JP2825236B2 - Fluid compressor - Google Patents

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 of a refrigeration cycle, for example.

(Related Art) Conventionally, various types of compressors such as a reciprocating type and a rotary type have been known. However, in these compressors, the structure of a drive unit such as a crankshaft for transmitting the rotational force to the compressor unit and the structure of the compression unit are complicated, and the number of parts is large. Furthermore, in such a conventional compressor, it is necessary to provide a check valve on the discharge side in order to increase the compression efficiency. However, since the pressure difference between both sides of the check valve is very large, gas is discharged from the check valve. Easy to leak and low compression efficiency. In order to solve such a problem, it is necessary to increase the dimensional accuracy and the assembly accuracy of each component, which increases the manufacturing cost.

Further, US Pat. No. 2,401,189 discloses a screw pump. According to this pump, a cylindrical rotating body is disposed in the sleeve, and a spiral groove is formed on the outer peripheral surface of the rotating body. A spiral blade is slidably fitted in this groove. By rotating the rotating body, the fluid confined between two adjacent windings of the blade between the outer circumferential surface of the rotating body and the inner circumferential surface of the sleeve is transferred from one end of the sleeve to the other end. I do. That is, the above-described screw pump merely transfers the fluid from one end to the other end, and does not have a function of compressing the fluid.

(Problems to be Solved by the Invention) As described above, the conventional fluid compressor has a complicated structure and a large number of parts. In addition, gas may leak from a check valve provided at the boundary between the high pressure side and the low pressure side, resulting in low compression efficiency. Further, a screw pump of a type in which a rotary body wound with a helical blade is disposed inside a sleeve simply transfers fluid, and has no compressing action.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid compressor in which the sealing performance is improved by a relatively simple structure, efficient compression can be performed, and the production and assembly of parts is easy.

[Configuration of the invention]

(Means and Actions for Solving the Problems) In order to achieve the above object, the present invention provides a cylindrical cylinder and an eccentrically disposed inside of the cylinder, a part of which is in contact with the inner peripheral surface of the cylinder. A cylindrical piston rotatable relative to the cylinder in a state, and two helical grooves provided on the outer periphery of the piston and formed so that the pitch gradually decreases in different directions from each other,
The piston is fitted in the groove so as to be able to freely enter and exit in a substantially radial direction of the piston, and has an outer peripheral surface that is in close contact with the inner peripheral surface of the cylinder. A blade that partitions the chamber into chambers, and a driving unit that relatively rotates the cylinder and the piston and sequentially transfers fluid flowing into the working chamber from the suction side of the cylinder to the working chamber on the discharge side of the cylinder. did.

On the other hand, a cylindrical cylinder, a cylindrical piston disposed eccentrically inside the cylinder, a part of which is rotatable relative to the cylinder in a state of being in contact with the inner peripheral surface of the cylinder, and An inner peripheral surface of the cylinder having two spiral grooves provided on an outer periphery thereof and an outer peripheral surface which is fitted into the groove so as to be able to freely enter and exit in a substantially radial direction of the piston and is in close contact with the inner peripheral surface of the cylinder; And a blade that partitions the space between the outer peripheral surface and the plurality of working chambers, the cylinder and the piston are relatively rotated, and the fluid flowing into the working chamber of the cylinder is transferred in different directions. The driving means is provided.

Preferably, the spiral groove is formed so as to reduce the volume of the working chamber toward the discharge side of the cylinder.

By doing so, the present invention can improve the performance and reliability with a simple configuration, improve the sealing performance, enable efficient compression, and
It is to facilitate the manufacture and assembly of parts.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. FIG. 1 shows a hermetic compressor 1 for a refrigerant gas used in a refrigeration cycle. This compressor 1 has a closed case 2
And an electric element 3 and a compression element 4 as drive means disposed in the closed case 2. The electric element 3 has a substantially annular stator 5 fixed to the inner surface of the closed case 2 and an annular rotor 6 provided inside the stator 5.

The compression element 4 has 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 and 9 fixed to the inner surface of the sealed case 2, and both ends of the cylinder 7 are hermetically closed by the bearings 8 and 9.

Further, a piston as a cylindrical rotating body having an outer diameter smaller than the inner diameter of the cylinder 7 is provided in the cylinder 7.
10 are provided along the axial direction of the cylinder 7. The center axis A of the piston 10 is the center axis B of the cylinder 7.
Eccentrically to the distance e
Part of the outer peripheral surface of 10 is in contact with the inner peripheral surface of cylinder 7. Both ends of the piston 10 are rotatably supported by the bearings 8 and 9, respectively.

Further, as shown in FIG. 1, a drive pin 12 is provided on the inner peripheral surface of the cylinder 7 so as to project toward the center.
An engagement groove 11 into which the drive pin 12 is inserted is formed on the outer peripheral surface of the rotor 11 at a position (the right end in the figure) facing the drive piston 12 of the piston 10 from the center to the outer periphery.

