JPH0739834B2 - Scroll compressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a seal for a scroll refrigerant compressor used for air conditioning, refrigeration, and the like.

[Conventional technology]

The principle of scroll fluid machines has been well known in the past, and it is considered to be applied to various things such as compressors, pumps, expanders and the like. Its basic components are configured as shown in FIG. This will be described with reference to the figure. In the figure, reference numeral (1) is a fixed scroll, (2) is an orbiting scroll, (1a) is a discharge port,
P is a compression chamber, O is a fixed point on the fixed scroll (1), O '
Is a fixed point on the orbiting scroll (2). Among them, the fixed scroll (1) and the orbiting scroll (2) have the same shape spiral side plates (101), (2) which are combined with each other by contacting side faces in the axial direction at points B on a base plate described later.
01) are integrally provided in the opposite winding direction. The shape of these spiral side plates (101), (201) is formed by a known involute curve or the like.

Next, the operation when the scroll fluid machine configured as described above operates as a compressor will be described.

In FIG. 6, the fixed scroll (1) is stationary with respect to the space, and the orbiting scroll (2) performs a rotational motion with respect to the space without changing its posture.
Exercise like °, 180 °, 270 °. When each of the points B moves toward the center along with the motion of the orbiting scroll (2), it is between the spiral side plate (101) of the fixed scroll (1) and the spiral side plate (201) of the orbiting scroll (2). Since the crescent-shaped compression chamber P that is formed gradually decreases its volume,
The gas sucked into the compression chamber P is compressed and discharged (1
Exhaled from a). During this period, the distances O to O'in the figure are kept constant, and if the gap between the spiral side plates (101) and (201) is Z and the thickness is t, then OO '= Z / 2-t. . Here, Z corresponds to the pitch of the spiral side plates 101 and 201.

A concrete configuration of a compressor that operates according to such an operating principle will be described with reference to FIG. 7. (1) is a fixed scroll, (2) is an orbiting scroll, (1a) is a discharge port,
(P) is the compression chamber, (1b) is the inlet, (3) is the main shaft,
(4) is a frame. Also, (101) and (201)
Are side plates of the fixed scroll (1) and the orbiting scroll (2), (102) and (202) are base plates, and (A) are end faces (101a) and (201a) of the spiral side plates (101) and (201). And base plate (20
2), a gap in the axial direction formed between the bottom surfaces (202a) and (102a) of (102).

Here, the orbiting scroll (2) and the fixed scroll (1) and the seventh scroll are supported by a frame (4) supporting a surface of the base plate (202) opposite to the surface on which the spiral side plate (201) is formed.
Combined as shown, the fixed scroll (1) is fixed to the frame (4). And the spindle (3)
When is rotated as shown by the arrow in the figure, the orbiting scroll (2) connected to it starts to move. In this case, the orbiting scroll (2) makes an orbital motion that does not rotate by a rotation preventing device (not shown). As a result, the inlet (1b)
The fluid to be compressed is further sucked, compressed according to the operating principle shown in FIG. 6, and discharged from the discharge port (1a).

In such a scroll compressor, since the leakage in the radial direction of the spiral passing through the gap (A) corresponds to the size of the spiral in the longitudinal direction, it is relatively large compared to the fluid suction volume, and the efficiency of the compressor is improved. It has a great impact. As means for preventing this radial leakage, for example, Japanese Patent Laid-Open No. 55-46081.
As disclosed in Japanese Patent Laid-Open Publication No. 2000-242242, a method is adopted in which the clearance (A) is made small so that oil is sucked together with the fluid to be compressed through the suction port (1b) and an oil film is generated in the minute clearance (A).

However, in such means, it is required to increase the dimensional accuracy of each component such as the fixed scroll (1), the orbiting scroll (2) and the frame (4) in order to uniformly set the minute gaps. In some cases, there was a problem in workability and assembling, such as having to select each part during assembly. Also, during operation, the temperature near the discharge port (1a) becomes high due to the compressed fluid, and as a result, the minute gap (A)
If the thermal expansion locally occurs, there is no escape and seizure occurs. Therefore, it is necessary to set a large gap in advance in consideration of the amount of thermal expansion, so that the gap is larger than the optimum gap required to form an effective oil film,
As a result, leakage often becomes large and the sealing performance is often deteriorated.

