JP2641479B2 - Variable displacement swash plate type compressor - Google Patents

Description

The present invention relates to capacity control of a swash plate type compressor, and is effective when used, for example, as a refrigerant compressor for an automotive air conditioner.

[Problems to be solved by the invention]

The present inventors previously, as a variable capacity swash plate type compressor,
A configuration has been proposed in which a swash plate that is rotationally driven by a shaft decreases its inclination angle in accordance with the axial movement of the spool, thereby varying the stroke of the piston. That is, the swash plate is attached to the shaft so as to be tiltable and displaceable in the shaft axis direction, and the tilt angle of the swash plate and the center position are displaced in conjunction with each other.

In such a variable displacement swash plate compressor, in one working chamber, there is a significant increase in dead volume according to a change in the swash plate inclination angle, but in the other working chamber, there is no significant increase in dead volume. Thus, the capacity can be gradually reduced.

FIG. 2 is a cross-sectional view showing the variable displacement type swash plate type compressor proposed by the present inventors. In this example, the swash plate 10 changes the inclination angle in accordance with the displacement of the spool 30. Therefore, in this compressor, the position of the spool 30 is displaced by controlling the pressure in the control pressure chamber 200, whereby the discharge capacity of the compressor can be continuously variably controlled.

The present invention relates to the improvement of the compressor proposed by the present invention as described above, and an object of the present invention is to improve the lubricating properties of a sliding portion, a rotating portion and the like.

[Configuration and operation]

In order to achieve the above object, in the compressor of the present invention, an inclined groove is formed in the shaft, and a swash plate is swingably connected to the shaft through the inclined groove. An oil supply passage extending in the axial direction and an oil supply hole extending in the radial direction are provided.

With such a configuration, the lubricating oil contained in the refrigerant that has flowed into the compressor flows into the inclined groove that is relatively large in the shaft. The lubricating oil that has flowed into the inclined groove then flows in the axial direction through the oil supply passage in the shaft, and is thereafter supplied from the oil supply hole toward the outer surface of the shaft by centrifugal force. As a result, in the compressor of the present invention, the lubricating oil can be satisfactorily supplied by the centrifugal force caused by the rotation of the shaft without providing a special oil supply mechanism such as an oil pump.

Accordingly, in the compressor of the present invention, the lubricating oil in the lubricated portion is satisfactorily provided, and smooth operation can be ensured until high-speed rotation.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a variable displacement swash plate type compressor. The aluminum alloy front housing 4, front side plate 8, suction valve 9, front cylinder block 5, rear cylinder block 6, suction valve 12, rear side plate 11, and rear housing 13 are integrally fixed by through bolts 16 for compression. The outer shell of the machine. Cylinder block 5, 6
As shown in FIG. 3, five cylinders 64 (641 to 645) are formed at five locations, respectively, so that the cylinders 64 are parallel to each other. The shaft 1 that rotates by receiving the driving force of an automobile driving engine (not shown) is rotatably supported by the front housing 4 and the rear housing 13 via bearings 3 and 14, respectively. Further, a thrust force (force acting in the left direction in the figure) applied to the shaft 1 is received by the front cylinder block 5 via the thrust bearing 15, and regulates the movement of the shaft 1 in the right direction in the figure.

The thrust force acting on the slide portion 40 (the force acting in the right direction in the figure) is received by the spool 30 via the thrust bearing 116, and the annular locking portion 17 prevents the slide portion 40 from coming off the spool 30. Note that the locking portion 17 is formed on the outer surface of the thrust portion 40. The spool 30 is axially slidably disposed in the cylindrical portion 65 of the rear cylinder block 6 and the cylindrical portion 135 of the rear housing 13.

A slit 105 is formed on the side surface of the swash plate 10 on the shaft 1, and a flat plate portion 16 is formed on the end surface of the shaft 1 on the swash plate 10 side.
5 are formed. Then, the flat plate portion 165 is
The rotation driving force applied to the shaft 1 is transmitted to the swash plate 10 by being arranged so as to be in surface contact with the inner wall.

