JPS6258084A - Vane back pressure applying device for sliding vane type compressor - Google Patents

Abstract

PURPOSE:To prevent malfunction of a vane and incomplete compression at start of a vane type compressor by feeding gas in a high pressure chamber into a vane back pressure chamber when starting under such condition as the differential pressure between high and low pressure sides is low. CONSTITUTION:Upon start of compressor under such condition as the differential pressure between high and low pressure sides is low, vane 4 will spring out to lower the pressure in a vane back pressure chamber 17. Consequently, gaseous fluid is fed through the second gas supply path 33 opening above a high pressure chamber 14 thus to assist spring out of the vane 4. Upon elapse of some interval, the differential pressure between high and low pressure sides will increase where over-compressed gas immediately before the delivery valve 11 of a working chamber 8 will function through a pressure lead-in path 31 to one side of a valve body 29 thus to seat the valve body 29 in a valve seat 30 and to interrupt the first and second gas supply paths 27, 33. Consequently, only high pressure oil is fed through a oil path 18 into the vane back pressure chamber 17.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vane backpressure applying device used in a sliding vane compressor used in automobile air conditioners and the like.

As is well known in the art, in sliding vane compressors, high-pressure lubricating oil is applied to the rear end of the vane by a pressure difference so that as the rotor rotates, the vane rotates and slides with its tip in contact with the inner wall of the sill. A structure in which the power is supplied by

An example of a vane back pressure applying device for the above-mentioned conventional sliding vane compressor will be described below with reference to the drawings.

FIG. 10 to FIG. 12 show the specific structure of a conventional sliding vane compressor having a differential pressure oil supply type vane backpressure applying device. In the figure, 1 is a cylinder having a cylindrical inner wall, 2 is a rotor whose outer periphery partially forms a minute gap with the inner wall of the cylinder 1, 3 is a plurality of vane slots provided in the rotor 2, and 4 is an inside of the vane slot 4. A plurality of vanes 5 are slidably inserted into the rotor 2, and drive shafts 6 and 7 are formed integrally with the rotor 2 and are rotatably supported.
are each closed at both ends of the shilling 1 and have a working chamber 8 inside.
The front side plate and the rear side plate form the front side plate and the rear side plate. 9 is a suction port communicating with the working chamber 8 on the low pressure side, and 10 is the working chamber 8 on the high pressure side.
11 is a discharge valve provided with no discharge,
Reference numeral 12 denotes a high-pressure case that forms a high-pressure chamber 14 that communicates with the high-pressure passage 13 and is provided with a screen 15 that separates and captures lubricating oil in the compressed high-pressure fluid. Reference numeral 16 denotes a main body of a vane back pressure applying device disposed on the rear side plate 7, which supplies lubricating oil from an oil reservoir below the high pressure chamber 14 to the vane back pressure chamber 17. 18 is the oil reservoir below the high pressure chamber 1.4 and the vane back pressure chamber 1
7, 19 is a passage that limits the amount of oil supplied by differential pressure, 20 is a spherical seat provided in the middle of the oil supply passage 18, and 21 is in contact with or separated from the spherical seat 20 to connect the oil supply passage 18.
22 is a plunger chamber that opens into the spherical seat 20; 23 is a plunger that is slidably disposed inside the plunger chamber 22 and releases the spherical body 21 from the spherical seat 20 when moved toward the spherical seat 20; 2.1-j This is a pressure introduction path that communicates the lower plunger chamber 25 at the lower end of the plunger with the straight-curved working chamber 8 of the discharge valve 11.

The operation of the vane back pressure applying device for a sliding vane compressor configured as described above will be described below.

