JP2005113841A - Variable displacement type swash plate compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable displacement type swash plate compressor, in which hunting of an inclination angle of a swash plate is suppressed when a variable control of a delivery capacity is performed with low capacity, in the variable displacement type swash plate having a drive shaft, a swash plate including an angle-changing mechanism part sliding along the drive shaft and interlocking with rotation of the drive shaft, and a piston engaged with the swash plate and reciprocating in a cylinder bore. <P>SOLUTION: The compressor comprises: the drive shaft; the swash plate including the angle-changing mechanism part sliding along the drive shaft and interlocking with rotation of the drive shaft; the piston engaged with the swash plate and reciprocating in the cylinder bore; and a friction coefficient adjusting member for adjusting friction coefficient between the angle-changing mechanism part and the drive shaft. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes a drive shaft, a swash plate having a variable angle mechanism that slides along the drive shaft and interlocking with the rotation of the drive shaft, and a piston that engages with the swash plate and reciprocates within a cylinder bore. The present invention relates to a variable capacity swash plate compressor.

  In an air conditioning system equipped with a variable capacity swash plate compressor, the compression reaction force applied to the swash plate is small and the friction between the angle changing mechanism and the drive shaft is small when the refrigerant gas flow rate is low. Thus, the swash plate is likely to swing with respect to the drive shaft. As a result, when the flow rate of the refrigerant gas is variably controlled at a low flow rate, that is, when the discharge capacity of the variable displacement swash plate compressor is variably controlled at a low capacity, the inclination angle of the swash plate increases beyond a desired value or Hunting by repeatedly decreasing, hunting by repeatedly increasing or decreasing the refrigerant gas flow rate beyond the desired value, and repeatedly increasing or decreasing the air temperature of the air conditioning system exceeding the desired value Hunting may occur. In order to prevent such hunting, in conventional air conditioning systems equipped with variable displacement swash plate compressors, the opening degree of the expansion valve is controlled based on experience so that the degree of heating is reduced at low refrigerant gas flow rates. Was.

If the opening of the expansion valve is controlled so that the degree of heating is reduced when the refrigerant gas is at a low flow rate, the variable displacement swash plate compressor may be forced to compress the liquid when the discharge capacity is low. The life of the machine may be reduced.

The present invention has been made in view of the above problems, and includes a drive shaft, a swash plate having a variable angle mechanism that slides along the drive shaft, interlocked with the rotation of the drive shaft, and engaging the swash plate. A variable displacement swash plate compressor having a piston that reciprocates in a cylinder bore, wherein the hunting of the swash plate tilt angle is suppressed when the discharge capacity is variably controlled at a low displacement. The purpose is to provide.

In order to solve the above problems, in the present invention, a drive shaft, a swash plate having a variable angle mechanism that slides along the drive shaft, interlocked with the rotation of the drive shaft, and a cylinder bore engaged with the swash plate. A variable displacement swash plate compressor is provided, comprising: a piston that reciprocates within the piston, and a friction coefficient adjusting member that adjusts a friction coefficient between the variable angle mechanism and the drive shaft.
In the compressor according to the present invention, the friction coefficient between the angle changing mechanism and the drive shaft can be increased using the friction coefficient adjusting member. As a result, when the discharge capacity of the variable displacement swash plate compressor is variably controlled at a low capacity, even if the compression reaction force applied to the swash plate is small, sufficient friction between the variable angle mechanism and the drive shaft is obtained. A force can be applied, the swash plate can be prevented from easily swinging with respect to the drive shaft, and the hunting can be suppressed by repeatedly increasing or decreasing the inclination angle of the swash plate beyond a desired value.

In a preferred aspect of the present invention, the friction coefficient adjusting member includes a screw that is screwed into the variable angle mechanism and a contact body that is driven by the screw and contacts the drive shaft.
By adjusting the screwing amount of the screw, the friction coefficient between the angle changing mechanism and the drive shaft can be easily adjusted. Since the contact body that contacts the drive shaft requires high-precision processing, it is desirable that the contact body be separate from the screw.

In a preferred aspect of the present invention, the friction coefficient adjusting member has a spring disposed between the screw and the contact body.
By bringing the contact body into contact with the drive shaft via the spring, the contact body can be reliably brought into contact with the drive shaft at all times.

In a preferred aspect of the present invention, the friction coefficient adjusting member is disposed on the opposite side of the driving force shaft with respect to the resultant force of the compression reaction force on the swash plate.
In response to the resultant force of the compression reaction force, the swash plate is twisted around the link mechanism that transmits the rotation of the drive shaft to the swash plate. The part is pressed against the drive shaft. Therefore, if the friction coefficient adjusting member is disposed on the opposite side of the angle-changing mechanism portion from the point where the resultant force is applied and the drive shaft, the angle-changing mechanism can be surely brought into contact with the drive shaft. The coefficient of friction between the part and the drive shaft can be increased.

In a preferred embodiment of the present invention, the contact body is made of metal or elastomer.
Since the temperature of the variable angle mechanism increases due to frictional heat, the contact body is preferably formed of a metal or elastomer that does not lose its elasticity even at a relatively high temperature.