Therefore, when the electric element 3 is energized and the cylinder 7 is driven to rotate integrally with the rotor 6, the drive pin 12 in the cylinder 7 rotates accordingly. At this time, the driving pin 12 is inserted into the engaging groove 11 and both are engaged with each other, so that the rotational force of the cylinder 7 is transmitted to the piston 10 via the driving pin 12 and the engaging groove 11. . This allows the piston
10 rotates together with the cylinder 7 in the same direction.

In addition, since the drive pin 12 in the cylinder 7 is only inserted into the engagement groove 11, the drive pin 12
The drive pin 12 is located at the position where the inner peripheral surface of the cylinder 7 and the outer peripheral surface of the rotor 6 are farthest from each other.
From the most protruding state to the position where the inner peripheral surface of the cylinder 7 and the outer peripheral surface of the rotor 6 are in contact, that is, the state in which the entire length of the drive pin 12 is completely immersed in the engagement groove 11. Therefore, the piston 10 inverts in the cylinder 7 with a part thereof in contact with the inner surface of the cylinder 7.

On the outer peripheral surface of the piston 10, there are formed two spiral grooves 13, 14 which extend from both end portions of the piston 10 to the intermediate portion and are inclined substantially symmetrically in different directions. I have. The pitch of these grooves 13, 14 is gradually reduced from one end of the piston 10 to the intermediate portion, that is, from the absorption side to the discharge side of the cylinder 7, as shown by dashed lines in FIG. It is formed so that it becomes.

Spiral blades 15, 16 shown in FIG. 1 are fitted into the grooves 13, 14, respectively. The thickness of these blades 15 and 16 is almost equal to the width of each of the grooves 13 and 14, and each part of the blades 15 and 16 is positioned in the radial direction of the piston 10 with respect to the grooves 13 and 14. It can move forward and backward along. Further, the outer peripheral surfaces of the blades 15 and 16 slide on the inner peripheral surface of the cylinder 7 in a state of being in close contact with the inner peripheral surface of the cylinder 7. These blades 15 and 16 are formed of an elastic material such as Teflon (trade name), and are wound around the piston 10 by screwing into the grooves 13 and 14 using the elasticity.

The space between the inner peripheral surface of the cylinder 7 and the outer peripheral surface of the piston 10 is partitioned by the blades 15 and 16 into a plurality of working chambers 17. That is, each working chamber 17 is formed between two adjacent turns of each of the blades 15 and 16, and the piston 10 extends along each of the blades 15 and 16.
It has a substantially crescent shape extending from the contact portion between the cylinder and the inner peripheral surface of the cylinder 7 to the next contact portion. The volume of the working chambers 17 gradually decreases from both ends of the cylinder 7 to the middle, that is, from the suction side to the discharge side.

In addition, as shown in FIG. 1, suction holes 18 and 19 extending substantially in the axial direction of the cylinder 7 penetrate through the bearings 8 and 9 located on the suction side of the cylinder 7, respectively.
One end of each of the suction holes 18 and 19 is open in the cylinder 7, and the other end is provided with a suction tube 2 of a refrigeration cycle.
0 and 21 are connected.

In FIG. 1, reference numeral 22 denotes a discharge passage provided in the rotor 6 and one end thereof communicates with a discharge hole 23 provided in the cylinder 7. The other end of the discharge passage 22 is And an opening in the space between the stator 5. And
The discharge hole 23 is provided at a position corresponding to an intermediate portion of the piston 10. In the figure, reference numeral 24 denotes a closed case 2
Is a discharge tube that allows the inside and the outside of the device to communicate with each other.

Next, the operation of the compressor configured as described above will be described.

First, when the electric element 3 is energized, the rotor 6 and the cylinder 7 rotate integrally, and the drive pin 12 in the cylinder 7 rotates accordingly. At this time, since the drive pin 12 is inserted into the engagement groove 11 and engaged with each other, the rotational force of the cylinder 7 is transmitted to the piston 10 via the drive pin 12 and the engagement groove 11, and the piston 10 7, a part of the cylinder 7 is driven to rotate while being in contact with the inner surface of the cylinder 7. The relative rotational drive between the piston 10 and the cylinder 7 is as follows.
This is ensured by the configuration in which the drive pin 12 is inserted into the engagement groove 11 so as to be able to advance and retreat. Then, the blades 15, 16 also rotate integrally with the piston 10.

Further, since the blades 15 and 16 rotate while their outer peripheral surfaces are in contact with the inner peripheral surface of the cylinder 7, both the blades 15 and 1 are rotated.
6 are pushed into the grooves 13 and 14 as they approach the contact portion between the outer peripheral surface of the piston 10 and the inner peripheral surface of the cylinder 7, respectively.
Move in the direction of jumping out of 3,14. On the other hand, when the compression element 4 is operated, refrigerant gas (not shown) is sucked into both ends of the cylinder 7 through the suction tubes 20 and 21 and the suction holes 18 and 19. The sucked refrigerant gas is confined in the crescent-shaped working chamber 17 between the windings of both blades 15 and 16, and the rotation of the piston 10 causes the working chamber on the middle part, that is, the working chamber on the discharge side. Transferred to 17 sequentially. And
The compressed refrigerant gas transferred from both ends of the piston 10 to the intermediate portion passes through a discharge hole 23 formed in the cylinder 7 and is discharged into the space of the closed case 2. Returned inside.