When the drive shaft 5 and rotor 2 rotate clockwise in FIG. 11 due to power transmission from a drive source such as an engine, low-pressure fluid flows into the working chamber 8 through the suction port 9. The high-pressure fluid compressed as the rotor 2 rotates pushes up the discharge valve 11 through the discharge port 10 and flows into the high-pressure chamber 14 through the high-pressure passage 13, and the lubricating oil is separated and captured by the screen 15. On the other hand, from the pressure introduction path 24, overcompressed gas in the working chamber 8, which has enough pressure to overcome the pressure of the high-pressure fluid and push up the discharge valve 11, flows into the lower plunger chamber 2.
5, the plunger 23 moves toward the spherical seat 20 and releases the spherical body 21 from the spherical seat 20. Therefore, the oil supply passage 18 is communicated with the lubricating oil separated from the high pressure fluid and stored below the high pressure chamber 14, and is supplied from the passage 19 and the oil supply passage 18 to the vane back pressure chamber 17 due to the differential pressure, and the It is subjected to suppression and flows into the working chamber 8 through the gap between the rotor 2 and the front side plate 6 and rear side plate 7. Furthermore, when the compressor stops, the pressure in the working chamber 8 rapidly drops to the pressure of the low-pressure side fluid, so the pressure in the lower plunge τ chamber 25 also drops to the pressure of the low-pressure side fluid, and the pressure at the lower end of the plunger 23 is smaller than the pressure at the upper end of the plunger 23, so the plunger 23 is in the lower plunge chamber 2.
Move to the 5th side. Therefore, the sphere 21 comes into contact with the sphere seat 20, and the oil supply passage 18 is blocked. Therefore, since no more lubricating oil is supplied, it is possible to prevent the liquid from being compressed when the compressor is started due to lubricating oil remaining in the working chamber 8.

Problems to be Solved by the Invention However, in the conventional vane backpressure applying device described above, the pressure of the fluid on the low pressure side and the pressure of the fluid on the high pressure side do not change as when a certain period of time has passed after the compressor has stopped. When the compressor is started in a state in which the rotor 2 rotates, the vanes 4 rotate as the rotor 2 rotates, and even if the vane 4 attempts to extend and retract into the vane slot 3, there is no differential pressure to supply lubricating oil, and the lubricating oil Since the resistance at the beginning of flow due to water head, viscosity, and inertia is large, as a result, a sufficient amount of lubricating oil cannot be supplied to cope with the volume fluctuation of the vane back pressure chamber 17 that occurs when the vane 4 expands and retracts. For this reason, especially when the rotational speed at the time of starting the compressor is low, the pressure in the vane back pressure chamber 17 decreases, causing the well-known malfunction phenomenon in which the vane 4 separates from the inner wall of the cylinder 1 and collides with it again, and the compression failure phenomenon in which the fluid is not compressed. In addition, expanding the passage area of the passage 19 in order to secure the amount of lubricating oil means that the vane 4 is moved excessively to the cylinder 1 during steady operation.
This causes increased wear on the tip of the vane 4 and the inner wall of the cylinder 1 and increases input to the compressor, which deteriorates the durability and efficiency of the compressor. There was a problem in that centrifugal force further aggravated this tendency.

In view of the above-mentioned problems, the present invention can prevent vane malfunction and compression failure even when the compressor is started at low speed when there is no or small pressure difference between the high and low pressures of the compressor, and it does not impair durability or efficiency. The present invention provides a vane back pressure applying device for a sliding vane compressor.

Means for Solving the Problems In order to solve the above problems, the vane back pressure applying device for a sliding vane compressor of the present invention provides an oil supply system that communicates the vane back pressure chamber with the oil reservoir portion of the high pressure chamber. A gas supply passage that communicates the passage with any high-pressure side space other than the oil reservoir in the refrigeration cycle including the vane back pressure chamber and the compressor, and there is at least no pressure difference between the high-pressure side fluid and the low-pressure side fluid. or a passage opening/closing means which connects the gas supply passage when the compressor is started from a small state and shuts off the gas supply passage at least during operation of the compressor except when starting.

According to the above-mentioned structure, even when the compressor is started in a state where there is no or a small pressure difference between high and low pressures, the passage opening/closing means communicates with the gas supply passage, so that the vanes are closed as the rotor rotates. Gaseous fluid can be instantaneously supplied from the gas supply passage in response to volume fluctuations in the vane back pressure chamber that occur when the vane rotates and attempts to extend and retract within the vane thrust. Therefore, since no pressure drop occurs in the vane back pressure chamber, it is possible to prevent vane malfunction and compression failure. Furthermore, since the passage opening/closing means shuts off the gas supply passage after startup, an appropriate amount of lubricating oil is supplied from the oil supply passage to the vane back pressure chamber, without impairing durability or efficiency.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 9 of the accompanying drawings.

