WO2001006124A1

WO2001006124A1 - Variable displacement swash plate type compressor

Info

Publication number: WO2001006124A1
Application number: PCT/JP2000/002481
Authority: WO
Inventors: Hiroshi Kanai
Original assignee: Zexel Valeo Climate Control Corporation
Priority date: 1999-07-19
Filing date: 2000-04-17
Publication date: 2001-01-25
Also published as: JP2001032768A

Abstract

A variable displacement swash plate type compressor, comprising a thrust flange (40) rotated integrally with a shaft (5), a swash plate (10) connected to the thrust flange (40) through a link mechanism (41), and a piston (7) which is connected to the swash plate (10) through shoes (60, 61) rotated on the sliding surfaces (10a, 10b) of the swash plate (10) relatively to each other, and performs a linear reciprocating motion in a cylinder bore (6) as the swash plate (10) is rotated, wherein carbon dioxide is used as a refrigerant, an annular height different part (10e) is formed only on the rear side sliding surface (10a) of the swash plate (10), and a plurality of needle rollers (52) and a race (53) rotatably holding these needle rollers (52) are disposed between the height different part (10e) and the shoe (60), whereby the tilt angle of the swash plate (10) varies according to a variation in pressure inside a crank case (8) in which the swash plate (10) is stored and the amount of stroke of the piston (7) varies accordingly.

Description

Description Variable capacity swash plate compressor Technical field

This invention relates to a variable capacity swash plate type compressor, of the preferred variable displacement swash plate type compressors especially co ₂ as a refrigerant compressor of an automotive air conditioner is used as a refrigerant. Background art

As a conventional variable displacement swash plate compressor, a thrust flange that rotates integrally with the shaft, a swash plate that is attached to the shaft so as to be tiltable and rotatable, and that rotates together with the rotation of the thrust flange, The crank chamber in which the swash plate is housed is provided with a piston that linearly reciprocates in the cylinder pores as it rotates, and a pair of shoes that are disposed between the swash plate and the biston and that relatively rotate on the swash plate. In some cases, the inclination angle of the swash plate changes according to the change in pressure, and the stroke amount of the piston changes (Japanese Patent Application Laid-Open No. 9-105376).

A plurality of needle rollers and a race for rotatably holding the needle rollers are disposed between the swash plate and the shoe. The needle roller is housed in a step formed annularly on both sliding surfaces of the swash plate. When the swash plate rotates, the needle roller rolls on the step of the swash plate, the shoe slides relatively on the race, and the sliding speed of the shoe decreases.

However, as described above, the step is provided on both sides of the swash plate, and despite the low strength of the swash plate, a large load is applied to the boundary of the step (the boundary between the step and the part other than the step). Causes swash plate to crack and break There is also a risk.

In particular, when co ₂ is used as the refrigerant, the difference between the high pressure and the low pressure becomes significantly larger (for example, about 12 MPa) than when the refrigerant is chlorofluorocarbon, and the refrigerant gas is compressed by the reciprocating motion of the biston accordingly. The reaction force also increases by about 30 to 40%, and the load acting on the swash plate also increases, so the swash plate is more likely to be damaged. Disclosure of the invention

The present invention, this order to solve the _c the purpose and an object thereof is to provide a variable capacity swash plate type compressor can be prevented with wear-ware between the swash plate and the shoes without incurring damage to the swash plate The variable displacement type swash plate compressor according to the present invention includes a rotating member fixed to a shaft and rotating integrally with the shaft, and a slidably and tiltably attached to the shaft and the rotating member via a link mechanism. A swash plate that is connected to the swash plate and rotates integrally with the rotating member; and a swash plate that is connected to the swash plate via a pair of shoes that relatively rotate on both sliding surfaces of the swash plate. A piston that linearly reciprocates in the cylinder pores, the inclination angle of the swash plate changes in accordance with a change in the pressure of the crank chamber in which the swash plate is housed, and the stroke amount of the biston changes. Capacitive swash plate In the compressor, a needle roller holding step is formed only on the sliding surface of the swash plate on the lear side, and a plurality of needle rollers are provided between the needle roller holding step and one of the shoes. And a race that rotatably holds these twenty-one rollers.

Preferably, the refrigerant as the working fluid is carbon dioxide.

As described above, an annular 21-dollar roller holding step is formed only on the sliding surface on the lear side of the swash plate, and a plurality of 21-dollar rollers are provided between the needle roller holding step and one of the shears. Keep these $ 21 rollers rotatable. The swash plate has a high strength because the race to be held is arranged. Therefore, even if CO ₂ is used as the refrigerant and a large load is applied to the swash plate via the swash plate, the swash plate is hardly damaged. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view showing a variable displacement swash plate type compressor according to one embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a variable displacement swash plate type compressor according to one embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG.

