JPH02146286A - Oilless compressor - Google Patents

Abstract

PURPOSE:To decrease the leakage loss of refrigerant gas by forming the front plate side in a casing into a low pressure space in which a low pressure fluid flows and the rear plate side into a high pressure space in which a high pressure fluid is discharged. CONSTITUTION:On the front plate 7 side in a casing 2, a low pressure fluid flows in so as to form a low pressure space 9, and the low pressure fluid flows into a compression chamber 15 from the low pressure space 9. On the other hand, a high pressure fluid is discharged from the compression chamber 15 so as to form a high pressure space 10 on the rear plate 8 side. Accordingly, the pressure of the interior of an axis hole 6b formed at a rotary piston 6 becomes low, and the force to forcibly press a tip seal to each of the plates 7, 8 is not thereby generated, so that frictional loss and the abrasion of the tip seal are decreased. Furthermore, as the refrigerant leakage area becomes smaller as the compression advances, the ullage is decreased, so that the improvement of volumetric efficiency can be promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotary oil-less compressor, and particularly to measures against leakage of high-pressure fluid.

(Prior Art) Generally, a refrigerator is configured such that refrigerant gas compressed by a compressor is liquefied in a condenser, expanded in an expansion mechanism, vaporized in an evaporator, and returned to the compressor again. ing.

As shown in FIG. 4, the compressor has a structure in which an electric motor (b) and a compressor main body (c) linked to the motor (b) are housed in a sealed casing (a). The compressor main body (c) has a cylinder (d) in which a rotary piston (e) is eccentrically provided, and the cylinder (d)
) have front and rear plates (f) on both upper and lower end surfaces.
, (g) are attached and the cylinder (d)
A blade (not shown) is configured in the shape of a fixture so that it can freely move in and out of the cylinder (d) and is pressed into contact with the rotary piston (e). Then, the compressor main body (c
), the suction pipe (i) is connected to the suction port (h) through the sealed casing (a), and the discharge port (j) is opened into the casing (a) via the discharge valve (k). It is made up like this. Further, a discharge pipe (N) connected to a condenser is connected to the casing (a).

Therefore, in this compressor, refrigerant gas vaporized in the evaporator is introduced into the cylinder (d) from the suction port (h) via the suction pipe (i), and the refrigerant gas is compressed by the rotation of the rotary piston (e). After that, the casing (
a) Discharge into.

The high-pressure refrigerant gas in the casing (a) is then sent to the condenser through the discharge pipe (Ω).

In this way, the casing internal space is at high pressure throughout the entire region when the compressor is operating (referred to as a high-pressure tom type).

Conventionally, in a rotary compressor configured in this way,
Compressors that use lubricating oil are often used. A rotary compressor using this lubricating oil consists of the front and rear plates (f) and (g) and the rotary piston (e).
) and block the clearance by infiltrating the clearance between the rotary piston (e) and the motor shaft hole (A) (see Figure 5) and the cylinder (d). The space between the inner compression chamber (B) and the inner compression chamber (B) is sealed. Therefore, in the cylinder (d), the oil effectively prevents refrigerant gas from leaking from the shaft hole (A) of the rotary piston (e) under high pressure to the compression chamber (B) under low pressure. This ensures its volumetric efficiency.

On the other hand, in recent years, oil-less compressors that do not use the above-mentioned lubricating oil have been proposed, and if the above-mentioned conventional rotary compressor is applied as an oil-less compressor, there will be no oil in each of the above-mentioned clearances. Therefore, sealing is not performed and a clearance remains. Therefore, in order to close the clearance, a chip seal (m) is applied to the outer periphery of the end face of the rotary piston (e) as shown in FIG. It seals the gap between This chip seal (m) is formed of a ring member that is formed to be able to fit freely into a groove (n) that is formed all around the outer periphery of the end surface of the rotary piston (e), and when it is inserted, the above-mentioned The shaft hole (high pressure side) (A) of the rotary piston (e) and the compression chamber (low pressure side) (B) are separated from each other by contacting each of the plates (f) and (g).

(Problem to be Solved by the Invention) However, in such a configuration, when the compressor is driven, the inside of the shaft hole (A) of the rotary piston is under high pressure, so as shown by the arrow in FIG. This pressure strongly presses the chip seal (m) toward the plate (g) in the space formed between the chip seal (m) and the groove (n), resulting in friction loss at the contact area. However, there is a problem in that the power consumption of the electric motor increases, and the tip seal (m) also suffers from a large amount of wear. Furthermore, it is difficult to completely prevent the leakage of refrigerant gas by the tip seal (m), and in particular, the rotation of the rotary piston (e) (in the direction of arrow C in Fig. 5) may cause the compression chamber (B) to be completely prevented. It contracts and compresses the refrigerant gas.
As this compression progresses, the boundary between the low-pressure compression chamber and the shaft hole (A) of the high-pressure side rotary piston (e) increases, that is, the leakage area of the refrigerant increases, and accordingly, The amount of refrigerant leaking increased, causing a decrease in compression efficiency.

