JPH0454288A - Variable capacity swash plate type compressor - Google Patents

Abstract

PURPOSE:To improve reliability, by providing passage connecting a discharge chamber and a swash plate chamber, and also providing a mechanism which separates lubrication oil that is discharge into the discharge chamber together with refrigerant gas, and returns this oil into the swash plate chamber, and storing sufficient lubrication oil within a compressor even at the time of a capacity control operation in which a refrigerant circulation amount is small. CONSTITUTION:When a compressor main shaft 13 is driven, a drive plate 14 and a swash plate 12 are rotated and a piston support 21 conducts swinging movements. With this, a piston 31 is reciprocated within a cylinder 33, and refrigerant gas is sucked and compressed. In this instance, a swash plate chamber 10 and a discharge chamber 9 lower portion provided at a rear cover 3 are connected to each other by means of introduction holes 405, 505 and 205 provided on a cylinder head 4, a suction valve plate and a cylinder block 2. Also, a throttle pipe 206 is inserted into the hole 205 and lubrication oil which is separated from refrigerant gas by colliding with the wall surface of the chamber 9 and accumulated in the lower area, is delivered into the swash plate 10 and again delivered to a sliding part for lubrication.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an air conditioning system for an automobile, and more particularly.

The present invention relates to a lubricating oil supply, separation, and reflux mechanism suitable for the variable stroke volume compressor used in this system.

[Conventional technology]

In variable capacity compressors used in conventional automobile air conditioning systems, as described in Japanese Patent Publication No. 58-4195, lubricating oil discharged from the compressor together with refrigerant gas goes through the refrigeration cycle. It is sucked into the cylinder of the compressor, and is ejected into the swash plate chamber along with the blow-by gas that leaks into the swash plate chamber from the gap between the cylinder and piston ring, or it adheres to the cylinder wall, is scraped away by the piston cylinder, and is stored in the swash plate chamber. It had a structure.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not give any consideration to the method for recovering the lubricating oil discharged into the discharge chamber together with the refrigerant gas. Therefore, under operating conditions where capacity control is performed and the amount of refrigerant circulated is small, the lubricating oil that is discharged during the refrigeration cycle along with the discharged refrigerant gas accumulates in the condenser and evaporator, reducing the amount returned to the compressor. However, there was a problem that the lubricating oil stored in the compressor was insufficient, causing damage such as seizure and wear of the sliding parts.

An object of the present invention is to provide a highly reliable variable capacity compressor that stores sufficient lubricating oil in the compressor even during capacity control operation with a small amount of refrigerant circulation.

[Means to solve the problem]

The above purpose is to provide a passage that connects the discharge chamber and the swash plate chamber through an appropriate throttle or valve, and a mechanism to separate the lubricating oil discharged into the discharge chamber together with the refrigerant gas and return it to the swash plate chamber. This is achieved by making it possible to recover

[Effect]

The lubricating oil discharged into the discharge chamber together with the refrigerant gas collides with the wall surface of the discharge chamber, a portion of which is separated from the refrigerant gas, and is stored in the lower part. By providing a flow path that connects the lower part of the discharge chamber and the swash plate chamber through a throttle, the lubricating oil accumulated in the discharge chamber, or the mist of lubricating oil and refrigerant gas, is slanted depending on the pressure difference between the discharge chamber and the swash plate chamber. The lubricating oil is sent to the plate chamber and stored in the swash plate chamber.

In addition, a valve that can be opened and closed is installed in the middle of this flow path, and by closing it when the refrigerant circulation is sufficiently high and opening it when it is low, performance is suppressed and sufficient lubricating oil is supplied to the swash plate chamber. It becomes possible to secure it.

〔Example〕

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

Figures 1 and 2 show the overall structure of a variable stroke swash plate compressor according to the present invention, and Figure 1 shows the state in which the piston stroke is at its maximum, that is, the swash plate inclination angle is at its maximum. FIG. 2 shows the state where the swash plate inclination angle is the minimum. Figure 3 shows the ■− of Figures 1 and 2.
■ Line sectional view 0 At one end of the cylindrical cylinder block 2, a main shaft 1 is connected via a radial bearing 18, 19 in the center.
A front housing 1 that rotatably supports the swash plate 3 is disposed to form a swash plate chamber 10. The cylinder block 2 is formed with a plurality of cylinders 33 arranged circumferentially around the main shaft 13 and parallel to the axis of the main shaft 13 .