This variable capacity swash plate compressor is used as a component of a refrigerator that uses co ₂ (carbon dioxide) as a refrigerant. In this variable displacement type swash plate type compressor, a cylinder head 1 is provided with a head 3 via one end surface of a cylinder block 1 via a valve plate 2 and a front head 4 at the other end surface. The front head 4, cylinder block 1, valve plate 2 and lya head 3 are integrally connected in the axial direction with a through bolt 31 and a nut 32.

The cylinder block 1 has a plurality of cylinder bores 6 formed at regular intervals along a circumference around a shaft 5. A piston 8 is slidably inserted into each cylinder bore 6. At one end of the piston 7, concave portions 51a and 51b that rotatably support a pair of shoes 60 and 61 described later are formed.

The front head 4 is formed with a crank chamber 8 for accommodating a swash plate 10 ° thrust flange (rotating member) 40 and the like described later. Also to Lya The head 3 has a suction chamber 13 and a discharge chamber 12 formed therein. The suction chamber 13 is located around the discharge chamber 12. The suction chamber 13 contains a low-pressure refrigerant gas to be supplied to the compression chamber 22. The suction chamber 13 is located around the discharge chamber 12. The discharge chamber 12 contains the high-pressure refrigerant gas discharged from the compression chamber 22.

One end of the shaft 5 is rotatably supported on the front head 4 via the radial bearing 26, and the other end of the shaft 5 is rotatable on the cylinder block 1 via the radial bearing 25 and the thrust bearing 24. The thrust flange 40 is fixed to the shaft 5 and rotates together with the shaft 5. The swash plate 10 is attached to the shaft 5 so as to be inclined and slidable. Further, the swash plate 10 is connected to the thrust flange 40 via the link mechanism 41, and rotates together with the rotation of the thrust flange 40.

The swash plate 10 and one end of the piston 7 are connected via a pair of shoes 60, 61. The channels 60 and 61 have convex surfaces (spherical surfaces) 60a and 61a and flat surfaces 60b and 61b. The radius of curvature of the convex surfaces 60a and 6la is the same. The force height (the length from the center of the planes 6Ob and 61b to the center of the convex surfaces 60a and 61a) is different. In other words, sh-61 is higher than sh-60. In addition, if two low shells 60 are used, the thickness of a step portion 10 e of the swash plate 10 described later can be further increased. The convex surfaces 60 a and 61 a contact the concave surfaces 51 a and 5 lb at one end of the piston 7, and the flat surface 61 b directly contacts the sliding surface 10 b of the swash plate 10 and the flat surface 6 b. 0b contacts the sliding surface 10a of the swash plate 10 (step portion 10e) via a needle roller 52 and a thrust trace 53 described later. A pair (two pairs) of shoes 60, 61 are respectively arranged so as to sandwich the swash plate 10 with respect to the plurality of pistons 7, and the shoes 60, 61 are rotated as the shaft 5 rotates. Sliding of swash plate 10 Rotate relatively on planes 10a and 10b.

Between the sliding surface 10a on the rear side of the swash plate 10 and the shoe 60a 60b, a plurality of 21 rollers 5 and a race 5 for rotatably holding the needle rollers 52 are provided. 3 and are arranged. The needle port rollers 52 are arranged in an annular step portion (step portion for holding the needle port rollers) 10 e provided on the sliding surface 10 b on the lia side of the swash plate. The distance from the center line O of the swash plate 10 to the boundary A between the step portion 10 e and the sliding surface 10 a is the distance from the center line の of the swash plate 10 to the sliding surface 10 b and the boss portion 10. It is longer than the distance to boundary B with f (see Fig. 2).

The valve plate 2 has a discharge port 16 for communicating the compression chamber 22 and the discharge chamber 12 and a suction port 15 for communicating the compression chamber 22 and the suction chamber 13 along the circumferential direction. Are provided at regular intervals. The discharge port 16 is opened and closed by a discharge valve 17, and the discharge valve 17 is fixed to the end face of the valve plate 2 on the lid head side together with a valve retainer 18 by bolts 19 and nuts 20. The suction port 15 is opened and closed by a suction valve 21, and the suction valve 21 is disposed on the front end face of the valve plate 2.

A communication path (not shown) is provided between the discharge chamber 12 and the crank chamber 8, and a pressure regulating valve (not shown) is provided in the middle of the communication path to open and close according to a change in suction pressure. The pressure in the crank chamber 8 is adjusted by opening and closing the pressure adjusting valve. A communication path (not shown) is provided between the suction chamber 13 and the crank chamber 8, and an orifice (not shown) is provided in the middle of the communication path.

