JP3243946B2 - Oil-cooled rotary compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-cooled rotary compressor, and more particularly to an oil-cooled rotary compressor which eliminates an inability to supply oil to a compressor main body due to a breakage of a pilot pressure introducing pipe or the like.

[0002]

2. Description of the Related Art Oil-cooled rotary compressors such as screw compressors and slide vane compressors are driven by being directly connected to a prime mover such as a diesel engine, and receive oil for cooling and lubrication of the compressor body. Compressed air is sent. FIG. 5 shows an example of a piping system of this conventional oil-cooled rotary compressor. The rotary compressor 31 includes an oil-cooled compressor main body 32, an oil tank 35A connected to the compressor main body 32 via an oil supply pipe 34, and compressed air containing oil discharged from the compressor main body 32. The pipeline
Separator 35B that stores through 36 and separates into compressed air and oil
And a receiver tank 35 having a built-in. The oil supply pipe 34 is provided with an oil cooler 37, an oil filter 38, and an oil check valve 39 from the upstream side. Further, a pipe 40 is connected to the receiver tank 35, and an automatic relief valve 41 for automatically releasing the pressure in the receiver tank 35 to the atmosphere when the compressor body 32 is stopped is provided in the pipe 40. I have. Oil check valve 39
The working pressure chamber 39A is connected to the discharge chamber 21 of the compressor body 32 via a pilot pressure introducing pipe 42. 41A is an air chamber.

The structure of an oil check valve 39 used in the rotary compressor 31 is, as shown in FIG. 6, connected to an oil inlet 44 connected to the oil feed pipe 34 and an oil inlet to the compressor body 32. Discharge port 45 and the pilot pressure introduction pipe 42
A valve body 48 for opening and closing an oil passage 47 communicating with the oil suction port 44 and the discharge port 45, and a valve body 48 that slides by receiving the pressure in the operation pressure chamber 39A. A piston 49 connected to the body 48 and a coil spring 50 as an elastic member that constantly urges the valve body 48 in a direction to close the oil passage 47 are provided.

In the conventional rotary compressor 31 provided with such an oil check valve 39, during operation, the compressor body 32
The air compressed in the compression action space 32 </ b> A is pressed into the receiver tank 35 through the pipe 36. Although the compressed air contains mist-like lubricating oil, it is separated into compressed air and oil by an oil separator 35B. The lubricating oil O is stored in an oil tank 35A of the receiver tank 35, and the oil supply pipe 34 is
From the oil cooler 37 and the oil filter 38 to the oil check valve 39. On the other hand, an operating pressure chamber 39A of an oil check valve 39 communicating with the discharge chamber 21 of the compressor main body 32 and the pilot pressure introducing pipe 42 presses the piston 49 with the discharge air pressure immediately after being discharged from the compressor main body 32,
The valve element 48 moves rightward in the figure against the elastic force of the coil spring 50, and opens the oil passage 47. As a result, the lubricating oil is supplied to the compression action space 32A of the compressor body 32, and the lubrication, sealing, cooling, and the like of the compression action space 32A are performed. When the compressor main body 32 is stopped, the pressure in the working pressure chamber of the auto relief valve 41 communicating with the discharge chamber 21 of the compressor main body 32 via a pilot pipe (not shown) decreases, and the auto relief valve 41 is opened. Thereby, the compressed air in the receiver tank 35 is automatically released to the atmosphere. With the stop of the compressor, the pressure in the discharge chamber 21 of the compressor body 32 also decreases, so the pressing force of the piston 49 weakens, and the urging force of the coil spring 50 moves the valve body 48 to the left side in the drawing.
The oil passage 47 is closed, and the supply of the lubricating oil to the compressor body 32 is immediately stopped. With this, the compressor body 32 at the time of stop
The lubricating oil is prevented from flowing into the inside, and an oil lock accident in the compression action space 32A at the next start is prevented.