Therefore, as disclosed in JP-A-61-26160,
A guide part for press-fitting a fine adjustment element having the same spiral shape as each scroll side plate of both scrolls is provided on the end face of the spiral side plate, and a gap is formed in a linear direction between each fine adjustment element and the guide part. However, a device having a gap fine adjustment mechanism having a communication groove (equal pressure equalizing groove) that allows the gap to communicate with the compression chamber has been adopted. This will be described with reference to FIGS. 8, 9 and 10, in which (5) is a guide groove provided on the end surface (201a) of the spiral side plate (201),
(6) is an element that is adjustably mounted in the guide groove (5) through a void (501), and (601) is provided in the element (6) and is provided with a compression chamber (P) and a void (50).
It is a communication groove that communicates with 1). Also, (g ₁ ) is the winding side plate (20
The gap formed between the end face (201a) of 1) and the end face (102a) of the base plate (102), (g ₂ ) is the end face (6a) of the element (6) and the bottom face of the base plate (102) ( 102a) is a gap formed between the two. Here, FIGS. 11 (a), (b) and (c) are diagrams showing the results of measuring the pressure during operation in the void (501) and the compression chamber (P), and FIGS. b) shows the case where the communication groove (601) is not provided, and (c) shows the case where the communication groove (601) is used. In the figure, if the fluctuating pressure of the air gap (501) from the measuring point S to the measuring point T is P ₁ , the corresponding fluctuating pressure P ₂ of the compression chamber P is ΔP, and the pressure difference between them is ΔP, (A)
As shown in, the pressure P ₂ in the compression chamber P is more than the pressure P _{2 in the} void (501).
_{When 1} becomes larger by ΔP, the element (6) projects from the guide groove (5) and slides on the base plates 102 and 202 to be worn. Further, as shown in FIG. (B) P ₂
If P ₁ becomes smaller than ΔP, the element (6) will be depressed in the guide groove (5). On the other hand, when the element (6) has the communication groove (601), it is found that ΔP is significantly reduced as shown in FIG. That is, since the gap (501) and the compression chamber (P) are approximately pressure-equalized by the communication groove (601), the element (6) due to the pressure fluctuation of the compression chamber (P) during operation.
Can be prevented from moving in the axial direction, there is no wear between the element (6) and the base plates (102) and (202), and the element (6) is depressed into the guide groove (5). Instead, the element (6) is positioned in the guide groove (5) in a stable state.

[Problems to be Solved by the Invention]

However, in the conventional scroll compressor, a plurality of communication grooves (601) are provided in the fine adjustment element (6),
Moreover, since the communication grooves (601) are set without considering the movement position of the orbiting scroll (2), the respective compression chambers P communicate with each other through the communication grooves (601) and the voids (501). Therefore, there is a problem in that the sealability between the compression chambers is deteriorated and the performance of the compressor is deteriorated. In addition, if the setting position of the communication groove (601) is not appropriate, when a large amount of liquid refrigerant is sucked into the compression chamber at the time of starting the bed or backing up the liquid, the element (6) locally collapses due to liquid compression. However, there is a problem that the performance is deteriorated due to the recompression due to the leakage of the compressed gas in that portion, and the discharge gas temperature rises. The present invention has been made in view of such circumstances, and improves the sealing property between the compression chambers,
(EN) Provided is a scroll compressor capable of improving the performance as a compressor.

[Means for Solving the Problems]

A scroll compressor according to the present invention is a scroll compressor that defines an innermost pressure chamber and an outer pressure chamber in a state immediately before a pair of innermost compression chambers and a discharge chamber communicate with each other. In the pair of parts where the spiral side plates come into contact with each other, a communication groove is provided in the vicinity of at least one of the parts so as to electrically connect the compression chamber on the innermost peripheral side and the gap on the back surface of the element.

[Work]

In the present invention, at the time of liquid compression, in the state immediately before the innermost peripheral compression chamber and the discharge chamber where the internal pressure is maximized communicate with each other,
Since a communication groove is provided so that the innermost circumferential compression chamber where this internal pressure is maximum and the element rear surface void are connected, the pressure in the void is equalized to this maximum internal pressure and element collapse is prevented. In addition, since the communication groove is open to the compression chamber of the same pressure, there is no leakage from the high pressure compression chamber to the low pressure compression chamber.

〔Example〕

Hereinafter, the configuration of the present invention will be described in detail with reference to the embodiments shown in the drawings.

FIG. 1 is a cross-sectional view of a compression section in which a fixed scroll and an orbiting scroll according to the present invention are combined. FIG. 2 is a perspective view showing a state in which the fine adjustment element of the present invention is incorporated into an orbiting scroll, FIG. 3 is an enlarged perspective view of the same main parts, and FIGS. 4 and 5 include another invention. It is an assembled sectional view of the fine adjustment element.

