JPH06341386A - Compressor with rolling piston - Google Patents

Abstract

PURPOSE:To suppress generation of wear loss between a cylinder and rotor by securing the gap between the two to a certain degree, and to reduce the leak of compressed fluid from the gap to a great extent. CONSTITUTION:At the inside surface of a cylinder 5 of a compressor of rolling piston type, a plurality of recesses 15, 15,... are formed in the circumferential arrangement so that a labyrinth seal is provided from the cylinder 5 inside surface and the rotor 6 outside surface. The leak amount of compressed refrigerant or oil willing to leak out to a low pressure chamber upon passing through the gap between the cylinder 5 and rotor 6 is reduced to a great extent by increasing the loss energy with this labyrinth seal. With this reduction of leak amount of compressed fluid, it is practicable to secure the gap to a certain degree, and the friction loss generated by the contact of them can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling piston type compressor and, more particularly, to improvement of measures for preventing fluid leakage from a high pressure chamber to a low pressure chamber due to a gap between a cylinder and a rotor.

[0002]

2. Description of the Related Art Generally, as one type of compressor provided in a refrigerator or the like, for example, a rolling piston type compressor as disclosed in Japanese Patent Laid-Open No. 63-167095 is known. In this type of compressor, as shown in FIG. 7, a rotor (b) is eccentrically arranged inside a cylinder (a), and a part of the outer peripheral surface of the rotor (b) is arranged inside the cylinder (a). A compression chamber (c) is formed between the cylinder (a) and the rotor (b) while being substantially in contact with the surface. Further, the cylinder (a) is formed with a blade groove (d) extending in the radial direction thereof, and the blade groove (d) can be retracted from the inner peripheral surface of the cylinder (a). The blade (e) is housed, and the tip of the blade (e) is brought into contact with the outer peripheral surface of the rotor (b) so that the compression chamber (c) becomes a high pressure chamber (c1) and a low pressure chamber.
It is divided into (c2) and. The rotor (b) rotates in the cylinder (a) to change the volume of the compression chamber (c), and the high pressure chamber (c1) contracts to obtain high temperature and high pressure discharge gas. Has become. In FIG. 7, (f) is a compressor casing, (g) is a suction port, and (h) is a discharge port.

[0003]

By the way, in the compressor of this type, as described above, the cylinder (a) and the rotor (b) are provided between the high pressure chamber (c1) and the low pressure chamber (c2). Since it is divided by the portions that are substantially in contact with each other, a slight gap (a few dozen μm) is formed between them (portion A in FIG. 7), and the lubricating oil is interposed in this gap to form a cylinder.
The leakage of the compressed fluid to the low pressure chamber side at the contact portion between (a) and the rotor (b) is suppressed. However, since the cylinder (a) and the rotor (b) slide at a high speed with each other, due to the effects of machining errors, the gap between the cylinder (a) and the rotor (b) causes the high pressure chamber (c1 ) To low pressure chamber
The compressed fluid may leak to (c2), which leads to a reduction in the volumetric efficiency of the compressor. In addition, a configuration has also been proposed in which the gap between the cylinder (a) and the rotor (b) is made as small as possible so that oil will not run out, and leakage of compressed fluid is prevented. There is a limit to the processing accuracy of (b), and this leakage of compressed fluid has not been significantly reduced. Further, there is a so-called oilless compressor in which no lubricating oil is interposed between the cylinder (a) and the rotor (b) .In this case, the cylinder (a) and the rotor ( The gap between b) and can be reduced,
In order to eliminate this gap, it is necessary to press the rotor (b) to the cylinder (a) side to some extent, which may lead to a reduction in compressor efficiency due to friction loss between the two. .

The present invention has been made in view of these points, and suppresses the generation of friction loss between the cylinder and the rotor by securing a certain amount of clearance between the cylinder and the rotor, and yet the gap between the two is suppressed. It is an object of the present invention to obtain a configuration capable of satisfying contradictory requirements such as a large reduction in the amount of compressed fluid leaking from the.

[0005]

In order to achieve the above object, the present invention provides a labyrinth seal between a cylinder and a rotor. Specifically, in the invention according to claim 1, the rotor (6) is housed in the cylinder (5), and the head portions (7), (8) are provided on both end faces of the cylinder (5).
Are arranged to form the inner peripheral surface of the cylinder (5) and the rotor.
A compression chamber (9) is formed between the outer peripheral surface of (6) and the rotor (6) is eccentric with respect to the cylinder (5). 5) It is designed to be in close contact with the inner peripheral surface to separate the high pressure chamber (9a) and the low pressure chamber (9b) of the compression chamber (9), and the rotor (6) inside the cylinder (5). It is premised on a rolling piston type compressor which is configured to rotate so as to contract the compression chamber (9) and compress the fluid in the compression chamber (9). Then, on the inner peripheral surface of the cylinder (5), a plurality of concave portions (15), () are formed so that a labyrinth seal is constituted by the inner peripheral surface of the cylinder (5) and the outer peripheral surface of the rotor (6). 15), ... Are formed along the circumferential direction of the inner peripheral surface.

