JPH0579455A - Variable capacity type swash plate type compressor - Google Patents

Abstract

PURPOSE:To provide a variable capacity type swash plate type compressor which prevents any wear from being generated in a contact part between a sleeve and a control piston and can maintain high performance and reliability for a long period. CONSTITUTION:In a variable capacity type swash plate type compressor wherein a sleeve 50 serving as a swash plate angle control member and a control piston 55 are formed in mutually different structures a bearing 52 is located between the sleeve 50 and the control piston 55. Since the sleeve 50 does not make direct contact with the control piston 55, this constitution prevents the occurrence of wear to a contact part even when relative rotation occurs therebetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type compressor having a variable capacity effective for use as a refrigerant compressor for an air conditioner for automobiles.

[0002]

2. Description of the Related Art The present inventors previously attached a swash plate to a shaft so that the swash plate can swing, and the inclination angle of the swash plate can be varied according to the displacement of a swash plate angle control member. We proposed a swash plate type compressor with variable capacity, which can also displace the center position of the compressor.

In this type of swash plate type compressor, the swash plate angle control member is displaced according to the pressure in a control pressure chamber formed on the back surface of the swash plate angle control member, and this displacement is transferred via a slider. The swash plate is transmitted to the swash plate to push the swash plate, thereby changing the inclination angle of the swash plate and displacing the center position of the swash plate. The discharge volume is adjusted by controlling the stroke.

In the swash plate type compressor described above, as shown in FIG. 3, the swash plate angle control member includes a sleeve 50 serving as a radial load sharing member and a pressure receiving member for receiving the pressure in the control pressure chamber. A control piston 5
A structure divided into 5 and 5 has been developed. In this structure, the rear side portion of the sleeve 50 has a small-diameter cylindrical shape 502, whereby the diameter of the cylindrical hollow portion 5a formed in the cylinder block 5 can be reduced, and the space between the working chamber 32 and the cylindrical hollow portion 5a can be reduced. The creepage distance 1 can be increased, a long seal length 1 can be secured, and the high-pressure refrigerant in the working chamber 32 can be prevented from leaking.

[0005]

However, in the case of such a conventional structure, the sleeve 50 receives the rotation of the shaft 13 via the radial bearing 17 mounted inside, and
That is, the shaft 13 rotates and rotates.
In this case, with the movement of the radial load transmitted from the shaft 13lk, the sleeve 50 moves in the cylindrical hollow portion 5a formed in the cylinder block 5 in the direction opposite to the rotation direction of the shaft 13 and in the rotation direction of the shaft 13. The orbit of the direction is repeated.

On the other hand, the control piston 5
Since 5 receives the sliding resistance of the O-ring 56 mounted on the outer peripheral portion, its rotation is restricted.

Therefore, the sleeve 50 and the control piston 55 rotate relative to each other, and the sleeve 55
Since the rear side end surface 503 of the above is in direct contact with the front side surface of the control piston 55, there is a concern that wear may occur at these contact portions.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent wear from occurring at a contact portion between a sleeve and a control piston and to achieve high performance and reliability for a long time. An object of the present invention is to provide a variable capacity swash plate type compressor that can be maintained for a long time.

[0009]

In order to achieve the above object, the present invention is characterized in that a bearing is interposed between the sleeve and the control piston.

[0010]

According to this structure, since the sleeve and the control piston do not come into direct contact with each other, wear does not occur at the contact portion even if relative rotation occurs between them. Moreover, since the thrust load transmitted from the control piston to the sleeve is transmitted through the bearing, the load can be surely transmitted.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIGS.

FIG. 1 is a vertical sectional view showing the entire structure of a variable displacement swash plate type compressor, and FIG. 2 is an enlarged sectional view showing a main part thereof.