Shoe 18 and shoe 19 are slidably disposed on both sides of the swash plate 10. On the other hand, the piston 7 is slidably disposed in the cylinder 64 of the front cylinder block 5 and the cylinder 64 of the rear cylinder block 6. As described above, the shoes 18 and 19 are slidably attached to the swash plate 10. The shoes 18 and 19 are rotatably engaged with the inner surface of the piston 7. Therefore, swash plate 10
The oscillating motion accompanying the rotation of is transmitted to the piston as reciprocating motion via the shoes 18 and 19. Shoe 18, 19
Are formed on the swash plate 10 such that the outer surface is on the same spherical surface.

The flat plate portion 165 of the shaft 1 is provided with an inclined groove 166, and the swash plate 10 is provided with a pin through hole. After the flat plate portion 165 of the shaft 1 is arranged in the slit 105 of the swash plate 10, it is locked by the pin 80 and the retaining ring in the pin through hole and the inclined groove 166 of the shaft 1. In this example, pin 80
Is a pin core material 801 and a cylindrical sliding material 802 fitted on the surface thereof.
Consists of

Although the inclination of the swash plate changes depending on the position of the pin 80 in the inclined groove 166, the position of the center of the swash plate changes as the inclination changes. That is, in the second working chamber 60 on the right side in FIG. 1, even if the inclination of the swash plate 10 changes and the stroke of the piston 7 changes, the top dead center of the working chamber 60 of the piston 7 hardly changes and the dead center is dead. The inclined groove 166 is provided so that the volume does not substantially increase. On the other hand, in the working chamber 50 in the left direction in the figure, since the inclination of the swash plate changes and the top dead center of the piston 7 changes, the dead volume also changes.

Oil supply passages 701 and 702 are formed in the center of the shaft 1 along the axis thereof. One end of each of the oil supply passages 701 and 702 is open to the inclined groove 166. Oil supply holes 703, 704 are formed in the shaft in the radial direction. One end of the oil supply hole is opened in the oil supply passages 701, 702, and the other end is opened in the outer surface of the shaft 1. In particular, the oil supply holes 703 and 704 are designed to open in a portion of the compressor where lubricating oil needs to be supplied. In this example, lubrication hole 70
Numeral 3 is formed in the vicinity of the shaft sealing device 21, and an oil supply hole 704 is formed in the slide portion 40.

Further, a lubrication hole 705 is formed in the slide portion 40 in the radial direction, and the lubricating oil supplied from the lubrication hole 704 flows through the lubrication hole 705 by centrifugal force.

The shaft sealing device 21 is attached to the front housing 4 to prevent refrigerant gas and lubricating oil from leaking to the outside along the shaft 1. In the figure, reference numeral 24 denotes a discharge port that opens to the working chambers 50 and 60 and communicates with the discharge chambers 90 and 93. The discharge port 24 is opened and closed by the discharge valve 22. The discharge valve 22 is fixed to the front side plate 8 and the rear side plate 11 by bolts (not shown) together with the valve holder 23. In the drawing, reference numeral 25 denotes a suction port which connects the working chambers 50, 60 and the suction chambers 72, 74, and is opened and closed by the suction valve 9 and the suction valve 12.

In the figure, reference numeral 500 denotes a control valve for controlling the pressure in the control pressure space 200. One of the control valves 500 is connected to a suction pressure space 69 at the rear end of the shaft 1 by a low pressure introduction passage 97. The other is connected to a control pressure chamber 200 via a control pressure control 98 and communicates with a discharge chamber 93 via a high pressure introduction passage 96 and a throttle 99.

In FIG. 1, a front discharge space 90 is guided to a discharge port by a discharge passage (not shown) formed in the cylinder block 5, and a rear discharge space 93 is discharged by a discharge passage formed in the cylinder block 6. Led to the port. Since the two discharge ports are connected by an external pipe, the pressures in the discharge space 90 and the discharge space 93 are the same. The suction space 72 on the front side is guided to the suction space 70 formed in the center of the housing by the suction passage 71, and the suction space 74 on the rear side is similarly guided to the suction space 70 by the suction passage 73.