Therefore, an object of the present invention is to lower the pressure applied to the tip seal by lowering the pressure in the internal space of the rotary piston, and to reduce the leakage loss of refrigerant gas.

(Means for Solving the Problems) The means taken by the present invention to achieve the above object are as follows.

In the invention described in claim (1), as shown in FIG. A rotary piston (6) is housed in the cylinder (5) in close contact with the surface (2a), and a drive means (6b) is provided in the shaft hole (6b) formed in the rotary piston (6). 3) into which one end of the drive shaft (3b) is fitted, a compression chamber (15) is formed in the cylinder (5), and a compression chamber (15) is formed in the cylinder (5). A blade (14) is provided, and a through hole (3b) of the drive shaft (3b) is provided on the cylinder end face (5b) on the drive means (3) side.
A front plate (7) having a perforation (7a) is provided to close the compression chamber (15), while a rear plate (8) is provided on the cylinder end surface (5c) on the drive shaft end side to close the compression chamber (15). ) and the shaft hole (6b) of the rotary piston are closed, and the front plate (7) side in the casing (2) is provided with a low pressure space (9) into which low pressure fluid leading to the compression chamber (15) flows. , the rear plate (8) side is a high pressure space (10) where high pressure fluid is discharged from the compression chamber (15).
It is an oil-less compressor characterized by being formed as follows.

In the invention described in claim ('2J), the above claim (1)
) In the oilless compressor described in ), the blade (14)
is provided in a guide groove (5e) formed in the cylinder (5), and the guide groove (5e) communicates with the high pressure space (10) so that high pressure fluid acts on the outer end surface (14C) of the blade (14). This is an oil-less compressor characterized by being configured to.

In the invention described in claim (3), the above claim (1)
Or (in the oil-less compressor described in 2), the end faces (5b), (5c) of the rotary piston (6) are provided with a concave groove (6c) extending over the entire circumference thereof; 6
c) two seal rings (16) of small diameter and large diameter;
This is an oil-less compressor characterized by being provided with a chip seal (T) consisting of (17).

(effect) The effects of the present invention with the above configuration are as follows.

First, in the invention described in claim (1), the cylinder (
The compression chamber (15) formed between the rotary pist (6) and the high pressure chamber (15a) is formed by the blade (14).
It is divided into a low pressure chamber (15b) and a low pressure chamber (15b).
The refrigerant introduced into 15b) is compressed by the rotation of the rotary piston (6) and discharged out of the cylinder (5). During this compression, the cylinder end face (5
c) is provided with a rear plate (8) closing the compression chamber (15) and the rotary piston shaft hole (6b), and a front plate (7) in the casing (2).
On the side, low-pressure fluid flows in to form a low-pressure space (9), and from the low-pressure space (9), low-pressure fluid flows into the compression chamber,
On the rear plate (8) side, high pressure fluid is discharged from a compression chamber (15) to form a high pressure space (10). Therefore, the pressure inside the shaft hole (6b) formed in the rotary piston (6) is low, and no force is exerted that strongly presses the tip seal against each plate, reducing friction loss and wear of the tip seal. Since the refrigerant leakage area becomes smaller as compression progresses, the amount of leakage is reduced and the volumetric efficiency can be improved.

In addition, in the invention described in claim 12), the plaid (
By adopting a configuration in which high-pressure fluid acts on the outer end surface (14c) of 14), the effect of claim 1 can be obtained without reducing the pressing force of the blade against the rotary piston.

Furthermore, in the invention described in claim (3), the sealing effect is further improved by applying two seal rings (16) and (17) of a small diameter and a large diameter to the rotary piston.

(Example) Next, an example of the present invention will be described with reference to the drawings.

