JPH0643837B2 - Vane back pressure application device for sliding vane compressor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane back pressure applying device used in a sliding vane compressor used for an air conditioner for automobiles and the like.

As is well known in the art, in a sliding vane compressor, high pressure lubricating oil is applied to the rear end of the vane by a pressure difference so that the vane makes a rotary sliding motion by contacting the tip of the vane with the inner wall of the cylinder as the rotor rotates. Supplying structures are widely used.

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

2 to 4 show a specific configuration of a sliding vane type compressor having a conventional differential pressure oil supply type vane back pressure 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 a vane slot 4. A plurality of vanes 5 slidably inserted into the rotor 5 are drive shafts formed integrally with the rotor 2 and rotatably supported therein. Reference numerals 6 and 7 respectively close both ends of the cylinder 1 to provide a working chamber 8 inside. Are a front side plate and a rear side plate that form a. Reference numeral 9 is an intake port communicating with the low pressure side working chamber 8, 10 is a discharge port communicating with the high pressure side working chamber 8, 11 is a discharge valve disposed at the discharge port, 12
Is a screen 15 for forming a high pressure chamber 14 communicating with the high pressure passage 13 and separating and capturing lubricating oil in the compressed high pressure fluid.
Is a high-pressure case in which Reference numeral 16 is a main body of the vane back pressure applying device disposed on the rear side plate 7, and supplies the lubricating oil in the oil reservoir below the high pressure side 14 to the vane back pressure chamber 17. 1
Reference numeral 8 is an oil supply passage that connects the oil sump below the high pressure chamber 14 and the vane back pressure chamber 17, 19 is a passage that limits the amount of oil supply by differential pressure, 20 is a ball seat provided in the middle of the oil supply passage 18, 21
Is a sphere that comes into contact with or separates from the ball seat 20 to cut off the communication of the oil supply passage 18, 22 is a plunger chamber that opens to the ball seat 20, and 23 is slidably disposed inside the plunger chamber 22 and is directed toward the ball seat 20 side. A plunger which disengages the spherical body 21 from the ball seat 20 when moved is a pressure introducing passage 24 which connects the lower plunger chamber 25 at the lower end of the plunger and the working chamber 8 immediately before the discharge valve 11.

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

When the drive shaft 5 and the rotor 2 rotate clockwise in FIG. 4 in response to power transmission from a drive source such as an engine,
Along with this, the low-pressure fluid flows into the working chamber 8 through the suction port 9. The high-pressure fluid compressed by the rotation of the rotor 2 pushes up the discharge valve 11 from the discharge port 10 and flows into the high-pressure chamber 14 through the high-pressure passage 13, and the screen 15 separates and captures the lubricating oil. On the other hand, from the pressure introducing passage 24, the overcompressed gas in the working chamber 8 having a pressure enough to overcome the pressure force of the high-pressure fluid and push up the discharge valve 11 is the lower plunger chamber 2
5, the plunger moves to the side of the ball seat 20 and separates the ball 21 from the ball seat 20. Therefore, since the oil supply passage 18 is communicated, the lubricating oil separated from the high pressure fluid and stored in the lower portion of the high pressure chamber 14 is supplied to the vane back pressure chamber 17 from the passage 19 and the oil supply passage 18 due to the differential pressure. It is used for pressing and flows into the working chamber 8 through the gap between the rotor 2 and the front side plate 6 and the rear side plate 7.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-mentioned conventional vane back pressure application device, when the compressor rotates at a high speed, the vane 4 rotates in accordance with the rotation of the row 2 and the vane slot 3 is extended and immersed at a high speed. The amount of lubricating oil supplied to the vane back pressure chamber 17 increases dramatically. The lubricating oil supplied to the vane back pressure chamber 17 is the rotor 2
And a minute gap between the front side plate 6 and the rear side plate 7, a minute gap between the vane 4 and the vane slot 3, and the vane 4.
Through the minute gap between the front side plate 6 and the rear side plate 7 and leaks into the working chamber 8 and flows out into the high pressure chamber 14 together with the compressed gas. In the high pressure chamber 14, a part of the lubricating oil is separated and captured by the screen 15 and collected under the high pressure chamber 14, but most of the lubricating oil jumps out into the refrigeration cycle (not shown) because the compressed gas flows at a high speed. Become. When the rotational speed of the compressor is rapidly decelerated from this state, the lubricating oil in the high-pressure chamber is almost exhausted, so that sufficient lubricating oil cannot be supplied.
As a result, the pressure in the vane back pressure chamber 17 is reduced, and the so-called vane malfunction occurs in which the vane 4 is separated from the inner wall of the cylinder 1 and collides again. Similarly, when the compressor is rotating at high speed, C. R. (Oil circulation rate) increases, the heat exchange rate in the evaporator (not shown) decreases, and the cooling performance as the refrigeration cycle decreases. Further, as a compressor, too much lubricating oil is supplied to the vane back pressure chamber 17, so that the vane 4 is pressed against the inner wall of the cylinder 1 excessively.
There is a problem that durability of the compressor and efficiency are deteriorated as a result of increasing wear of the tip end of the cylinder and the inner wall of the cylinder 1 and increasing input of the compressor.