The operation of the compressor with the above configuration will be described. When an electromagnetic clutch (not shown) is connected, and the driving force from the engine is transmitted to the shaft 1, the compressor starts.

At startup, no pressure difference occurs inside the compressor, and in this state, no pressure difference occurs before and after the spool 30. That is, at the time of startup, the slide portion 40
No load is applied in the direction in which the swash plate 10 is tilted via the.

When the shaft 1 starts rotating in such a state, the rotation of the shaft 1 reciprocates the piston 7 via the swash plate 10. As the piston 7 reciprocates, the refrigerant is sucked, compressed, and discharged in the working chambers 50, 60.

However, in this case, the force based on the pressure difference between the rear working chamber 60 and the front working chamber 50 is generated by the piston 7 and the shoe 1.
It joins the swash plate 10 via 8,19. In particular, since the swash plate 10 is swingably supported by the spherical support portion 405 and receives the rotational force of the shaft 1 by fitting the slit 105 and the flat plate portion 165, the force applied to the piston 7 Operates as a moment in the direction of decreasing the inclination angle of the swash plate 10.

For example, when the transmission pin 80 is located on the axis X in FIG. 3, no moment is generated from the piston disposed in the first cylinder space 641 with respect to the swash plate 10 to change the inclination angle. However, a rotational moment is generated from the pistons 7 disposed in the second to fifth cylinder spaces 642, 643, 644, 645 in a direction to decrease the inclination angle of the swash plate 10. This rotational moment is received by the moment generated around the piston 80. The rotational moment generated by this piston 7 is
A pressing force is applied to 405.

That is, when there is no differential pressure before and after the spool 30,
The slide part 40 and the spool 30 are displaced rightward in the figure. As a result, the swash plate 10 reduces its inclination angle. However, since the swash plate 10 is restricted by the transmission pin 80 in the inclined groove 166 of the shaft 1, the inclination 10 reduces the inclination and applies a force to the center of the swash plate 10 in the left direction in the figure. Ten
Move the center position to the right. The rightward force acting on the slide portion 40 in the figure is transmitted to the spool 30 via the slide bearing 116, and the spool 30 moves until it hits the bottom of the rear housing 13. This state is a state in which the displacement of the compressor is minimized.

The refrigerant gas sucked from the suction port 710 (connected to the evaporator of the refrigeration cycle) is supplied to the suction space at the center.
70, then through the suction passage 73, the rear suction chamber 74
Enter. Thereafter, in the suction stroke of the piston 7, the air is sucked into the working chamber 60 from the suction port 25 via the suction valve 12. The sucked refrigerant gas is compressed in a compression stroke, and when compressed to a predetermined pressure, the discharge valve 22 is pushed open from the discharge port 25 to open the discharge chamber 93.
Is discharged to The high-pressure refrigerant gas passes through the discharge passage, and is discharged from the discharge port to a condenser (not shown) of the refrigeration cycle.

At this time, since the first working chamber 50 on the front side has a large dead volume, the compression ratio is smaller than that of the second working chamber 60 on the rear side, and the pressure of the refrigerant gas in the first working chamber 50 is reduced in the discharge space.
The internal pressure is lower than the internal pressure 90 (the discharge pressure of the rear-side second working chamber 60 is guided), and the suction and discharge operations of the refrigerant gas in the front-side first working chamber 50 are not performed.

The suction port 710 is opened at a substantially intermediate position between the cylinder blocks 5 and 6, and the refrigerant sucked from the suction port 710 directly passes through the center of the swash plate 10 and the flat plate 16 of the shaft 1.
5 will abut. Here, in a compressor used for an air conditioner, it is known that lubricating oil is mixed into a refrigerant and each part is lubricated with the lubricating oil. In particular, since the volume of the suction space 70 of the compressor is rapidly increased as compared with that of the refrigerant pipe or the like, the lubricating oil is easily separated from the refrigerant sucked into the compressor. Moreover, most of the refrigerant flows toward the flat plate portion 165 of the shaft 1,
Lubricating oil having a larger mass than the refrigerant directly contacts the flat plate portion 165. Therefore, the lubricating oil contained in the refrigerant is
Dew condensation easily occurs on the flat plate portion 165.