A thrust flange 40 fixed to the front end of the shaft 5 is rotatably supported on the inner wall surface of the front head 30 via a thrust bearing 33. As described above, the thrust flange 40 and the swash plate 10 are linked. The swash plate 10 is connected via a mechanism 41 and can be inclined with respect to an imaginary plane perpendicular to the shaft 5. The link mechanism 41 includes a bracket portion 10c provided on the sliding surface 10b side of the swash plate 10; a linear guide groove 10d formed in the bracket portion 10c; And a rod 43 screwed to the flange 40. The longitudinal axis of the guide groove 10 d is inclined at a predetermined angle with respect to the sliding surface 10 b of the swash plate 10. The spherical tip portion 43a of the rod 43 is fitted into the guide groove 10d so as to be relatively slidable.

A winding panel 48 is mounted between the thrust flange 40 and the swash plate 10, and the swash plate 10 is urged toward the lya side by the urging force of the winding spring 47, so that the thrust bearing 24 and the swash plate A winding spring 47 is mounted between the swash plate 10 and the swash plate 10 by the urging force of the winding panel 47.

Next, the operation of the variable displacement type swash plate type compressor will be described.

When the rotational power of the vehicle-mounted engine (not shown) is transmitted to the shaft 5, the rotating force of the shaft 5 is transmitted to the swash plate 10 via the thrust flange 40 and the link mechanism 41, and the swash plate 10 rotates.

The rotation of the swash plate 10 causes the shafts 60 and 61 to relatively rotate on the sliding surfaces 10 a and 10 b of the swash plate 10, and the rotational force from the swash plate 10 reciprocates linearly with the piston 7. Is converted to When the piston 7 reciprocates in the cylinder bore 6, the volume of the compression chamber 22 in the cylinder bore 6 changes, and the suction, compression and discharge of the refrigerant gas are sequentially performed by this volume change, and the tilt angle of the oscillating plate 10 is changed. The high-pressure refrigerant gas having a capacity corresponding to the pressure is discharged.

At the time of suction, the suction valve 21 opens, and low-pressure refrigerant is sucked from the suction chamber 13 into the compression chamber 22 in the cylinder bore 6, and at the time of discharge, the discharge valve 17 opens and the compression chamber 22 discharges from the compression chamber 22. High-pressure refrigerant gas is discharged to the The high-pressure refrigerant gas in the discharge chamber 12 is discharged from the discharge port 3a to a cooler (not shown).

During compression, a large load acts on the swash plate 10 via the shears 60, A step portion 10e is formed only on the sliding surface 10a on the rear side of the plate 10 and a plurality of needle rollers are formed between the step portion 10e and the plane 60b of the one shoe 60. Since the swash plate 10 is rotated when the swash plate 10 is rotated, the needle roller 52 rolls over the stepped portion 10 e, and the swash plate 10 is rotated. The plane portion 60b of 60 slides relatively on the race 53, and the plane portion 60b of the shoe 60 and the sliding surface 10a on the rear side of the swash plate 10 are brought into direct contact. The sliding speed (m / se) of SHU 60 is lower than when

When the heat load decreases and the pressure regulating valve opens and the pressure in the crankcase 8 increases, the inclination angle of the swash plate 10 decreases, so that the stroke amount of the piston 7 decreases and the discharge capacity decreases. Decrease. On the other hand, when the heat load increases and the pressure regulating valve closes and the pressure in the crank chamber 8 decreases, the inclination angle of the swash plate 10 increases, so that the stroke amount of the piston 7 increases and discharge occurs. The capacity increases.

According to this embodiment, the step portion 10 e is provided only on the lear-side sliding surface 10 a of the swash plate 10. Since the strength of the step portion 10 e of the swash plate 10 is high, the refrigerant Even if CO ₂ is used, the swash plate 10 is less likely to be cracked, its durability is improved, and wear and seizure between the swash plate 10 and the swash plate 61 can be prevented. . Industrial applicability

According to the variable capacity swash plate compressor of the present invention, the strength of the swash plate is high, using C_〇 ₂ as a refrigerant, when a large load to the swash plate via the shoes acts, damage of the swash plate Can be prevented.

Claims

The scope of the claims

1. A rotating member fixed to a shaft and rotating integrally with the shaft, and slidably and tiltably attached to the shaft and connected to the rotating member via a link mechanism to rotate integrally with the rotating member. Swash plate and

A piston that is connected to the swash plate via a pair of shafts that relatively rotate on both sliding surfaces of the swash plate, and that linearly reciprocates in a cylinder bore as the swash plate rotates;

In the variable displacement type swash plate type compressor in which the inclination angle of the swash plate changes according to a change in the pressure of a crank chamber in which the swash plate is housed, and the stroke amount of the piston changes, A step portion for holding the $ 21 roller is formed only on the sliding surface of

A variable capacity, comprising: a plurality of needle rollers; and a race rotatably holding these needle rollers, between the step portion for holding the needle roller and one of the shoes. Type swash plate type compressor.

2. The variable displacement swash plate type compressor according to claim 1, wherein the refrigerant as the working fluid is carbon dioxide.