According to a second aspect of the present invention, in the rolling piston type compressor according to the first aspect, the molding pitches of the plurality of concave portions (15), (15), ... The angular interval with respect to the center of (5) is 10
It was set to be below °.

[0007]

With the above construction, the present invention provides the following actions. In the invention according to claim 1, the rotor (6) rotates in the cylinder (5), thereby compressing the fluid in the compression chamber (9). During such compression operation, the inner peripheral surface of the cylinder (5) and the rotor
Since the labyrinth seal is composed of the outer peripheral surface of (6), the compressed fluid that tries to leak from the high pressure chamber (9a) to the low pressure chamber (9b) through the gap between the cylinder (5) and the rotor (6). The labyrinth seal increases the loss energy of oil and oil, and the amount of leakage to the low pressure chamber (9b) side is significantly reduced. Also, since the amount of compressed fluid leakage is reduced in this way, the cylinder (5) and rotor
It is not necessary to set the gap between (6) and the gap to a smaller value, and the friction loss caused by these contacts can be reduced.

According to the second aspect of the present invention, between the cylinder (5) and the rotor (6), a concave portion is formed in the flow path as an angular interval of 10 ° which contributes to resistance to fluid leakage. With the presence of (15), the labyrinth seal can be reliably formed in this leak resistance region, and the leak prevention effect can be reliably obtained.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. 1, the rolling piston compressor (1) according to the present embodiment is provided in an air conditioner, and includes a drive means (3) and a compressor body (4) in a casing (2).
And are stored.

The drive means (3) comprises an electric motor (3a) and a crankshaft (3b) as a drive shaft. Electric motor
The stator (3a) is disposed above the inner space (2a) of the casing (2) and is fixed to the inner peripheral surface of the casing (2).
c) and a rotor (3d) arranged in the center of the stator (3c)
It is composed of and. The crankshaft (3b) has its upper end connected to the center of the rotor (3d), and has its lower end extended downward and linked to the compressor body (4). Lubricating oil (O) is stored in the bottom of the casing (2), and the lower end of the crankshaft (3b) is immersed in this lubricating oil (O). A centrifugal pump (3e) is arranged at the lower end of the crankshaft (3b), and an oil supply passage (not shown) extending vertically is formed in the crankshaft (3b) to penetrate the compressor. When driving (1), the centrifugal pump (3e) pumps the lubricating oil (O) into the oil supply passage and then supplies it to the sliding parts of the compressor (1).

On the other hand, the compressor body (4) is the electric motor.
It is arranged below (3a). This compressor body (4)
As shown in FIGS. 1 and 2, the rotor (6) is housed in a cylindrical cylinder (5) fixed to the inner wall of the casing (2), and the upper end surface of the cylinder (5) is A front head (7) as a head part and a rear head (8) as a head part are attached to the lower end surface of the cylinder (5) by the front head (7) and the rear head (8), respectively. A compression chamber (9) is formed between the surface and the outer peripheral surface of the rotor (6). The front and rear heads (7), (8) are formed with through holes (7a), (8a) which have a diameter substantially the same as that of the crankshaft (3b) and extend in the vertical direction. The crankshaft (3b) is rotatably supported in the holes (7a), (8a) via a metal seal or the like. Further, the cylinder (5) is formed with a suction port (5a) as a suction passage for the refrigerant, which opens into the compression chamber (9), and the suction port (5a) extends from a not-shown accumulator. 10) are connected. Meanwhile, the rotor (6)
A cam portion (3f) integrally formed with the crankshaft (3b) and eccentric in a predetermined direction with respect to the axis of the crankshaft (3b) is fitted in the central portion of the. Thereby, the rotor
(6) is provided eccentrically with respect to the cylinder (5) so that a part of the outer peripheral surface of the rotor (6) substantially contacts the inner peripheral surface of the cylinder (5) (Fig. 2). Section B).

