KR100274970B1 - Variable displacement swash plate compressor - Google Patents

Abstract

The swash plate of the variable displacement swash plate type compressor has a center hole and is attached to the drive shaft to move in the axial direction via the inner circumferential surface of the variable displacement swash plate compressor. It rotates integrally with the rotation of the above-mentioned rotating member. Several pistons are housed so that they can each slide in several cylinder bores formed axially in the cylinder block. Several shoes are connected to several pistons and rotate relatively on the sliding surface of the swash plate in accordance with the rotation of the drive shaft to convert the rotation around the drive shaft of the swash plate into the axial movement of the several pistons. The stroke amount of the piston changes with the change of the inclination angle of the swash plate. The drive shaft is formed with a recess for moving the rotary shaft of the swash plate to the top dead center side when the stroke amount of the piston is maximized.

Description

Variable displacement swash plate compressor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement swash plate type compressor, and more particularly, to a variable displacement swash plate type compressor in which the shoe of the top dead center in the case of the maximum piston stroke can reduce the surface pressure.

1 and 2 are longitudinal cross-sectional views showing a conventional variable displacement swash plate compressor, Figure 1 shows the state of the maximum piston stroke, Figure 2 shows the state of the minimum piston stroke.

Conventional variable displacement swash plate type compressors have shafts on the drive shaft 105, the drive shaft 105, and a thrust flange 140 and the drive shaft 105 that are integrally rotated with the drive shaft 105. And a swash plate 110 and a plurality of cylinder bores which are attached to be moved in the direction and connected to the thrust flange 140 via the link mechanism 141 and rotate integrally with the rotation of the thrust flange 140. A plurality of pistons 107 accommodated to slide in the 106 and a plurality of shoes 150 relatively rotating on the sliding surface 110a of the swash plate 110 in accordance with the rotation of the drive shaft 105, The retainer 153 which supports the shoe 150, several connecting rods 111, etc. are provided.

One end on the spherical surface of the connecting rod 111 is supported so that the shoe 150 can be relatively rolled, and the other end of the connecting rod 111 is fixed to the piston 107.

When the rotational power of the on-board engine is transmitted to the drive shaft 105 in a vehicle not shown in the drawing, the rotational force of the drive shaft 105 is transmitted to the swash plate 110 via the link mechanism 141 by the thrust flange 140 to the swash plate 110. ) Rotates.

The shoe 150 rotates relative to the sliding surface 110a of the swash plate 110 by the rotation of the swash plate 110, so that the rotational force from the swash plate 110 is converted into a linear reciprocating motion of the piston 107. When the piston 107 reciprocates in the cylinder bore 106, the volume of the compression chamber in the cylinder bore 106 changes, and the volume change causes the suction, compression and discharge of the refrigerant gas to be smooth.

Since the inclination angle of the swash plate 110 (angle with respect to the imaginary plane orthogonal to the driving shaft 105) changes according to the change in the pressure of the crank chamber 108 in which the swash plate 110 is accommodated, the capacity corresponding to the inclination angle of the swash plate 110. High pressure refrigerant gas of the will be discharged. That is, when the pressure of the crank chamber 108 is lowered, the inclination angle of the swash plate 110 becomes large, and as shown in FIG. 1, when the portion 110g of the swash plate 110 hits the thrust flange 140, the piston The stroke amount of 107 becomes maximum and the discharge capacity becomes maximum.

On the other hand, when the pressure of the crank chamber 108 increases, the inclination angle of the swash plate 110 decreases, and as shown in FIG. 2, when a part 110g of the swash plate 110 is further separated from the thrust flange 140. The stroke amount of the piston 107 is minimum and the discharge capacity is minimized.

However, as the inclination angle of the swash plate 110 increases according to the pressure change of the crank chamber 108, the outermost circumferential position of the swash plate 110 approaches the drive shaft 105, so that the shoe 150 of the top dead center (top dead center) The shoe 150 corresponding to the piston 107 of the swash plate 110 moves relative to the radially outward direction of the swash plate 110 as the inclination angle of the swash plate 110 increases, so that the inclination angle of the swash plate 110 is maximized. ), The contact area between the shoe 150 is minimized, and the surface pressure (surface pressure in the compression stroke) that the shoe 150 receives increases, and the wear of the sliding portion (particularly the swash plate side) increases.