The main shaft 13 is located approximately on the center line of the cylinder block 2, and is rotatably supported by radial bearings 18 and 19 provided at the center of the cylinder block and the front housing 1, and is supported by a press-fit pin 11 or a plastic coupling. A drive plate 14 is fixed. The drive plate 14 is provided with a cam groove 142, and the swash plate lug 12 is provided with a cam groove 142.
A pivot bin 16 engaged with 1 is movably mounted. Further, the side surface 141 of the drive plate 14 provided with the cam groove 142 is in contact with the side surface of the swash plate lug 121. As a result, when the main shaft 13 rotates, the drive plate 14 rotates, a rotational force is applied from the side surface 141 of the drive plate to the swash plate lug 121, and the swash plate 12 rotates. The cam groove 142 formed in the drive plate 14 is a closed curve, and even if the tilting angle of the swash plate changes and the pivot pin 16 moves within this cam groove, the top dead center position of the piston 31 does not change. It is a curved line.

A sleeve 15 is incorporated into the main shaft 13 so as to be slidable in the axial direction with respect to the main shaft 13, and the swash plate 12 is rotatably fastened to the sleeve 15 by a sleeve pin 17. Therefore, when the main shaft 13 rotates, the drive plate 14 . The swash plate 12° and the sleeve 15 rotate together.

A piston support 21 is fastened to the swash plate 12 via a bearing 23, and a stopper 22 fixed to the swash plate 12 prevents the bearing 23 from moving in the axial direction of the swash plate 12. It is fixed to the hub portion 122 of. On the other hand, the piston support 21 is restricted from moving in the right direction in FIGS. Movement to the left in FIGS. 1 and 2 is also restricted.

Further, a support bin 26 is fixed to the piston support 21 in the radial direction by a method such as press fitting, screwing, or plastic coupling, and a slide ball 27. A pair of semi-cylindrical slide shoes 29 having spherical surfaces that come into contact with the slide balls are rotatably and slidably mounted. The piston support 21 reciprocates along the guide groove 28, and movement around the axis is restrained so that the piston support 21 does not rotate around the main axis 13.

The piston support 21 has balls 321°32 at both ends.
One end of a plurality of connecting rods 32 having a diameter of 2 is rotatably attached to the center opening of the ball 321, and a piston 31 is attached to the other end around the center of the ball 322. The piston 31 has a piston ring 34
．． 35 is installed.

It is incorporated into a cylinder 33 provided in the cylinder block 2. In addition, the cylinder block 2 includes a suction valve 5.
．． Cylinder head 4. Discharge valve6. The packing 7, the rear cover 3 are arranged, and the drive plate 14. Swash plate 12. The front housing 1 is integrally connected to the front housing 1, which is arranged to surround the piston support 21 and the like, with bolts (not shown) or the like.

The front housing 1 and the cylinder block 2 are connected by an O-ring 38, and the rear cover 3 and the cylinder block 2 are connected by an O-ring 38.
It is kept secret by O-ring 39. The cylinder head 4 is provided with a suction boat 401 and a discharge port 402 corresponding to each cylinder 33, which communicate with a suction chamber 8 and a discharge chamber 9 provided in the rear cover 3, respectively.

The rear cover 3 has an inlet 301 and an outlet (not shown).
A control valve 41 is provided between the suction passage 302 and the suction chamber 8. The upstream side of the control valve 41 and the swash plate chamber 10 in the front housing 1 are connected to the rear cover 3. Packing 7, discharge valve 6° cylinder head 4, and suction valve 5
Conduction holes 303, 304, 703, provided in the center of
603° 403 and 503, a passage 131 provided in the center of the main shaft 13, and a drive plate 14 connected thereto.
It is communicated by a passage 143 that opens in the radial direction.