In a preferred embodiment of the present invention, the contact body is a sphere.
In a preferred embodiment of the present invention, the contact body is a cone.
In order to stably engage the screw or spring and contact the drive shaft, the contact body is preferably a sphere or a cone.

In the compressor according to the present invention, the friction coefficient between the angle changing mechanism and the drive shaft can be increased using the friction coefficient adjusting member. As a result, when the discharge capacity of the variable displacement swash plate compressor is variably controlled at a low capacity, even if the compression reaction force applied to the swash plate is small, sufficient friction between the variable angle mechanism and the drive shaft is obtained. A force can be applied, the swash plate can be prevented from easily swinging with respect to the drive shaft, and the hunting can be suppressed by repeatedly increasing or decreasing the inclination angle of the swash plate beyond a desired value.

  A swash plate compressor according to an embodiment of the present invention will be described.

A variable capacity swash plate compressor according to an embodiment of the present invention will be described.
As shown in FIG. 1, a variable capacity swash plate compressor A mounted on an air conditioning system (not shown) includes a drive shaft 1, a rotor 2 fixed to the drive shaft 1, and a swash plate into which the drive shaft 1 is inserted. 3 is provided. A plurality of single-headed pistons 5 moored to the swash plate 3 via the shoe 4 are slidably fitted to a plurality of cylinder bores 6a formed in the cylinder block 6. A front housing 7 that houses the drive shaft 1, the rotor 2, and the swash plate 3 is disposed. A cylinder head 8 that forms a suction chamber and a discharge chamber is disposed. The cylinder block 6, the front housing 7, and the cylinder head 8 are assembled together. The drive shaft 1 is rotatably supported by a front housing 7 and a cylinder block 6.

A rotor arm 2 a extends from the rotor 2 toward the swash plate 3. An oblong journal pivot pin insertion hole 2b is formed in the rotor arm 2a. A boss arm 3 a extends from the swash plate 3 toward the rotor 2. A journal pivot pin 3b is fixed to the boss arm 3a. The journal pivot pin 3b is inserted into the journal pivot pin insertion hole 2b. A link mechanism 9 is formed by the rotor arm 2a, the journal pivot pin insertion hole 2b, the boss arm 3a, and the journal pivot pin 3b. The link mechanism 9 connects the rotor 2 and the swash plate 3 so as not to be relatively rotatable around the drive shaft 1 while allowing the tilt angle fluctuation of the swash plate 3 with respect to the drive shaft 1, and transmits the swash plate 3 from the one-head piston 5 to the swash plate 3. The compressed reaction force is transmitted from the swash plate 3 to the rotor 2. The applied point of the resultant force F of the compression reaction force on the swash plate 3 is the swash plate rotation direction of the swash plate top dead center P with respect to the plane formed by the center axis X of the drive shaft 1 and the top dead center P of the swash plate 3. (The direction indicated by the white arrow in FIG. 2) It is on the minute front side, moves linearly outward along the straight line L in FIG. 2 as the discharge pressure increases, and decreases as the discharge pressure decreases. It moves radially inward along a straight line L in FIG.

As shown in FIG. 1, a variable angle mechanism portion 3 c having a pair of opposing saddle-shaped curved surfaces 3 c ′ slidable along the drive shaft 1 is formed in the drive shaft 1 insertion portion of the swash plate 3. A spring 10 that biases the variable angle mechanism 3 c along the drive shaft 1 is disposed between the variable angle mechanism 3 c and the rotor 2.
2-4, between the point of application of the resultant force F of the compression reaction force against the swash plate 3 and the pair of saddle-shaped curved surfaces 3c 'facing each other across the drive shaft 1, and the drive shaft 1 A screw 11 is screwed into the variable angle mechanism 3c at an angle close to a right angle with respect to the central axis X. A spherical contact body 12 that engages with the tip of the screw 11 is in contact with the drive shaft 1. The screw 11 and the contact body 12 constitute a friction coefficient adjusting member 13 that adjusts the friction coefficient between the variable angle mechanism portion 3 c and the drive shaft 1.

In the variable displacement swash plate compressor A, the drive shaft 1 is rotationally driven by an external drive source (not shown). The rotation of the drive shaft 1 is transmitted to the swash plate 3 via the link mechanism 9. The rotation of the swash plate 3 is converted into a reciprocating motion in the direction of the central axis X of the drive shaft 1 by the shoe 4 and transmitted to the piston 5, and the piston 5 reciprocates within the cylinder bore 6a. As the piston 5 reciprocates, the refrigerant that has recirculated from the refrigerating circuit of the air conditioning system (not shown) to the suction chamber is sucked into the cylinder bore 6a and compressed. The compressed refrigerant returns to a refrigerating circuit of an air conditioning system (not shown).
As the journal pivot pin 3b moves in the major axis direction of the ellipse within the elliptical journal pivot pin insertion hole 2b, the inclination angle of the swash plate 3 with respect to the drive shaft 1 varies, and the variable displacement swash plate compressor A The discharge capacity varies. The contact point between the angle changing mechanism 3c of the swash plate 3 and the drive shaft 1 moves along the saddle-shaped curved surface 3c 'of the angle changing mechanism 3c, and the angle changing mechanism while receiving the biasing force of the spring 10. By sliding 3c along the drive shaft 1, the tilt angle fluctuation of the swash plate 3 is realized without any trouble.