In the figure, reference numeral 1 is a main body which forms the outer shell of the compressor. The main body 1 has a front cylinder block 4 and a rear cylinder block 5 interposed between a front housing 2 and a rear housing 3 made of an aluminum alloy, and the front housing 2 and the front cylinder block 4 are connected to each other.
The front side plate 6 is sandwiched between the rear housing 3 and the rear cylinder block 5, and the rear side plate 7 is sandwiched between the rear housing 3 and the rear cylinder block 5.

The front housing 2, the front side plate 6, the front cylinder block 4, the rear cylinder block 5, the rear side plate 7 and the rear housing 3 are integrally connected by a through bolt 10.

Reference numeral 11 denotes a cylinder bore formed so as to straddle the front cylinder block 4 and the rear cylinder block 5, and these cylinder bores 11 ... Are formed so as to be parallel to each other, for example, at five locations in the circumferential direction. There is.
Pressurizing pistons 12 ... Are fitted in the cylinder bores 11 so as to be slidable in the axial direction.

Reference numeral 13 denotes a shaft which rotates by receiving a driving force of an automobile running engine, which is not shown. This shaft 13 has a front radial end 1 at its front end.
It is supported by the front cylinder block 4 via 6 and its rear end is inserted in a sleeve-shaped slider 15. A flat plate portion 14 is formed at a substantially central portion of the shaft 13, and the slider 15 is axially slidably fitted to an end portion on the rear side of the flat plate portion 14.

The slider 15 is rotatably supported by a sleeve 50 serving as a radial load sharing member of the swash plate angle control member via a rear radial bearing 17.

The force acting on the shaft 13 in the left direction in the figure is received by the front cylinder block 4 via the front thrust bearing 18, and when the shaft 13 is acted in the right direction in the figure. Is received by the sleeve 40 via the rear thrust bearing 19. The thrust load of the sleeve 50 is received by the control piston 55 described later.

Reference numeral 20 is a swash plate, and the swash plate 20 is swingably supported by the slider 15. This swash plate 2
0 is provided with a guide pin 21. This guide pin 2
1 is slidably penetrated into a guide groove 22 formed in the flat plate portion 14 of the shaft 13. This guide groove 22
The inclination of the swash plate 20 changes depending on the position of the pin 21 therein.

Further, shoes 23, 23 are slidably arranged on both sides of the peripheral edge of the swash plate 20. These shoes 23 are rotatably engaged with the inner surface of the pressure piston 12. Therefore, the swinging movement of the swash plate 20 accompanied by the rotation is transmitted as reciprocating movement to the pressure pistons 12 through the shoes 23.

First and second working chambers 31 and 32 are formed inside the front cylinder block 4 and the rear cylinder block 5, respectively, on the left and right of the pressurizing pistons 12 ... When the pressurizing pistons 12 ... Are moved to the left, the refrigerant in the first working chamber 31 is compressed, and when moved to the right, the second working chamber 32 is compressed.
The refrigerant is compressed.

Discharge chambers 33 and 34 are formed in the front housing 2 and the rear housing 3, and these discharge chambers 33 and 34 are discharged through the discharge ports 35 and 36 opened in the front side plate 6 and the rear side plate 7, respectively. It communicates with the first and second working chambers 31 and 32. The discharge ports 35 and 36 are connected to the discharge valve 37,
The discharge valves 37 and 38 are fixed to the front side plate 6 and the rear side plate 7 by the through bolt 10 together with the valve retainers 39 and 49.

Reference numerals 40 and 41 denote suction chambers formed in the front housing 2 and the rear housing 3, respectively. The suction chambers 40 and 41 are provided with the suction ports 42 and 43 opened in the front side plate 6 and the rear side plate 7, respectively. And communicates with the second working chambers 31 and 32. These suction ports 42, 43 are opened and closed by suction valves 8, 9.

The discharge chamber 33 on the front side is guided to the discharge muffler 70 by a discharge passage (not shown), and the discharge chamber 34 on the rear side is also guided to the discharge muffler 70 by a discharge passage (not shown). It has been. The discharge muffler 70 is also guided to a discharge port (which is also connected to the condenser of the refrigeration cycle) not shown.