Further, the downstream side of the control valve 41 communicates with the suction chamber 8 .

The lower part of the discharge chamber 9 provided in the rear cover 3 and the swash plate chamber 1
0 means cylinder head 4. The inlet valve plate and the through hole 405 provided in the cylinder block 2 communicate with each other through 505 and 205. Furthermore, a throttle pipe 206 is inserted into the conduction hole 205 .

With this configuration, when the main shaft 13 of the compressor is driven by the engine (not shown), the drive plate 14. The swash plate 12 rotates, and the piston support 21 swings in response to the rotation of the main shaft. Along with this, the piston 31 reciprocates within the cylinder 33, sucks in refrigerant gas,
Compress.

Note that the radial force that acts when compressing gas is supported by two radial bearings 18 and 19 provided in the front housing 1 and the cylinder block 2.

Next, the flow of lubricating oil stored in the swash plate chamber 28 will be explained. The lubricating oil stored at the bottom of the swash plate chamber is stirred up by the rotation of the swash plate and the rocking motion of the piston support, and is used to lubricate the bearings and sliding parts. The oil adhering to the cylinder wall surface is subjected to the sliding movement between the piston 31 and the cylinder wall, and a portion is scraped up by the piston rings 34 and 35 and enters the cylinder chamber (not shown). On the other hand, the lubricating oil that has circulated through the refrigeration cycle and returned to the compressor together with the refrigerant gas is sucked into the cylinder chamber, adheres to the cylinder wall, and is partially discharged to the swash plate chamber 28 along with the blow-by gas. The lubricating oil remaining in the cylinder chamber is discharged to the discharge chamber 9 together with the refrigerant gas again. The lubricating oil discharged into the discharge chamber 9 collides with the wall surface of the discharge chamber 9, and since the flow velocity becomes slow, it is separated from the refrigerant gas, and falls to the lower part by gravity and is stored. The oil stored in the lower part is sent to the swash plate chamber through a flow path connecting the discharge chamber and the swash plate chamber due to the pressure difference between the discharge chamber and the swash plate chamber. The amount of oil returned to the swash plate chamber is determined by the flow path 20.
It is adjusted by the diameter and length of the restrictor tube 206 provided in 5. The lubricating oil returned to the swash plate chamber 28 is stored at the bottom of the swash plate chamber, is scraped up by the rotation of the swash plate, the rocking motion of the piston support, etc., and is sent to the sliding portion again for lubrication. on the other hand,
Blow-by gas and refrigerant gas mixed with lubricating oil from the discharge chamber 8 and flowing into the swash plate chamber 28 are transferred to the drive plate 14.
From a passage 143 opening in the radial direction to the cylinder head 4. - From the flow path 303 provided in the rear cover 3 via the discharge valve 6 and the conduction holes 503, 403, 603° 703 provided in the center of the packing 7, the control valve 4
1 is returned to the upstream suction passage. As shown in FIG. 2, when the heat load of the air conditioner decreases, this is detected and the control valve 50 operates to reduce the opening area from the suction passage 302 to the suction chamber 8. Therefore, the pressure at the cylinder inlet, that is, downstream of the control valve, decreases.

Since the swash plate chamber 28 communicates with the upstream side of the control valve 50,
The pressure in the swash plate chamber 28 becomes higher than the pressure in the cylinder 33, and a moment is generated in the swash plate 12 in a direction that reduces the swash plate inclination angle. As a result, the piston stroke of the swash plate 12 decreases to the tilt point, and the discharge amount of the compressor decreases. Even in this state, the flow of the lubricating oil does not change, and the lubricating oil discharged into the discharge chamber 9 together with the refrigerant gas is separated from the refrigerant gas in the discharge chamber 9 and sent to the swash plate chamber 28 due to the pressure difference. The more the swash plate 12 is tilted, the piston stroke is reduced, and the discharge amount of the compressor is lowered, the less the amount of refrigerant gas discharged into the discharge chamber is included in this. Separation of lubricating oil is promoted, and the proportion of lubricating oil recovered into the swash plate chamber 28 increases.

