JPH02201089A - Fluid compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a fluid compressor for compressing refrigerant gas in a refrigeration cycle, for example, and particularly to a helical blade type fluid compressor.

(Prior Art) Various types of compressors, such as reciprocating type and rotary type, have been known so far. However, in these compressors, the structure of the drive section such as a crankshaft that transmits rotational force to the compressor section and the compressor section is complicated, and the number of parts is large. Furthermore, in order to improve compression efficiency in such conventional compressors, it is necessary to install a check valve on the discharge side, but since the pressure difference on both sides of this check valve is very large, Gas leaks and compression efficiency is low.

On the other hand, there is a helical blade type compressor that does not have the above problems. Fig. 11 shows the main parts of a conventional helical blade type fluid pressure Wi machine, which consists of a cylinder a and an eccentrically arranged cylinder (e in the figure indicates the amount of eccentricity) inside the cylinder a. , a rotating body that makes a rotational movement (eccentric rotational movement) relative to the cylinder a, and a blade d that is inserted into a groove C formed in a spiral shape on the outer surface of the rotating body. Blade d is cylinder a
The rotating body slides into and out of the groove C as the rotating body rotates relative to the rotating body. Both ends of the cylinder a and the rotating body are rotatably supported by bearings f and g, and each bearing f2
g is provided with an inlet port and a discharge date j, respectively. The groove C discharges from the suction opening, and the pitch gradually increases to 1 flame toward the opening J.

Therefore, when the cylinder a and the rotating body 81 are rotated in pairs, the compressed fluid such as gas sucked into the space between the cylinder a and the rotating body from the suction port is compressed. In other words, the two-legged space is moved toward the discharge port j due to the rotational movement of the rotating body relative to the cylinder a.
Since the pitch of the grooves C gradually decreases and the volume of the space partitioned by the blades d gradually decreases, the fluid to be compressed that enters the space is gradually compressed and the final It is discharged from the discharge port j.

By the way, in a compressor with such a structure, a pressure difference in the fluid to be compressed acts on the blades d from the discharge port j side to the suction port side, and a thrust force also acts on the rotating body. . Therefore, this thrust force causes compressor losses.

Therefore, in order to reduce the loss due to such thrust force, a thrust bearing is interposed between one end of the rotating body on the suction side and a bearing that rotatably supports this end. It is thought that it will receive thrust force.

(Problem to be Solved by the Invention) However, in the structure that uses a thrust bearing to receive thrust force as described above, the bearing may be damaged due to the gap that exists between the balls and the retainer that supports them. There was a problem in that it generated a lot of noise.

An object of the present invention is to obtain a fluid compressor that can receive thrust force while suppressing noise generation.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above three problems, the present invention provides a mechanism for solving the above-mentioned suction end side of a rotating body disposed in a cylinder having a suction end side and a discharge end side. A support shaft portion having a pressure-receiving surface along a direction perpendicular to the axis of the rotary body is provided at an end thereof, and has a smaller diameter than a large-diameter portion of the rotor to which the spiral blade is attached and protrudes from the pressure-receiving surface. A pressure chamber is formed between the bearing on the suction end side that supports the suction end and the pressure receiving surface, and the pressure inside the sealed case from which the compressed fluid is discharged from the discharge end is transferred to the pressure chamber. A communication path for guiding the air is provided in the bearing on the suction end side indicated by L.

(Function) In the helical blade type fluid compressor of the present invention, when the compression operation is carried out, 1) F-contracted fluid such as compressed gas is discharged from the discharge end side of the cylinder into the case, and the airtight air is sealed. There will be high pressure inside the case. The pressure within this sealed case is led to the pressure chamber through the communication path, acts on the pressure receiving surface of the end of the rotating body forming this pressure chamber, and pushes the rotating body toward the discharge end side. That is, the pressure within the sealed case acts in the opposite direction to the thrust force acting on the rotating body toward the suction end. Therefore, the thrust force can be alleviated, and the thrust bearing that was conventionally necessary to receive the thrust force can be omitted, and therefore, noise can be reduced.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 9. FIG. 1 shows a hermetic compressor 1 for refrigerant gas used in a refrigeration cycle. The compressor 1 includes a hermetic case 2, an electric element 3 as a driving means disposed inside the hermetic case 2, and a compression element 3@-4. The electric element 3 has a substantially annular stator 5 fixed to the inner surface of the sealed case 2 and an annular rotor 6 provided inside the stator 5.

