JPH0129997B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a lubricating device for a vane rotary compressor, and in particular a lubricating device suitable for use in a vane rotary compressor used in an automobile air conditioner. It provides:

Conventional configuration and its problems As is well known, in vane rotary compressors, high-pressure lubrication is constantly applied to the bottom of the vane so that as the rotor rotates, the vane rotates and slides with its tip in contact with the inner wall of the cylinder. A structure that allows oil to act is used. Generally, the means to achieve this are the forced lubrication system, which uses a pump installed on the drive shaft of the compressor to forcibly supply lubrication, and the other, which uses the pressure of high-pressure fluid compressed by the compressor to create a pressure difference between the high and low pressures of the compressor. A differential pressure lubrication system is widely used.

However, in the forced lubrication system, the amount of oil supplied increases as the rotation speed of the compressor increases, and this, combined with the centrifugal force acting on the vanes, causes the vanes to be pushed into excessive contact with the cylinder inner wall, increasing wear on the vane tips and the cylinder inner wall. This results in an increase in the input power of the compressor, which has the disadvantage of deteriorating the durability and efficiency of the compressor.

On the other hand, in the differential pressure lubrication type, the above phenomenon can be alleviated by eliminating excessive lubrication, which causes the same drawbacks as in the case of the forced lubrication type, and by providing a mechanism in the lubrication passage to limit the amount of lubrication. However, in this case, even when the compressor is stopped after operation, the high-pressure side lubricating oil and high-pressure fluid continue to be supplied to the bottom of the vane due to the pressure difference between the high and low pressures of the compressor, and the lubricating oil accumulates inside the cylinder, preventing the compressor from starting. This sometimes causes problems such as oil compression or reversing the compressor.

For this reason, the conventional differential pressure oil supply type has a mechanism in the oil supply passage that shuts off the oil supply passage when the compressor is stopped, and connects the oil supply passage when the compressor is in operation.

Figures 1 to 3 show the specific configuration of a vane rotary compressor having a conventional differential pressure oil supply system, in which 1 is a cylinder having a cylindrical inner wall, and 2 is a cylinder with a part of its outer periphery. A rotor 3 forms a small space between the inner wall and a plurality of vanes slidably inserted into a vane slot 4 provided in the rotor 2.
5 is a drive shaft formed integrally with the rotor 2 and rotatably supported, and 6 and 7 are cylinders 1, respectively.
A front side plate and a rear side plate which close both ends to form a working chamber 8 inside, 9 is an inlet that communicates with the working chamber on the low pressure side, 10 is a discharge port that communicates with the working chamber 8 on the high pressure side, and 11 is a a discharge valve disposed at the discharge port 10;
12 communicates with a high pressure passage 13 and has a high pressure chamber 1 therein.
4, a high-pressure case is provided with a screen 15 for separating and capturing lubricating oil in the compressed high-pressure fluid;
25 is a fuel supply device body attached to the rear side plate 7;
Reference numeral 16 indicates an oil supply passage that communicates the oil reservoir below the high pressure chamber 14 with the vane bottom space 17, 18 indicates a passage that limits the amount of oil supply, 19 indicates a spherical valve seat provided in the middle of the oil supply passage 16 and holds the sphere 20, and 21 23 is a sliding chamber whose one end is open to the spherical valve seat 19 and whose other end is communicated with the working chamber 8 on the high pressure side through a passage 22b and a passage 22a formed in the screw portion of the stopper body 22c; It is slidably arranged inside the room and has a fuel supply passage 1 at one end.
This is a plunger that receives the fluid pressure of the working chamber 8 on the high pressure side at the other end.

The operation of the vane rotary compressor oil supply system configured as described above will be described below. When the drive shaft 5 and rotor 2 rotate clockwise in FIG. 2 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 is discharged from the discharge port 10 through the discharge valve 11.
The lubricating oil is pushed up and flows into the high pressure chamber 14 from the high pressure passage 13, and the lubricating oil is separated and captured by the screen 15. The lubricating oil separated from the high pressure fluid is stored below the high pressure chamber 14.