FIG. 1 shows immediately before the fixed scroll (1) and the orbiting scroll (2) communicate with a pair of innermost compression chambers (81), (82) symmetrical to the discharge chamber (70). Shows the state,
The spiral side plates (101) and (201) of the fixed scroll (1) and the orbiting scroll (2) have points (B ₁ on the lines E and F connecting the tangents of the respective involute base circles (100) and (200). ) To (B ₆ ) are in contact with each other. Here, the compression chambers (81), (82) on the innermost peripheral side and the pair of symmetrical compression chambers (91), (92) on the outer side are (B ₂ ),
It is divided by (B ₅ ), and the compression chambers (81), (82)
And the discharge chamber (70) are separated by (B ₁ ) and (B ₄ ). As a result the discharge chamber (70) is a pressure P _0, the pressure of the compression chamber (81) and (82) pressure is equal to P ₁ compression chamber (91) and (92) is P _2, and the further outside thereof is still compressed The chamber is not formed and the pressure is P ₃ . During normal compression, P ₃ is suction pressure, P ₀
Is the discharge pressure and P ₀ ≧ P ₁ > P ₂ > P ₃ . On the other hand, when a large amount of liquid refrigerant is sucked in when the refrigerant starts sleeping or when the liquid is backed up,
It is in a liquid compression state, and according to actual measurement, the compression chambers (81), (82)
May reach 100 to 200 atg in a pulsed manner with the maximum pressure P1 immediately before communicating with the discharge chamber (70). In this case P
₀ <P ₁ > P ₂ > P ₃

In such a positional relationship, communication grooves (601a) and (601b) are provided at point-symmetrical positions so as to conduct to the compression chambers (81) and (82) near the contacts (B2) and (B5), respectively. is there.
This groove (601) is provided on the side surface of the element (6), and the communication groove (601a) that is in conduction with the compression chamber (81) is on the outer surface side (6a) of the element (6) on the inner end side of the element. ,
The communication groove (601b) that is electrically connected to the compression chamber (82) is formed as a vertical groove on the inner surface side (6b) of the element (6) on the element outer end side.

FIG. 2 is a perspective view showing an assembled state in which the element (6) is mounted in the groove (5) of the orbiting scroll (2). A concrete shape of the communication groove (601a) is shown in FIG. Communication groove (60
1b) also has the same shape and is a U-notch-shaped vertical groove in this figure.

Also for the fixed scroll (1), the spiral side plate (10
The winding direction of 1) is opposite to that of the orbiting scroll (2), and the positions of the communication grooves (601a) and (601b) are the orbiting scroll (2).
180 ° apart from the contact points (B5) and (B2), respectively, but the other arrangements and shapes are exactly the same as those of the orbiting scroll (2).

4 and 5 are sectional views showing an example of a more detailed shape of the present invention. FIG. 4 shows a state before the element (6) is assembled in the groove (5), and FIG. The state after installation is shown. Since details of the assembling method and the like are described in JP-A-62-126207, the description thereof is omitted here, but the element (6)
Is made of a flexible material and has a rectangular cross section as shown in FIG. 4 and has a width W and a thickness D. On the other hand, the groove (5) has a depth D1 and has a step (5c) along the longitudinal direction of the spiral in the depth direction, and the groove width of the upper opening is W1, the bottom width of the lower part. The groove width is W2, where W1>W> W2
Have a relationship.

FIG. 5 shows a state in which the element (6) having such a shape is press-fitted into the groove (5). The end face of the spiral side plate (201) is combined with the mating base plate (102) in a state where a small gap δ ₁ is maintained in the section A, and the element (6) is in close contact with the base plate (102). , When pressure P ₁ > P ₂ , a seal is obtained against this differential pressure. Further, the element (6) is plastically deformed into the shape of the groove (5) at the time of press-fitting, and is locked by the step portion (5c) to prevent the depression or the like during normal operation of the compressor. The void (501) has a size of δ ₂ where it absorbs a shape tolerance at the time of assembly and is a relief when the element (6) receives a reaction force in the arrow direction due to thermal expansion or the like. The communication groove (601b) electrically connects the space (501) and the compression chamber (82).

As described above, due to liquid compression, etc., the internal pressure P ₁ of the compression chamber (82)
When it rises abnormally, the gap (50
Since 1) is pressure-equalized, the element (6) is prevented from falling into the groove (5).

On the other hand, the void (501) is also in communication with the communication groove (601a) and further opens to the compression chamber (81), but the compression chamber (81),
Since (82) has a symmetrical shape, the pressures are almost the same, so there is no pressure imbalance and the time for pressure equalization is
Compared to the case where only one side is opened, it is only half as effective as the fall prevention effect. Further, even during normal compression, the compression chambers (81) and (82) always have the same pressure, so that, for example, the communication groove (601a) may leak to the communication groove (601b) through the void (501). There is no such thing.