Moreover, in the compressor of this embodiment, the inclined groove 166 is formed in the flat plate portion, and the inclined groove has a large opening area. It is easy to flow into 166.

The lubricating oil flowing into the inclined groove 166 then flows into the oil supply passage 70
Flows axially through 1,702. Here, since the oil supply holes 703, 704 are opened in the oil supply passages 701, 702, the lubricating oil in the oil supply passages 701, 702 flows out of the oil supply holes 703, 704 by centrifugal force so as to flow outward. Therefore, the lubricating oil flowing into the inclined groove 166 flows through the oil supply passages 701 and 702, and
It will be supplied to the non-lubricating point of the compressor more.

In this example, since the oil supply hole 703 is opened near the shaft sealing device 21, cooling and lubrication of the sealing surface in the shaft sealing device are smoothly performed. Further, since the oil supply hole 704 is opened on the inner surface of the slide portion 40, the slide portion 40 can slide smoothly along the outer surface of the shaft 1.

Further, a lubrication hole 705 is also formed in the slide portion 40 in the radial direction, and the lubrication of the spherical support portion 405 of the slide portion 40 is smoothly performed by the lubrication hole 705.

When the compressor is started, the compressor displacement becomes the minimum displacement as described above. However, when the suction pressure is equalized with the discharge pressure as described above, the absolute pressure of the refrigerant pressure in the suction pressure chamber 74 is also higher than the set pressure. For this reason, the pressure introduced into the pressure chamber 501 with the low-pressure introduction passage 97
Higher than the set pressure of the high pressure introduction passage 9
6 communicates with the control pressure passage 98.

Similarly, it is known that even after the operation of the compressor, the pressure in the suction chamber 74 of the compression chamber increases when the capacity required by the refrigeration cycle is high. This is due to the superheat in the evaporator of the refrigeration cycle. If the pressure of the refrigerant sucked into the compressor increases in this way, the control pressure chamber 200 passes through the high-pressure introduction passage 96 similarly to the above-described start-up. Outlet chamber 9
Conducted with 3. Therefore, the high pressure in the discharge chamber 93 is
It will be gradually introduced into the control pressure chamber 200 via 9.
Thereby, the pressure in the control pressure chamber 200 gradually increases.

Therefore, the force acting on the spool 30 in the leftward direction in FIG. 1 (due to the pressure difference between the control pressure chamber 200 and the suction space 74) gradually increases as the compressor rotates. Then, when this force overcomes the above-described force for pushing the slide portion 40 rightward in the drawing, the spool 30 gradually starts moving leftward in the drawing. Then, by the action of the inclined groove 166 of the shaft 1 and the transmission pin 80, the swash plate 10 increases its inclination while moving its center of rotation to the left in the drawing. When the pressure in the control pressure chamber 200 further increases, the spool 30 moves leftward in the figure until the shoulder 305 hits the rear side plate 11 to realize the maximum capacity state. In this state, the refrigerant gas sucked from the suction port 710 enters the central suction space 70, flows into the suction chambers 72 and 74 through the suction passages 71 and 73, respectively. In the suction stroke, the air enters the working chambers 50 and 60 from the suction port 25 through the suction valves 9 and 12, respectively.
, And enters the discharge spaces 90 and 93 from the discharge port 24 via the discharge valve 22, is discharged from the discharge port through the discharge passage, and merges with the external pipe. In this state, both the working chambers 50 and 60 suck refrigerant gas,
The discharge action is performed.

Thereafter, when the compressor displacement required from the refrigeration cycle decreases, the pressure of the refrigerant sucked into the compressor decreases accordingly. This is due to a decrease in superheat in the evaporator of the refrigeration cycle and an increase in the throttle amount of the expansion valve of the refrigeration cycle.