The suction chamber 40 on the front side is provided with a suction passage 4
5 is guided to the suction chamber 46 formed in the central portion of the housing, and the rear suction chamber 41 is also guided to the suction chamber 46 by the suction passage 47.

The sleeve 50 is slidably fitted in a cylindrical hollow portion 5a formed in the rear cylinder block 5. The sleeve 50 has a large-diameter cylindrical portion 501 that receives the rear radial bearing 17 at the front end, and a small-diameter cylindrical portion 502 that is formed at the rear end. The large-diameter cylindrical portion 501 is the rear cylinder block 5.
It is slidably fitted and inserted in the cylindrical hollow portion 5a formed in.

The rear end of the sleeve 50 is in contact with the control piston 55 via the thrust bearing 52.

The control piston 55 is a pressure receiving member of a swash plate angle control member, and is slidably fitted in a control pressure chamber 60 formed in the rear housing 3. An O-ring 56 is mounted on the outer peripheral surface of the control piston 55, and the O-ring 56 is adapted to be in sliding contact with the inner surface of the control pressure chamber 60. Control piston 55
A support boss portion 55a is formed on the front end surface of the above, and the thrust bearing 52 is supported by the support boss portion 55a.

The suction chamber 41 on the rear side is separated from the control pressure chamber 60 by the control piston 55. Therefore, the control piston 50 is operated according to the pressure difference between the control pressure chamber 60 and the rear suction chamber 41.

Although not shown, either the suction pressure or the discharge pressure is introduced into the control pressure chamber 60 via the control valve 61 according to the operating condition of the air conditioner.

Then, when a high discharge pressure is introduced into the control pressure chamber 60, the control piston 55 is pushed to the left side in the figure, and the sleeve 50 is pushed to the left side via the thrust bearing 52 to move. Therefore, since the sleeve 50 pushes the slider 15 to the left via the rear thrust bearing 19 and thus pushes the swash plate 20 through the guide pin 21, the tilt angle of the swash plate 20 is changed.

In the compressor having such a structure, when the driving force from the engine is transmitted to the shaft 13 by the operation of the electromagnetic clutch (not shown), the compressor operates.

Since the pressure is balanced inside the compressor at the time of starting, there is no pressure difference before and after the control piston 55, and at the time of starting, no load is applied in the direction of tilting the swash plate 20 via the slider 15. .. Therefore, in the initial stage of starting, the inclination angle of the swash plate 20 is relatively small due to the compression reaction force.

When the shaft 13 starts rotating in such a state, the rotation of the shaft 13 reciprocally drives the pressurizing piston 12 via the swash plate 20. With the reciprocating movement of the pressurizing piston 12, the refrigerant is sucked, compressed, and discharged in the working chambers 31, 32.

That is, the refrigerant gas sucked from a suction port (which is connected to the evaporator of the refrigeration cycle) (not shown) enters the suction chamber 46 at the central portion, and then the suction passage 45,
47, the front and rear suction chambers 40, 41
Enter Then, in the intake stroke of the pressurizing piston 12, the intake air is sucked into the working chambers 31 and 32 from the suction ports 42 and 43 via the suction valves 8 and 9, respectively.

The sucked refrigerant gas is compressed in a compression stroke, and when compressed to a predetermined pressure, the discharge valves 37 and 38 are pushed open from the discharge ports 35 and 36 and discharged into the discharge chambers 33 and 34.

After that, the refrigerant gas in the discharge chambers 33 and 34 enters the discharge muffler 70 through a discharge passage (not shown) and merges, and is discharged from a discharge port (not shown) to the condenser of the refrigeration cycle.

When the compressor is started, the discharge capacity of the compressor is set to the minimum capacity as described above.