The compression element 4 forms a cylinder 7, and the rotor 6 is coaxially fixed to the outer peripheral surface of the cylinder 7. Both ends of the cylinder 7 are rotatably supported by bearings 8.9 fixed to the inner surface of the sealed case 2.
Both ends of the cylinder 7 are hermetically closed by these bearings 8 and 9. That is, the bearing 8.9 has a boss portion 8.9 into which the end of the cylinder 7 is rotatably fitted.
9a, and base portions 8b, 9b which have a larger diameter than these boss portions 8a, 9a and are fixed to the inner surface of the sealed case 2.

Inside the cylinder 7, a piston 1 as a cylindrical rotating body having an outer diameter smaller than the inner diameter of the cylinder 7 is disposed along the axial direction of the cylinder 7. This piston 1
1, the central axis A of the piston 11 is arranged eccentrically downward by a distance jlle with respect to the central axis B of the cylinder 7 in FIG. Line contact with the surface.

At both ends of the piston 11 in the axial direction, the piston 1
Support shaft portions 12a and 12b each having a smaller diameter than the large diameter portion 11a of No. 1 are provided, and these support shaft portions 12a and 12b are rotatably inserted into the bearing hole 8Cs9c formed in the bearing 8.9, respectively. Insert supported. One end of the piston 11 located on the suction end side of the cylinder 7 is formed with a pressure receiving surface 11b from which the support shaft portion 12a is protruded.

This pressure receiving surface 11b is provided along the direction perpendicular to the axis of the piston 11.

A pressure chamber 20 is formed between this pressure receiving surface 11b and the bearing 8 on the suction end side that supports the support shaft portion 12a. That is, in this embodiment, in order to form the pressure chamber 20, the bearing 8 is provided with a recess 8d. The pressure chamber 20 has a donut shape because the support shaft 812a is disposed through the center thereof.

The pressure chamber 20 is airtightly separated from a working chamber 22, which will be described later. As a sealing means for this purpose, in this embodiment, as shown in FIGS. 1 and 2, a seal ring 33 is provided on the outer peripheral side of the pressure chamber 20, and a donut-shaped leaf spring that presses the ring 33 against the pressure receiving surface 11b. It stores 34. Although such a single-stage seal is considerably cheaper than a thrust bearing, the sealing means may be formed by an O-ring instead of the leaf spring and the seal ring 33, and the sealing performance can be further improved. To improve this, an O-ring 35 may be interposed between the outer periphery of the seal ring 33 and the inner periphery of the pressure chamber 20, as shown in FIG.

Further, a communication passage 36 connecting the pressure chamber 20 and the inside of the sealed case 2 is provided in the bearing 8 on the suction end side. In this embodiment, the communication passage 36 communicates with lubricating oil 29 stored in the inner bottom of the sealed case 2 via a communication pipe 37.

FIG. 3 shows an Oldham mechanism for rotating the cylinder 7 and piston 11 in 81 pairs.

To explain this mechanism, the partition plate 13, whose axial position is regulated by the step 7a formed on the cylinder 7 (see FIG. 1) and the cylindrical portion 9d protruding from the front end surface of the bearing 9, moves into the cylinder. It is press-fitted into 7. This partition plate 1
No. 3 has a square hole 13a, and the edge of this square hole 13g has a step. A rectangular Oldham ring 14 is fitted into the hole 13a so as to be slidable in the first X direction within a space parallel to the partition plate 13. This Oldham ring 14 has a second square hole 14a.

The support shaft portion 12b of the piston 11 facing the Oldham ring 14 has a partition plate 1 inside the second rectangular hole 14a.
A prismatic portion 15 is formed so as to be slidable in a second direction y perpendicular to the first direction X in a direction parallel to the first direction X.

With such a mechanism, the rotation of the rotor 6 is transmitted to the cylinder 7 and then further transmitted to the piston 11 via the partition plate 13 and the Oldham ring 14. In this case, the Oldham ring 14 is moved in the first direction X with respect to the partition plate 13.
The piston 11 reciprocates in a second direction y perpendicular to the direction of the reciprocating movement of the Oldham ring 14.

Therefore, the piston 11 does not rotate, but rolls into contact with the inner surface of the cylinder 7 and rotates relative to the inner surface of the cylinder 7. In this case, the rotation speeds of the cylinder 7 and the piston 11 are the same.