[0005]

However, in the conventional oil-cooled rotary compressor 31, if the pilot pressure introducing pipe 42 is damaged due to vibration or deterioration of the machine, the transmission of the pilot pressure to the oil check valve 39 is not possible. Because it stops,
The pressing force of the piston 49 disappears, and the valve body 48 moves to the left side in the figure by the urging force of the coil spring 50, the oil passage 47 closes, and the supply of the lubricating oil to the compressor body 32 stops. Therefore, when the compressor is started in this state, the compressor body 32
If the supply of lubricating oil to the compressor becomes impossible and the operation is continued as it is, there is a problem that burnout is caused due to an increase in the temperature of the discharge air of the compressor body 32 and heating of the bearing due to poor lubrication. For this reason, the pilot pressure introduction pipe of the oil-cooled rotary compressor 31
Improvement in reliability at the time of breakage such as 42 was desired.

The present invention has been made based on the above problems, and an object of the present invention is to provide an oil-cooled rotary compressor which eliminates an inability to supply oil to a compressor main body due to breakage of a pilot pressure introduction pipe or the like. And

[0007]

According to a first aspect of the present invention, there is provided an oil-cooled rotary compressor, wherein the oil-cooled rotary compressor communicates with the compressor main body via an oil supply pipe. An oil storage unit for storing oil to be supplied to the main body, a receiver tank containing a separator for storing compressed air containing oil discharged from the compressor main body and separating the compressed air into oil, and the compressor In an oil-cooled rotary compressor having an automatic relief valve that automatically discharges compressed air in a receiver tank to the atmosphere when the main body is stopped, an oil feed pipe communicating with a compressor main body from an oil reservoir of the receiver tank is provided. An oil check valve for closing the oil passage by pilot pressure is provided on the way, and an operating pressure chamber of the oil check valve is connected to a secondary piping port of the auto relief valve via a pilot pressure introducing pipe. It is connected to an air chamber via a three-port air control valve that branches off to the pipe and communicates and shuts off a passage, and the air control valve communicates with a discharge chamber of the compressor body to discharge the pressure of the compressor body. It is constituted so that it may operate.

[0008]

According to the first aspect of the present invention, since the air control valve is configured to communicate with the discharge chamber of the compressor main body to operate by the discharge pressure of the compressor main body, the operation of the compressor main body is performed. Sometimes, while the pilot pressure introduction pipe is closed to open the oil check valve, when the compressor body stops and the pressure in the discharge chamber of the compressor body decreases, the pilot pressure introduction pipe opens to open the air chamber 11.
The oil check valve can be forcibly closed by the compressed air pressure introduced through the air control valve 12 from above. Also, even if the pilot pressure introduction pipe is broken and the pilot pressure is no longer introduced into the oil check valve, the valve is opened by the lubricating oil pressure, so lubricating oil can be supplied to the compressor body. Therefore, the reliability can be improved without being burned out due to the inability to supply the lubricating oil as in the related art.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. In FIG. 1, reference numeral 1 denotes an oil-cooled rotary compressor. The oil-cooled rotary compressor 1 includes an oil-cooled rotary compressor main body 2 and an oil that communicates with the compressor main body 2 via an oil feed pipe 3 to store oil to be supplied to the compressor main body 2. And a receiver tank 4 having a storage section 4A. The receiver tank 4 has a built-in separator 4B, stores compressed air discharged from the compressor body 2 through a pipe line 5, and separates mist-like oil contained in the compressed air.
The receiver tank 4 is connected to the air chamber 11 through a pipe 61, and the air chamber 11 is stopped when the compressor body 2 is stopped.
An automatic relief valve 6 for automatically discharging the compressed air in the receiver tank 4 to the atmosphere via an 11 is connected. An oil cooler 7, an oil filter 8, an oil check valve 9 are provided in the middle of an oil supply pipe 3 that communicates with the compressor body 2 from an oil reservoir 4 </ b> A of the receiver tank 4.
And are arranged. The operating pressure chamber 9A of the oil check valve 9 is connected to the secondary side piping port 6A of the auto relief valve 6 via the pilot pressure introducing pipe 10, while branching off to the piping to communicate / block the passage. It is connected to the air chamber 11 via a port type air control valve 12. The air control valve 12 is
A pilot pressure introducing pipe 10 which communicates with a discharge chamber 21 of the compressor main body 2 via a pipe line 13 and operates by the discharge pressure of the compressor main body 2 and extends from the air chamber 11 to the operating pressure chamber 9A of the oil check valve 9 is provided. It is configured to open and close the communication. That is, the air control valve 12 closes the compressed air in the air chamber 11 by the air control valve 12, and connects the pilot pressure introduction pipe 10 from the air control valve 12 to the operating pressure chamber 9 A of the oil check valve 9.
And a B-side port for opening a pilot pressure introducing pipe 10 so that the compressed air in the air chamber 11 is conducted through the air control valve 12 to the operating pressure chamber 9A of the oil check valve 9. At the same time, the pressure can be switched by the discharge pressure of the compressor body 2. In the present embodiment, a branch pipe 14 is formed in the oil supply path before the oil check valve 9.
Thus, the lubricating oil can be supplied to the bearing portion and the shaft seal portion of the compressor body 2 via the oil pump 15.

