Variable capacity swash plate type compressor

The present invention relates to a variable capacity swash plate type compressor, and more particularly, to a variable capacity swash plate type compressor, which has a stopper protruding from the inner surface of a hub and being in contact with a sleeve when a swash plate is at the maxi mum inclination angle to shorten a stroke distance of the stopper for supporting the maximum inclination angle of the swash plate, thereby reducing a hitting noise when the stopper is moved at the maximum inclination angle and when an air conditioner is turned off.

In general, a compressor constituting an air conditioning system for an automobile is a device to selectively receive driving power from a power source by a restricting action of an electromagnetic clutch, compress refrigerant gas by a straight reciprocating motion of pistons after absorbing the refrigerant gas from an evaporator, and discharge it toward a condenser. Such a compressor is classified into various kinds according to compression methods and structures, and out of the compressors of the various kinds, a variable capacity compressor, which can vary a compression volume, has been widely used.

Hereinafter, referring to FIG. 1, a prior art variable capacity swash plate type compressor will be described as an example.

The variable capacity swash plate type compressor 1 includes: a cylinder block 10 having a plurality of cylinder bores 11 axially formed inside the cylinder block 10 along a concentric circle; a front housing 20 mounted on the front of the cylinder block 10 and having a crank chamber 21 formed therein; a rear housing 30 mounted on the rear of the cylinder block 10 and having a suction chamber 31 and a discharge chamber 32 formed therein; a plurality of pistons 40 reciprocatingly inserted into each of the cylinder bores 11 of the cylinder block 10 and having a bridge 41 at the rear end portion thereof; a driving shaft 50 having an end portion rotatably passing through the front housing 20 and the other end portion inserted and rotatably mounted into the center of the cylinder block 10; a rotor 60 combined to the driving shaft 50 and rotating with the driving shaft 50 inside the crank chamber 21; a swash plate 70 mounted on the circumference of the driving shaft 50 by slidably combining a sleeve 65, having an edge rotatably mounted to an insertion space of the piston bridge 41 by interposing a shoe 45 between the insertion space and the edge of the swash plate 70, and movably connected to a hinge arm 61 of the rotor 60 so as to be rotated together with the rotor 60 and adjust its inclination angle against the driving shaft 50; and a valve unit 80 mounted between the cylinder block 10 and the rear housing 30 to inhale refrigerant from the suction chamber 31 into the cylinder bore 11 during a suction stroke and discharge compressed refrigerant from the cylinder bore 11 into the discharge chamber 32 during a compression stroke.

In addition, the inclination angle of the swash plate 70 against the driving shaft 50 can be adjusted according to a pressure change inside the crank chamber 21 by a control valve 90 mounted in the rear housing 30.

Furthermore, a compression coil spring 55 interposed on the driving shaft 50 located between the rotor 60 and the swash plate 70 elastically supports the sleeve 65, to which the swash plate 70 is rotatably combined, against the rotor 60, so that the swash plate 70 can be returned to its original position.

Meanwhile, the rotor 60 has a slot 62 formed on the hinge arm 61 thereof, and a connection hinge arm 73 having a hinge pin 74 is formed on a hub 71 of the swash plate 70, which is faced to the hinge arm 61 of the rotor 60. The connection hinge arm 73 protrudes toward both sides of the hinge arm 61 and is movably combined to the slot 62 of the hinge arm 61.

As described above, in the variable capacity swash plate type compressor 1, a plurality of the pistons 40 arranged along the concentric circle of the cylinder block 10 perform the forward and backward reciprocating motion in order by the rotation of the swash plate 70.

Here, during the suction stroke of the pistons 40, a suction valve (not shown) of the valve unit 80 is opened by a drop of pressure inside the cylinder bore 11, whereby the cylinder bore 11 and the suction chamber 31 are fluidically communicated with each other and the refrigerant is induced from the suction chamber 31 into the cylinder bore 11.

Additionally, during the compression stroke of the pistons 40, a discharge valve (not shown) of the valve unit 80 is opened while the refrigerant is compressed by a rise of pressure inside the cylinder bore 11, whereby the cylinder bore 11 and the discharge chamber 32 are fluidically communicated with each other and the compressed refrigerant is discharged from the cylinder bore 11 into the discharge chamber 32.

In addition, the swash plate 70 adjusts its inclination angle in correspondence to a difference between pressure inside the crank chamber 21 and suction pressure inside the cylinder bores 11, whereby a discharge volume of the compressor 1 is varied.

Meanwhile, the hub 71 of the swash plate 70 has a stopper 72 formed oppositely to the connection hinge arm 73 to support the maximum inclination angle of the swash plate 70.

Therefore, when the compressor 1 is at the maximum angle, the inclination angle of the swash plate 70 is changed into the maximum angle, and in this instance, the compression coil spring 55 is compressed and at the same time the stopper 72 is in contact with a side surface of the rotor 60 to support the maximum inclination angle of the swash plate 70.

However, when the swash plate 70 is changed into the maximum inclination angle, it may cause noise due to a hitting noise generated while the stopper 72 is in contact with the rotor 60.

In addition, the prior art may cause a great hitting noise due to expansion of refrigerant inside the crank chamber 21 when the air conditioner is turned off.

That is, a stroke distance of the stopper 72 is enlarged while the stopper 72 is gradually spaced apart from the hinge arms 61 and 73 connecting the swash plate 70 and the rotor 60 with each other, and thereby, it causes more severe hitting noise.

Accordingly, it is an object of the present invention to provide a variable capacity swash plate type compressor, which has a stopper protruding from the inner surface of a hub and being in contact with a sleeve when a swash plate is at the maximum inclination angle to shorten a stroke distance of the stopper for supporting the maximum inclination angle of the swash plate, thereby reducing a hitting noise when the stopper is moved at the maximum inclination angle and when an air conditioner is turned off.

To achieve the above objects, the present invention provides a variable capacity swash plate type compressor including: a cylinder block having a plurality of cylinder bores therein; a front housing mounted on the front of the cylinder block and having a crank chamber therein, and a rear housing mounted on the rear of the cylinder block and having a suction chamber and a discharge chamber therein; a driving shaft rotatably mounted on the cylinder block and the front housing; a rotor combined to the driving shaft and rotating together with the driving shaft inside the crank chamber; a swash plate having a hub movably connected to a hinge arm of the rotor and a swash plate board combined to the hub, the hub being rotatably combined to a sleeve which is slidably combined to the driving shaft, the swash plate varying its inclination angle in correspondence to a pressure change of the crank chamber; and a spring mounted on the driving shaft located between the rotor and the swash plate for returning the swash plate to the initial position, wherein maximum inclination angle supporting means is provided between the hub and the sleeve.