As shown in FIG. 1, an oil-less compressor (
1) includes a drive means (3) in a sealed casing (2), and a compressor main body (4) connected to an electric motor (3a) of the drive means (3) via a crankshaft (3b) as a drive shaft.
). The compressor main body (4) is in the form of a fixture and includes a rotary piston (6) provided within a cylinder (5). The outer peripheral surface (5a) of the cylinder (5) is in contact with the inner peripheral surface (2) of the sealed casing (2).
a), and is fixedly supported by the upper end surface (5b) of the cylinder (5).
A front plate (7) is attached to the bottom end face (
A rear plate (8) is attached to 5c), and a compression chamber (15) is formed between the cylinder (5) and the rotary piston (6) by both plates (7) and (8). . The rotary piston (6) is provided at the lower end of the crankshaft (3b) eccentrically with respect to the cylinder (5) via a cam (3C) and a needle bearing (11), and the crankshaft (3b) Electric top (
3a) and is directly connected to the front and rear brakes) (7
), (8) are bearings (12) and (13), respectively.
) is rotatably supported. The upper rotary piston (6) is provided so that a part of the circumferential surface (6a) is in contact with the inner surface (5d) of the cylinder (5). More specifically, the rotary piston (6) is a cylindrical member as shown in FIG.
6d), (6e) have an annular groove (6c) on the outer periphery.
are carved around the entire circumference. In addition, the groove (6c)
is made of PTFE (
Two inner and two inner and outer seal rings (16) made of polytetrafluoroethylene, etc.

A chip seal (T) composed of (17) is fitted. In addition, the groove (6c) and the seal ring (16)
, (17), a spring (18) as a pressing means is compressed and interposed between the seal rings (16) and the spring (18).

(17) is the front and rear plate (7).

(8) (see Figure 3), closing the clearance between both plates (7), (8) and the rotary piston (6).

Further, a guide groove (5e) is formed in the cylinder (5), and a blade (14) (see FIG. 2) is provided in the guide groove (5e) so as to be freely retractable into the cylinder (5). There is. A flat sealing material (not shown) is interposed between the upper surface (14a) of the blade (14) and the front plate (7) to prevent leakage of refrigerant gas. The tip (14b) of the blade (14) is brought into pressure contact with the circumferential surface (6a) of the rotary piston (6) by the urging force of the spring and high-pressure refrigerant gas, which will be described later. 6) makes the cylinder (5
), there is a high pressure chamber (15a) on the discharge port (5g) side and an inlet port (
5f) side low pressure chamber (15b) and a compression chamber (1
5) is formed.

As a feature of the present invention, the front plate (
7), the outer peripheral surface (7b) is the inner surface (2) of the casing (2).
a) and is attached to the upper end surface (5b) of the cylinder (5) in close contact with the cylinder (5), and a through hole (7a) for the crankshaft (3b) is bored in the center. Then, the through hole (7
As described above, the crankshaft (3b) is inserted into the crankshaft (3b) through the bearing (12) as described above, and the shaft hole (6b) is formed to communicate with the shaft hole (6b) of the rotary piston (6). On the other hand, the rear plate (8) has four parts (8a) formed in the center of a disk shape to protrude downward, and the outer diameter of the rear plate (8) is larger than the inner diameter of the cylinder (5).
It is formed smaller than the casing (2) and is attached to the lower end surface (5c) of the cylinder (5). Furthermore, as described above, the lower end of the crankshaft (3b) is fitted into the fourth part (8a) via the bearing (13), and
The rear plate (8) is provided to close the lower part of the compression chamber (15) and the lower part of the shaft hole (6b). and the cylinder (5) and both plates (7),
(8), the inside of the casing (2) is configured such that the front plate (7) side is a low pressure space (9) and the rear plate (8) side is a high pressure space (10). The inside of the shaft hole (6b) of the piston (6) is configured to communicate with the low pressure space (9) via the through hole (7a) of the front plate (7) and to be maintained in a low pressure state. Furthermore, the high-pressure space (10) is communicated with the guide groove (5e), and the pressure of the high-pressure refrigerant acts on the outer end surface (14c) of the blade (14) inserted into the guide groove (5e). It is supposed to be done.

Next, the operation of this oilless compressor will be explained.

First, when the rotary piston (6) is rotated, refrigerant gas flows from the low pressure space (9) through the suction port (50) and into the low pressure chamber (15).
b) and is compressed by the rotation of the rotary piston (6), and then released from the discharge port (5g) into the casing (2).
) is discharged into the high pressure space (10). The characteristic effect of the present invention during compression is that the shaft hole (6b), which is the internal space of the rotary piston (6), is a low-pressure space (
9) and is under low pressure, high pressure does not act on the tip seal (T), and therefore, friction loss and wear of the tip seal, which are conventional, are suppressed. Furthermore, as the compression due to the rotation of the rotary piston (arrow C in Figure 2) progresses, the circumferential area of the rotary piston on the high pressure chamber (15a) side becomes smaller, so that the pressure difference between the rotary piston and the low pressure shaft hole (6b) decreases. Since the leakage amount of high-pressure refrigerant is reduced, the volumetric efficiency of the compressor is improved. In addition, in FIG. 3, the tip seal (T) is composed of two seal rings (16) and (17), so that it is recessed from the high pressure chamber (15a) side. 16 (6c) and insert each seal ring (16), (17) into the groove (6c).
) to improve its sealing performance. In addition, this pressure also acts on each plate side, but it changes with the rotation of the rotary piston (6), so high pressure is not always applied, so friction loss and seal ring wear are reduced compared to conventional ones. This will be significantly reduced in comparison.

