JPH01290987A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To settle the inner pressure quickly upon abrupt boost thereof by arranging a pair of openings for communicating the compression chamber at the innermost circumferential side with the gap at the back face of an element. CONSTITUTION:When the liquid is compressed and immediately before compression chambers 81, 82 at the innermost circumferential side are communicated with a delivery chamber 70, the inner pressure is at the highest level. A pair of openings 601a, 601b are provided such that the compression chambers 81, 82 at the innermost circumferential side are communicated with a gap 501 at the back face of an element 6. Consequently, the pressure in the gap section 501 is uniformed within the maximum level thus preventing collapse of the element 6. Since the pair of openings 601a, 601b are opened respectively to a pair of symmetrical compression chambers 81, 82, the pressure level is identical at all times and no pressure leak between them.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a seal for a scroll refrigerant compressor used for air conditioning, refrigeration, etc.

[Conventional technology]

The principles of scroll fluid machines are well known, and applications are being considered for a variety of applications, such as compressors, pumps, and expanders. Its basic constituent elements are constructed as shown in FIG. To explain this based on the figure, in the figure, the symbol fll i is the fixed scroll, (2) is the swinging scroll, (la) is the discharge port, P is the compression chamber, and 0 is the fixed scroll on the fixed scroll (1). The fixed point, 0, is the fixed point on the swinging scroll (2). Of these, the fixed scroll (1) and the oscillating scroll (2) have spiral side plates (101
) and (201) are integrally provided with opposite winding directions. The shape of these spiral side plates (101) and (201) is formed by a well-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 (11) is stationary with respect to space, and the swinging scroll (2) performs rotational movement without changing its attitude with respect to space.
Move like 0, 180, 270. As each point B moves toward the center with the movement of the oscillating scroll (2), the spiral side plate (10) of the fixed scroll (1) moves toward the center.
1) and the spiral side plate (201) of the oscillating scroll (2)
Since the volume of the crescent-shaped compression chamber P formed during this period is gradually reduced, the gas sucked into this compression chamber P is compressed and discharged from the discharge port (1a).

During this time, the distance from θ to O' in the figure is kept constant.

The gap between the spiral side plates (101) and (201) is Z, and the thickness is t.
If expressed as 0O=Z/z-t. Here, 2 corresponds to the pitch of the spiral side plates 101.201.

The specific configuration of a compressor that operates according to such an operating principle is explained using FIG. 7. fil C is a fixed scroll, (2) is an oscillating scroll, (la) is a discharge port, and (to) is a compression chamber. , (lb) is the suction port, (3) is the main shaft, and (4) is the frame. In addition, (101) and (201) are the side plates of the fixed shumir (1) and the oscillating scroll (2), respectively, (102) and (202) are plywood, and (to) are the spiral side plates (101) and (201). The end face of (2
02), the bottom surface (2021L) of (102), and the gap in the @ line direction formed between (102).

Here, the swinging scroll (21 is the stand 1i (202)
The fixed scroll (1) is combined with the fixed scroll (1) as shown in Fig. 7 with the opposite side to the side on which the spiral side plate (201) is formed supported by the frame (4), and the fixed scroll is)
is fixed to the frame (4). And the main axis f3
1 rotates as shown by the arrow in the same figure, the rigidly connected swinging scroll (2) begins to interlock. in this case.

The oscillating scroll (2) performs a revolving motion without rotating on its own axis by means of an anti-rotation device (not shown). As a result, the inlet (
The fluid to be compressed is sucked through fL1 (lb), compressed according to the operating principle shown in FIG. 6, and discharged from the discharge port (1a).

In such a scroll compressor, the leakage in the radial direction of the volute through the gap corresponds to the longitudinal dimension of the vortex, so it is relatively large compared to the fluid suction volume, which affects the efficiency of the compressor. The impact is significant. As a means for preventing this radial leakage, for example, Japanese Patent Application Laid-Open No. 55-460
As disclosed in No. 81, a mechanism is adopted in which the inside of the gap is made small and oil is sucked together with the compressed fluid from the suction port (1b) to form an oil film in the minute gap (2).

However, with such means, in order to uniformly set minute gaps, it is required to have high dimensional accuracy of each component such as the fixed scroll fil, the m-moving scroll (2), and the frame (4), and in some cases In some cases, each part must be selected during assembly.