Furthermore, when the heat load of the air conditioner decreases, the swash plate 12 tilts, the piston stroke becomes smaller, and the discharge amount of the compressor decreases, the flow rate of the refrigerant gas circulating in the refrigeration cycle decreases. Lubricating oil that accumulates in the evaporator will no longer return to the compressor. Even in such a case, since the amount of refrigerant gas discharged into the discharge chamber 9 is reduced, most of the lubricating oil contained in the pump is separated and returned to the swash plate chamber 28, so that the lubricant stored in the swash plate chamber 28 is The amount of oil does not decrease and a sufficient amount of lubricating oil can be secured. That is, as shown in FIG.
8, the lubricating oil or blow-by gas that has been scooped up directly into the cylinder chamber is returned to the suction path 302.
The lubricating oil that has entered the cylinder chamber through the refrigerant gas is discharged to the discharge chamber 9 together with the refrigerant gas, is separated from the gas in the discharge chamber 9, and returns to the swash plate chamber 28. The lubricating oil will circulate along the path shown by the solid line in FIG.

In this way, even when the compressor capacity is controlled and the compressor is operated at a small capacity, lubricating oil can be ensured within the compressor and highly reliable operation can be performed over a long period of time.

Next, other embodiments will be described. FIG. 5 shows an example in which a valve that can be opened and closed is installed in the middle of a flow path 205 that connects the discharge chamber 9 and the swash plate chamber 28. The valve is structured so that it closes when the heat load of the air conditioner is large and the discharge pressure is high, and opens when the heat load decreases and the discharge pressure becomes low. That is, as shown in FIG. 5, the valve is composed of a valve body 6 and a valve spring 62 that presses the valve body 6. A pressure difference between the pressures in the discharge chamber 9 and the swash plate chamber 28 acts on the valve body 61 . If this force is larger than the force of the valve spring 62 pushing the valve body 61, the valve body 61
is in close contact with the valve seat 63, and the flow path 205 is closed. on the other hand,
When the force due to the differential pressure is smaller than the force of the valve spring 62, the valve body 61 is pushed up by the valve spring 62, opening the flow path. By providing such a valve in the middle of the flow path, heat from the air conditioner can be removed. When the load is large and the amount of refrigerant circulating in the refrigeration cycle is large enough, the flow path 205 is closed to suppress the slight performance deterioration caused by the refrigerant mixed with the lubricating oil returning from the discharge chamber to the swash plate chamber, and to operate at maximum capacity. I can do it. - On the other hand, when the heat load decreases, the discharge pressure decreases, the pressure difference between the discharge chamber and the swash plate chamber becomes smaller, the valve body 61 is pushed up by the valve spring 62, the flow path is opened, and the discharge chamber 9 is separated. The lubricating oil is returned to the swash plate chamber 28, and it becomes possible to hold sufficient lubricating oil in the swash plate chamber 28.

FIG. 6 shows that in the middle of the flow path connecting the discharge chamber 9 and the swash plate chamber 28,
This is an example in which a valve that is electrically opened and closed is provided.

When the valve section is energized from outside the compressor, it is attracted by the magnet 63 and the flow path 205 is opened. When the current is cut off, the valve body 61 is pushed by the valve spring 62 and the flow path 205 is opened.
closes. When the heat load of the air conditioner is large, the current is cut off and the flow path is closed, and when the heat load is small, the current is turned on and the flow path is opened, thereby achieving the same effect as described above.

Further, in FIG. 7, a discharge chamber 9 configured from a cylinder is provided to collect the device gas, a flow path 205 is provided to connect the discharge chamber 9 and the swash plate chamber 28, and a flow path 206 is further provided to connect the swash plate chamber 28 and the suction chamber 8. An example is shown below.

With this configuration, oil separated in the discharge chamber or a mist of oil and refrigerant gas is returned from the discharge chamber to the swash plate chamber 28. Further, oil stored in the swash plate chamber 28 is sent to the suction chamber 8 and sucked into the cylinder chamber, where it is used to lubricate the wall surface of the cylinder 33.

