JP3054643B2 - Fluid compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical blade type fluid compressor suitable for compressing refrigerant gas in a refrigeration cycle, for example.

[0002]

2. Description of the Related Art Reciprocating compressors, rotary compressors and the like are generally known as conventional compressors. In addition, refrigerant flowing into a working chamber from a suction end side of a cylinder is discharged to a discharge end side of the cylinder. A helical blade type fluid compressor is provided which compresses while sequentially transferring the fluid to the working chamber and discharges the fluid to the outside.

The outline of the helical blade type compressor is as follows.
For example, as shown in FIG.
Cylinder 105 rotated by driving means comprising
And a rotating rod 109 eccentrically disposed within the cylinder 105 by e, and receives the rotating force of the cylinder 105 via the Oldham ring 107 to rotate relatively to the cylinder 105. Has become. A spiral groove 111 is formed on the outer peripheral surface of the rotating rod 109 over substantially the entire length of the rod 109.
A spiral blade 113 is fitted to 11 so as to be able to move in and out. The outer peripheral surface of the blade 113 is in contact with the inner peripheral surface of the cylinder 105. Therefore, a plurality of working chambers 115 are formed in the space between the rotating rod 109 and the cylinder 105 by the blade 113 along the axial direction. The working chamber 115 has a capacity of the blade 1 as shown in FIG.
13 is determined by the pitch P of the spiral groove 111 to be fitted, and the pitch P of the groove 111 gradually decreases from the suction side to the discharge side of the rotating rod 109.
Therefore, the volume of the working chamber 111 formed by the blade 113 gradually decreases from the suction end side of the rotary rod 109 on the suction pipe 117 side to the discharge end side on the discharge pipe 119 side. It is configured to be compressed and discharged to the outside while being sequentially transferred to the discharge end side.

[0004]

As described above, in the helical blade type fluid compressor, the working chamber 115
The volume when the refrigerant is confined in the working chamber 115 and the volume of the working chamber 115 immediately before discharge are formed mechanically determined by the blades 113 having different pitches, and the discharge pressure is determined by the suction pressure. . Therefore, when operating based on a constant discharge pressure condition, for example, if the operating conditions change to close the refrigerant beyond the specified amount in the working chamber 115, or to close the refrigerant less, It cannot cope with it, resulting in over-compression or under-compression.
In particular, in the case of over-compression, there is a problem that a large load acting on the drive unit and the blade is exerted, which is not desirable in terms of reliability.

Accordingly, it is an object of the present invention to provide a fluid compressor capable of obtaining an operating pressure corresponding to the operating conditions even if the operating conditions change during a compression stroke.

[0006]

In order to achieve the above object, according to the present invention, there is provided a cylinder, a rotating body disposed eccentrically inside the cylinder, and rotatable relative to the cylinder. A helical groove provided on the outer periphery of the rotating body and formed so that the pitch gradually decreases from the suction side to the discharge side of the cylinder; in the fluid compressor having the compression element comprising a spiral blade that divides the space into a plurality of working chambers between closely the cylinder to the inner surface and the rotating body, the compression element, working chambers
And the discharge pressure space from the working chamber to the closed container
Compression stroke consisting of a passage that opens and closes and a control valve that opens and closes this passage
When the pressure difference between the pressure in the inner working chamber and the discharge pressure exceeds a specified pressure, a release means configured to release the pressure in the working chamber is provided.

[0007]

According to such a fluid compressor, operating conditions change during the compression stroke. For example, when the working chamber is in an over-compressed state, the pressure causes the control valve to operate, thereby releasing the pressure to the communication passage. Thus, an operating pressure corresponding to the operating conditions can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. In FIG. 1, 1
1 shows a closed case of a hermetic type fluid compressor 3 used for a refrigeration cycle. One of the closed cases 1 is provided with a suction pipe 5 for the refrigeration cycle, and the other is provided with a discharge pipe 7. An electric element 9 as a driving unit and a compression element 11 as a compression unit are arranged in the closed case 1.

The electric element 9 has a stator 13 fixed to the inner surface of the sealed case 1 and a rotatable rotor 15 provided inside the stator 13.

The compression element 11 has a cylinder 17 whose both ends are open. The cylinder 17 is rotatably supported at both ends by bearings 19 and 20 fixed to the inner surface of the sealed case 1. The bearings 19 and 20 include bosses 19a and 20a in which the ends of the cylinder 17 are rotatably fitted, and bases 19b and 20b which are larger in diameter than the bosses 19a and 20a and are fixed to the inner surface of the sealed case 1. And both ends of the cylinder 17 are hermetically closed.