In the rotary compressor 1 of the first embodiment as described above, the oil check valve 9 is connected to the oil inlet 91 connected to the oil supply pipe 3 and to the compressor body 2 as shown in FIG. A discharge port 92 that communicates, a connection port 93 with the pilot pressure introduction pipe 10, a working pressure chamber 9A, and an oil suction port 91
A valve body 95 that opens and closes an oil passage 94 communicating with the discharge port 92; and a coil spring 96 that is an elastic member that slightly biases the valve body 95 in a direction to close the oil passage 94. Note that the elastic force of the coil spring 96 is weaker than the pressure of the lubricating oil and is such that the valve body 95 is simply pressed to open and close.

The operation of the above configuration will be described. First, during operation of the compressor main body 2, air compressed in the compression action space 2 </ b> A of the compressor main body 2 is pressed into the receiver tank 4 from the pipe line 5. The compressed air contains mist-like lubricating oil, but is separated into compressed air and oil by the oil separator 35B. Further, lubricating oil O is stored in an oil tank 4A of the receiver tank 4 and is compressed from the oil supply pipe 3 through an oil cooler 7 and an oil filter 8 by compressed air pressure injected into the receiver tank 4. The pressure is sent to the oil check valve 9. When the compressor is stopped, the pressure in the receiver tank 4 is transmitted from the secondary piping port 6A of the automatic relief valve 6 to the air control valve 12 through the air chamber 11 as shown in FIG. On the other hand, during operation of the compressor, the air control valve
As shown in FIG. 3 (a), the valve 12 is in the valve closed state (A side) due to the discharge pressure from the discharge chamber 21 of the compressor body 2, so that the pressure in the pilot pressure introducing pipe 10 is atmospheric pressure. . Therefore, the valve body 95 of the oil check valve 9 is urged in the direction of closing the oil passage 94 (right side in the figure) only by the elastic force of the coil spring 96.
Is weaker than the lubricating oil supply pressure as described above, the valve body 95 is easily opened by the lubricating oil supply pressure to lubricate the compression action space 2A of the compressor body 2. It injects oil to perform functions such as lubrication, sealing, and cooling of the compression action space 2A.

Next, when the pressurization of air from the pipe line 5 into the receiver tank 4 is stopped as shown in FIG. 4 when the compressor body 2 is stopped, the discharge chamber 21 of the compressor body 2 and a pilot pipe (not shown) are connected. Relief valve 6 communicating through
Is opened, and the compressed air in the receiver tank 4 is automatically discharged to the atmosphere. From the opening of the auto relief valve 6 until the pressure in the receiver tank 4 returns to atmospheric pressure,
It takes 30 to 40 seconds, but when the compressor body 2 stops, the discharge pressure from the discharge chamber 21 of the compressor body 2 becomes 0 kg / cm ² (atmospheric pressure).
As shown in FIG. 3B, the air control valve 12 is switched to the B-side port, and the residual pressure in the receiver tank 4 via the air chamber 11 is reduced through the pilot pressure introducing pipe 10 to the oil. It is introduced into the operating pressure chamber 9A of the check valve 9. The compressed air pressure from the auto relief valve 6 also joins from the secondary side piping port 6A through the pilot pressure introduction pipe 10 and is introduced into the operating pressure chamber 9A of the oil check valve 9. Due to these air pressures, the valve body 95 pushes the pressing force of the coil spring 96 and the operating pressure chamber 9A.
2, the oil passage 94 is forcibly closed against the supply pressure of the lubricating oil pushed out by the residual pressure in the receiver tank. Lubricating oil is prevented from flowing into the main body 2. This prevents an accident due to an oil lock in the compression chamber at the next start.