Further, the liquid compression reaches a peak immediately before the compression chambers (81) and (82) communicate with the discharge chamber (70), and after the communication, it is conducted to the high-pressure side line of the refrigeration cycle and does not compress, so the pressure drops sharply. . Since pulses are generated in synchronism with the rotation speed of the compressor, the air gap (501) and the compression chambers (81), (82) are
The pressure equalizing speed with the pressure P ₁ is preferably at least the same order as the rotational speed. Therefore, as shown in FIG. 5, setting D = D1 in FIG. 4 so that when the element (6) is projected from the end face of the spiral side plate (201) by δ ₁ , a gap gap δ ₂ δ ₁ is set. Thus, it was confirmed that there is no time delay with respect to pressure equalization, and therefore the reliability of preventing the element (6) from falling due to liquid compression is further improved.

〔The invention's effect〕

As described above, according to the present invention, the compression chamber on the innermost peripheral side and the spiral side plates of each scroll that define the compression chamber on the outer side of the compression chamber are located near at least one of the pair of regions that are in contact with each other. Since the communication groove that connects the compression chamber on the innermost peripheral side and the gap of the concave groove is provided, the element does not locally collapse even if the pressure in the compression chamber increases abnormally during liquid compression. It is possible to prevent compressed gas from leaking due to such depression and to prevent performance deterioration due to maximum compression and abnormal rise in discharge gas temperature.In addition, during normal operation, compression chambers with different pressures may communicate via normal grooves and gaps. In addition, it is possible to secure a sealing property between the compression chambers, a simple structure, and a scroll compressor with high sealing reliability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a compression section in which a fixed scroll and an orbiting scroll according to the present invention are combined. FIG. 2 is a perspective view showing a state where the fine adjustment element of the present invention is incorporated in an orbiting scroll. FIG. 3 is an enlarged perspective view of an essential part, and FIGS. 4 and 5 are sectional views showing a fine adjustment element including another invention. 6 (a), (b),
(C), (d) is sectional drawing which shows the operation state of a scroll compressor. FIG. 7 is a sectional view showing the main part of the scroll compressor,
8, 9 and 10 are sectional views showing a conventional gap fine adjustment mechanism. 11 (a), (b), and (c) are diagrams showing the relationship between the pressure acting on the element of the gap fine adjustment mechanism and the pressure acting on the compression chamber during the operation of the scroll compressor. In these figures, (1) is a fixed scroll, (2)
Is an orbiting scroll, (101) and (201) are spiral side plates,
(5) is a concave groove, (501) is a void, (102) (202) is a base plate, (6) is an element, (601a) and (601b) are communication grooves, (70) is a discharge chamber, (81) , (82), (91), (92)
Is a compression chamber. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (5)

[Claims] 1. A compression chamber and a discharge which form a plurality of symmetrical pairs between the scroll side plate and the base plate by combining a fixed scroll and an orbiting scroll formed by projecting the spiral side plate on the base plate, respectively. A chamber is formed, and the fluid taken into the compression chamber is compressed by orbiting the orbiting scroll,
In addition to communicating with the central discharge chamber, a concave groove is formed on the end surface of each spiral side plate along the longitudinal direction of the spiral, and is press-fitted along the spiral concave groove through the gap at the groove bottom of the concave groove. In the scroll compressor provided with the fine adjustment element described above, in the state immediately before the pair of innermost compression chambers of the compression chambers communicate with the discharge chamber, the innermost compression chambers And, of the pair of parts where the scroll side plates of each scroll defining the outer compression chamber contact each other, at least in the vicinity of one part, a communication groove for conducting the above-mentioned innermost compression chamber and the above-mentioned void is formed. A scroll compressor characterized by being provided. 2. An innermost compression chamber and a groove are formed in the vicinity of a pair of portions where the scroll side plates of each scroll defining the innermost compression chamber and the outer compression chamber contact each other. The scroll compressor according to claim (1), characterized in that each of the communication grooves is provided with a communication groove that allows the voids to communicate with each other. 3. The fine adjustment element has a thickness substantially equal to the depth of the concave groove, and when the fixed scroll and the orbiting scroll are combined with each other, the end face of the spiral side plate and the other scroll base plate The scroll compressor according to claim (1), characterized in that the fine adjustment element is protruded from the end face of the spiral side plate by a minute gap formed therebetween. 4. The recessed groove has a stepped portion midway in the depth direction, the groove width of the opening above the stepped portion is larger than the groove width of the lower bottom portion, and the fine adjustment is performed. The scroll compressor according to claim (1), characterized in that the width of the working element is smaller than the opening groove width above the stepped portion and larger than the bottom groove width below. 5. The communication groove is a vertical groove formed on a side surface portion of the fine adjustment element mounted on each of the fixed scroll and the orbiting scroll, the side surface being in contact with the side surface of the concave groove. The scroll compressor according to item (2), (3), or (4).