An object of the present invention is to provide a variable displacement swash plate type compressor capable of reducing the surface pressure received by a shoe at the time of maximum piston stroke and suppressing abrasion of the sliding portion between the swash plate and the shoe.

In order to achieve the above object, the present invention is fixed to the drive shaft and the drive shaft is formed with a rotating member and the center hole which is integrally rotated with the above-described drive shaft is attached to be axially moved to the drive shaft via the inner peripheral surface of the center hole It is connected to the rotating member so as to be inclined and accommodates the swash plate and the cylinder block which rotates integrally with the rotation of the rotating member, the plurality of cylinder bores formed in the axial direction in the cylinder block, and the respective sliding in the multiple cylinder bores. It is connected to several pistons and several pistons, which are relatively rotated on the sliding surface of the swash plate according to the rotation of the drive shaft, and several shoes for converting the rotation around the drive shaft of the swash plate into the axial movement of the pistons. Does the stroke amount of the piston change with the change of the inclination angle of the swash plate? The present invention provides a variable displacement swash plate compressor.

The variable displacement swash plate compressor of the present invention is characterized in that the above-described driving shaft is provided with a recess for moving the rotary shaft of the swash plate to the top dead center side when the stroke amount of the piston is maximized.

According to the variable displacement swash plate compressor, the center of rotation of the swash plate moves to the top dead center when the piston stroke is the maximum piston stroke, so that the contact area between the shoe of the top dead center and the sliding surface of the swash plate is secured so that the surface pressure receiving the shoe does not increase As a result, abrasion of the sliding part can be suppressed.

Preferably, the recessed part is formed in the axial direction at the bottom dead center side half of the intermediate part of the drive shaft.

According to this preferred embodiment, the movement to the top dead center of the rotary shaft of the swash plate can be ensured at the time of the maximum piston stroke.

More preferably, the bottom surface of the recessed portion of the drive shaft has a curved surface with a predetermined radius of curvature, and a curved surface that can fit to the recessed portion at the inner circumferential surface of the central hole of the swash plate is formed.

According to this preferred embodiment, the swash plate and the drive shaft are stably engaged.

More preferably, the inclined guide surface is formed in the drive shaft from a recess to a portion having a uniform radius of the drive shaft to guide the curved surface of the inner circumferential surface of the swash plate.

According to this preferred aspect, the transition from the recess corresponding to the maximum piston stroke (top dead center side position) to the center of the swash plate has a uniform radius corresponding to the minimum pin stroke (bottom dead center side position) and vice versa. It can be done.

Or the bottom face of the recessed part of a drive shaft is planar, and the plane which can surface-contact with the bottom face of the plane of a recessed part is formed in the inner peripheral surface of the center hole of a swash plate.

According to this preferred embodiment, the swash plate and the drive shaft are stably engaged similarly to the preferred embodiment described above.

More preferably, the driving shaft is formed with an inclined guide surface leading from the recess to a portion having a uniform radius of the driving shaft to guide the plane of the inner circumferential surface of the swash plate.

According to this preferred embodiment, in the same manner as in the preferred embodiment described above, there is a portion having a uniform radius corresponding to the minimum pin stroke (lower dead center side position) from the recess corresponding to the maximum piston stroke (top dead center side position) of the central portion of the swash plate. The opposite can be done smoothly.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

1 is a longitudinal sectional view showing a conventional variable displacement swash plate compressor, showing a state of the maximum piston stroke.

FIG. 2 is a longitudinal sectional view of the variable displacement swash plate compressor of FIG. 1, showing a state of the minimum piston stroke. FIG.

Fig. 3 is a longitudinal sectional view showing the variable displacement swash plate compressor according to the first embodiment of the present invention, showing the state of the maximum piston stroke.

4 is a longitudinal sectional view showing the variable displacement swash plate compressor of FIG. 3, showing the state of the minimum piston stroke.

5A is a cross-sectional view taken along the line A-A in FIG. 3;

FIG. 5B is a cross sectional view taken along the line B-B in FIG. 4; FIG.

6A and 6B are views for explaining the variable displacement swash plate compressor according to the second embodiment of the present invention.

Fig. 6A is a cross-sectional view showing the relationship between the drive shaft at the time of maximum piston stroke and the inner circumferential surface of the center hole of the swash plate.

Fig. 6B is a sectional view showing the relationship between the drive shaft at the time of minimum piston stroke and the inner circumferential surface of the center hole of the swash plate;

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing.

