KR100558705B1 - Wobble plate type compressor with variable displacement - Google Patents

Abstract

The present invention provides a swash plate suitable for use in a variable displacement swash plate compressor, comprising: 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 drive shaft to change the inclination angle according to the pressure change of the rank chamber; Hinge means disposed between the rotating body and the swash plate to change the inclination angle of the swash plate; A plurality of pistons reciprocally disposed in each of the cylinder bores; A plurality of shoes for converting the rotational motion of the swash plate into the reciprocation of the pistons; And a first axis formed through the swash plate to accommodate the drive shaft, the first inner surface being in contact with the first cylinder having a central axis passing through the center point of the swash plate, and a central axis formed at an angle with respect to the central axis of the first cylinder. A center hole formed by a second cylinder formed by a second cylinder including a part of the first inner surface of the swash plate among the center holes formed by the first cylinder, and as a result, the processing is easy and thus the time for processing the swash plate This reduces the cost and cost and also minimizes the wear of the drive shaft and swash plate.

Description

Wobble plate type compressor with variable displacement

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

2A is a cross-sectional view showing a method of processing a swash plate for use in the compressor shown in FIG. 1;

Figure 2b is a cross-sectional view showing another embodiment of the swash plate,

Figure 3 is a cross-sectional view showing the components around the swash plate in a conventional variable displacement swash plate compressor.

* Description of the symbols for the main parts of the drawings *

42; swash plate 90; center hole

92; center axis 93; first inner surface

94; second inner surface 96; first cylinder

98; second cylinder

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 includes a swash plate 1, a drive shaft 3 disposed on the central axis of the compressor, and a spherical sleeve rotatably mounted to the drive shaft 3. Has (2). 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. .

A rotor 6 is fixed on the drive shaft 3 and rotatably supported by a thrust bearing 7 provided in the front housing 5.

In addition, the first arm member 8 constituting the hinge mechanism protrudes from the rotating body 6 and the second arm member 9 having a rectangular hole is protruded from the swash plate 1 and hinged by the pin 10. Thus, when the compressor is driven, the rotational force of the drive shaft 3 is transmitted to the rotating body 6, and accordingly, the swash plate 1 is also rotated together, wherein the pin 10 moves up and down along the rectangular hole 11. By varying the inclination angle of the swash plate 1 to change the stroke length of the piston 12, the compressor capacity is varied.

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 into a reciprocating motion in the cylinder chamber of the piston 12.

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 swash plate 1, 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, a complicated work process that requires processing a central hole forming a curved surface on the spherical sleeve 2 and the swash plate 1 is required, 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, which states that a conical hole having two central axes intersects at the center of the swash plate to form an annular edge inside the hole. By forming the edge portion, the annular edge portion is adapted to support the rotational inclination motion of the swash plate while being in contact with the drive shaft.

However, the annular edge portion where the first and second inner surfaces of the central hole of the swash plate disclosed in this patent intersect has a sharp shape, thereby causing abnormal wear on both the drive shaft and the swash plate at the point where the driving shaft and the annular edge portion of the swash plate contact each other. Will be raised. In addition, the work of forming the central hole of the swash plate is complicated, which requires a lot of effort and time.

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

Another object of the present invention is to provide a swash plate suitable for use in a variable displacement swash plate compressor.

In order to achieve this object, the present invention is 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; A plurality of pistons reciprocally disposed in each of the cylinder bores; A plurality of shoes for converting rotational motion of the swash plate into reciprocating motion of the pistons; And a first inner surface formed through the swash plate to accommodate the driving shaft, the first inner surface being in contact with the first cylinder having a central axis passing through the center point of the swash plate, and a central axis formed at a predetermined angle with respect to the central axis of the first cylinder. And a center hole formed by a second inner surface formed by a second cylinder including a part of the first inner surface of the swash plate among the center holes formed by the first cylinder.

According to this, it is easy to process the swash plate, and thus it is possible to reduce the time and cost of the swash plate processing and to minimize the wear of the driving shaft and the swash plate.

1 is a longitudinal sectional view of a compressor having a mechanism for minimizing a bending moment, for example a variable capacity swash plate compressor, in which a variable capacity swash plate type compressor 20 comprises a plurality of cylinders. It has a cylinder block 22 having a bore 24, a front housing 26, and a 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 30 is provided between the cylinder block 22 and the rear housing 28. It is interposed. The cylinder block 22 and the front housing 26 define an air-tight sealed crank chamber 32. The drive shaft 34 is disposed to extend beyond the front housing 26 to the cylinder block 22 and is rotatably supported by the 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 shaft.

The rotor 40 is fixedly mounted to the drive shaft 34 located in the crank chamber 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 39 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 portion 62 located outside the cylinder bore 24. The support 62 is provided with a recess 64, which is formed with a pair of hemispherical shoe pockets 66, each of which is slipped with a hemispherical shoe 68. 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 communicate with the suction chamber 74 and the discharge chamber 76 through the inlet 78 and the outlet 80 formed in the valve plate 30, respectively. 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, the discharge valve 84 opens and closes the discharge port 80 in accordance with the reciprocating movement 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 pressure level in the crank chamber 32.