A spiral groove 19 is formed on the outer peripheral surface of the piston 11 along its axial direction. The pitch of the grooves 19 is gradually smaller (formed) from the right side to the left side in FIG. 1, that is, from the suction end side to the discharge end side of the cylinder 7. The thickness of this blade 21 is almost the same as the width of the spiral groove 19, and the troughs of the blade 21 are similar to the width of the spiral groove 19.
9, the piston 11 can move forward and backward in substantially the radial direction. The outer circumferential surface of the blade 21 is in close contact with the inner circumferential surface of the cylinder 7, and in this state, the inner circumferential surface of the cylinder 7''-
Slide.

- The space between the inner circumferential surface of the cylinder 7 and the outer 14 surface of the piston 11 is partitioned into a plurality of working chambers 22 by the blades 21. In other words, each working chamber 22 is formed between two adjacent windings of the blade 21, and extends along the blade 21 from the contact area between the piston 11 and the inner peripheral surface of the cylinder 7 to the contact area at the end. form.

The volume of the working chamber 22 gradually decreases from the suction end side to the discharge end side of the cylinder 7.

”-One bearing 8 located on the suction end side of the H-bi cylinder 7
As shown in FIG. 1, a suction hole 23 extends through the shaft in the axial direction. One end of this suction hole 23 passes through the support shaft portion 12a in the axis lj direction and communicates with the inside of the cylinder 7 via a passage 11c provided in the piston 11, and the other end is connected to the suction tube 24 of the refrigeration cycle. ing. Further, a discharge hole 25 is bored at the end of the cylinder 7 on the bearing 9 side. This discharge hole 25 communicates the inside of the cylinder 7 and the inside of the sealed case 2.

Note that, as shown in FIG. 1, a discharge tube 32 is connected to the sealed case 2 to communicate the inside and outside thereof.

Next, the operation of the pressure w4 machine configured as described above will be explained.

First, when the electric element 3 is energized, the rotor 6 rotates, and the cylinder 7 also rotates together with the rotor 6.

When the cylinder 7 rotates, the piston 11 is driven to rotate at the same time with a portion of its outer circumferential surface contacting the inner circumferential surface of the cylinder 7. The rotation direction of the cylinder 7 and the piston 11 is clockwise when viewed from the suction end side, as shown in FIG. Such a relative rotational movement between the piston 11 and the cylinder 7 is caused by x in the Oldham mechanism described above.
, secured by movement in the y direction. The blade 21 also rotates integrally with the piston 11.

"-2 Since the blade 21 rotates with its outer circumferential surface in contact with the inner circumferential surface of the cylinder 7, each part of the blade 21 rotates as it approaches the contact area between the outer circumferential surface of the piston 11 and the inner circumferential surface of the cylinder 7. Therefore, it is pushed into the groove 19 and moves in the direction of protruding from the groove 19 as it moves away from the contact portion.

When the compression element 4 is operated in this manner, refrigerant gas is sucked into the cylinder 7 through the suction tube 241 passage 11c and the suction hole 23. As shown in FIG. 4, the refrigerant gas sucked into the first working chamber 22 is trapped there and is discharged as the piston 11 rotates as shown in FIGS. 5 to 8. They are sequentially transferred to the working chamber 22 on the end side. The transferred and compressed refrigerant gas is then discharged into the space inside the sealed case 2 from the discharge hole 25 formed on the discharge end side of the cylinder 7, and is discharged from the discharge tube 32.
and then returned to the refrigeration cycle.

Incidentally, the spiral grooves 19 formed in the piston 11 are formed such that the pitch thereof gradually decreases from the suction end side to the discharge end side of the cylinder 7. In other words, the working chamber 22 partitioned by the blades 21 is formed so that the volume gradually decreases toward the discharge end. Therefore, while the refrigerant gas is transferred from the suction end to the discharge end of the cylinder , this refrigerant gas can be compressed. Further, since the refrigerant gas is transferred and compressed while being confined within the working chamber 22, the refrigerant gas can be efficiently compressed even if no check valve is provided on the discharge side of the compressor.

When the refrigerant gas compressed in this way is discharged into the closed case 2 and the pressure inside the closed case 2 rises, the lubricating oil 29 stored at the bottom of the closed case 2 is pressurized, and the lubricating oil 29 37 and the communication path 36 to the pressure chamber 20. Therefore, after all, the high pressure inside the sealed case 2 acts on the pressure chamber 20 and presses the piston 11 toward the discharge end side. Therefore, a thrust force is applied to the piston 11 in the direction of the suction end due to the pressure difference between the adjacent working chambers 22, but this thrust force is relieved by the pressure in the pressure chamber 20 indicated in -.