In this state, the signal pressure passage 98 and the low pressure introduction passage 97 are conducted. Thereby, the pressure in the control pressure chamber 200 becomes
It is released to the suction pressure space 69 side. As a result, the pressure difference generated before and after the spool 30 is reduced, and the spool is displaced rightward in FIG. 1 by the same pressure state as described at the time of starting.

That is, in the compressor of the present embodiment, the spool 30 is continuously displaced in accordance with the pressure of the refrigerant drawn into the compressor, whereby the displacement of the compressor is also continuously changed.

In this manner, in the compressor of the present embodiment, the displacement of the compressor can be continuously variably controlled from the minimum displacement to the maximum displacement in accordance with the control of the control valve 500.

Moreover, in the compressor of the present embodiment, since the inclined groove 166 is opened at an intermediate position of the suction space 70, the lubricating oil in the refrigerant easily flows into and flows into the inclined groove 166. Then, the lubricating oil flowing into the inclined groove 166 is supplied to a non-lubricating point of the compressor through the lubrication passages 701, 702 and the lubrication holes 703, 704.
Therefore, the lubrication in each part of the compressor is smoothly performed in the whole range from the small displacement state to the large displacement state of the compressor discharge capacity.

In the above-described example, the fuel supply passages 701 and 702 are formed on both the front side and the rear side of the shaft.
This may be, for example, only on the rear side. Also,
The positions of the oiling holes 703 and 704 are not limited to the above-described example, and may be set to other locations so as to open toward the oiled location of the compressor. Conversely, in the above example, the lubrication hole 705 is also provided in the slide portion 40, but this lubrication hole 705 may be eliminated as necessary. Further, the oil supply holes 704, 705 may be formed from the oil supply passages 701, 702 toward the outer surface of the shaft. Therefore, the oil supply holes 704, 705 need not necessarily be orthogonal to the oil supply passages 701, 703. The "radial direction" which is the direction in which the oil supply hole is formed in the present invention broadly includes the direction from the oil supply passages 701, 703 toward the outer surface of the shaft.

〔The invention's effect〕

As described above, in the compressor of the present invention, the oil supply passage communicating with the inclined groove in the shaft and the oil supply hole connecting the oil supply passage and the outer surface of the shaft are formed.
Lubricating oil inside the compressor passes through the shaft and is smoothly supplied to the oiled portion. Therefore, in the compressor of the present invention,
It has an excellent effect that a smooth rotation operation can be ensured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the compressor of the present invention, FIG. 2 is a sectional view showing a compressor previously proposed by the present inventors, and FIG.
FIG. 1 is a sectional view showing a cylinder block of the compressor shown in FIG. 1 ... shaft, 7 ... piston, 10 ... swash plate, 30 ... spool, 40 ... slide part, 80 ... pin, 105 ... slit part, 165 ... plate part, 166 ... inclined groove, 710, 702: Oil supply passage, 703, 704: Oil supply hole.

Claims (1)

(57) [Claims] 1. A cylinder block having a cylinder chamber therein, a shaft rotatably supported in the cylinder block and having a flat portion in a part thereof, and a slit into which the flat portion of the shaft fits. ,
A swash plate that rotates integrally with the shaft by engagement of the slit and the flat plate portion; and a piston that is slidably disposed in the cylinder chamber and that reciprocates in the cylinder chamber in response to the rotational movement of the swash plate. A working chamber formed at each of both ends of the piston between the inner surface of the cylinder and for sucking, compressing, and discharging a fluid; and a support for swingably supporting the swash plate with respect to the shaft. And a spool for displacing the support portion in the axial direction of the shaft. The flat plate portion has an inclined groove formed therein, and the slit portion has a pin through hole formed therein. When the hole and the pin inserted into the inclined groove slide along the inclined groove, the swash plate is connected to the shaft so that its inclination angle is variable, and An oil supply passage having one end opening in the inclined groove is formed in the shaft axial direction, and an oil supply hole having one end communicating with the oil supply passage and the other end opening in the outer surface of the shaft is formed in the shaft radial direction. A variable displacement swash plate type compressor characterized by the following.