On the other hand, the pressure in the working chamber 8 on the high pressure side acts on the lower end surface of the plunger 23, so the plunger 23 moves upward to overcome the pressure on the upper end surface of the plunger 23, releasing the sphere 20 from the spherical valve seat 19. The oil supply passage 16 is communicated. Therefore, hyperbaric chamber 1
4 The lubricating oil stored below flows into passage 1 due to the differential pressure.
8 and passage 16 to the vane bottom space 17 and used to press the vane 3.

Next, when the compressor stops, the pressure in the working chamber 8 rapidly decreases to the pressure of the fluid on the low pressure side due to leakage from the longitudinal gap of the vane 3, so the force acting on the lower end surface of the plunger 23 is It is smaller than the force due to the pressure of the high pressure chamber 14 acting on the upper end surface,
As the plunger 23 moves downward, the sphere 20 is also held in close contact with the spherical valve seat 19 and the oil supply passage 16
is blocked. Therefore, since the lubricating oil below the high pressure chamber 14 is no longer supplied to the vane bottom chamber 17, the lubricating oil will not accumulate inside the cylinder 1 and cause oil compression when the compressor is started, or This prevents the high pressure lubricating oil and fluid flowing into the working chamber 8 from re-expanding and causing the compressor to reverse rotation.

However, when the compressor is started after a certain period of time has passed since the compressor stopped and the pressure of the fluid on the low pressure side becomes equal to the pressure of the fluid on the high pressure side,
In the above-mentioned conventional oil supply system, since the oil supply passage 16 is blocked, lubricating oil is not supplied from immediately after the compressor starts until the plunger 23 releases the sphere 20 from the sphere valve seat 19, and the high and low pressure immediately after the compressor starts. If the difference is small, use the passage 18 with a small passage area.
Therefore, in the conventional oil supply system described above, especially when the rotation speed at the time of starting the compressor is low and the centrifugal force acting on the vanes is small, an insufficient amount of lubricating oil is supplied, that is, an insufficient pressure on the vanes 3, and the vanes are damaged. 3
This has disadvantages in that the well-known malfunction phenomenon in which the fluid is separated 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 occur.

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention is designed to prevent vane malfunction and poor compression even when the compressor is operated at low speed when there is no or small pressure difference between high and low pressures of the compressor, and to improve durability and efficiency. To provide a vane rotary compressor oiling system that does not damage the oil supply system.

Composition of the Invention The present invention provides a lubricating device for supplying lubricating oil for pressing vanes in a vane rotary compressor from an oil reservoir in a high pressure chamber to a vane bottom space, and includes a passage opening/closing means for disconnecting communication between an oil supply passage and an oil supply passage. and passage area control means for controlling the communication area of the passage area to be large or small,
The passage opening/closing means operates for a certain period of time from the time when the compressor stops operating, or after the compressor stops operating, when the pressure difference between the high pressure side and the low pressure side inside the compressor decreases over time and becomes lower than a certain value. The passage area control means operates to shut off the oil supply passage until the pressure becomes small and to open it in other cases, and the passage area control means shuts off the oil supply passage when the pressure difference between high and low pressures is small within a certain period of time immediately after the compressor starts operating. The communication area of the passage is made large, and the communication area of the oil supply passage is made small after a certain period of time has passed after the start of operation of the compressor.

With this configuration, 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, the oil supply passage from the high pressure chamber to the vane bottom space is communicated at the time of startup, and the passage area of the oil supply passage is controlled. Since the means operates to increase the passage area, the necessary amount of lubricating oil can be supplied, and has the unique effect of preventing vane malfunctions and poor compression phenomena.

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

FIG. 4 shows an enlarged cross-sectional view of the essential parts of the oil supply system for a vane rotary compressor according to an embodiment of the present invention, which is the same part as the oil supply system for the conventional vane rotary compressor. Components having the same functions and effects will be designated by the same reference numerals and the description thereof will be omitted.

In the figure, 26 is the high pressure chamber 1 of the oil supply passage 16.
4 a valve body sliding chamber provided in the communicating portion and in which the valve body 27 is slidably disposed; 28 a valve seat provided in the communicating portion of the oil supply passage 16 of the valve body sliding chamber 26; 29 a valve body 27; An auxiliary passage 30 is provided in the valve body 27 and is cut off from the oil supply passage 16 when the valve body 27 comes into contact with the valve seat 28 and has a large passage area. Even if the oil supply passage 16
31 is a spring that biases the valve body 27 in a direction to separate from the valve seat 28; 32 is a retaining ring that restricts the sliding of the valve body 27;
3 is a spring that biases the plunger in a direction to release the sphere 20 from the sphere valve seat 19.