1 to 4 show a vane back pressure applying device for a sliding vane compressor according to a first embodiment of the present invention. Those having the same functions and effects as the vane back pressure applying device are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 26 is the main body of the vane back pressure applying device disposed on the rear side plate 7, 27 is a first gas supply passage communicating with the vane back pressure chamber 17, 28 is a sliding chamber into which this first gas passage opens, 29 is slidably disposed within the sliding chamber 28,
A valve body forming a first sliding chamber 28a and a second sliding chamber 28b at both ends thereof, 30 a valve seat provided on the first sliding chamber 2aa side of the first gas supply passage 27, and 31 a valve seat provided on the first sliding chamber 2aa side of the first gas supply passage 27; 2 sliding chamber 28
a pressure introduction path that communicates b with the working chamber immediately before the discharge valve 11;
32 is a spring provided in the first sliding chamber 28a to bias the valve body 29 toward the second sliding chamber 2ab, and 33 is a spring provided in the first sliding chamber 28a as shown in FIG. When the valve body 29 moves toward the first sliding chamber 2aa and comes into contact with the valve seat 30, it is cut off from the first gas supply passage 27, and as shown in FIG. When moving to the sliding chamber 28b side, the second gas supply opens one end into the first sliding chamber 28a and the other end into the upper part of the high pressure chamber 14 so as to communicate with the first gas supply passage 27. It is a passage.

The 1111th construction of the vane back pressure applying device for a sliding vane compressor constructed as above will be described below.

In a steady operating state in which there is a pressure difference between the high pressure side and the low pressure side that is sufficient for refueling after a certain period of time after the compressor is started, the compressor has enough pressure to overcome the pressure of the high pressure fluid and push up the discharge valve 11. The overcompressed gas in the working chamber 8 flows into the second sliding chamber 28b from the pressure introduction path 31, and the pressure in the high pressure chamber 14 applied to the end face of the valve body 29 on the first sliding chamber 2aa side and the attachment of the spring 32 are reduced. The valve body 29 is held in the position shown in FIG. 1 against the force. Therefore, since the valve body 29 contacts the valve seat 30 and blocks off the first gas supply passage 27 and the second gas supply passage 33, the high pressure chamber 14 is not connected to the vane back pressure chamber 17.
The lubricating oil stored in the lower oil reservoir is supplied from the passage 19 and the oil supply passage 18 and is used to suppress the vane 4, similar to the vane back pressure applying device of a conventional sliding vane compressor. be.

Furthermore, when the compressor stops, the pressure in the working chamber 8 rapidly decreases, so the pressure in the second sliding chamber 28b also decreases, and the pressure in the first sliding chamber 28a and the spring 32 cause the valve body 29 to move to the second Move to the position shown in the diagram.

Therefore, the first gas supply passage 27 and the second gas supply passage 3
3, the flow from the high pressure chamber 14 to the vane back pressure chamber 17 is a gaseous fluid with a smaller viscosity and water head than the lubricating oil flow through the passages 19 and 18. 2 gas supply passage 33, first gas supply passage 2
Since the flow through 7 and the oil supply passage 18 is preferential,
Even in this case, the inflow of lubricating oil into the working chamber 8 can be prevented, similar to the vane back pressure applying device of the conventional squeezing vane type compressor.

If the compressor is started after a certain period of time has passed after the compressor has stopped and there is no pressure difference between the high pressure side and the low pressure side, the vanes 4 will rotate as the rotor 2 rotates, and the inside of the vane slot 3 will be rotated. When the pressure inside the vane back chamber 17 becomes low due to a change in the volume of the expelling vane back pressure chamber 17 that expands and retracts, gaseous fluid is instantly supplied to the vane back pressure chamber from the second gas supply passage 26 that opens above the high pressure chamber 14. 17, a drop in pressure in the vane back pressure chamber 17 can be prevented. and then 1i7
7, the valve body 29 comes into contact with the valve seat 30, and the first gas supply passage 27 and the second gas supply passage 33 are cut off.

