JPS5944517B2 - vane rotary compressor - Google Patents

Description

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

More specifically, when the vane rotary compressor rotates, the lubricating oil is continuously supplied to the bottom of the vane groove, which improves the vane's ability to follow the inner wall of the cylinder and improves compression efficiency, and when the vane rotary compressor is stopped, the lubricating oil is supplied to the bottom of the vane groove. This prevents liquid from flowing into the compressor, thereby preventing liquid compression that occurs when restarting the compressor, and also prevents reversal that occurs immediately after the compressor is stopped.

Conventionally, in this type of rotary compressor, lubricating oil is pressurized by high pressure generated on the discharge side as a force that presses the vane against the cylinder wall and introduced into the bottom of the vane groove, and while pushing the vane with this high-pressure lubricating oil, It lubricates both sides of the rotor, the tips of the vanes, etc.

However, with this structure, once the compressor is stopped, the lubricating oil continues to flow to the bottom of the vane groove due to the high pressure remaining on the discharge side, and some lubricating oil flows into the cylinder from the gap between the vanes and the vane groove. enter.

After a certain period of time, the residual pressure mentioned above also passes through the expansion valve,
Alternatively, the lubricating oil flows through the gap inside the compressor to balance with the low-pressure side and stops flowing into the cylinder, but even a small amount of lubricating oil causes the characteristic oil compression phenomenon that causes the compressor to rotate again, causing the vane. This can cause major problems such as damage to the valve or deformation of the valve.

In addition to the damage caused by the inflow of lubricating oil when the compressor is stopped, this type of compressor performs reverse rotation due to the high pressure that remains immediately after the compressor is stopped and is applied to the bottom of the vane.

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

The adverse effects of restarting the compressor are as described above.

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

That is, the intake gas is overheated by the backflow high pressure gas, leading to an increase in the temperature of the discharge gas during restart.

As a method to prevent such oil compression or reversal, (1) installing a check valve on the suction side of the electric compressor directly prevents the back flow of high-pressure gas when the compressor is stopped, thereby eliminating oil inflow and reversal. method of knowledge.

(2) A method of eliminating oil inflow and reversal by using an oil passage opening/closing member that rotates synchronously with the rotor at the end of the rotor shaft to block the oil passage;
For example, the method disclosed in Japanese Patent Application Laid-open No. 133811/1983.

and so on.

The former increases the passage resistance of the suction gas, leading to a decrease in the performance of the compressor.

In the latter case, as the rotor rotational speed increases, the passage resistance of the oil passage increases, the supply of lubricating oil to the bottom of the vane groove decreases, and the durability of the compressor decreases.

In addition, the latter is a structure that prevents lubricating oil from flowing into the bottom of the vane groove due to the pressure difference immediately after the compressor stops. Since the seal structure is a contact seal only between the metal plane of the disc and the mating member, it is insufficient to prevent the lubricant from flowing in, and the lubricant will not flow back until the pressure difference falls to a certain level.
This method has drawbacks such as reverse rotation of the compressor, which causes the above-mentioned problems to some extent.

The present invention focuses on the pressure difference before and after the discharge valve, where there is a significant pressure change when the compressor is rotating and when it is stopped, and uses this pressure difference to lubricate a spherical object that moves by the operation of a reciprocating plunger. The above drawbacks are solved by providing a plunger valve mechanism in which the spherical object opens the lubricating oil passage when the compressor is rotating and closes it when the compressor is stopped.

As a configuration for this purpose, the present invention includes a cylinder having a cylindrical wall, a vane that is located eccentrically in this cylinder and is slidably inserted into a plurality of vane grooves, and whose tip end is inscribed in the cylindrical wall of the cylinder, an oil passage consisting of a vane inscribed in a cylindrical wall of the cylinder, the cylinder, and a side wall that closes off both sides of the rotor and the vane, and communicating the bottom space of the vane groove with a lubricating oil reservoir in a discharge high pressure region; A spherical object is arranged on the upstream side of the oil passage, and a plunger valve mechanism is provided that opens and closes the oil passage by moving the spherical object by reciprocating movement of the plunger, and the plunger valve mechanism The opening and closing of the oil passage is performed by reciprocating the plunger mainly using the differential pressure between the discharge pressure before passing the discharge valve and the discharge pressure after passing the discharge valve,
When the overheating pressure through the discharge valve is smaller than the pressure passing through the discharge valve, the plunger valve mechanism opens the oil passage, and when the pressure before passing the discharge valve is less than or equal to the pressure after passing the discharge valve, the plunger valve mechanism opens the oil passage. A pressure passage is provided to guide the pressure before passing through the discharge valve to the bottom of the plunger hole so as to close the passage.