The operation of the vane rotary compressor oil supply system configured as described above will be described below.

During steady operation of the compressor, fluid pressure on the high pressure side acts on the lower end surface of the plunger 23, the sphere 20 is released from the spherical valve seat 19, the oil supply passage 16 is communicated, and the valve body 27 is filled with lubricating oil from the high pressure chamber 14. Due to the flow resistance caused by the flow, the biasing force of the spring 31 and the valve body 27
The lubricating oil stored below the high pressure chamber 14 is supplied to the bottom space of the vane from the passage 30 and the passage 16, and is pressed against the valve seat 28 by overcoming its own weight and the sliding resistance of the valve body 27. What is provided is the same as the oil supply system for the conventional vane rotary compressor.

Also, when the compressor stops operating, the plunger 23
The pressure of the high pressure chamber 14 acting on the upper end surface overcomes the force acting on the lower end surface of the plunger 23 and the biasing force of the spring 33, causing the plunger 23 to move downward, and the spherical body 20 is also held in close contact with the spherical valve seat 19. Similarly to the conventional vane rotary compressor oil supply system, the oil supply passage 16 is blocked to prevent oil compression or reverse rotation of the compressor when starting the compressor.

When the compressor stops and the oil supply passage 16 is shut off, the valve body 27 is moved by the biasing force of the spring 31 and comes into contact with the retaining ring 32, so that the auxiliary passage 29 is closed.
communicates with the oil supply passage 16. When a certain period of time passes after the compressor stops and the pressure difference between high and low pressures gradually decreases to a certain value or less, the plunger 23 moves upward due to the biasing force of the spring 33 to remove the sphere 20 from the sphere valve seat 19. Release. In this case spring 33
By appropriately selecting the biasing force, the pressure difference between the high and low pressures at the time when the oil supply passage 16 communicates with each other can be set so as to prevent the problems of oil compression and reversal from occurring.

Therefore, when there is no pressure difference between the high and low pressures of the compressor, the sphere 20 is separated from the sphere valve seat 19 and the oil supply passage 16 is in communication with the high pressure chamber 14.
The bottom space of the vane is an auxiliary passage 2 with a large passage area.
9 and an oil supply passage 16. When the compressor is started in this state, high pressure chamber 1
4. Since lubricating oil can be supplied through the passage with a large passage area, there is no insufficient pressure on the vanes even when the compressor is started, and therefore the aforementioned vane malfunction and poor compression phenomenon can be prevented. be.

As the operation continues, the pressure difference between high and low pressures gradually increases, and the amount of lubricating oil supplied from the oil supply passage 16 to the bottom of the vane increases. seat 28
Since the compressor is in contact with the compressor, the durability and efficiency of the compressor will not be impaired due to excessive oil supply over a long period of time.

As described above, according to this embodiment, the spherical body provided in the middle of the oil supply passage is used as the oil supply device for supplying lubricating oil for vane pressing in the vane rotary compressor from the oil reservoir of the high pressure chamber to the vane bottom space. a spherical valve seat to be held; a sliding chamber having one end open to the spherical valve seat and the other end communicating with a high-pressure side working chamber; a plunger slidably disposed within the sliding chamber;
The plunger is arranged to be able to slide freely within the valve body sliding chamber provided in the high pressure chamber communication portion of the oil supply passage, and a spring that exerts a biasing force in a direction to release the sphere from the spherical valve seat. When the valve body is in contact with the valve seat, the valve body is cut off from the oil supply passage and has a large passage area. an auxiliary passage provided in the valve body, a passage provided in the valve body that communicates with the oil supply passage and limits the amount of oil supplied even when the valve body contacts the valve seat, and a direction in which the valve body is separated from the valve seat. By providing a spring that biases the valve body and a retaining ring that restricts the sliding of the valve body, even if the compressor is started at low speed when there is no or small pressure difference between the high and low pressures of the compressor,
The oil supply passage from the high pressure chamber to the vane bottom space is communicated at the time of startup, and the passage area of the oil supply passage is also increased by communication with the auxiliary passage, so the lubricating oil necessary for pressing the vane can be quickly supplied. Furthermore, when the difference in high and low pressure becomes large and it becomes possible to supply sufficient lubricating oil through the differential pressure, the passage area can be reduced to limit the amount of lubricating oil that can be supplied to the bottom space of the vane, improving the durability and efficiency of the compressor. It is possible to prevent vane malfunctions and compression failures without damaging the performance.