Fig. 3 is a longitudinal sectional view showing the whole of the variable displacement swash plate compressor according to the first embodiment of the present invention.

A rear head 3 is fixed to one end of the cylinder block 1 of the variable displacement swash plate compressor via a valve plate 2 and a front head 4 is fixed to the other end of the cylinder block 1. The cylinder block 1 is provided with several cylinder bores 6 at predetermined intervals in the circumferential direction around the drive shaft 5. Each of these cylinder bores 6 is accommodated so that the piston 7 can slide.

The crank chamber 8 is formed in the front head 4, and the swash plate 10 which rotates with the rotation of the drive shaft 5 is accommodated in this crank chamber 8. The shoe 50 is supported by the retainer 53 on the sliding surface 10a of the swash plate 10. The shoe 50 is connected to the spherical one end portion 11a of the connecting rod 11 so that relative movement is possible, and the other end 11b of the connecting rod 11 is fixed to the piston 7.

As the swash plate 10 rotates, the piston 7 reciprocates in the cylinder bore 6. The inclination angle of this swash plate 10 changes in accordance with the pressure of the crank chamber 8.

The shoe 50 is formed after the first support member 51 supporting the front end surface of the spherical one end 11a of the connecting rod 11 and the one end 11a of the connecting rod 11. And a second support member 52 for supporting the end face relative to the end face.

The retainer 53 is provided with a central hole 53b into which the boss portion 10b of the swash plate 10 is inserted and at the same time allows the convex portion 52a of the second support member 52 of the shoe 50 to escape to the piston side. Several holes (not shown) are arranged one after the other in the circumferential direction. The retainer 53 is mounted on the outer circumference of the boss portion 10b of the swash plate 10, and the retainer 53 is a ring-shaped retainer support plate (fixed with a snap ring 54) to the boss portion 10b of the swash plate 10. 55) to support relative rotation.

In the above-mentioned rear head 3, the discharge chamber 12 and the suction chamber 13 located around this discharge chamber 12 are formed.

The valve plate 2 has a discharge port 16 for communicating the compression chamber of the cylinder bore 6 with the discharge chamber 12, and an inlet 15 for communicating the compression chamber of the cylinder bore 6, the suction chamber 13, and the like. Each of them is provided at predetermined intervals in the circumferential direction. The outlet 16 is opened and closed by the outlet valve 17 so that the outlet valve 17 is provided with a bolt 19 and a nut 20 together with a valve guard 18 at the end face of the rear head of the valve plate 2. ) Is fixed.

In addition, the suction port 15 is opened and closed by the suction valve 21, and the suction valve 21 is disposed between the front end face of the valve plate 2 and the cylinder block 1. The bolt 19 is provided with a guide hole (not illustrated) for guiding the high pressure refrigerant gas in the discharge chamber 12 to the radial bearing 24 and the thrust bearing 25.

The radial bearing 24 and the thrust bearing 25 support the rear end of the drive shaft 5, and the radial bearing 26 supports the front end of the drive shaft 5 so as to be rotatable.

A communication path 60 is provided between the suction chamber 13 and the crank chamber 8, and a pressure regulating valve 61 is provided in the middle of the communication path.

At the front end of the drive shaft 5, a thrust flange (rotating member) 40 for transmitting rotation of the drive shaft 5 to the swash plate 10 is fixed, and the thrust flange 40 has a thrust bearing ( It is rotatably supported by the inner wall surface of the front head 4 via 33). The thrust flange 40 and the swash plate 10 are connected via a link mechanism 41, and the swash plate 10 is inclined with respect to an imaginary surface perpendicular to the drive shaft 5.

The link mechanism 41 is screwed to the linear guide groove 10f provided in the bracket 10e installed on the front surface 10c of the swash plate 10 and the swash plate side end surface 40a of the thrust flange 40. Rod 43 or the like. The longitudinal axis of the guide groove 10f is inclined at an angle with respect to the front surface 10c of the swash plate 10. The spherical portion 43a of the rod 43 is fitted to slide relative to the guide groove 10f.

The swash plate 10 is mounted on the drive shaft 5 so as to be movable in the axial direction and to be inclined. A coil spring 44 is mounted between the swash plate 10 and the thrust flange 40, and the swash plate 10 is applied to the cylinder block 1 by the coil spring 44. In addition, a stopper 45 is fixed to the drive shaft 5, and a coil spring 47 is mounted between the stopper 45 and the swash plate 10, and the swash plate 10 is thrust by the coil spring 47. The force is applied to the flange 40 side.