In operation, even if the pilot pressure introduction pipe 10 is damaged, the air control valve 12 is closed by the discharge pressure from the discharge chamber 21 of the compressor body 2 (A Side), the pilot pressure is not transmitted from the pilot pressure introducing pipe 10 to the oil check valve 9, so that the valve body 95 remains open and the compressor main body 2 remains open.
The lubricating oil can be continuously supplied to the compression action space 2A. On the other hand, if the line 13 is broken, the air control valve 12 is switched to the B-side port, and the compressed air pressure in the receiver tank 4 via the air chamber 11 is introduced into the operating pressure chamber 9A of the oil check valve 9. Valve body
95 is closed and the supply of the lubricating oil from the discharge port 92 to the compressor body 2 is stopped. In this embodiment, the branch pipe 14 is formed before the oil check valve 9. Therefore, even if the oil check valve 9 is closed,
Lubricating oil is supplied from the branch pipe 14 to a bearing portion and a shaft sealing portion of the compressor body 2 via an oil pump 15.

As described in detail above, the oil-cooled rotary compressor 1 of the first embodiment communicates with the oil-cooled rotary compressor main body 2 and the compressor main body 2 via the oil supply pipe 3. A receiver tank 4 having a built-in oil reservoir 4A for storing oil to be supplied to the compressor main body 2 and a separator 4B for storing compressed air discharged from the compressor main body 2 and separating the compressed air and oil.
An automatic relief valve 6 for automatically releasing the compressed air in the receiver tank 4 to the atmosphere when the compressor body 2 is stopped.
An oil check valve 9 for closing an oil passage by pilot pressure in the middle of an oil supply pipe 3 communicating with the compressor main body 2 from an oil storage section 4B of the receiver tank 4; Working pressure chamber 9
A is connected to the secondary piping port 6A of the auto-relief valve 6 via the pilot pressure introducing pipe 10, while the air is branched through the 3-port air control valve 12 which branches off to the piping and communicates / blocks the passage. Since the air control valve 12 is connected to the chamber 11 and communicates with the discharge chamber 21 of the compressor main body 2 to operate by the discharge pressure of the compressor main body 2, the operation of the compressor main body 2 is performed. Sometimes the air control valve 12 is in the closed state (A side),
When the pilot pressure introducing pipe 10 is closed to open the oil check valve 9, the compressor main body 2 is stopped and the pressure from the discharge chamber 21 of the compressor main body 2 drops to near 0 kg / cm ² , air is released. The control valve 12 operates to move to the side B, and the residual pressure in the receiver receiver tank 4 is introduced into the operating pressure chamber 9A of the oil check valve 9 through the air chamber 11, so that the oil check valve 9 is forced to operate. The valve can be closed. Even if the pilot pressure introducing pipe 10 is broken and the pilot pressure is no longer introduced into the oil check valve 9, the air control valve 12 is closed by the discharge pressure from the discharge chamber 21 during operation of the compressor body 2. A side), pilot pressure introduction pipe
Since the pilot pressure is not transmitted from 10 to the oil check valve 9 and the valve body 95 is kept open, the compressor body 2
Lubricating oil can be continuously injected into the compression action space 2A. Further, if the pipe 13 is broken, the air control valve 12 is switched to the B side port, the pressure in the air chamber 11 is introduced into the working pressure chamber 9A via the air control valve 12, and the valve body 95 is closed. As a result, the supply of the lubricating oil from the discharge port 92 to the compressor body 2 is stopped. However, since the branch pipe 14 is formed before the oil check valve, the oil is supplied via the oil pump 15. Lubricating oil can be supplied to the bearing portion and the shaft sealing portion of the compressor body 2 without any trouble. Therefore, it is possible to prevent the compressor main body 2 from being burned due to the inability to supply the lubricating oil, and to improve the reliability of the oil-cooled rotary compressor 1.

Although the present invention has been described with reference to the accompanying drawings, the present invention can eliminate the inability to supply lubricating oil to the compressor body even when the compressor is started, and is not limited to this. Various applications are possible without departing from the spirit of the present invention. For example, as the oil-cooled rotary compressor 1, various models such as a screw compressor and a slide vane compressor can be applied. Further, in the case of a parallel type oil-cooled rotary compressor, two oil check valves may be provided to have substantially the same configuration.

