difference between the pressure after passing the discharge valve and the pressure that can at least push the discharge valve 8 open is generated, and the pressure before the discharge valve is high.

That is, the pressure on the oil passage 23 side communicating with the oil separation chamber 10 with the seal ring 28 attached to the plunger 22 as a boundary and the plunger hole 21 where the pressure passage 18 is opened.
The pressure on the lower side is the pressure on the lower side of the plunger hole 21, which has a pulsation depending on the number of rotations of the rotor 1 and the number of vanes 5 used.

Therefore, the plunger 22 moves upward and the steel ball 25 is pushed up by the tip of the plunger 22, causing the oil separation chamber 10 to
The high pressure lubricating oil 16 communicates with the oil passage 19 and the vane groove 14.
is fed to the bottom of the

At this time, the seal ring 28 attached to the plunger 22
has elasticity like a rubber O-IJ song, and has a suitably large frictional resistance, so the plunger 22 does not directly respond to the pressure pulsations and repeat vertical vibrations.

Next, the operation when the compressor is stopped will be explained.

When the power transmission mechanism (not shown) to the compressor is cut off, the discharge valve 8 closes immediately.

As a result, since the pressure on the refrigerant outlet 11 side is connected to the high pressure side of the refrigeration cycle as is well known, the oil separation chamber 11
The same pressure will be applied.

The pressure on the refrigerant outlet 11 side is controlled by a pressure reducer (not shown).
Although the pressure is reduced to balance with the low pressure side of the refrigeration cycle through the refrigeration cycle, the speed at which this balance occurs is slow, and the pressure in the discharge lower decreases quickly.

That is, the gap between the rotor 1 and the front side wall 3 and the rear side wall 4, the vane 5 and the inner wall of the cylinder 2, or the vane 1 and the front and rear side walls 3.
The internal pressure of the discharge lower decreases rapidly due to refrigerant gas leakage from gaps such as the gap between the rotor 1 and the cylinder 2, the gap between the top of the rotor 1 and the cylinder 2, and a slight reversal of the rotor 1 due to the pressure difference within the cylinder.

Due to this, the pressure in the pressure passage 18 decreases faster than the pressure in the oil passage 20.

Therefore, the force applied to both end faces of the plunger 22 is in the opposite direction to the rotation of the compressor, and the plunger 22 moves downward in the figure, causing the steel ball 25 to shut off the oil passage 20 and the oil passage 23. , lubricating oil 1 under pressure due to residual discharge pressure
6 stops flowing into the bottom of the vane groove 14 and into the cylinder.

- As time passes, this residual pressure on the high pressure side is balanced through an expansion valve (not shown) provided in the evaporator (not shown), and eventually the pressure in the suction port 6 provided in the cylinder 2 is balanced. The pressure in the discharge port γ becomes equal to the pressure in the discharge port γ.

That is, the pressure inside the plunger hole 21 and the oil separation chamber 10
The difference in pressure inside will almost disappear.

As described above, in the present invention, while the compressor is rotating, the oil passage is always open due to the differential pressure generated at two points, and the amount of oil supplied to the bottom of the vane groove of the rotor is affected by the compressor rotation speed. The vane can be continuously supplied without any friction, the vane can always be pressed against the inner wall of the cylinder, and there is no so-called jumping action of the vane that occurs during reciprocating rotational movement of the vane, resulting in less wear on the vane.

In addition, a rotary compressor with good compression efficiency and less leakage of compressed gas can be obtained.

- Also, when the compressor is stopped, the oil supply to the bottom of the vane groove of the rotor is immediately cut off, and there is no inflow of refrigerant gas or lubricating oil from the high pressure side to the low pressure side, so there is no reversal of the compressor.

Therefore, the above-mentioned conventional drawbacks that occur when the compressor is restarted are eliminated.

In addition, even if pulsation occurs in the differential pressure used to open the oil passage of the plunger valve mechanism, which is determined by the compressor rotation speed and the number of vanes, the plunger valve mechanism is equipped with vibration prevention means. The plunger valve mechanism is not repeatedly opened and closed in response to pulsations, and the plunger valve mechanism is reliably closed only when the rotor stops rotating, thereby effectively preventing the rotor from rotating in reverse.

In addition, a seal ring with frictional resistance is used between the plunger and the plunger hole to prevent vibration.
The pressure difference generated between both ends of the plunger has little leakage, and the plunger can be operated even with a low pressure difference, thereby increasing the responsiveness of the plunger valve mechanism.

In addition, it suppresses the movement of the plunger that attempts to vibrate back and forth due to the pulsation of differential pressure, and the opening degree of the plunger valve mechanism can always be kept constant when differential pressure occurs. Since the oil supply can be kept more constant, an improved rotary compressor can be realized.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the rotor of a vane rotary compressor according to an embodiment of the present invention in the main axis direction, and FIG. 2 is a cross-sectional view taken along the line AA in FIG.
FIG. 1...Loader, 2...Cylinder, 3.
...Front wall, 4...Rear wall, 5...
...Vane, 10...Oil separation chamber, 14...
...Vane groove, 19,20...Oil passage, 21...
... Plunger hole, 22 ... Plunger, 28 ... Seal ring.

Claims (1)

[Claims] 1 a cylinder having a cylindrical wall and a refrigerant suction port;
a rotor that is eccentrically located within the cylinder and has a plurality of vane grooves; a vane that is slidably inserted into each of the vane grooves and whose tip slides on the cylindrical wall of the cylinder; the cylinder and the rotor; It is composed of a front side wall and a rear side wall that close the vane from both sides, and the bottom space of the vane groove is communicated with an oil separation chamber located in a discharge high pressure area in the compressor body through an oil passage, and rotation of the rotor is controlled. Inside is a plunger valve mechanism that opens and closes the oil passages based on the pressure difference between the pressure before passing the discharge valve and the oil separation chamber, and the pressure difference when the rotor is stopped. A vibration prevention means is provided to prevent the plunger from vibrating when the plunger has almost disappeared, and the vibration prevention means includes a seal ring on the plunger that has frictional resistance against the plunger hole that guides the reciprocating movement of the plunger. A rotary vane type in which a refrigerant outlet is provided in the oil separation chamber, and a refrigeration cycle is connected between the refrigerant inlet and the refrigerant outlet to form a closed circuit.