As described above, the thrust force applied to the piston 11 in the direction of the suction end can be received by the pressure inside the sealed case 2, so that the need for a thrust bearing conventionally required to receive the thrust force can be eliminated. Therefore, it is possible to reduce not only the loss of H caused by the thrust force but also the noise at this thrust receiving part.The seal ring 33 makes sliding contact with the pressure receiving surface 11b of the piston 11, but the sliding contact noise at this part can be reduced. is much smaller than when using a thrust bearing.

Moreover, in the case of this embodiment, since the lubricating oil 29 is introduced into the pressure chamber 20, the sliding contact surface is lubricated by this oil 29, and the sliding loss can be minimized. Further, this lubricating oil 29 also provides lubrication between the bearing hole 8c of the bearing 8 and the support shaft portion 12a.

Furthermore, since the check valve can be omitted as described above, the configuration of the compressor can be simplified and the number of parts can be reduced. Furthermore, since the rotor 6 of the electric element 3 is supported by the cylinder 7 of the compression element 4, there is no need to provide a dedicated rotating shaft or bearing for supporting the rotor 6. Therefore, it goes without saying that the configuration of the compressor can be further simplified and the number of parts can be reduced.

In the above embodiment, the bearing 8 is provided with four parts 8d to form the pressure chamber 20, but instead of the four parts 8d, the piston 11 is
The pressure receiving surface 11b may be provided with four parts. Also,
The communication vibrator 37 is omitted and the pressure chamber 20 is equipped with a sealed case 2.
It is also possible to directly introduce the high pressure inside.

[Effects of the Invention] As described above, the present invention provides a helical bushito type 11 fluid compressor in which the suction end is located at the - mark of the rotary body disposed in the cylinder with the suction end side and the discharge end side H. A pressure receiving surface is provided at the end of the side, and a pressure chamber is formed between this pressure receiving surface and the bearing on the suction end side that supports the support shaft of the "-2 rotating body,"
By providing a communication path in the bearing on the suction end side that guides the pressure inside the sealed case through which the compressed fluid is discharged into the pressure chamber, thrust force is exerted on the rotating body by the pressure inside the sealed case. As a result, noise reduction can be achieved.

[Brief explanation of the drawing]

Figures 1 to 9 show an embodiment of the present invention, in which Figure 1 is a longitudinal sectional view of the entire fluid compressor, Figure 2 is a sectional view of the suction end side of the compression element, and Figure 3 is a sectional view of the suction end side of the compression element. An exploded perspective view showing the configuration of the Oldham mechanism, FIGS. 4 to 8 are explanatory views sequentially showing the refrigerant gas compression process, and FIG. 9 is a side view of the compression element. FIG. 10 is a sectional view showing another embodiment of the suction end side portion of the compression element. FIG. 11 is a sectional view of a compression element in a conventional helical blade type compressor. 2... Sealed case, 3... Electric element (driving means),
7... Cylinder, 8... Bearing, 11... Piston (rotating body) 11a... Large diameter portion, llb... Pressure receiving surface, 14... Oldham ring, 19... Groove, 20・・・
・Pressure chamber, 21...Blade, 22...Working chamber, 3
6...Communication path. Applicant's Representative Patent Attorney Takehiko Suzue

Claims (1)

[Scope of Claims] A sealed case, a cylinder provided within the case and having a suction end side and a discharge end side; A cylindrical rotating body that can rotate relative to the cylinder while in contact with the inner peripheral surface of the cylinder, and a pitch that is provided on the outer periphery of the rotating body and gradually decreases from the suction end side to the discharge end side of the cylinder. between the inner circumferential surface of the cylinder and the outer circumferential surface of the rotating body; a spiral blade that divides a space into a plurality of working chambers; and a spiral blade that rotates the rotating body in synchronization with the cylinder so that the fluid flowing into the working chamber from the suction end of the cylinder is transferred to the working chamber at the discharge end of the cylinder. A fluid compressor equipped with a mechanism for sequentially transferring the fluid to a fluid compressor, wherein a pressure receiving surface is provided at an end of the rotating body on the suction end side along a direction perpendicular to the axis thereof, and a pressure receiving surface is provided at the end of the rotating body on the suction end side, and A pressure chamber is formed between the bearing on the suction end side and the pressure receiving surface that supports a support shaft having a small diameter and protruding from the pressure receiving surface, and a pressure chamber is formed in the bearing on the suction end side in the sealed case. A fluid compressor, characterized in that a communication path is provided for guiding the pressure of the pressure into the pressure chamber.