However, when the capacity of the compressor required from the refrigeration cycle side is high, the control valve 61 is operated to introduce the high pressure side of the discharge pressure into the control pressure chamber 60.

Therefore, the pressure difference between the control pressure chamber 60 and the suction chamber 41 increases, and this pressure difference gradually rises as the compressor rotates. This force serves as a force for pushing the control piston 55 to the left in FIG. 1, and this pushing force pushes the slider 15 to the left from the sleeve 50 through the rear thrust bearing 19.

Therefore, by the action of the guide groove 22 and the guide pin 21 of the shaft 13, the swash plate 20 moves its rotation center to the left in the figure and increases its inclination.

Therefore, since the reciprocating stroke of the pressurizing pistons 12 increases, the discharge amount increases. Thus, in the present compressor, the capacity of the refrigerant discharged from the compressor can be controlled according to the displacement of the control piston 55.

In such a compressor, as shown in detail in FIG. 2, the sleeve 50 and the control piston 55.
Since the above is separated to be a separate member, the rear side portion of the sleeve 50 can be formed into a small diameter cylindrical shape 502, and thus the diameter of the cylindrical hollow portion 5a formed in the cylinder block 5 can be reduced. Therefore, the creepage distance 1 between the working chamber 32 and the cylindrical hollow portion 5a can be increased, and a long seal length 1 can be secured, so that the high pressure refrigerant in the working chamber 32 is prevented from leaking. Can be prevented.

In this case, since the thrust bearing 52 is mounted between the sleeve 50 and the control piston 55, the rotating force is transmitted from the shaft 13 to the sleeve 50, and the sleeve 50 is not in the rotational direction of the shaft 13. The thrust bearing 52 provided between the sleeve 50 and the control piston 55 allows the sleeve 50 to rotate even if the rotation in the opposite direction and the revolution in the same direction as the rotation direction of the shaft 13 are repeated. Further, the thrust bearing 52 prevents the sleeve 50 and the control piston 55 from directly contacting each other, so that the wear of these can be prevented.

The bearing 52 installed between the sleeve 50 and the control piston 55 is not limited to the structure in which the roller is provided between the pair of thrust traces. For example, when the sleeve 50 and the control piston 55 are both made of aluminum. Alternatively, it may be constituted by a single thrust trace made of a metal having better wear resistance than this, for example, iron or stainless steel.

[0046]

As described above, according to the present invention, since the bearing is provided between the sleeve and the control piston, the two do not come into direct contact with each other, and even if a relative rotation occurs between them, they come into contact with each other. No wear occurs on the part. Therefore, high performance and reliability can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view showing an overall configuration of a compressor showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of the main part of the embodiment.

FIG. 3 is a sectional view showing a structure of a main part of a conventional compressor.

[Explanation of reference numerals] 1 ... Main body, 2, 3 ... Housing, 4,5 ... Cylinder block, 11 ... Cylinder bore, 12 ... Pressurizing piston, 13
... shaft, 15 ... slider, 20 ... swash plate, 50 ... sleeve, 52 ... thrust bearing, 55 ... control piston, 60 ... control pressure chamber.

Claims (1)

[Claims] 1. A cylinder block having a cylinder chamber formed therein, a shaft rotatably provided in the cylinder block, and a swash plate which is swingably connected to the shaft and rotates integrally with the shaft. A pressurizing piston slidably disposed in the cylinder chamber and reciprocating in the cylinder chamber in response to the swinging motion of the swash plate; and both end portions of the pressurizing piston and the inner surface of the cylinder chamber. A working chamber for sucking, compressing and discharging fluid, a slider arranged coaxially with the shaft for swingably supporting a center point position of the swash plate, and a slider for supporting the shaft. A sleeve that displaces in the axial direction, a control piston that moves in the axial direction according to the pressure in the control pressure chamber and actuates the sleeve in the axial direction, the sleeve and the control piston. Variable capacity swash plate type compressor comprising: the bearing provided between the tons, the.