There were problems with workability and assembly. Also, during operation, the area near the discharge port (1a) becomes high temperature due to the compressed fluid;
As a result, if the local thermal expansion exceeds the minute gap (A),
Burn-in occurs because there is no escape. Therefore, the gap must be uniformly set large in advance assuming thermal expansion sensitivity, which results in a gap greater than the optimum gap required to form an effective oil film, resulting in increased leakage. ,
Sealing performance often deteriorated.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 61-26160, a guide portion is provided on the end face of each spiral side plate to press-fit a fine adjustment element having the same spiral shape as each spiral side plate of both scrolls. A gap is formed in the axial direction between the fine adjustment element and the guide part, and this gap communicates with the compression chamber. A device equipped with a gap fine adjustment mechanism having J (pressure equalizing groove) was adopted. This will be explained based on FIGS. 8, 9, and 10. In the same figure, (
5) is a guide groove provided on the end surface (201, a) of the spiral side plate (201), and (6) is an element mounted in this guide groove (5) through a gap (50) so that the pieces can be adjusted freely. ,
(610) is a communication groove provided in this element (6) and communicating with the compression chamber (P) and the cavity (501). In addition, 01) is the gap formed between the end surface (201) of the winding side plate (201) and the end surface (102) of the base plate (102), and (g2) is the gap formed between the end surface (6a) of the element (6) and the base plate (102). i formed between the end surface (xoza) of the plate (102)
It is between.

Here, Figures 11 (a), (b) and (C) are diagrams showing the results of measuring the pressure during operation in the gap (501) and the compression chamber (one); b) shows the case without the communication groove (601), and (C
) shows the case where the communication groove (601) is used. In the figure, the air gap (
P1 is the fluctuating pressure of the compression chamber P2. If the pressure difference between the two is ΔP, then the pressure P2 in the compression chamber P is lower than the gap (50
When the pressure P1 in 1) becomes larger by ΔP, the element (6) protrudes from the guide groove (5), and the plywood 102.
It will slide on 202 and wear out. Also, the same figure (
As shown in b), when Pl is smaller than P2 by an amount of P, the element (6) will sink into the guide groove (5). On the other hand, when the element (6) has a communication groove ((iol)), ΔP is found to be significantly smaller as shown in FIG.
Since the air gap (501) and the compression chamber (I) are approximately equalized in pressure by the communication groove (601), 116 in the axial direction of the element (6) due to pressure fluctuations in the compression chamber (P) during operation can be prevented. is completed, element (6) and plywood (102),
There is no wear between the element (202) and the element (6
The element (6) is positioned in the guide groove (51) in a stable state without the element (6) sinking into the guide groove (51).

[Problem to be solved by the invention]

However, in the conventional scroll compressor, the fine adjustment element (6) is provided with a plurality of communication grooves (601), and these connections, 11! ! Since the groove (601) is set without considering the movement position of the oscillating scroll (2), each compression chamber P communicates with each other via the communication groove (601) and the gap (501). There was a problem in that the sealing performance between the compression chambers deteriorated accordingly, and the performance of the compressor deteriorated. Also, if the setting position of the communication groove (6 ot) is not appropriate, problems such as when starting from a sleep position or when liquid backs up, etc.
If liquid refrigerant is drawn into the compression chamber for too long, the element (6) will locally collapse due to liquid compression, and the compressed gas in that area will leak and be recompressed, resulting in a decrease in performance and an increase in the temperature of the discharged gas. There were some problems. This invention was made in view of the above circumstances, and it is an object of the present invention to provide a scroll compressor that can improve the sealing performance between each compression chamber and thereby improve the performance of pressure piping. be.

[Means to solve the problem]

In the scroll compressor according to the present invention, in a state immediately before the pair of compression chambers on the innermost side and the discharge chamber communicate with each other, the scrolls of each scroll defining the compression chamber on the innermost side and the compression chamber on the outer side thereof are provided. Near the pair of portions 8-I where the side plates contact each other, a pair of openings are provided at symmetrical positions to allow at least four passages between the pressure chamber on the innermost circumference and the gap on the back of the element.

Yet another invention is that, in such a configuration, the thickness of the element and the depth of j' and '4 to which the element is mounted are made equal, and the element is formed between the end face of the spiral side plate and the mating scroll base plate. The element is made to protrude from the end face of the spiral side plate by the amount of the minute gap created, and the gap on the back side is made substantially equal to the minute gap.