In view of the above problems, the present invention suppresses the excessive supply of the lubricating oil to the vane back pressure chamber 17 when the compressor is rotating at high speed, and can prevent the malfunction of the vane when the speed is rapidly reduced,
A vane back pressure applying device for a sliding vane compressor having high efficiency and high durability.

Means for Solving the Problems In order to solve the above problems, the vane back pressure imparting device of the sliding vane compressor of the present invention, in addition to the oil supply passage and the oil passage opening / closing means of the conventional compressor, The gas passage opening / closing means includes a gas passage that is in the middle of the oil supply passage and communicates with the upper portion of the high pressure chamber, and a spring that biases a piston that is slidably provided so as to block the gas passage.

Operation According to the present invention, with the above configuration, when the compressor is rotating at a low speed, the piston provided in the gas passage is in a state where the gas passage is closed by the spring, and the lubricating oil accumulated in the lower part of the high pressure case is An appropriate amount of oil is supplied from the oil passage to the back pressure chamber of the vane, and the malfunction of the vane can be prevented. Further, when the compressor rotates at high speed, since the compressor is fixed to the engine, its vibration acceleration causes the piston forming the one-degree-of-freedom vibration system to vibrate, and the gas passage is repeatedly opened and closed. In such a state, the distribution resistance of the high-pressure gas when the high-pressure gas passes through the gas passage is smaller than the distribution resistance when the lubrication oil passes through the oil supply passage. Limited to. Therefore, it is possible to prevent a malfunction of the vane when the compressor is rapidly decelerated, and to provide a highly efficient and highly durable compressor.

Embodiment One embodiment of the present invention will be described below with reference to FIG. 1 of the accompanying drawings.

In the figure, components having the same effects as those of the conventional vane back pressure imparting device of the sliding vane compressor are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 26 is a gas passage communicating from the oil supply passage 18 to the upper portion of the high pressure chamber 14. A piston 27 is slidably provided inside the gas passage 26 in a direction to block the gas passage 26. A spring 29 is provided to urge the piston 27 to come into contact with a valve seat 28 provided in the middle of the gas passage 26.

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

When the compressor is rotating at a low speed, the piston 27 is in contact with the valve seat 28 provided in the middle of the gas passage 26 by the urging force of the spring 29, and the gas passage is blocked.
In this state, the lubricating oil is sent to the vane back pressure chamber 17 through the oil supply passage 18 by the high pressure gas pressure in the high pressure chamber 14 and is used for pressing the vane. This is because the vane back pressure of the conventional sliding vane compressor is applied. It is similar to the device. When the compressor rotates at high speeds, the vibration of the engine to which it is fixed-vibrates the piston 27 and the spring 29 forming a vibration system of degrees of freedom, which causes the valve seat 28 to open or shut off. Or At this time, the distribution resistance when the high-pressure gas passes through the gas passage 26 is smaller than the distribution resistance when the lubricating oil passes through the oil supply passage 18, so that the lubricating oil does not pass through the oil supply passage. Therefore, from the vane back pressure chamber 17 to the rotor 2, a minute gap between the front side plate 6 and the rear side plate 7, a minute gap between the vane 4 and the vane slot 3, and between the vane 4 and the front side plate 6, the rear side plate 7. The amount of lubricating oil that leaks into the working chamber 8 through the minute gap is reduced, and the amount of lubricating oil that jumps out into the refrigeration cycle is also reduced. Therefore, even if the compressor is rotating at a high speed, if the lubricating oil is retained in the high pressure chamber 12 and the rotation speed is rapidly reduced from this state, the vibration acceleration of the compressor fixed to the engine becomes small and the piston 27 becomes The gas passage 26 is immediately shut off by the biasing force of the spring 29, so that the lubricating oil accumulated in the high pressure chamber 12 is supplied to the vane back pressure chamber 17 through the oil supply passage 18 in an appropriate amount. Therefore, since the vane back pressure chamber 17 is operated without a pressure drop, the vane malfunction does not occur. Further, excessive supply of lubricating oil to the vane back pressure chamber 17 during high speed rotation can be prevented, the efficiency of the compressor can be improved, and damage to the vane tip due to wear can be minimized.