As described above, according to this embodiment, the first gas supply passage communicating with the vane back pressure chamber serves as a vane back pressure applying device for a sliding vane compressor, and the sliding passageway through which the first gas supply passage opens. a first sliding chamber and a second sliding chamber that are slidably inserted into the sliding chamber and have first gas supply passages opening at both ends thereof;
A valve body forming a sliding chamber, a valve seat provided at the opening of the first gas supply passage of the first lumping chamber, and a second sliding chamber and a discharge passage immediately before the discharge valve or in the vicinity of the discharge valve. a pressure introduction path that communicates with the working chamber; a spring that biases the valve body toward the second sliding chamber;
When the valve body moves toward the first sliding chamber, it is cut off from the first gas supply passage, and when the valve body moves toward the second sliding chamber, it is communicated with the first gas supply passage. One end of it is the first
The second end opens into the sliding chamber and the other end opens into the upper part of the high pressure chamber.
By providing a gas supply passage, when the compressor is started from a state where there is no or small pressure difference between the high-pressure side fluid and the low-pressure side fluid, the gas supply passage is communicated with the vane as the rotor rotates. As the vane rotates and tries to expand and retract into the vane slot, gaseous fluid can be instantly supplied from the first and second gas supply passages to respond to the volume fluctuation of the vane back pressure chamber, which occurs when the vane rotates and attempts to expand and retract into the vane slot. Since no pressure drop occurs, vane malfunctions and compression failures can be prevented. In addition, after startup, the valve body contacts the valve seat and blocks the first and second gas supply passages, so the appropriate amount of lubricating oil is supplied to the vane back pressure chamber from the oil supply passage, which may impair durability and efficiency. There is no.

Next, a %2 embodiment of the present invention will be described with reference to FIGS. 5 to 9.

In the same figure, the same reference numerals as in FIGS. 10 to 12 showing the vane back pressure applying device of the conventional sliding vane type compressor and FIGS. 1 to 4 showing the first embodiment are shown. Items with ``mark'' have the same effects. In the figure, 34 is a main body of the vane backpressure applying device disposed on the rear side plate 7, and 35 is a spring disposed within the lower plunger chamber 25 for biasing the plunger 23 toward the spherical seat 20 side.

The difference from the first embodiment is that there is a plunger chamber 22, a plunger τ23, a pressure introduction path 24, and a sphere in the middle of the oil supply passage 18 from the communication part between the oil supply passage 18 and the first gas supply passage 27 to the vane back pressure chamber 17. 21 and a ball seat 20, and a spring that biases the plunger 23 toward the ball seat 20. However, as shown in FIG. By contacting the seat 30, an appropriate amount of lubricating oil can be supplied from the passage 19 and the oil supply passage 18 to the vane back pressure chamber 17, and when the compressor is stopped, the valve body 29 is released from the valve seat 30, as shown in FIG. However, the ball 21 receives the pressure in the high pressure chamber 14, overcomes the plunger 723 by the biasing force of the spring 35, and comes into contact with the ball seat 20, so that the gaseous fluid in the high pressure chamber 14 does not flow into the working chamber 8. If the pressure difference between the high-pressure side and the low-pressure side becomes small after a certain period of time has passed after the compressor is stopped, the spring 35 moves the plunger 23 toward the ball seat 20, resulting in the state shown in FIG. 7, and from this state. When the compressor is started, gaseous fluid is instantly supplied from the second gas supply passage 33 to the vane back pressure chamber 17 via the first gas supply passage 27 and the oil supply passage 18.
This embodiment has the same effects as the first embodiment, such as being able to prevent a pressure drop.

Note that in the first embodiment, the first gas supply passage 27 communicates with the oil supply passage 18, but the first gas supply passage 27 may communicate with the vane back pressure chamber 17 independently of the oil supply passage 18. Further, in the second embodiment, the pressure introduction passage 31 was opened to the working chamber 8 independently of the pressure introduction passage 24, but the pressure introduction passage 31 may be opened to the pressure introduction passage 24, or the lower plunger chamber Spring 35 in 25) may be omitted.

Further, in the first and second embodiments, the sliding vane type compressor has a perfect circular type having only one suction port 9 and one discharge port 10, but a type having multiple suction ports 9 and multiple discharge ports 10 each has been described. The number of vanes shown is four, but any number of vanes may be used.

Effects of the Invention As described above, the present invention, as a vane back pressure applying device for a sliding vane compressor, includes an oil supply passage that communicates a vane back pressure chamber with an oil reservoir portion of a high pressure chamber, and a vane back pressure chamber. A gas supply passage that communicates with any high-pressure side space other than the oil reservoir in the refrigeration cycle including the compressor, and the compressor from a state where there is no or small pressure difference between at least the high-pressure side fluid and the low-pressure side fluid. By including a passage opening/closing means that communicates the gas supply passage at the time of startup and shuts off the gas supply passage at least during compressor operation except at the time of startup, the compressor is started with no or small pressure difference between high and low pressures. Even in this case, the passage opening/closing means communicates with the gas supply passage, so the vane rotates as the rotor rotates, and the volume change in the back pressure chamber of the vane, which is being removed when the vane attempts to expand and retract into the vane slot, is Since gaseous fluid can be supplied instantaneously, there is no pressure drop in the vane back pressure chamber, which prevents vane malfunctions and compression failures.After startup, the passage opening/closing means shuts off the gas supply passage, so the vane An appropriate amount of lubricating oil is supplied to the back pressure chamber from the oil supply passage without compromising durability or efficiency.