[For production]

In this invention, during liquid compression, in a state immediately before the innermost compression chamber and discharge chamber communicate with each other, where the internal pressure is maximum,
This internal pressure is the maximum. A pair of openings are provided so that the compression chamber on the innermost circumferential side and the rear cavity of the element are electrically connected, so that the pressure in the cavity is equalized to this maximum internal pressure, preventing the element from collapsing. Since the openings open into a pair of symmetrical compression chambers, the pressure is always the same and there is no leakage from one opening to the other.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention will be explained in detail by the Example shown in the figure.

FIG. 1 is a sectional view of a compression section combining a fixed scroll and an oscillating scroll according to the present invention.

FIG. 2 is a perspective view showing a state in which the fine adjustment element of the present invention is assembled into an oscillating scroll, and FIG. 3 is an enlarged perspective view of four parts of the same. FIGS. 4 and 5 are all cross-sectional views of fine adjustment elements including another invention.

Figure 1 shows that the fixed scroll (1) and the oscillating scroll (2) are connected to the discharge chamber (? The status of the spiral side plates (101) and (201) of the fixed scroll (1) and the oscillating scroll (2) are finely tuned to the tangents of the involute base circles (Zoo) and (200), respectively. They are in contact with each other at points (B1) to (B6) on the lines E and F.Here, the innermost compression chamber SO,a and the symmetrical pair of compression chambers 8υ, 192 on the outside thereof are respectively (B2
). (B5) is partitioned with il, and the compression chamber [F]
D, (c) and the discharge chamber G'■ are separated by (Bl) and (B4). As a result, the pressure in the discharge chamber is Po and the pressure in the 8 compression chambers (811 and phantom pressure is equal to P).

The pressure in the compression chambers 0υ and 2 becomes P2, and since the compression chambers are still formed outside of them, the pressure becomes P3.

During normal compression, P3 is suction pressure, Po is discharge pressure, and P
o≧PI>P2>P3. On the other hand, when a large amount of liquid refrigerant is sucked when starting up a cold tofu or when liquid is pumped back up, it becomes compressed, and according to actual measurements, the compression chambers υ and ■ are reduced to the discharge chamber σO
In some cases, the pressure P1 becomes the maximum pressure just before the communication with the pressure P1 and reaches 100 to 200 atg in a pulsed manner. In this case P
6 P, ) P2) P! becomes.

In this positional relationship, the points (B2) and (B5)
Communication grooves (6ota) and (6oxb) are provided at point-symmetrical positions so as to be electrically connected to the compression chambers (811, vJ), respectively, near the openings.

This groove (601,) is an opening provided on the side surface of the Niremen l-tel, and is a communication groove (601,) that communicates with the compression chamber l811.
1 is on the outer surface side (6a) of the element inner end side of the element (6), and a communication groove (601b) that conducts compression is formed on the inner 11111 surface side (6b) of the element outer end side of the element (6). ) It is formed as a vertical groove.

FIG. 2 is a perspective view showing an assembled state in which the element (6) is attached to the 11 yen (5) of the swinging scroll (2). Further, the communication groove (601b) whose specific shape is shown in FIG. 3 has the same shape, and is a U-notch-shaped vertical groove in this figure.

Regarding the fixed scroll (11), the spiral side plate (10
The winding direction of the scroll (1) is opposite to that of the rocking scroll (21), and the positions of the communication grooves (601 and (6 oib) are shifted by 180 degrees from the rocking scroll (2), resulting in contact points (Bs) and (B2), respectively.
), but the arrangement and shape of the pond are exactly the same as the swinging scroll (2).

4 and 5 are cross-sectional views showing an example of the detailed shape of the center of the present invention, and FIG. 4 shows an element (6) with a groove (5).
FIG. 5 shows the state before being assembled into 1, and FIG. 5 shows the state after being assembled. The details of the assembly method etc. are described in JP-A-62-126207, so they are omitted here, but the elements (
6) is made of a flexible material and has a rectangular cross-sectional shape as shown in FIG. 4, and has a width W and a thickness D. On the other hand, the groove (5) has a depth DI and has a stepped part (5c) halfway in the depth direction along the longitudinal direction of the spiral, the groove width of the upper opening is Wl, and the groove width of the lower bottom is The groove width is W2, and has the relationship Wl>w>w2.