A blade groove (5b) extending in the radial direction of the cylinder (5) is formed in the cylinder (5) near the position where the suction port (5a) is arranged.
A blade (11) is arranged in (5b) so as to be retractable in the cylinder (5). The outer end of the blade groove (5b) is closed by the casing (2). And
The tip of the blade (11) is pressed against the outer peripheral surface of the rotor (6) by the pressure of the spring (S) and the refrigerant gas,
The compression chamber (9) is divided into a high pressure chamber (9a) and a low pressure chamber (9b). Further, a discharge port (5c) is provided on the high pressure chamber (9a) side near the position where the blade (11) is arranged. One end of this discharge port (5c) is opened to the inner peripheral surface of the cylinder (5), and a reed valve (not shown) that can be opened as the pressure in the high-pressure chamber (9a) rises is opened in this opening. It is provided. On the other hand, the other end of the discharge port (5c) is opened to the internal space (2a) of the casing (2).

A discharge pipe (14) connected to a condenser (not shown) is connected to the upper surface of the casing (2),
The high temperature and high pressure refrigerant discharged from the compressor body (4) is led out to the condenser side from the discharge pipe (14). With such a configuration, when the compressor is driven, the electric motor (3a) is driven to rotate the crankshaft (3b),
The rotor (6) rotates in the cylinder (5) and the compression chambers (9a),
It is designed to contract (9b).

The characteristic feature of the present embodiment is the shape of the inner peripheral surface of the cylinder (5). The inner peripheral surface of this cylinder (5) has a plurality of concave portions (15), (15), ... It is formed over the entire circumference of the inner peripheral surface of the cylinder (2), thereby forming a so-called labyrinth seal between the cylinder (5) and the rotor (6). Specifically, the inner peripheral surface of the cylinder (5) is cut into a rectangular shape from the upper end surface to the lower end surface to form the recessed portion (15), and the formation of the recessed portion (15). The forming pitch for setting the position is 10 ° or less with respect to the center of the cylinder (about 5 in this example).
Angle) is set. This allows the rotor
On the outer peripheral surface of (6), a portion facing the recessed portion (15) and a portion facing the recessed portion (15) (the original cylinder inner peripheral surface portion) are alternately present. It will be.
That is, the gap formed between the cylinder (5) and the rotor (6), that is, the portion serving as the leakage passage of the compressed refrigerant,
While the passage area is large in the portion where the concave portion (15) is formed, the passage area is small in the portion where the concave portion (15) is not formed. , The cylinders (5) and the rotors (6) are alternately present in the proximity portion (B portion in FIG. 2). And in such a configuration, the high pressure chamber
When high pressure refrigerant is about to leak from (9a) to the low pressure chamber (9b) (see the arrow in Fig. 3), the cylinder (5) and rotor
From the small-sized part (the part where the concave part (15) is not formed) to the large-sized part (the part where the concave part (15) is formed) in the gap formed between (6) and When flowing out (when the refrigerant leaks out from a portion with a small passage area to a portion with a large passage area), the pressure of the refrigerant decreases as the flow path expands, and therefore the energy of the refrigerant decreases. Leakage to the low pressure chamber side is suppressed. In addition, since the leakage of the compressed refrigerant from the high pressure chamber (9a) to the low pressure chamber (9b) is suppressed in this way, the shape of the cylinder (5) and the rotor (6) may be more than necessary. Since it is not necessary to set a small gap between the outer peripheral surface of the rotor (6) and the inner peripheral surface of the cylinder (5), the lubricating oil should be sufficiently interposed between the two so that the oil will not run out. As a result, friction loss between the rotor (6) and the cylinder (5) due to the rotation of the rotor (6) is reduced.