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

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

In the figure, 1 is the rotor, 2 is the cylinder, 3 is the front wall,
4 is a rear side wall, 5 is a vane, 6 is a refrigerant inlet provided in the cylinder 2, 7 is a discharge port, 8 is a discharge valve, 9 is a cylinder head, 10 is an oil separation chamber, and 11 is a refrigerant from the oil separation chamber 10. A refrigerant outlet, 12 a roller bearing, and 13 a shaft sealing device form the basic structure of the vane rotary compressor.

14 is a vane groove provided in the rotor 1, and 15 is a circumferential groove for supplying high-pressure lubricating oil 16 to the vane groove 14, which is provided in the rear side wall 4.

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

18 is a pressure passage that transmits the pressure of the outlet 11, 19 is an oil passage that sends lubricating oil 16 to the circumferential groove 15, and is located downstream of the plunger valve mechanism described below; 20 is the same oil passage as described above; Located upstream of the plunger valve mechanism, the other end is the oil separation chamber 1
It opens below the oil level of the lubricating oil 16 in 0.

21 is a plunger hole, 22 is a plunger having a protrusion on its upper part, 23 is an oil passage connecting the oil passage 19 and the oil passage 20, surrounding the protrusion 22a of the plunger 22,
An oil passage 24 whose lower end has a conical shape is formed upstream of the oil passage 23, into which a steel ball 25 of a size that can block the oil passage 23 is inserted in a loose state, and a plunger is inserted into the oil passage 24. The steel ball 25 opens and closes the passage 23 by moving the steel ball 22 up and down.

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

When the rotor 1 starts rotating in the direction of arrow B shown in FIG. 2, refrigerant gas containing refrigerating machine oil is sucked into the cylinder 2G through the refrigerant suction port 6, compressed by the rotation of the vanes 5 and the rotor 1, and reaches the discharge lower. Pushing open the discharge valve 8 leads to the oil separation chamber 10, where the refrigerating machine oil is separated from the refrigerant gas due to the difference in specific gravity and is stored at the bottom of the oil separation chamber 10 as lubricating oil 16, while the refrigerant gas is passed through the refrigerant outlet 11. After that, it is sent to the refrigeration cycle.

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

That is, the pressure on the plunger 221 side is higher than the pressure in the oil passage 23 communicating with the oil separation chamber 10 with the plunger 22 as a boundary and on the plunger hole 21 side where the pressure passage 18 is open.

The plunger 22 and the plunger hole 21 are combined with a very high-precision play gap, and the plunger 22 moves toward the ground due to the above-mentioned pressure difference, and the steel ball 25 is pushed up by the protruding end of the plunger 22. oil separation chamber 10 and oil passage 1
The high-pressure lubricating oil 16 communicates with the vane groove 14 due to the pressure difference.
The vane 5 is pressed against the inner wall of the cylinder 2.

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

The discharge valve 8, which cuts off the power transmission mechanism (not shown) to the compressor, immediately closes.

As a result, since the pressure on the refrigerant outlet 11 side is connected to the high pressure side of the refrigerant cycle as is well known, the oil separation chamber 10
The same pressure will be applied.

The pressure on the refrigerant outlet 11 side is controlled by a pressure reducer (not shown).
The pressure in the discharge lower is reduced quickly to balance the low pressure side of the refrigeration cycle, but the speed at which the pressure is balanced is slow.

That is, the refrigerant gas and refrigerating machine oil in the compressor 27 and the vane groove 14 are distributed between the rotor 1 and the front wall 3 and the rear wall 4, between the vane 5 and the cylinder inner wall, or between the vane 1 and the front wall 3.
, the gap with the rear side wall 4, the top gap between the rotor 1 and the cylinder 2, etc. leak to the low pressure side, and the pressure difference before and after the discharge valve is reversed.

That is, the pressure in the plunger hole 21 communicating with the pressure passage 18 is lower than the pressure in the oil passage 23 communicating with the oil separation chamber 10, and the force received by the plunger 22 is in the opposite direction to that when the compressor is rotating. is descending.

Similarly, the steel ball 25 descends toward the oil passage 23 due to the pressure difference between the oil passage 23 and the oil passage 24, presses the open end of the oil passage 23, cuts off the communication between the oil passage 23 and the oil passage 24, and releases the remaining discharge. The vane groove 14 of the lubricating oil 16 that becomes pressurized due to pressure and the inside of the cylinder 2
Stop the flow to 6.

At this time, since the side of the oil passage 24 in contact with the oil passage 23 has a conical shape concentric with the oil passage 23, the resting position of the steel ball 25 is constant and the open end of the oil passage 23 is reliably closed.

As time passes, this residual pressure on the high pressure side is balanced through an expansion valve (not shown) that constitutes the refrigeration cycle, and the pressure within the compressor becomes equal.

