JP2954757B2 - 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 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. The spiral type fluid compressor which compresses while sequentially transferring the fluid to the working chamber and discharges the fluid to the outside is provided.

[0003] An outline of a spiral compressor is shown in, for example, FIG.
And a cylinder 105 rotated by a driving means including a stator 101 and a rotor 103 as shown in FIG.
05 and placed eccentrically by e
And a rotating rod 109 which can be relatively turned with respect to the cylinder 105 via a spiral. 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 blade 113 is fitted so that it can freely enter and exit. The outer peripheral surface of the blade 113 is in close contact with the inner peripheral surface of the cylinder 105, and the blade 113 turns integrally with the rotating rod 109. Working chamber 115 formed in the space between rotating rod 109 and cylinder 105
Is determined by the pitch P of the spiral groove 111 into which the blade 113 is fitted as shown in FIG.
One pitch P gradually decreases from one end of the rotating rod 109 to the other end. Therefore, the volume of the working chamber 111 formed by the blade 113 is
Since the size of the refrigerant gradually decreases from the suction end of the rotary rod 109 on the suction pipe 117 side toward the discharge end on the discharge pipe 119 side, the refrigerant is compressed and discharged while being sequentially transferred to the discharge end. Is discharged.

[0004]

As described above, in the spiral type fluid compressor, the working chamber 115 is formed by blades 113 having different pitches, and discharges the volume when the refrigerant is closed in the working chamber 115 and discharges the same. Working chamber 115 immediately before
Is determined mechanically, and the discharge pressure is determined by the suction pressure. Therefore, the operation is performed based on a constant discharge pressure condition. For example, a refrigerant exceeding a prescribed amount is taken into the working chamber 115 during operation,
When the lubricating fluid for lubricating the blade is taken in, an over-compression state occurs. If an over-compression state occurs, there is no place for pressure to escape, so a heavy load is imposed on the blade, and in some cases, a problem leading to breakage is caused.

Accordingly, it is an object of the present invention to provide a fluid compressor in which an excessive load does not act on a blade even if an over-compression state occurs 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; And a helical blade that divides a space between the cylinder and the rotator into a plurality of working chambers, the compression element having a pressure during a compression process adjacent to the compression element. Higher than the pressure in the working chamber on the discharge side
In this case, a relief passage is provided for releasing the pressure in the working chamber to the adjacent working chamber on the discharge side. In a preferred embodiment, a relief passage is formed in the blade to communicate the groove with the working chamber on the discharge side.

[0007]

According to such a fluid compressor, during the compression stroke, for example, when the working chamber is over-compressed, the pressure causes the blade to be strongly pressed toward the high-pressure working chamber on the discharge side. The chamber communicates with the groove. At this time, the pressure exceeding the specified pressure escapes to the working chamber on the discharge side via the escape passage, and pressure control is performed. As a result, a large load does not act on the blade.

[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.

FIG. 5 shows one support shaft 21a of the rotating body 21.
As shown in FIG.
A prism section 25 having a square cross section that functions as a power transmission surface to which rotational power from the side is transmitted is formed. The prism 25 has play with a rectangular elongated hole 26 formed in the Oldham ring 23, and the prism 25 can slide within the range of play. A pair of transmission pins 2 is provided on the outer peripheral surface of the Oldham ring 23 in a radial direction orthogonal to the longitudinal direction of the long hole 26.
One end of each of 7, 27 is slidably fitted,
The other ends of the transmission pins 27 are fitted and fixed in fitting holes 29 formed in the peripheral wall of the cylinder 17. As a result, the rotating body 21 is easily secured in a eccentric position with respect to the cylinder 17, and the rotating force of the cylinder 17 is transmitted to the rotating body 21 through the Oldham ring 23.
It is transmitted to.

Accordingly, the cylinder 17 rotates integrally with the rotor 15 by the operation of the electric element 9, so that the rotating body 21 eccentrically rotates with respect to the cylinder 17 via the Oldham ring 23.