Effects of the Invention As described above, the present invention is an oil supply device that supplies lubricating oil for pressing vanes in a vane rotary compressor from an oil reservoir in a high pressure chamber to a vane bottom space. means and a passage area control means for restricting the communication area of the oil supply passage to a large or small one, and the passage opening/closing means is configured to open and close the inside of the compressor for a certain period of time from the time when the compressor stops operating, or after the compressor stops operating. The passage area control means operates to shut off the oil supply passage until the pressure difference between the high pressure side and the low pressure side decreases over time and becomes smaller than a certain value, and otherwise communicates with the oil supply passage. When the pressure difference between high and low pressures is small within a certain period of time immediately after the compressor starts operating, the communication area of the oil supply passage is made large, and after a certain period of time after the compressor starts operation, the communication area of the oil supply passage is made small. Even if the compressor is started at low speed when there is no or small pressure difference between the high and low pressures of the compressor, the oil supply passage from the high pressure chamber to the vane bottom space is connected at the time of startup, and the passage of the oil supply passage is Since the area control means operates so that the passage area becomes large, the necessary lubricating oil can be quickly supplied, and as time passes, the difference in high and low pressure increases and sufficient lubricating oil is supplied by the differential pressure. When this becomes possible, the passage area control means operates to reduce the passage area, thereby limiting the amount of lubricating oil and supplying it to the vane bottom space. The phenomenon of poor compression can be prevented, and its practical effects are great.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view of a vane rotary compressor equipped with a conventional oil supply device, Figure 2 is a cross-sectional view taken along the line X--X of Figure 1, and Figure 3 is a conventional oil supply of a vane rotary compressor. FIG. 4 is an enlarged sectional view of a main part of an oil supply device for a vane rotary compressor according to an embodiment of the present invention. 1... Cylinder, 2... Rotor, 3... Vane, 4... Vane slot, 5... Drive shaft, 6...
...Front side plate, 7...Rear side plate, 8...Working chamber, 9
...Suction port, 10...Discharge port, 11...Discharge valve,
12...High pressure case, 14...High pressure chamber, 16...
Refueling passage.

Claims (1)

[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 cylinder inner wall, and a rotor slidably inserted into a vane slot provided in the rotor. a plurality of vanes, a drive shaft formed integrally with the rotor and rotatably supported; a front side plate and a rear side plate that close openings at both ends of the cylinder to form an operating chamber therein; a suction passage and a discharge passage formed by communicating with the working chamber across a portion where the rotor outer periphery and the cylinder inner wall are close to each other;
A case having a discharge valve disposed in the middle of the discharge passage, a high pressure chamber that separates lubricating oil in the compressed high pressure fluid that communicates with the discharge passage and forms an oil reservoir in the lower part thereof, and A lubrication device for a vane rotary compressor, comprising an oil supply passage that communicates an oil reservoir in a chamber with the vane slot and supplies lubricating oil into the vane slot, the oil supply passage being cut off from communication in the middle of the oil supply passage. The passage opening/closing means has a passage opening/closing means and a passage area control means for controlling the communication area of the oil supply passage to be large or small, and the passage opening/closing means is configured to open and close the passage for a certain period of time after the compressor stops operating or after the compressor stops operating. The oil supply passage is shut off until the internal pressure difference between the high pressure side and the low pressure side decreases with the passage of time and becomes smaller than a certain value, and otherwise communicated, and the passage area control means compresses the oil supply passage. Vane rotation that increases the communication area of the oil supply passage when the pressure difference between high and low pressures is small within a certain period of time immediately after the compressor starts operating, and reduces the communication area of the oil supply passage after a certain period of time after the compressor starts operation. Oil supply system for type compressor.