[Brief explanation of drawings]

1 and 2 are enlarged sectional views of main parts of a vane back pressure applying device according to a first embodiment of the present invention, and FIG.
FIG. 4 is a longitudinal cross-sectional view of a sliding vane compressor equipped with a vane back pressure applying device according to an embodiment of the present invention; FIG. 4 is a cross-sectional view taken along line Y-Y in FIG. 3; 2
FIG. 8 is an enlarged cross-sectional view of essential parts of a vane back pressure applying device in the second embodiment of the present invention, and FIG. 9 is a longitudinal cross-sectional view of a sliding vane compressor equipped with a vane back pressure applying device in a second embodiment of the present invention. is a cross-sectional view taken along line 2-2 in Fig. 8;
The figure is a longitudinal cross-sectional view of a sliding vane compressor equipped with a conventional vane back pressure applying device, and Figure 11 is the X of Figure 10.
12 is an enlarged sectional view of a main part of a conventional vane back pressure applying device. 1... Cylinder, 2... Rotor, 3...
... Vane slot, 4 ... Vane, 5
...ffi movement [1iEII, 6...Face side plate, 7...Rear side plate, 8...Working chamber, 9...Intake port , 1o...discharge port,
11: Discharge valve, 12: High pressure case, 14: High pressure chamber, 17: Vane back pressure chamber, 18: Oil supply passage, 27...First gas supply passage, 28...Sliding chamber, 29...
・Valve body, 31... Pressure introduction path, 32...
- Spring, 33...Second gas supply passage. Name of agent Patent attorney Ken Nakao Male and 1 other person Gupitee #Se11 Yu] Oka 5. Figure 2/--- Sirin 7- IL- Discharge valve 17 -- Vane back 1 is rainbow 1? Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 1110 Figure 11, 9

Claims (2)

[Claims] (1) A cylinder having a cylindrical inner wall, a rotor disposed inside the cylinder and having a part of its outer periphery forming a minute gap with the inner wall of the cylinder, and a rotor that can freely slide into a vane slot provided in the rotor. a plurality of inserted vanes, a drive shaft formed integrally with the rotor and rotatably supported, and a front side plate and a rear side plate that close both ends of the cylinder to form a working chamber therein; A suction port and a discharge port that communicate with the working chamber across a portion where the outer circumference of the rotor and the inner wall of the cylinder are close to each other, a discharge valve provided at the discharge port, and a compressed high-pressure fluid that communicates with the discharge port. a high-pressure case having a high-pressure chamber that separates lubricating oil therein and includes an oil reservoir in its lower part; a vane back pressure chamber formed by the vane slot and the vane end; and an oil reservoir of the high-pressure chamber; a gas supply passage communicating between the vane back pressure chamber and any high-pressure side space other than the oil reservoir in the refrigeration cycle including the compressor; and at least a high-pressure side fluid and a low-pressure side fluid. a sliding vane type comprising a passage opening/closing means that communicates the gas supply passage when the compressor is started from a state where there is no or small pressure difference, and shuts off the gas supply passage at least during the compressor operation except at the time of starting; Compressor vane back pressure application device. (2) The passage opening/closing means includes a first gas supply passage communicating with the vane back pressure chamber, a sliding chamber into which the first gas supply passage opens, and a sliding chamber that is slidably inserted into the sliding chamber and has both ends thereof. a valve body forming a first sliding chamber and a second sliding chamber into which the first gas supply passage opens; and a valve body that forms a first sliding chamber and a second sliding chamber in which the first gas supply passage opens, and the second sliding chamber and a discharge passage immediately before the discharge valve or an operating chamber in the vicinity of the discharge valve. a pressure introduction path that communicates with the valve body, a spring that biases the valve body toward the second sliding chamber, and a spring that is cut off from the first gas supply passage when the valve body moves toward the first sliding chamber. When the valve body moves toward the second sliding chamber, one end thereof is opened to the first sliding chamber and the other end thereof is opened to the upper part of the high pressure chamber so as to communicate with the first gas supply passage. Claim 1, comprising: a second gas supply passage;
A vane back pressure applying device for a sliding vane compressor as described in 2.