[0016]

According to the first aspect of the present invention, there is provided an oil-cooled rotary compressor, wherein the oil-cooled rotary compressor is connected to the compressor main body via an oil feed pipe and is supplied to the compressor main body. An oil reservoir for storing the oil to be compressed and a receiver tank containing a separator for storing the compressed air discharged from the compressor body and separating the compressed air and oil from each other, and the receiver tank when the compressor body is stopped. An oil-cooled rotary compressor equipped with an automatic relief valve for automatically discharging compressed air to the atmosphere, a pilot pressure in the oil passage in the middle of an oil feed pipe communicating from the oil reservoir of the receiver tank to the compressor body. An oil check valve that is closed by a valve is provided, and the working pressure chamber of the oil check valve is connected to the secondary piping port of the auto relief valve via a pilot pressure introducing pipe, while branching to the pipe to form a passage. Since it is connected to an air chamber via a three-port air control valve for passing and shutting off, and the air control valve is connected to a discharge chamber of the compressor main body to operate by the discharge pressure of the compressor main body. At the time of operating or starting the compressor body, the pilot pressure introducing pipe is closed to open the oil check valve. On the other hand, when the compressor body is stopped and the pressure in the discharge chamber of the compressor body decreases, the pilot pressure is reduced. When the introduction pipe is opened, the pressure in the air chamber 11 can be sent to the oil check valve 9 via an air control valve to forcibly close the valve body 95. Even if the pilot pressure introduction pipe is broken and pilot pressure is no longer introduced into the oil check valve, the air control valve 12 is closed by the discharge pressure from the discharge chamber during operation of the compressor body. Since the pilot pressure is not transmitted from the pressure introduction pipe to the oil check valve, the valve body 95 of the oil check valve is pushed open by the lubricating oil pressure, and the lubricating oil can be continuously supplied into the compressor body. In the event that the pipe connecting the discharge chamber of the compressor body to the air control valve is broken, the air control valve is switched to the B-side port, and the pressure in the air chamber is increased through the air control valve 12 to the operating pressure. The valve body is introduced into the chamber and the valve body is closed. However, since the branch pipe is formed before the oil check valve, the bearing portion and the shaft seal portion of the compressor body can be lubricated via the oil pump without any trouble. Since the oil is supplied, burnout due to inability to supply the lubricating oil can be prevented, so that the reliability of the oil-cooled rotary compressor can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a flow during operation of a piping system of an oil-cooled rotary compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing an oil check valve of the oil-cooled rotary compressor according to the first embodiment.

FIG. 3 is a schematic view showing an air control valve of the oil-cooled rotary compressor according to the first embodiment.

FIG. 4 is a schematic diagram showing a flow when the piping system of the oil-cooled rotary compressor according to the first embodiment is stopped.

FIG. 5 is a schematic diagram showing a piping system of a conventional oil-cooled rotary compressor.

FIG. 6 is a sectional view showing an oil check valve of the conventional oil-cooled rotary compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oil-cooled rotary compressor 2 Compressor main body 3 Oil supply pipe 4 Receiver tank 4A Oil storage part 4B Separator 6 Auto-relief valve 9 Oil check valve 9A Working pressure chamber 10 Pilot pressure introduction pipe 11 Air chamber 12 Air control valve

Claims (1)

(57) [Claims] 1. An oil-cooled rotary compressor main body, an oil reservoir communicating with the compressor main body via an oil feed pipe and storing oil to be supplied to the compressor main body, and discharge from the compressor main body. A receiver tank incorporating a separator for storing compressed air containing the separated oil and separating the compressed air and oil, and an automatic relief valve for automatically discharging the compressed air in the receiver tank to the atmosphere when the compressor body is stopped. An oil check valve that closes an oil passage by pilot pressure in the middle of an oil feed pipe communicating from the oil storage portion of the receiver tank to the compressor body. A three-port air that connects the working pressure chamber of the check valve to the secondary piping port of the auto relief valve via a pilot pressure introduction pipe, and branches to the piping to communicate and shut off the passage. An oil-cooled rotary compressor, which is connected to an air chamber via a control valve and is configured to communicate with the discharge chamber of the compressor body to operate by the discharge pressure of the compressor body. Machine.