KR20020045038A - Variable capacity swash plate type compressor - Google Patents

Abstract

PURPOSE: A variable capacity swash plate type compressor is provided to reduce manufacturing cost and time by making a central hole of a swash plate easily formed. CONSTITUTION: A compressor(20) includes a cylinder block(22); a front housing(26) and a rear housing(28); a pressure control valve(88); a driving shaft(34); a rotor(40); a swash plate(42); a hinge device; and a central hole(56). The cylinder block has a plurality of cylinder bores(24) radially placed therein. The front housing and the rear housing are placed in front and back of the cylinder block. The pressure control valve controls pressure in a crank chamber(32). The driving shaft is rotatably supported by the front housing, the rear housing and the cylinder block. The rotor is installed on the driving shaft. The swash plate is connected to the rotor and slidably installed on the driving shaft so that sloping angle thereof is changed by change of pressure in the crank chamber. The hinge device is placed between the rotor and the swash plate to change the sloping angle of the swash plate. The central hole penetrates the swash plate to receive the driving shaft and has an annular inner surface where edges thereof on both sides of the swash plate have same diameters when the sloping angle of the swash plate is maximized. Dxtan(A/2) is same to or larger than W, where D is a diameter of the driving shaft, A is maximum sloping angle of the swash plate and W is thickness of the swash plate where the central hole is formed.

Description

Variable capacity swash plate type compressor

The present invention relates to a variable displacement swash plate type compressor, and more particularly, to the formation of a central hole of a swash plate for mounting a swash plate to a drive shaft.

Variable capacity swash plate type compressors for use in vehicle air conditioning systems are well known, and in this type of compressor, the capacity of the compressor can be controlled by varying the inclination angle of the swash plate.

Referring to FIG. 3 for clarity, the variable displacement swash plate compressor has a swash plate 1, a spherical sleeve 2 rotatably mounted to a drive shaft 3 disposed on the central axis of the compressor. The swash plate 1 is rotatably supported on the outer support surface 2a of the spherical sleeve 2, one end of the drive shaft 3 is supported by the front housing 5 and the other end is supported by the cylinder block 4. .

The rotor 6 is supported at the inner end of the front housing 5 via the bearing 7 and is fixed to the drive shaft 3 so as to rotate with the drive shaft 3. The first arm member 8 constituting the hinge mechanism protrudes from the rotating body 6 and the second arm member 9 protrudes from the swash plate 1 and is hinged by the pin 10. A rectangular hole 11 is formed in the second arm member 9. As the drive shaft 3 rotates by the hinge mechanism, the rotating body 6 also rotates, so that the swash plate 1 also rotates together. In addition, as the pin 10 moves up and down along the rectangular hole 11, the inclination angle of the swash plate 1 is changed and thus the stroke length of the piston is changed, thereby changing the compressor capacity according to the load of the air conditioning system.

On both sides of the outer circumference of the swash plate 1 the swash plate 1 is engaged with the hemispherical shoes 13 so that the rotational movement of the swash plate 1 is converted to the reciprocating motion of the piston 12 in each cylinder bore.

In the compressor having the above-described structure, the spherical sleeve 2 has an outer spherical surface 2a which serves as a support surface for supporting the drive shaft 3, and the spherical outer surface of this spherical sleeve 2 is provided. According to this, the swash plate 1 must also be provided with a spherical inner surface 14. Therefore, machining the central hole in the spherical sleeve 2 and the swash plate 1 requires a complicated work process and also requires a lot of time and energy, causing a cost increase.

One solution to this problem is U.S. Patent No. 5,125,803, in which the angles of inclination are constant with each other past the center point of the circle defined by the annular edge portion to form a central hole in the swash plate. Two central axes with and two pyramids are used. However, the work of forming the central hole of the swash plate disclosed in this patent is still complicated and requires a lot of effort and time.

Accordingly, an object of the present invention is to provide a swash plate type compressor having a piston for solving the above-described problems occurring in the conventional variable displacement swash plate type compressor.

Another object of the present invention is to provide a swash plate suitable for use in a variable capacity swash plate type compressor, whereby the swash plate is easy to be processed, thereby reducing the time and cost of swash plate processing.

1 is a longitudinal sectional view of a payload swash plate compressor according to the present invention;

Figures 2a, b are detailed views of a swash plate for use in the compressor shown in Figure 1 in accordance with the present invention;

Figure 3 shows the components around the swash plate in a variable displacement swash plate compressor of the prior art.