Next, the operation of the rolling piston compressor (1) constructed as described above will be described. First,
When the electric motor (3a) is driven, this driving force is
It is transmitted to the rotor (6) of the compressor body (4) via (3b) and the cam portion (3f) of the crankshaft (3b), and the rotor (6) rotates in the cylinder (5). This allows the refrigerant gas to
0) through the suction port (5a) to the low pressure chamber (9
Inflow into b). After that, with the rotation of the rotor (6),
As the low pressure chamber (9b) becomes the high pressure chamber (9a), the refrigerant gas is compressed, and when the pressure of this refrigerant reaches a predetermined value, the reed valve is opened by this pressure, and the refrigerant gas in the high pressure state is discharged from the discharge port ( 5c) to the internal space (2a) of the casing (2),
Then, it is led out to the condenser side by the discharge pipe (14). In such a compression operation state, in a situation where the pressure in the high pressure chamber (9a) becomes high (for example, the rotational position of the rotor (6) as shown in FIG. 2), the high pressure chamber (9a) and the low pressure chamber (9a) Chamber (9b)
Because of the large pressure difference between the high pressure chamber (9a) and the cylinder (5) and the rotor (6), the high pressure refrigerant will leak to the low pressure chamber (9b) from the contact part (B in FIG. 2). To do. At this time, as described above, in the gap formed between the cylinder (5) and the rotor (6), a small-sized portion (concave portion)
When compressed refrigerant or oil flows out from the part where (15) is not formed) to the larger part (the part where concave part (15) is formed) (passage area from the portion where the passage area where the refrigerant leaks is small) (When flowing out to a large area), the pressure decreases with the expansion of the flow path, so that the energy loss of the refrigerant increases. This kind of operation is
5), (15), etc. are performed at the formation position, whereby the leakage of the compressed refrigerant to the low pressure chamber (9b) side is suppressed. That is, the labyrinth seal structure formed between the cylinder (5) and the rotor (6) suppresses the leakage of the compressed refrigerant into the low pressure chamber (9b). Further, as described above, the lubricating oil is sufficiently interposed between the inner peripheral surface of the cylinder (5) and the outer peripheral surface of the rotor (6), so that the cylinder (5) Friction loss due to sliding with the rotor (6) is small. Therefore, according to the configuration of the present example, the generation of the friction loss between the cylinder (5) and the rotor (6) is suppressed to some extent by securing the gap between the cylinder (5) and the rotor (6), and the compressed refrigerant from the gap between the two is suppressed. It is possible to meet the contradictory demands of significantly reducing the amount of leakage of the refrigerant, and improve the efficiency of the compressor by reducing this friction loss and suppress the leakage of the compressed refrigerant to the low pressure chamber (9b). The volumetric efficiency associated with this can be improved.

Next, the reason why the formation pitch for setting the formation position of the recessed portion (15) is set to an angular interval of 10 ° or less with respect to the center of the cylinder will be described (note that the letters of the mathematical formulas shown below are (See FIGS. 4 and 5). Now, consider a situation where an incompressible fluid flows between parallel plates as shown in FIG. In this case, the flow velocity u of this incompressible fluid is given by the following equation.

[Equation 1] (Μ: Viscosity of fluid) At this time, the flow velocity u is 0 on the wall surface of the parallel plate, and the flow velocity distribution is as shown in FIG. That is, it can be seen that the fluid flow is greatly influenced by the wall surface. Then, when the flow rate q of the fluid is obtained by integrating the above equation, the following equation is obtained.

[Equation 2] (B: Flow path width dimension in the vertical direction to the paper surface in FIG. 4) From this equation, it is understood that the flow rate q increases in proportion to the cube of the flow path height h. That is, when the flow path height h increases, the frictional force due to the wall surface decreases and the flow rate increases.

When this theory is developed in the gap between the cylinder (5) and the rotor (6) of a rolling piston compressor,
The flow rate in the gap between the cylinder (5) and the rotor (6), that is, the amount of leakage from this gap is given by the following equation.

[Equation 3] The flow rate will be changed by changing the integration range based on this equation. That is, in the above-mentioned parallel plate model, the flow rate is changed by changing the length of the flow path in which the fluid is influenced by the wall surface. Then, in this case, it was found that if the integration range was increased to some extent, the flow rate (leakage amount) hardly changed even if the integration range was further increased. In other words, the reason why the flow rate converges in this way is that the following equation converges, and by examining the change in this equation, resistance to leakage between the cylinder (5) and the rotor (6) is obtained. It is possible to know the range of the contributing flow paths.

[Equation 4] [B: cylinder height dimension, L = R-r, x = 1- (δ /
L), h = L (1 + xcos φ)] Then, the theory described above is applied to a sufficient integration range (rotor rotation angle π / 2 to 3π for the gap between the cylinder (5) and the rotor (6). The ratio of the value of the formula of the arbitrary integration range to (between / 2) is shown in FIG. It should be noted that, in FIG. 6, this is performed for two types of compressors.
Type A has a relatively large rotor diameter,
The type B type has a relatively small rotor diameter.
As shown in the graph of FIG. 6, when the integration range is 10 ° (region in which the contact point between the cylinder and the rotor is divided into left and right by 5 ° in the circumferential direction), the ratio is 9 in both types.
Since it exceeds 0%, it can be considered that the values of the equation have substantially converged. That is, the area within 10 ° (leakage resistance area) occupies most of the flow path that contributes to the resistance between the cylinder (5) and the rotor (6) as a resistance, and the other area. It can be seen that the region hardly contributes as resistance. Therefore, the above-mentioned recess (15) is present in the flow path that contributes to the leakage as a resistance, and the labyrinth seal is configured in this leakage resistance region to surely exhibit the leakage prevention effect. Will be done. For this reason, the formation pitch for setting the formation position of the concave portion (15) is set at an angular interval of 10 ° or less with respect to the center of the cylinder, and at least one concave portion (15) has this leakage. The above-mentioned formation pitch is set so as to be located in the resistance region. In addition, the smaller the formation pitch, the greater the number of recesses (15) located in the leakage resistance region, so the leakage prevention effect is improved.
Since the formation step of (15) will be increased, this formation pitch is set in consideration of these, and is set to 5 ° in the above-mentioned example.