According to the compressor configured as described above, the piston 10
The two spiral grooves 13 and 14 are formed so that the pitch gradually decreases from one end of the cylinder 7 toward the middle. That is, the working chambers 17 divided by the two blades 15 and 16 are formed such that the volume gradually decreases toward the discharge side.
Therefore, the refrigerant gas can be compressed while the refrigerant gas is transferred from the suction side at both ends of the cylinder 7 to the discharge side. In addition, since the solvent gas is transferred and compressed while being confined in the working chamber 17, the gas can be compressed efficiently even when no discharge valve is provided on the discharge side of the compressor.

Further, since the discharge valve can be omitted, the structure of the compressor can be simplified and the number of parts can be reduced. Further, 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, the structure of the compressor can be further simplified,
The number of parts can be reduced.

The compressor 1 has two helical blades 15, 16
Are wound around the piston 10 in different directions from each other, and refrigerant gas is sucked into the cylinder 7 from both ends of the piston 10. Then, the refrigerant gas sucked into the cylinder 7 is transferred while being compressed to an intermediate portion of the piston 10, and the compressed high-pressure gas is discharged into the closed case 2. That is, since the refrigerant gas is sucked from two directions, the pitch between the grooves 13, 14 and the cylinder 7 and the piston 1
The transfer capacity can be increased without increasing 0. Therefore, the efficiency can be improved without generating excessive deformation stress on both blades 15 and 16, and a high-performance compressor can be obtained. Further, since the suction ports are provided at two places, the suction efficiency is good. Further, since suction is performed from both ends of the cylinder 7, both ends of the cylinder 7 and the piston 10 are placed under the same pressure environment. That is, the forces between both ends of the cylinder 7 and the piston 10 are balanced, and the generation of the thrust force due to the differential pressure can be prevented. Therefore, it is possible to increase the differential pressure between the suction side and the discharge side, and it is possible to reduce the input pressure of the refrigerant gas.

Further, the cylinder 7 and the piston 10 are in contact with each other while rotating in the same direction. For this,
The friction between these members is small and each can rotate smoothly, so that there is little vibration and noise.

Although the transfer capacity decreases, as the number of turns of the blades 15 and 16 increases, the pressure difference between adjacent working chambers decreases, the amount of gas leak between the working chambers decreases, and the compression efficiency improves.

In this embodiment, the pitch of the two grooves 13 and 14 of the piston 10 is gradually reduced from both ends of the piston 10 to the intermediate portion. However, the present invention is not limited to this. 13 and 14 may be formed as shown in FIG. 3 or FIG. That is, in the one shown in FIG. 3, the two spiral grooves 13 and 14 have the same pitch, and one end of each is substantially connected in a wedge shape at the intermediate portion of the piston 10. Then, as shown by arrows C in the figure, the refrigerant gas sucked from both ends of the piston 10 is transferred to an intermediate portion of the piston 10, where it is compressed and discharged.

Also, in FIG. 4, two spiral grooves 13, 14
Are gradually reduced from the middle part of the piston 10 to both ends. And the arrow D in the figure ...
As shown by, the refrigerant gas is transferred while being compressed from the middle part of the piston 10 to both ends, and is discharged in two directions.

The compressor of the present invention is not limited to a refrigeration cycle, but can be applied to other compressors.

〔The invention's effect〕

As described above, the present invention enables high performance with a simple configuration and suppresses generation of thrust force generated in a cylinder or a piston.

[Brief description of the drawings]

1 and 2 show an embodiment of the present invention.
1 is a longitudinal side view showing the entire fluid compressor, FIG. 2 is a side view schematically showing a groove provided in a piston, and FIGS. 3 and 4 each show a modified example of a spiral groove. FIG. 2 ... closed case, 3 ... electric element, 7 ... cylinder, 10 ...
… Piston, 13,14 …… helical groove, 15,16 …… blade, 1
7 ... Working room.

Claims (1)

(57) [Claims] A cylindrical cylinder; a cylindrical piston eccentrically disposed inside the cylinder, a part of which is rotatable relative to the cylinder while a part thereof is in contact with an inner peripheral surface of the cylinder; Two helical grooves provided on the outer periphery of the piston and formed so that the pitch gradually decreases in different directions from each other; A blade having an outer peripheral surface closely contacting the inner peripheral surface of the cylinder and partitioning a space between the inner peripheral surface of the cylinder and the outer peripheral surface into a plurality of working chambers, and relatively rotating the cylinder and the piston; And a driving means for sequentially transferring fluid flowing into the working chamber from the absorption side of the cylinder to the working chamber on the discharge side of the cylinder.