(Effects of the Invention) As described above, the present invention provides the following effects.

In the invention set forth in claim (1), during compression due to rotation of the rotary piston, a rear plate is provided on the cylinder end face on the drive shaft end side to close the compression chamber and the rotary piston shaft hole, The front plate side of the casing is a low-pressure space into which low-pressure fluid leading to the compression chamber flows, and the rear plate side is a high-pressure space from which high-pressure fluid is discharged from the compression chamber, forming a rotary piston. The pressure inside the shaft hole is low, and the force that presses the tip seal against each plate as in the past is suppressed, reducing friction loss and wear of the tip seal, and reducing the refrigerant leak area by compression. Since it becomes smaller as it progresses, the amount of leakage is reduced, resulting in good volumetric efficiency and improved performance of the compressor.

In the invention described in claim (2), by adopting a configuration in which high-pressure fluid acts on the outer end surface of the blade, the effect according to claim (1) can be achieved without reducing the pressing force of the blade against the rotary piston. It becomes possible to obtain.

In the invention described in claim (3), by applying two seal rings, one small diameter and one large diameter, to the rotary piston, high pressure enters the groove and strongly presses each seal ring against the side surface of the groove. This further improves the sealing effect between the inside and outside of the rotary piston.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention, with Figure 1 being a longitudinal cross-sectional view showing the internal structure of the compressor, Figure 2 being a cross-sectional view of the compressor body, and Figure 3 being a cross-sectional view of the compressor body. 1 is a longitudinal cross-sectional view of a state in which a tip seal is fitted into a groove of a rotary piston. Figure 4~
6 shows a conventional example, FIG. 4 is a diagram corresponding to FIG. 1, FIG. 5 is a diagram corresponding to FIG. 2, and FIG. 6 is a diagram corresponding to FIG. 3. (1)... Oil-less compressor, (2)... Sealed casing, (2a)... Inner peripheral surface, (3)... Drive means, (3b)... Crank 6111, (5 )-...Cylinder, (5a)...Outer peripheral surface, (5b)...Top end surface,
(5c)...lower end surface, (5e)...guide groove, (6)
... Rotary piston, (6b) ... Shaft hole, (6c
)...Concave groove, (7)...Front plate, (7a
)...Through hole, (8)...Rear plate, (9)...
...Low pressure space, (10)...High pressure space, (14)...
・Blade, (14c)...outer end surface, (15)...
Compression chamber, (T)...Tip seal, (16)...Small diameter seal ring, (17)...Large diameter seal ring.

Claims (3)

[Claims] (1) A cylinder (5) is housed in a sealed casing (2) with the outer circumferential surface (5a) of the cylinder (5) in close contact with the inner circumferential surface (2a) of the casing (2), and the cylinder (5) A rotary piston (6) is housed inside, and one end of a drive shaft (3b) of a drive means (3) is fitted into a shaft hole (6b) formed in the rotary piston (6).
A compression chamber (15) is formed in the cylinder (5), and the cylinder (5) is provided with a blade (14) that can freely retract from the cylinder (5). The end surface (5b) has a through hole (
A front plate (7) having a perforation (7a) is provided to close the compression chamber (15), while a rear plate (8) is provided on the cylinder end surface (5c) on the drive shaft end side to close the compression chamber (15). ) and the shaft hole (6b) of the rotary piston are closed, and the front plate (7) side in the casing (2) is provided with a low pressure space (9) into which low pressure fluid leading to the compression chamber (15) flows. , the rear plate (8) side is a high pressure space (10) where high pressure fluid is discharged from the compression chamber (15).
An oil-less compressor characterized by being formed. (2) In the oil-less compressor according to claim (1), the blade (14) is provided in a guide groove (5e) formed in the cylinder (5), and the guide groove (5e) is arranged in the high pressure space (10). ) of the plate (14) and the outer end surface (1
4c) An oil-less compressor characterized in that it is configured such that high-pressure fluid acts on it. (3) In the oil-less compressor according to claim (1) or (2), the end surface (6d) of the rotary piston (6)
, (6e) is provided with a concave groove (6c) extending around its entire circumference, and two seal rings (16) and (17) of a small diameter and a large diameter are formed in the concave groove (6c). Chip seal (T
) An oil-less compressor characterized by being provided with.