As described above, the rotary compressor of the present invention is provided with an oil passage that communicates between the bottom space of the vane groove and the discharged high-pressure lubricating oil,
A plan in which a spherical object is arranged on the upstream side of this oil passage, and a plunger separated from the spherical object is arranged on the downstream side, and the spherical object is moved by the reciprocating movement of the silanger to open and close the oil passage. A plunger valve mechanism is provided, and the oil passage of the plunger valve mechanism is opened and closed by reciprocating the plunger mainly using the differential pressure between the discharge pressure before passing the discharge valve and the discharge pressure after passing the discharge valve. When the pressure before passing the discharge valve is greater than the pressure after passing the discharge valve, the plunger valve mechanism opens the oil passage, and when the pressure before passing the discharge valve is less than or equal to the pressure after passing the discharge valve, the plunger valve mechanism opens the oil passage. The valve mechanism is characterized by a structure that closes the passage, and when the compressor is rotating, the oil passage is always open due to the generation of a pressure difference before and after the discharge valve, and the supply of lubricating oil to the bottom of the vane groove is compressed. Can be performed continuously without being affected by machine rotation speed,
Furthermore, since the valve body that opens and closes the oil passage is spherical, there is little resistance to the passage of lubricating oil, and sufficient lubricating oil can be supplied, so the vane can always be pressed against the inner wall of the cylinder, and during reciprocating rotation of the vane, There is no so-called jumping effect and there is less wear on the vanes.

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

Furthermore, the first point that is particularly effective in the present invention is that since the valve body that opens and closes the oil passage is a spherical object, there is little resistance to the passage of lubricating oil and the opening degree of the valve body can be set small. Immediately after the compressor stops, when the pressure difference across the discharge valve reverses and the plunger leaves the valve body, the valve body can quickly close the oil passage.

The second point is that, as mentioned above, the opening degree of the valve body can be set small, so the differential pressure before and after the discharge valve is low at the beginning of compressor startup, and the distance the valve body is moved by the plunger in the direction of opening the oil path is low. The oil passage is open even when the compressor is low, and lubricating oil is quickly supplied to the vane grooves at the beginning of compressor startup, so that so-called vane jumping, which tends to occur at the beginning of startup, can be prevented at an early stage.

Furthermore, the third characteristic effect is that when the valve body blocks the oil passage immediately after the compressor stops, using the residual discharge pressure and the flow of lubricating oil before the compressor stops, the valve body is a spherical object, and Since it is separate from the plunger, the valve body can easily follow the flow of lubricating oil and instantly block the oil passage.

The contact state between the valve body of the oil passage blockage part and the mating member is close to a line contact, and the oil passage blockage density is high, and when the compressor is stopped, refrigerant gas from the oil passage, lubricating oil inside the cylinder, and vane groove. for example, to prevent it from flowing into the bottom of the tank or the low-pressure side.

These effects make it possible to realize a rotary compressor that does not have the above-mentioned conventional drawbacks that occur when the compressor is reversed or stopped or restarted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a vane rotary compressor according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA shown in FIG. 1...Data, 2...Cylinder, 5...
...Vane, 8...Discharge valve, 18...
...Pressure passage leading to discharge valve pressure, 19, 20, 23, 2
4...Oil passage guiding pressure after the discharge valve, 16...
... Lubricating oil, 21 ... Plunger hole, 22
... Plunger, 22a ... Discharge part, 25 ... Steel ball.

Claims (1)

[Claims] 1 a cylinder having a cylindrical wall and a refrigerant suction port;
a rotor located eccentrically in the cylinder and having a plurality of vane grooves; a vane that is slidably inserted into each of the vane grooves and whose tip is inscribed in the cylindrical wall of the cylinder; the cylinder; the rotor; and the vane. An oil passage is provided that communicates the bottom space of the vane groove with a lubricating oil reservoir in the discharge high pressure area, and a spherical object is placed on the upstream side of the oil passage, and a spherical object is arranged on the upstream side of the oil passage. is provided with a plunger valve mechanism in which a plunger separate from the spherical object is disposed, and the plunger valve mechanism moves the spherical object to open and close the oil passage by reciprocating the plunger, and the plunger valve mechanism opens and closes the oil passage. The plunger is opened and closed by reciprocating the plunger using the differential pressure between the discharge pressure before passing the discharge valve and the discharge pressure after passing the discharge valve, and when the pressure before passing the discharge valve is greater than the pressure passing the discharge valve. When the plunger valve mechanism opens the oil passage and the pressure before passing the discharge valve is less than or equal to the pressure after passing the discharge valve, the plunger valve mechanism closes the oil passage. A vane rotary compressor comprising a pressure passage leading to the bottom of the plunger hole, a refrigerant outlet in the lubricating oil reservoir, and a refrigeration cycle connected between the refrigerant inlet and the refrigerant outlet to form a closed circuit.