5A is a cross-sectional view taken along the line A-A of FIG. 3, and FIG. 5B is a cross-sectional view taken along the line B-B of FIG.

Half of the lower dead center side of the middle of the drive shaft 5 is formed with an inclined guide surface 71 extending from the recess 70 and the recess 70 to a portion having a uniform radius toward the cylinder block 1 side. The bottom of the recess 70 has a curved surface with a constant radius of curvature in the cross section, and the inclined guide surface 71 is a curved surface with a radius of curvature that increases at a constant rate in the cylinder block side direction in the cross section. The part facing the half of the bottom dead center side of the intermediate part of the drive shaft of the inner peripheral surface of the center hole 10d of the swash plate 10 has a curved surface formed so as to stably and smoothly engage the recessed portion 70 and the inclined guide surface 71. When the maximum piston stroke, as shown in Fig. 5, the inner circumferential surface of the center hole 10d of the swash plate 10 abuts against the recessed portion 70 of the drive shaft 5, and when the minimum piston stroke, The central portion moves to the rear side and the inner circumferential surface of the center hole 10d of the swash plate 10 falls from the recessed portion 70 of the drive shaft 5 as shown in Fig. 5B. At the minimum piston stroke, the drive shaft of the swash plate 10 coincides with the axis center of the drive shaft 5, but at the maximum piston stroke, the rotation center of the swash plate 10 moves to the top dead center side (as shown in Fig. 3 upward). .

Next, the operation of the variable displacement swash plate compressor will be described.

When the rotational power of the on-board engine is transmitted to the drive shaft 5 in a vehicle not shown in the drawing, the rotational force of the drive shaft 5 reaches the swash plate 10 via the thrust flange 40 and the link mechanism 41 and the swash plate 10. It rotates.

Since the shoe 50 rotates relative to the sliding surface 10a of the swash plate 10 by the rotation of the swash plate 10, the rotational force from the swash plate 10 is converted into a linear reciprocating motion of the piston 7. The piston 7 reciprocates in the cylinder bore 6, and as a result, the volume of the compression chamber in the cylinder bore 6 changes, so that the suction, compression and discharge of the refrigerant gas are sequentially made by this volume change. The high pressure refrigerant gas having a capacity corresponding to the inclination angle of the swash plate 10 is discharged. When suctioning, the suction valve 21 is opened and low pressure refrigerant is sucked from the suction chamber 13 into the compression chamber in the cylinder bore 6, and when discharged, the discharge valve 17 is opened and high pressure is discharged from the compression chamber to the discharge chamber 12. The refrigerant is discharged.

Since the inclination angle of the swash plate 10 changes according to the change in the pressure of the crank chamber 8 in which the swash plate 10 is accommodated, the capacity corresponding to the inclination angle of the swash plate 10 (angle with respect to the imaginary plane orthogonal to the drive shaft 5) High pressure refrigerant gas of the will be discharged. That is, when the pressure of the crank chamber 8 increases, the inclination angle of the swash plate 10 decreases, and as shown in FIG. 4, when a part 10g of the swash plate 10 is farthest from the thrust flange 40. The stroke amount of the piston 7 is minimum, and the discharge capacity is minimized.

At this time, the inclination angle of the swash plate 10 is small and the contact area between the first support member 51 of the shoe 50 and the sliding surface 10a of the swash plate 10 is large.

On the other hand, when the pressure of the crank chamber 8 decreases, the inclination angle of the swash plate 10 becomes large, and the center of the swash plate 10 moves to the front side, and as shown in FIG. 3, the center hole 10d of the swash plate 10 is shown. The inner circumferential surface of the drive shaft 5 is guided to the front side by the inclined guide surface 71 of the drive shaft 5 so as to fit to the recessed portion 70 of the drive shaft 5 and at the same time a part 10g of the swash plate 10 is the thrust flange 40. The stroke amount of the piston 7 becomes the maximum when it hits, and the discharge capacity becomes maximum.

At this time, the inclination angle of the swash plate 10 is large, but since the center of rotation of the swash plate 10 moves to the top dead center side, the first supporting member 51 of the shoe 50 at the top dead center (the shoe corresponding to the piston 7 at the top dead center). ) And the contact area between the sliding surface 10a of the swash plate 10 are largely secured.