As described above, according to the present embodiment, the oil supply passage that connects the vane back pressure chamber and the oil reservoir of the high pressure chamber, the gas passage that is in the middle of the oil supply passage and that communicates with the upper portion of the high pressure chamber, and the gas passage are blocked. Even if the compressor rotates at high speed, it is possible to prevent excessive supply of lubricating oil by providing the gas passage opening / closing means that consists of a spring that biases the piston that is slidable in the desired direction. Damage to the vane tips due to wear can also be minimized. Furthermore, since the lubricating oil in the high pressure case can be retained even when the speed is rapidly reduced from the high speed rotation, the vane malfunction phenomenon can be prevented.

In this embodiment, the sliding vane type compressor has a perfect circular type having only one suction port 9 and one discharge port 10 but may have a plurality of suction ports 9 and plural discharge ports 10. Also, the number of vanes 4 is shown as four, but any number may be used.

As described above, the present invention is, as a vane back pressure applying device for a sliding vane compressor, an oil supply passage communicating with an oil sump portion of a vane back pressure chamber and a high pressure chamber, and the high pressure in the middle of the oil supply passage. Even if the compressor rotates at a high speed, the lubricating oil is provided by providing the gas passage communicating with the upper part of the chamber and the gas passage opening / closing means including the spring for biasing the piston slidably provided so as to block the gas passage. It prevents excessive supply of oil, can achieve high efficiency, can minimize damage due to vane tip wear, and retain lubricating oil in the high pressure chamber even when the speed is rapidly reduced from high speed. Therefore, the vane malfunction phenomenon can be prevented and a highly reliable compressor can be provided.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a vane back pressure applying device according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a sliding vane compressor equipped with a conventional vane back pressure applying device.
FIG. 3 is a sectional view taken along the line XX in FIG. 2, and FIG. 4 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 ... Drive shaft, 6 ... Front side plate, 7
...... Rear side plate, 8 ...... Working chamber, 9 ...... Intake port, 10 ......
Discharge port, 11 ... Discharge valve, 14 ... High pressure chamber, 17 ... Vane back pressure chamber, 18 ... Oil supply passage, 26 ... Gas passage, 2
7 ... piston, 28 ... valve seat, 29 ... spring.

Claims (1)

[Claims] 1. A cylinder 1 having a cylindrical inner wall, a row 2 arranged inside the cylinder 1 and a part of the outer periphery of which forms a minute gap with the inner wall of the cylinder, and a vane slot provided in the rotor 2. 3, a plurality of vanes 4 slidably inserted in the shaft 3, a drive shaft integrally formed with the row 2 and rotatably supported, and both ends of the cylinder 1 closed to form a working chamber inside. Front side 6 and rear side plate 7 forming a
A suction port 9 and a discharge port 10 which communicate with the working chamber across a portion where the outer circumference of the rotor 2 and the inner wall of the cylinder 1 are close to each other, a discharge valve provided at the discharge port 10 and a discharge port 10. A high pressure case 12 having a high pressure chamber 14 for separating lubrication in a compressed high pressure fluid and including an oil sump portion in a lower portion thereof, and a vane back pressure chamber formed by the vane slot 3 and the vane end portion. An oil supply passage 18 that communicates 17 with the oil sump of the high pressure chamber 14, and a gas passage 26 that is in the middle of the oil supply passage 18 and that communicates with the upper portion of the high pressure chamber 14.
A vane back pressure applying device for a sliding vane compressor, comprising: a gas passage opening / closing means for urging a piston 27 slidably provided so as to block the gas passage 26.