Figure 2a is a view showing a method for processing a swash plate as an example of a swash plate for use in the compressor shown in Figure 1 according to the present invention. As shown in FIG. 2A, the swash plate 42 is in the position of the maximum inclination angle. The central hole 90 is formed through the swash plate. The central axis 92 is perpendicular to the axial end faces of the swash plate 42 and passes through the center point of the swash plate 42. The first inner surface 93 corresponds to a portion of the first cylinder 96, which is defined by extension lines 100 and 102 parallel to the central axis 92, respectively. The diameter of the first cylinder 96 is equal to or slightly larger than the diameter of the drive shaft 34.

The second inner surface 94 corresponds to a portion of the second cylinder 98, the second cylinder 98 has a central axis to maintain a certain angle with respect to the central axis 92 of the first cylinder 96, In addition, the second cylinder 98 is defined by extension lines 104 and 106 that contact or partially overlap the edge of one side of the central hole formed by the first cylinder 96 (the edge formed on the right end surface of the swash plate in FIG. 2A). All. The diameter of the second cylinder 98 is also equal to or slightly larger than the diameter of the drive shaft 34 and the diameter of the second cylinder 98 is equal to or larger than the diameter of the first cylinder 96.

The swash plate 42 changes the inclination angle while moving along the drive shaft 34 with the portion P in contact with the drive shaft 34 as the point P. FIG. The right edge of the central hole 90 is curved to prevent wear.

In order to process the center hole 90 of the swash plate 42, a hole having a predetermined circular cross-sectional shape is formed in advance around the central axis 92 of the swash plate 42. The swash plate 42 is then bitten by a chuck (not shown) in a state inclined by the maximum inclination angle with respect to the imaginary vertical line. The chuck rotates around the central axis and simultaneously moves the cutting tool axially along one of the extension lines 100, 102 defining the first cylinder 96 to complete the formation of the first inner surface 93. Next, when the cutting tool is axially moved along one of the extension lines 104 and 106 defining the second cylinder 98, the formation of the second inner surface 94 is completed. As described above, the center hole of the swash plate 42 is easily formed.

2B is another example of the swash plate for use in the compressor shown in FIG. 1 according to the present invention, which is different from the swash plate of FIG. 2A in that the depression 111 is formed. The same reference numerals are used. Therefore, except that the depression 111 is formed in FIG. 2B, the method of forming the central hole on the swash plate is the same as that of FIG. However, for the reason and method of forming the depressions in the swash plate, Patent Application No. 98-48041 filed by the present applicant, which is cited as a part of this application specification (October 10, 1998. Piston ”) and patent application no. 98-48043 (filed Nov. 10, 1998, application titled“ variable displacement swash plate compressor ”).

The depression 111 described above prevents the swash plate 42 from being eccentric and the overall center of gravity is constant because the contact point P moves toward the center of the swash plate 42 when the swash plate 42 is at the minimum inclination angle position. Helping to improve the durability of the swash plate 42.

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 also rotates 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 for adjusting 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 chamber 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 pins 52 that make up the hinge means slide along the rectangular hole 56 toward the lower end of the rectangular hole 56. Thus, the swash plate 42 is moved forward of the compressor against the spring 44 force. 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, thereby increasing the compression capacity of the compressor.

On the other hand, when the load of the evaporator decreases, the pressure Psc in the suction chamber 74 is lowered, and accordingly, the control valve 88 is opened to supply the compressed refrigerant gas of the discharge chamber 76 to the crank chamber 32. Therefore, the pressure level Pdc of the discharge chamber 76 becomes high. As the pressure level of the crank chamber 32 increases, the back pressure acting on each piston 58 increases, and thus the inclination angle of the swash plate 42 decreases. 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 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 (3)

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; A plurality of pistons reciprocally disposed in each of the cylinder bores; A plurality of shoes for converting rotational motion of the swash plate into reciprocating motion of the pistons; And It is formed through the swash plate to receive the drive shaft, and has a first inner surface made in contact with the first cylinder having a central axis passing through the center point of the swash plate and a central axis forming a predetermined angle with respect to the central axis of the first cylinder. And a center hole formed by a second inner surface formed by a second cylinder including a part of the first inner surface of the swash plate among the center holes formed by the first cylinder. A variable displacement swash plate compressor of claim 2, wherein the second cylinder is in contact with or partially overlaps the first cylinder at one end edge of the center hole such that a point (P) contacting the drive shaft is formed at one end edge of the center hole. The variable diameter of the second cylinder is larger than the diameter of the first cylinder, the first inner surface and the second inner surface is variable, characterized in that partially overlapping at a position adjacent to the one end surface of the swash plate Capacity swash plate compressor. The variable displacement swash plate compressor of claim 1, wherein a depression is formed in the swash plate such that the contact point (P) of the swash plate and the drive shaft is positioned inside the swash plate.

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