According to the variable displacement swash plate compressor of the first embodiment, the center of rotation of the swash plate 10 moves to the top dead center when the piston stroke is the maximum piston, so that the first support member 51 and the swash plate ( The contact area with the sliding surface 10a of 10 is largely secured, so that the surface pressure received by the first supporting member 51 of the shoe 50 does not increase, and as a result, wear of the sliding surface 10a of the swash plate 10 is caused. Can be suppressed.

Fig. 6 is a view for explaining the variable displacement swash plate compressor according to the second embodiment of the present invention. Fig. 6A is a cross-sectional view showing the relationship between the drive shaft and the inner circumferential surface of the center hole of the swash plate at the time of maximum piston stroke. 6b is a cross-sectional view showing the relationship between the drive shaft at the time of the minimum piston stroke and the inner circumferential surface of the center hole of the swash plate. The same reference numerals are given to parts common to the above-described embodiments, and the description thereof is omitted.

In the above-described first embodiment, the bottom surface of the recessed part 70 of the drive shaft 5 is a curved surface having a constant curvature radius in the cross section, and the inner peripheral surface of the center stiffness 10d of the swash plate 10 can be fitted with the recessed part 7. In the second embodiment, as shown in Figs. 6A and 6B, the bottom surface of the recessed portion 80 of the drive shaft 65 is flat, and the inclined guide surface 81 is also flat. On the inner circumferential surface of the center hole 90d of the swash plate 10, a plane which is in surface contact with the bottom surface of the recessed portion 80 and the inclined guide surface 81 is formed.

According to this second embodiment, the same effects as in the first embodiment can be obtained.

Furthermore, in each of the above embodiments, the swash plate 10 and the piston 7 are connected by using the connecting rod 11 and the shoe 50 is rotated relative to one side of the swash plate 10. When the present invention is applied to a compressor, the present invention is described, but the scope of the present invention is not limited thereto, and the swash plate and the piston are connected through a shoe that rotates relatively on both sides of the swash plate without using the connecting rod 11. The present invention can also be applied to a variable displacement swash plate type compressor.

The foregoing is a description of preferred embodiments of the present invention, and it will be apparent to those skilled in the art that various changes can be made without departing from the spirit and scope of the present invention.

Claims (6)

A driving shaft, a rotating member fixed to the driving shaft, which rotates integrally with the driving shaft, and a central hole, which are attached to be axially movable to the driving shaft through the inner circumferential surface of the central hole, and connected to the rotating member so as to be tiltable. Connected to a swash plate which rotates integrally with the rotation of the member, several cylinder bores axially formed in the cylinder block and the cylinder block, several pistons accommodated to slide in the various cylinder bores, and several pistons A plurality of shoes and the like for relatively rotating the sliding surface of the swash plate in accordance with the rotation of the drive shaft to convert the rotation around the drive shaft of the swash plate into the axial movement of the pistons, and according to the change of the inclination angle of the swash plate. Drive in variable displacement swash plate compressor in which the stroke amount is changed A variable capacity swash plate type compressor, characterized in that the recess is formed in improving moving the axis of rotation of the swash plate toward the top dead center when the amount of stroke of the piston to be up to the. The variable displacement swash plate type compressor according to claim 1, wherein the main portion is formed in the axial direction at the bottom dead center side half of the middle portion of the drive shaft. The variable displacement swash plate type compressor according to claim 2, wherein a bottom portion, which is a recessed portion of the drive shaft, forms a curved surface with a constant radius of curvature, and a curved surface is formed on the inner circumferential surface of the center hole of the swash plate to fit the recessed portion. 4. The variable displacement swash plate compressor of claim 3, wherein an inclined guide surface is formed in the drive shaft to a portion having a uniform radius of the drive shaft to guide the curved surface of the inner circumferential surface of the swash plate. 3. A variable displacement swash plate compressor according to claim 2, wherein a bottom surface of the recessed portion of the drive shaft is flat and an inner circumferential surface of the center hole of the swash plate is formed in surface contact with the bottom surface of the bottom surface of the recessed portion. 6. The variable displacement swash plate compressor of claim 5, wherein an inclined guide surface is formed in the drive shaft to a portion having a uniform radius of the drive shaft to guide the plane of the inner circumferential surface of the swash plate.