Inside the cylinder 17, a cylindrical rotating body 21 smaller than the inner diameter of the cylinder 17 is arranged along the axial direction of the cylinder 17. The rotating body 21 is made of an iron-based or other material, and its central axis A is disposed eccentrically downward with respect to the central axis B of the cylinder 17 by a distance e in FIG. doing.

At both ends of the rotating body 21, there are provided spindle portions 21a and 21b having small diameters.
a and 21b are boss portions 19 of the bearings 19 and 20, respectively.
a and 20a are rotatably inserted and supported in bearing holes 19c and 20c.

A prism section 25 having a square cross section that functions as a power transmission surface through which rotational power from the cylinder 17 side is transmitted via an Oldham ring 23 is formed on one support shaft section 21a of the rotating body 21. . The prism 25 has play with a rectangular elongated hole 26 formed in the Oldham ring 23 and can slide the prism 25 within the range of play. One end of a pair of transmission pins 27, 27 is slidably fitted on the outer peripheral surface of the Oldham ring 23 in a radial direction orthogonal to the longitudinal direction of the long hole 26, respectively. The end is a fitting hole 2 formed in the peripheral wall of the cylinder 17.
9. Thereby, the rotating body 21
Is secured at an eccentric position with respect to the cylinder 17, and the rotational force of the cylinder 17 is transmitted to the rotating body 21 via the Oldham ring 23.

[0014]

On the other hand, a spiral groove 31 is provided on the outer peripheral surface of the rotating body 21. The spiral groove 31 has the largest pitch P on the suction end side (left side in FIG. 1). The pitch is set so as to gradually decrease toward the discharge end side (right side in the drawing).

A spiral blade 33 made of an elastic material such as a synthetic resin is fitted in the spiral groove 31 so as to be able to move in and out of the groove 31 by utilizing elastic force. This allows
Each of the working chambers 35 is formed, and the capacity of the working chamber 35 on the suction end side is the largest. Hereinafter, the volume of each working chamber 35 is set so as to gradually decrease toward the discharge end side, and the final working chamber 35 serving as the discharge side is provided with a discharge hole 37 opened in the sealed case 1 formed in the bearing 20. Is in communication with 7, each of the working chambers 35 is formed along the inner circumferential surface 1 of the rotating body 21 and the cylinder 17 along the blade 33.
It is an almost crescent-shaped area extending from the contact portion with 7a to the next contact portion. First working chamber 35 on the suction end side
Is connected and connected to the suction pipe 5 of the refrigeration cycle through a first suction hole 39 for communication provided at the shaft end of the rotating body 21 and a second suction hole 41 provided in the bearing 19. doing. Thus, the refrigerant sucked into the cylinder 17 from the suction pipe 5 is surely introduced into the first working chamber 35 without interruption.

Further, the rotary shaft 21 is provided with a communication passage 43 communicating with the groove bottom of the spiral groove 31 along the longitudinal direction of the rotary shaft 21. One end of the communication passage 43 communicates with the discharge end side of the cylinder 17 and the other end is closed.
A control valve 47 that opens when the pressure reaches a specified pressure is provided in a passage 45 that connects the groove bottom of the spiral groove 31 and the communication passage 43. Therefore, the communication passage 43 and the control valve 47 constitute release means, and this release means
Pressure between the working chamber 35 and the discharge end of the cylinder 17 during the compression process
When the differential pressure of the force exceeds the specified pressure, it is released and the pressure in the working chamber 35 is reduced.
Force is released to the communication passage 43.

The control valve 47 is provided with a valve seat 49 fitted in the passage 45 and an openable / closable valve element 5 elastically contacting the valve seat 49.
1 is a unit integrally assembled, and can be assembled by forcibly inserting the blade 33 from above the helical groove 31 in a previous step of assembling the blade 33.

The pressure in the working chamber 35 on the high pressure side, which is always in elastic contact with the valve seat 49, becomes higher than a specified pressure, and the pressure F of the valve body 49 is increased as shown in FIG. As shown in FIG. 3, the blade 33 is separated from the valve seat 49 by the pressure passing through the gap α formed on the side of the blade 33 and is rotated to the stopper 53.

