KR100558704B1 - 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 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 central hole formed through the swash plate to accommodate the drive shaft and having a trapezoidal cross-sectional shape so that the inclination angle of the swash plate can be changed. This saves time and money, and minimizes wear on 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 processing method of the present invention,

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

4 is an explanatory diagram showing a center hole structure of a conventional swash plate;

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

42; swash plate 90; central hole

92; inner side 96; center point

98; central axis 100; circular cone

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, which constitutes the hinge mechanism, protrudes from the rotating body 6, and the second arm member 9 having the longitudinal hole 11 is protruded from the swash plate 1 to be pinned by the pin 10. The hinges are combined. Thus, when the compressor is driven, the rotational force of the drive shaft 3 is transmitted to the rotating body 6 by the hinge mechanism, whereby the swash plate 1 is also rotated, and the pin 10 is moved up and down along the rectangular hole 11. The compressor capacity is varied by varying the inclination angle of the swash plate 1 while moving to the room to change the stroke length of the piston 12.

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. Referring to FIG. 4, a conical hole 15 having two central axes is formed to cross the central portion C of the swash plate 16. By forming an annular edge portion 18 inside the hole, the annular edge portion 18 is in contact with the drive shaft 17 to support the rotational tilt movement of the swash plate.

However, the annular edge portion 18 where the first and second inner surfaces of the central hole of the swash plate disclosed in this patent intersect has a sharp shape, so that the annular edge portion 18 of the drive shaft 17 and the swash plate 16 has a sharp shape. At this point of contact, abnormal wear occurs on both the drive shaft 17 and the swash plate 16. In addition, the work of forming the central hole of the swash plate is still complicated and 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 centerline formed through the swash plate to accommodate the drive shaft and inclined with respect to the drive shaft at an angle substantially equal to the maximum inclination angle of the swash plate to accommodate the change of the inclination angle of the swash plate, the cross section of which has a trapezoidal shape. Containing a central hole; thereby, it is easy to process the swash plate, thereby reducing the time and cost during swash plate processing and it is possible to minimize the wear of the drive 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 with 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 and the discharge valve 84 opens and closes the discharge port 80 according to 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 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 placed at the position of the maximum inclination angle. The central hole 90 is formed through the swash plate 42 and has a trapezoidal cross-sectional shape. The virtual circle 94 has a center point 96 that lies in the center of the swash plate 42. The central axis 98 is perpendicular to the axial end faces of the swash plate 42 and also passes through the center point 96 of the imaginary circle 94. The central axis 98 is placed at a position inclined by an angle with respect to the virtual horizontal line, that is, the central axis of the drive shaft. The inner surface 92 corresponds to a portion of the pyramid 100, which is defined by extension lines 101 and 102 that pass through the apex of the pyramid, respectively, and correspond to the uppermost position 91 and the lowermost position of the inner surface 92. All. Then, the vertex of the pyramid 100 and the center point of the bottom surface of the pyramid pyramid lie on the central axis 98. The angle of the vertex and the shape of the pyramid may vary depending on the design of the swash plate 42.

The central hole 90 of the swash plate 42 is formed in the following manner. First, the swash plate 42 having a preformed hole around the central axis 98 is bitten by a chuck (not shown) in a state inclined by a maximum inclination angle as shown in FIG. The chuck rotates around the central axis 98 and simultaneously moves the tool, such as a bite, axially along one of the extensions 101, 102 to complete the machining of the central hole 90. Thus, according to the present invention, the central hole 90 of the swash plate 42 is easily formed by one machining operation.

As shown in FIG. 2A, the center hole 90 may be processed while the swash plate 42 is inclined by the maximum inclination angle and is kept vertical to an imaginary horizontal line without being bitten by the chuck. In this case, the central axis 98 is parallel to the imaginary horizontal line and the machining of the central hole 90 is completed when the tool is moved axially along one of the extension lines 101 and 102.

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 from being eccentric 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, and the overall center of gravity is constant so that durability of the swash plate is constant. It will help you improve.

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 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. 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.

When the compressor 20 is operating at full capacity, ie when the swash plate 42 is in the position of the maximum inclination angle (see FIG. 1), the bottom surface of the drive shaft 34 is the center hole 90 of the swash plate 42. Since the surface-to-face contact with the entire area of the inner surface located at the lowermost portion of the inner surface 92 of the, the abrasion at the contact portion of the drive shaft 34 and the swash plate 42 is prevented.

The swash plate for use in the variable displacement swash plate compressor according to the present invention can be easily formed by a single process can reduce the manufacturing cost and time.

In addition, according to the present invention, when the swash plate is in the position of the maximum inclination angle, the entire portion of the inner surface of the swash plate which is in contact with the lower part of the drive shaft is in contact with the drive shaft, thereby preventing abnormal wear of the swash plate and the drive shaft.

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 And a central hole formed through the swash plate to accommodate the driving shaft, the center hole having a cross-sectional shape having a trapezoidal shape. The center hole is a variable displacement swash plate compressor characterized in that the drive shaft and the lower inner surface is in surface contact when the swash plate attains the maximum inclination angle, and the lower inner surface is in line contact when the swash plate attains the minimum inclination angle. delete The variable displacement swash plate type of claim 1, wherein a depression is formed on the swash plate such that a contact portion of the lower end surface of the driving shaft and the swash plate center hole is formed inside the swash plate when the swash plate reaches a minimum inclination angle. compressor.

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