1 is an example of a longitudinal cross-sectional view of a variable displacement swash plate compressor according to the present invention, in which a variable capacity swash plate type compressor 20 has a cylinder block having a plurality of cylinder bores 24. 22, the front housing 26, and the rear housing 28. Both ends of the cylinder block 22 are coupled to be sealed by the front housing 26 and the rear housing 28, respectively, and a valve plate 80 is provided between the cylinder block 22 and the rear housing 28. It is interposed. The cylinder block 72 and the front housing 76 define an air-tight sealed crank seal 32. The drive shaft 34 is arranged to extend past the front housing 26 to the cylinder block 22 and is also rotatably supported by radial bearings 35, 36, 37. The cylinder block 22 and the front and rear housings 26 and 28 are coupled to each other by screws 38 of the long axis.

The rotor 40 is fixedly mounted to the drive shaft 34 located in the crank seal 32 so as to rotate together with the drive shaft 34. The rotor 40 is supported by a thrust bearing 41 provided at an inner end of the front housing 26. A swash plate 42 is rotatably supported by the drive shaft 34. In FIG. 1, the swash plate 42 is in the position of the maximum inclination angle, in which the spring 44 is in the maximum compressed state, and the stop surface 46a of the protrusion 46 is in contact with the rotating body 40. Since the inclination angle of the swash plate 42 is limited by the rotating body 40. The minimum inclination angle of the swash plate 42 is limited by the swash plate 42 contacting the stopper 46 provided on the drive shaft 34.

The swash plate 42 and the rotating body 40 are connected by a hinge mechanism so that the swash plate 42 rotates together with the rotating body 40. That is, the support arm 48 protrudes outward along an axis from one side of the rotating body 40, and the arm 50 protrudes from one surface of the swash plate 42 toward the supporting arm 48 of the rotating body 40. do. The support arm 48 and the arm 50 are connected to each other by the pin 52, the pin 52 is a pin hole 54 and the swash plate 42 formed through the support arm 48 of the rotating body 40 It extends through the generally rectangular hole 56 formed long through the arm 50 of the (). As such, the rotating body 40 and the swash plate 42 are hinged to each other so that the inclination angle of the swash plate 42 is changed by the sliding motion of the pin 52 in the rectangular hole 56. Will change.

Each piston 58 has a cylindrical head portion 60 which is slidably disposed in the corresponding cylinder bore 24 and a U-shaped support 62 located outside the cylinder bore 24. The support 62 is provided with a recess 64, which is provided with a pair of hemispherical shoe pockets 66, each of which has a hemispherical shoe 68 sliding. Possibly seated. On both sides of the outer circumference of the swash plate 42, the swash plate 42 is slidably engaged with the inner surface of each of the shoes 68, so that the swash plate 42 is also engaged with the support 62. By such engagement, the rotational motion of the swash plate 42 is converted into the reciprocating motion of the individual pistons 58.

The rear housing 28 has an inlet 70, an outlet 72, a suction chamber 74, and a discharge chamber 76 for inflow and outflow of the refrigerant gas. The individual cylinder bores 24 are in communication with the suction chamber 74 and the discharge chamber 76, respectively, through the suction port 78 and the discharge port 80 formed in the valve plate 30. Each suction port 78 is closed by the suction valve 82 and the suction valve 82 opens and closes the suction port 78 according to the reciprocating motion of the piston 58. Each discharge port 80 is closed by the discharge valve 84 and the discharge valve 84 opens and closes the discharge port 80 in accordance with the reciprocating motion of the piston 58. Retainer 86 limits the degree of opening of discharge valve 84.

The compressor 20 is provided with a control valve 88 to change the inclination angle of the swash plate 42 by adjusting the fluid pressure level in the crank chamber 32.

Figure 2 shows a method of processing a swash plate as an example of a swash plate for use in the compressor of Figure 1 according to the present invention. In FIG. 2A, the central hole 90 of the swash plate 42 corresponds to a portion of a cylinder defined by extension lines 94 and 96 parallel to the extension line 92 passing through the center point of the swash plate 42 and the center hole 90. ) Is processed at one time. In order to process the central hole 90 at this time, a certain condition is required. When the swash plate 42 is at the position of the maximum inclination angle, the maximum inclination angle of the swash plate is A, the thickness of the swash plate 42 at the portion where the central hole 90 is formed is W, and the diameter of the drive shaft 34 is D. ,

Must satisfy the relationship

That is, the diameter of the swash plate 42 center hole 90 when the swash plate 42 is in the position of the maximum inclination angle L, the diameter L and the drive shaft of the center hole 90 when the swash plate 42 is in the position of the minimum inclination angle When the difference from the diameter D of (34) is L ', the condition that the driving shaft and the swash plate center hole 90 can be coupled without interference with each other at both the maximum inclination angle and the minimum inclination angle is

Equation (1) must be satisfied.