Upon receiving the resultant force F of the compression reaction force, as shown by the white arrow in FIG. 3, the swash plate 3 is twisted around the link mechanism 9, and the point of application of the resultant force F of the variable angle mechanism 3c and the drive shaft 1 is pressed against the drive shaft 1. In the variable displacement swash plate compressor A, the coefficient of friction adjustment provided in the opposite portion 3c ″ of the variable angle mechanism 3c is adjusted. Even when the resultant force F is small, the contact mechanism 12 of the member 13 is brought into contact with the drive shaft 1 to increase the friction coefficient of the contact portion between the change mechanism mechanism 3c and the drive shaft 1. A sufficiently large frictional force can be applied to the contact portion between the drive shaft 1 and the drive shaft 1. As a result, when the discharge capacity of the variable capacity type swash plate compressor A is variably controlled at a low capacity, the angle changing mechanism portion 3c and the variable angle mechanism portion 3c are coupled with each other although the resultant force F of the compression reaction force applied to the swash plate 3 is small. Sufficient frictional force can be exerted between the drive shaft 1 and the variable angle mechanism 3c can be prevented from sliding along the drive shaft 1, and as a result, the swash plate 3 swings relative to the drive shaft 1. It is possible to suppress the hunting by repeating the increase or decrease of the inclination angle of the swash plate 3 beyond a desired value.
By adjusting the screwing amount of the screw 11, the friction coefficient between the angle changing mechanism portion 3c and the drive shaft 1 can be easily adjusted. Since the contact body 12 that contacts the drive shaft 1 requires high-precision processing, it is desirable that the contact body 12 be separate from the screw 11.
Since the friction coefficient adjusting member 13 is disposed on the opposite side of the driving force 1 from the point of application of the resultant force F of the angle changing mechanism 3c, the link mechanism 9 receives the resultant force F of the compression reaction force. The contact body 12 of the friction coefficient adjusting member 13 can surely come into contact with the drive shaft 1 by twisting the swash plate 3 around, and the friction coefficient of the contact portion between the angle changing mechanism 3c and the drive shaft 1 is ensured. Can be reliably increased.

As shown in FIG. 4, a spring 14 such as a disc spring may be disposed between the screw 11 and the contact body 12.
By bringing the contact body 12 into contact with the drive shaft 1 via the spring 14, the contact body 12 can be reliably brought into contact with the drive shaft 1 at all times.

Since the bending mechanism portion 3c becomes relatively high due to frictional heat, the contact body 12 is preferably formed of a metal or elastomer that does not lose elasticity even at a relatively high temperature.

In order to stably engage with the screw 11 or the spring 14 and to contact the drive shaft 1, the contact body 12 is preferably a sphere or a conical body with the tip portion directed to the drive shaft 1.

  The present invention is widely applicable to variable displacement swash plate compressors.

It is sectional drawing of the swash plate type compressor which concerns on the Example of this invention. It is an II-II arrow line view of FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 3 is a sectional view taken along line III-III in FIG.

Explanation of symbols

A Capacitance variable type swash plate compressor P Top dead center of swash plate F Combined force L of compression reaction force Straight line 1 Drive shaft 2 Rotor 2b Journal pivot pin insertion hole 3 Swash plate 3a Boss arm 3b Journal pivot pin 3c Deflection mechanism 3c ' Vertical curved surface 4 Shoe 5 Piston 6 Cylinder block 9 Link mechanism 10, 14 Spring 11 Screw 12 Contact body 13 Friction coefficient adjusting member

Claims (7)

A drive shaft, a swash plate having a variable angle mechanism that slides along the drive shaft, and interlocking with the rotation of the drive shaft; a piston that engages with the swash plate and reciprocates within the cylinder bore; and a variable angle mechanism; A variable displacement swash plate compressor, comprising: a friction coefficient adjusting member that adjusts a friction coefficient between the drive shaft and the drive shaft. 2. The variable capacity swash plate compressor according to claim 1, wherein the friction coefficient adjusting member includes a screw that is screwed into the variable angle mechanism and a contact body that is driven by the screw and contacts the drive shaft. 3. The variable capacity swash plate compressor according to claim 2, wherein the friction coefficient adjusting member includes a spring disposed between the screw and the contact body. 4. The variable coefficient according to claim 1, wherein the friction coefficient adjusting member is disposed on the opposite side of the drive shaft with respect to the point of application of the resultant compression reaction force to the swash plate. 5. Capacity type swash plate compressor. The variable capacity swash plate compressor according to any one of claims 1 to 4, wherein the contact body is made of metal or elastomer. The variable capacity swash plate compressor according to any one of claims 1 to 5, wherein the contact body is a sphere. The variable displacement swash plate compressor according to any one of claims 1 to 5, wherein the contact body is a conical body.

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