In this embodiment, valve devices 71 and 72 are installed in the middle of the flow path 206, and under normal operating conditions with a high heat load, the compressor is operated at maximum capacity and connects the discharge chamber 9 and the swash plate chamber 28. The valve device A installed in the flow path is closed as described above, and the valve device B installed in the flow path connecting the swash plate chamber and the suction chamber is also closed as the valve body 71 is pushed by the valve spring 72. On the other hand, when the heat load becomes smaller and the piston stroke decreases to enter the capacity control operation state, the pressure difference between the discharge chamber 9 and the swash plate chamber 28 decreases and the valve device A opens as described above. In this case, the pressure in the swash plate chamber 28 is higher than the pressure in the suction chamber 8, and this pressure difference pushes up the valve body 71 and opens the valve device B. By providing such valve devices A and B in the middle of the flow path, When the heat load of the air conditioner is high and the amount of refrigerant circulating during the cycle is sufficiently large, the flow paths 205 and 206 are closed to suppress the slight performance degradation caused by opening the flow paths. On the other hand, when the heat load is small and the refrigerant circulation amount is reduced, the flow path 20
5, 206 is opened, and the oil separated in the discharge chamber 9 is transferred to the swash plate chamber 2.
By supplying the lubricating oil stored in the swash plate chamber 28 to the suction chamber 8, the lubricating oil is sucked into the cylinder chamber, and the lubricating oil is sucked into the cylinder chamber 33.
Wall and piston 31 or piston cylinder 34.35
This provides sufficient lubrication under any operating conditions, allowing for highly reliable operation.

In such a configuration, even in operating conditions where the compression capacity is reduced, the amount of refrigerant circulated is reduced, and oil return from the cycle cannot be expected, the swash plate chamber → suction chamber → cylinder chamber → discharge chamber → swash plate chamber is always maintained. This creates a flow of lubricating oil that enables highly reliable operation over a long period of time.

〔Effect of the invention〕

According to the present invention, the lubricating oil discharged into the discharge chamber together with the refrigerant gas can be efficiently returned to the swash plate chamber, so that sufficient lubricating oil is retained in the swash plate chamber and used to lubricate each sliding part. becomes possible.

Moreover, the lubricating of sliding parts such as the cylinder wall surface is also performed reliably.

Therefore, even when the capacity of the compressor is controlled and the amount of refrigerant circulated in the refrigeration cycle is small, lubricating oil can always be maintained in the swash plate chamber and the system can be operated for a long time.

[Brief explanation of drawings]

Figure 1 is a sectional view of one embodiment of the present invention at maximum capacity;
The figure is a cross-sectional view at the minimum capacity, Figure 3 is a cross-sectional view along the ■-■ line in Figures 1 and 2, Figure 4 is a system diagram of the flow of lubricating oil, and Figure 5 is a cross-sectional view at the minimum capacity.
Figures 7 through 7 are top views of the flow path. l...Front housing, 2...Cylinder block. 3... Rear cover, 12... Swash plate, 13... Main shaft, 14... Drive plate, 15... Sleeve,
16... Pivot pin, 17... Sleeve pin, 3
1... Piston, 32... Connecting rod,
5o...control valve.

Claims (1)

[Claims] 1. A swash plate whose inclination angle can be changed is installed coaxially with the circle in a housing in which a plurality of cylinders are arranged on the same circumference, and the swash plate is tilted and rotated to perform reciprocating motion. A variable displacement swash plate compressor in which a piston is disposed within the cylinder and the stroke of the piston changes when the inclination angle of the swash plate is changed, and refrigerant gas discharged from the plurality of cylinders is collected. A discharge chamber is provided, and a flow path is provided that connects the discharge chamber and a swash plate chamber that accommodates the swash plate, and oil separated from the refrigerant gas in the discharge chamber or a mist of oil and refrigerant gas is transferred from the discharge chamber to the slant plate. A variable displacement swash plate compressor characterized in that it is configured to return the air to the plate chamber.