Here, in the relationship with the contacts M, N, and O where the swash plate 42 and the drive shaft 34 come into contact with each other when the swash plate 42 is at the maximum inclination angle position.

Substituting Equation (2) and (3) into Equation (1),

Here, from the trigonometric formula

Using the trigonometric formulas (6) and (7) to develop equation (5) above,

Therefore, by using the relational equation (10) between the diameter D of the drive shaft 34 and the thickness W of the swash plate 42 coupled with the drive shaft 34, the swash plate 42 has the same diameter as the swash plate when in the maximum inclination angle condition. By forming the central hole 90 by one machining, it is possible to form a through hole through which the change of the inclination angle of the swash plate 42 can be made smoothly under both the maximum inclination angle condition and the minimum inclination angle condition.

Referring to the operation of the compressor having the above-described structure, when the drive shaft 34 rotates, the swash plate 42 having a constant inclination angle is also rotated through the hinge mechanism, so that the rotation of the swash plate 42 through the shoes 68 The motion is converted into reciprocating motion in the individual cylinder bores 24 of the pistons 58. Accordingly, the refrigerant gas flows into the respective cylinder bores 24 from the suction chamber 74 of the rear housing 28 and is compressed by the reciprocating motion of the piston 58. The compressed refrigerant gas is discharged from the respective cylinder bores 24 to the discharge chamber 76.

At this time, the amount of the refrigerant gas discharged from the individual cylinder bores 24 to the discharge chamber 76 is controlled by the control valve 88 which adjusts the pressure level of the crank chamber 32. That is, when the load of the evaporator increases, the pressure Psc in the suction chamber 74 becomes high, and accordingly, the control valve 88 blocks the refrigerant gas that is moved from the discharge chamber 76 to the crank chamber 32, so that the crank The pressure level Pcc of the seal 32 is lowered. When the pressure level of the crank seal 32 is lowered, the back pressure acting on each piston 58 is reduced, so that the inclination angle of the swash plate 42 is increased. In other words, the pin 52 constituting the hinge means slides along the rectangular hole 56 toward the upper end of the rectangular hole 56. Thus, the swash plate 42 is moved forward of the compressor against the force of the spring 44. As such, the inclination angle of the swash plate 42 is increased, and as a result, the stroke length of each piston 58 is extended. Compressor capacity of the compressor is increased.

On the other hand, when the load of the evaporator decreases, the pressure Psc in the suction chamber 74 is lowered, and the control valve 88 sends the compressed refrigerant gas of the discharge chamber 76 to the crank chamber 32. The pressure level Pdc of the discharge chamber 76 is in a high state. As the pressure level of the crank seal 32 rises, the back pressure acting on each piston 58 increases, so that the inclination angle of the swash plate 42 decreases. That is, the pin 52 constituting the hinge means slides along the rectangular hole 56 toward the lower end of the rectangular hole 56. Thus, the swash plate 42 is moved to the rear of the compressor, whereby the inclination angle of the swash plate 42 is reduced. As a result, the stroke length of the piston 58 is shortened, which reduces the compression capacity of the compressor.

The center hole of the swash plate for use in the variable displacement swash plate compressor according to the present invention can be easily formed, thereby reducing the manufacturing cost and time.

Claims (2)

A cylinder block having a plurality of cylinder bores disposed radially therein; A housing disposed before and after the cylinder block; Pressure adjusting means for adjusting the pressure of the crank chamber; A drive shaft rotatably supported by the housing and the cylinder block; A rotating body mounted to the drive shaft; A swash plate connected to the rotating body and slidably mounted to the driving shaft to change an inclination angle according to a pressure change of the crank chamber; Hinge means disposed between the rotator and the swash plate to change the inclination angle of the swash plate; It is formed through the swash plate to receive the drive shaft, and when the swash plate is in the position of the maximum inclination angle includes a central hole having an annular inner surface of the edges of both ends of the swash plate having the same diameter, A variable displacement swash plate type compressor that satisfies (where D is the diameter of the drive shaft, A is the maximum inclination angle of the swash plate, and W is the thickness of the swash plate on which the center hole is formed). The method of claim 1, The variable displacement swash plate compressor of the swash plate is formed, only the portion where the center hole is formed to satisfy the formula (1).