In FIG. 1, reference numeral 55 denotes an oil introduction passage provided in the rotating body 21. One end of the oil introduction passage 55 communicates with the spiral groove 31, and the other end thereof is on the suction end side. Is connected to an introduction pipe 59 through which a suction port 59a faces the bottom of the sealed case 1 via a communication hole 57 formed in the bearing 19 of FIG. Therefore, when the pressure in the closed case 1 rises, the lubricating oil stored in the bottom of the closed case 1 is fed into the groove 31 through the introduction pipe 59, the communication hole 57 and the oil introduction path 55, so that the blade The lubrication at the time of entry and exit of 33 is ensured.

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

First, when power is supplied to the electric element 9, the rotor 15
Rotates, and the cylinder 17 also rotates integrally with the rotor 15. When the cylinder 17 rotates, the Oldham ring 23
The rotator 21 also rotates via. The rotating body 21 rotates relative to the cylinder 17. As a result, the fluid such as the refrigerant sent to the working chamber 35 on the suction end side is compressed while being sequentially sent to the working chamber 35 on the discharge end side, and is discharged from the discharge pipe 7 to the outside.

In this operation, for example, when a large amount of refrigerant is confined in the working chamber 35 due to a change in operating conditions, the working chamber 35 enters an over-compressed state exceeding a specified pressure.
When this overcompression occurs, the pressure is
3 acts on the valve element 51 from the gap α on the side, and the valve element 51 is separated from the valve seat 49.
To run away. When the pressure in the working chamber 35 returns to the regulation pressure, the control valve 47 closes the passage 45. As a result, an unreasonable load that adversely affects the blade 33 and the driving element 9 does not act, and an operating pressure corresponding to the operating condition can be obtained.

The control valve 47 for releasing the pressure F of the working chamber 35 to the communication passage 43 is constantly controlled by an urging spring 61 having a specified spring pressure as shown in FIGS.
A rod 63 urged to be in contact with the bottom surface of the spiral groove 31 is provided in a passage 45 connecting the groove bottom of the spiral groove 31 and the communication passage 43, and the rod 63 is provided with a relief groove 65 as a piston rod type. It is also possible.

According to this embodiment, when the inside of the working chamber 35 is over-compressed by exceeding the spring pressure of the biasing spring 61, the pressure is pushed down by the pressure and the communication passage 43 through the relief groove 65.
Pressure will escape. In the case of this embodiment, the blade 33 is constantly moved by the rod 61 to the cylinder 17.
Since the shape is urged toward the side, the contact pressure between the inner peripheral surface of the cylinder 17 and the outer peripheral surface of the blade 33 is reliably ensured, and a good sealing state can be obtained.

[0026]

As described above, according to the fluid compressor of the present invention, overcompression and the like are eliminated, an operating pressure corresponding to the operating conditions is obtained, and reliability can be improved.

[0027]

[Brief description of the drawings]

FIG. 1 is a sectional view of a fluid compressor.

FIG. 2 is an explanatory diagram of a control valve.

FIG. 3 is an explanatory diagram of a control valve.

FIG. 4 is an explanatory view similar to FIG. 2 showing a piston rod type control valve.

FIG. 5 is an explanatory view similar to FIG. 3, showing a piston rod type control valve.

FIG. 6 is a perspective view of a rod.

FIG. 7 is a sectional view of the Oldham ring.

FIG. 8 is a sectional view similar to FIG. 1 showing a conventional example.

FIG. 9 is a perspective view of the rotating body of the above.

[Explanation of symbols]

 9 Driving means 17 Cylinder 21 Rotating body 31 Spiral groove 33 Blade 35 Working chamber 43 Communication passage 47 Control valve

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takuya Hirayama 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Pref. Toshiba Corporation Living Space Systems Research Laboratory (56) References JP-A-2-264185 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) F04C 18/30-18/352 F04C 29/10 331

Claims (1)

(57) [Claims] 1. A cylinder, a rotator disposed eccentrically inside the cylinder and rotatable relative to the cylinder, and provided on an outer periphery of the rotator from a suction side to a discharge side of the cylinder. A spiral groove formed so that the pitch becomes gradually smaller, and is fitted in the groove so as to be able to freely enter and exit, and the outer peripheral surface is in close contact with the inner surface of the cylinder. In a fluid compressor having a compression element comprising a spiral blade defining a chamber, the compression element may include a working chamber and a working chamber.
And a passage communicating with the discharge pressure space
Working chamber during the compression stroke consisting of a control valve that opens and closes this passage
And a release means configured to release the pressure in the working chamber when the pressure difference between the pressure and the discharge pressure exceeds a specified pressure.