On the other hand, a spiral groove 31 is provided on the outer peripheral surface of the rotary body 21. The spiral groove 31 has the largest pitch P on the suction end side (right side in FIG. 1). The pitch is set so as to gradually decrease toward the discharge end side (left 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 by utilizing elastic force. The blade 33 has
As shown in FIG. 3, the left high-pressure working chamber 35 on the discharge side
When strongly pressed to the side, a relief passage 41 is provided to communicate with the spiral groove 31 and the inside of the working chamber 35 on the high pressure side. The position where the escape passage 41 is provided is not limited to this embodiment. For example, the escape passage 41 may be provided so as to penetrate the blade 33 as shown in FIG.

Further, the volume of the working chamber 35 on the suction end side formed by the blade 33 is the largest, and hereinafter, the volume of each working chamber 35 is set so as to gradually decrease toward the discharge end side. The final working chamber 35 is the bearing 2
0 and is connected and connected to a discharge hole 37 opened in the closed case 1. As shown in FIG. 5, each working chamber 35 is a substantially crescent-shaped area extending from a contact portion between the rotating body 21 and the inner peripheral surface 17a of the cylinder 17 to the next contact portion along the blade 33. The first working chamber 35 on the suction end side has a first suction hole 39 for communication provided at the shaft end of the rotating body 21 and a second suction hole 43 provided on the bearing 19. Is connected and connected to the suction pipe 5 of the refrigeration cycle via the refrigeration cycle. Thus, the refrigerant sucked into the cylinder 17 from the suction pipe 5 is surely introduced into the first working chamber 35 without interruption.

In FIG. 1, reference numeral 45 denotes an oil introduction passage provided in the rotating body 21. One end of the oil introduction passage 45 communicates with the spiral groove 31, and the other end thereof is on the suction end side. Is connected to an introduction pipe 49 through which a suction port 49a faces the bottom of the sealed case 1 through a communication hole 47 formed in the bearing 19 of FIG. Therefore, when the pressure in the closed case 1 increases, the lubricating liquid stored in the bottom of the closed case 1 passes through the introduction pipe 49, the communication hole 47, and the oil introduction passage 45 to form the groove 3
The lubrication when the blade 33 enters and exits is ensured by being sent into the inside 1.

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 is turned on.
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. 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, when operating at a specified pressure, as shown in FIG. 2, the blade 33 moves toward the right working chamber 35 on the suction side because the pressure in the working chamber 35 on the discharge side is high. Pressed and normal compression is performed. During this operation, for example, when a large amount of lubricating liquid or refrigerant is taken into the working chamber 35, the working chamber 35 that becomes the suction side becomes the discharge side.
An over-compression state exceeding the specified pressure of the working chamber 35 results. When this overcompression state occurs, as shown in FIG. 3, the pressure presses the blade 33 toward the high-pressure working chamber 35 side.
The blade 33 is strongly pressed against the wall of the groove 31. At this time, the pressure in the working chamber 35 in the over-compressed state escapes from the groove 31 to the inside of the high-pressure working chamber 35 on the discharge side through the relief passage 41 as shown by the arrow, and pressure control is performed. As a result, a large load does not act on the blade 33.

[0022]

As described above, according to the fluid compressor of the present invention, the escape passage eliminates excessive compression in the working chamber, prevents the blade from being damaged, and provides a stable working pressure for a long period of time. become.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of a main part.

FIG. 3 is an explanatory diagram of a main part.

FIG. 4 is an explanatory view similar to FIG. 2 showing a modified example of the escape passage.

FIG. 5 is a sectional view of the Oldham ring.

FIG. 6 is a sectional view similar to FIG. 1 showing a conventional example.

FIG. 7 is a perspective view of the rotating body of the above.

[Explanation of symbols]

 9 Driving means 17 Cylinder 21 Rotating body 31 Helical groove 33 Blade 35 Working chamber

Claims (2)

(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 into the groove so as to freely enter and exit, and the outer peripheral surface is in close contact with the inner surface of the cylinder so that a space between the cylinder and the rotating body is divided into a plurality of working chambers. In a fluid compressor having a compression element consisting of a spiral blade partitioned into a compression element, a pressure during a compression step is adjacent to the compression element.
When the pressure becomes higher than the pressure in the working chamber on the discharge side
A fluid passage for evacuating the pressure in the working chamber to an adjacent working chamber on the discharge side. 2. The fluid compressor according to claim 1, wherein a relief passage is formed in the blade to communicate the groove with the working chamber on the discharge side.