Although each of the above-described examples has been described with respect to the compressor provided in the air conditioner, the present invention is not limited to this, and can be applied to various fluid compressors. It is also applicable to an oilless compressor. Further, the shape of the recessed portion (15) formed on the inner peripheral surface of the cylinder (5) is not limited to the rectangular shape as described above, but various shapes such as a V-shaped shape may be cut. Is applicable.

[0019]

As described above, according to the present invention, the following effects are exhibited. According to the invention described in claim 1, a plurality of labyrinth seals are formed on the inner peripheral surface of the cylinder (5) by the inner peripheral surface of the cylinder (5) and the outer peripheral surface of the rotor (6). By forming the recesses (15), (15), ... In the circumferential direction of the inner peripheral surface, the high pressure chamber (9
The labyrinth seal increases the loss energy of the compressed fluid and oil that leaks from a) through the gap between the cylinder (5) and the rotor (6) into the low pressure chamber (9b), and the low pressure chamber (9
The amount of leakage to the b) side is significantly reduced, and the amount of compressed fluid leakage is also reduced in this way.
The structure that sets the gap between (5) and the rotor (6) even smaller is not necessary, and the friction loss caused by these contacts can be reduced, so that the cylinder (5) and rotor (6) can be reduced. By securing a certain gap between the two, it is possible to suppress the occurrence of friction loss between the two and still meet the conflicting demands of significantly reducing the amount of compressed refrigerant leaking from the gap between the two. ,
The efficiency of the compressor can be improved by reducing the friction loss, and the volumetric efficiency can be improved by suppressing the leakage of the compressed refrigerant to the low pressure chamber (9b).

According to the second aspect of the present invention, the molding pitch of each of the plurality of recessed portions (15), (15), ... Constituting the labyrinth seal is set at an angular interval of 1 with respect to the center of the cylinder (5).
Since it is set to be 0 ° or less, a concave portion is formed in the flow path between the cylinder (5) and the rotor (6) as an angular interval of 10 ° which contributes to the fluid leakage as a resistance. (15) can be present, and the labyrinth seal can be surely constructed in this leak resistance region, and the reliability of the leak prevention effect can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rolling piston compressor.

FIG. 2 is a cross-sectional view at a position corresponding to line II-II in FIG.

FIG. 3 is an enlarged view showing part B in FIG.

FIG. 4 is a diagram showing a model for analyzing a fluid flowing between parallel plates.

FIG. 5 is a diagram showing a model when analyzing the amount of refrigerant leakage from between the cylinder and the rotor.

FIG. 6 is a diagram showing a relationship between an integration range regarded as a leakage flow path and a friction ratio for a sufficiently large range in the integration range.

FIG. 7 is a view corresponding to FIG. 2 in a conventional example.

[Explanation of symbols]

 (1) Rolling piston type compressor (5) Cylinder (6) Rotor (7) Front head (head part) (8) Rear head (head part) (9) Compression chamber (9a) High pressure chamber (9b) Low pressure chamber (15 ) Recess

Claims (2)

[Claims] 1. A rotor (6) is housed in a cylinder (5), and a head portion (7) is provided on both end faces of the cylinder (5).
(8) is disposed to form a compression chamber (9) between the inner peripheral surface of the cylinder (5) and the outer peripheral surface of the rotor (6), and the rotor (6) includes the cylinder (5). The rotor (6) is partially eccentric to the inner peripheral surface of the cylinder (5) so that the high pressure chamber (9a) and the low pressure chamber (9b) of the compression chamber (9) are separated from each other. The rotor (6) is a cylinder
(5) A rolling piston compressor configured to contract in the compression chamber (9) by rotating in the compression chamber to compress the fluid in the compression chamber (9), The inner peripheral surface is provided with a plurality of recesses (15), (15), ... so that a labyrinth seal is formed by the inner peripheral surface of the cylinder (5) and the outer peripheral surface of the rotor (6). A rolling piston type compressor, which is formed in the circumferential direction of the circumferential surface. 2. The molding pitch of each of the plurality of recesses (15), (15), ... Constituting the labyrinth seal is such that an angular interval with respect to the center of the cylinder (5) is set to 10 ° or less. The rolling piston type compressor according to claim 1, which is characterized in that.