The state in which the element (6) is press-fitted into the groove (5) in this shape is shown in Figure 5.The end face of the spiral side plate (201) has a slight gap δ between the mating plywood (102) and the part A! element (6) is made of plywood (102
Since the state of close contact between )l and i becomes imaginary, a seal against this differential pressure can be obtained when the pressures are P and )P. Also, the element (
6) is plastically deformed into the shape of time groove +51, and the step part (5
C), which prevents the compressor from falling during normal compressor operation. The void (501) has a dimension of δ2 and serves to absorb shape tolerances during assembly and to provide relief when the element (6) receives a reaction force in the direction of the arrow due to thermal expansion or the like. The communication groove (6oxa) is connected to this gap (50
1) and the compression chamber f811.

ni] As mentioned above, when the internal pressure P1 in the compression chamber increases abnormally due to liquid compression, etc., the pressure in the gap (501) is equalized through the communication groove (601a), so the groove ( 5) Inward depression is prevented.

On the other hand, the gap (501) is also connected to the communication groove (601b) and opens into the compression chamber;
Since it has a symmetrical shape, the pressure is almost the same, so there is no unbalance in the pressure, and the time required to equalize the pressure is 1/2 compared to when only one side is open, which is effective in preventing depression. will rise further. In addition, even during normal compression, the pressure in the compression chamber 31) is always the same. Also, the liquid compression reaches its peak just before the compression chambers 18D and @ communicate with the discharge chamber qa, and after the communication, the liquid is conducted to the high pressure side fin of the refrigeration cycle and is not compressed, so the pressure drops rapidly. Since this occurs in a pulsed manner in synchronization with the compressor rotational speed, the air gap (501) and the compression chamber are connected, and the pressure P1 of
It is desirable that the pressure equalization speed is at least on the same order as the rotation speed.

Therefore, when D=D1 in FIG. 4 and the element (6) in FIG. 5 is made to protrude from the end face of the spiral side plate (201) by δl, the air gap δ! By setting the pressure so that the pressure is equal to δ1, there is no time delay for equalizing the pressure, and therefore, the process using liquid compression is possible. It was confirmed that the reliability of preventing drop in /ment (6) was further improved.

〔Effect of the invention〕

As described above, according to the present invention, among the compression chambers formed by combining a fixed scroll and an oscillating scroll, immediately before the innermost pair of compression chambers and the discharge chamber communicate with each other, The innermost compression chamber and the outside 1i111
In the vicinity of the pair of parts where the spirals tll + 1 of each scroll that define the compression chamber of the scroll are in contact with each other, at least the pair of openings that connect the compression chamber on the innermost circumferential side and the gap on the back side of the element for fine adjustment are symmetrical. Since they are provided at ff and f, even if the white clay is abnormally pressurized due to liquid compression, the pressure is quickly equalized, preventing the element from falling, and there is no leakage through the openings even during normal compression, making the structure simple. Thus, a scroll compressor with high seal reliability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a compression section combining a fixed scroll and an oscillating scroll according to the present invention. FIG. 2 is a perspective view showing a state in which the fine adjustment element of the present invention is assembled into an oscillating scroll. FIG. 3 is an enlarged perspective view of the main part, and FIGS. 4 and 5 show the second factor (a
), (b), (C), and (d) are cross-sectional views showing the operating state of the scroll compressor. FIG. 7 is a sectional view showing the main parts of the scroll compressor, and FIGS. 8 and 9. Figure 1O is a cross-sectional view showing a conventional gap fine adjustment mechanism.
Figures (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 operation of the scroll compressor. In these figures, (1) is a fixed scroll, (2j
is an oscillating scroll, (IOI), (201) is a spiral side plate, (5) is a concave groove, (501) is a gap, (102
X202) is the base plate, (6) is the element, (601a
), (601b) is a communication groove, □ is a discharge chamber, SU,
@. all, ■ are compression chambers. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (5)

[Claims] (1) A fixed scroll and an oscillating scroll, each formed by protruding a spiral side plate from plywood, are combined with each other to form a plurality of symmetrical pairs of compression chambers and discharge chambers between the spiral side plates and base plate. By rotating the oscillating scroll, the fluid taken into the compression chamber is compressed and communicated with the discharge chamber in the center, and grooves are formed in the end faces of each of the spiral side plates along the longitudinal direction of the spiral. However, in a scroll compressor equipped with a fine adjustment element press-fitted along the spiral groove through the groove bottom of the groove and the gap,
Immediately before the pair of compression chambers on the innermost side of the compression chambers and the discharge chamber communicate with each other, each scroll defining the compression chamber on the innermost side and the compression chamber on the outside thereof A scroll compressor characterized in that a pair of communication grooves are provided at symmetrical positions near a pair of portions where the spiral side plates contact each other, at least connecting the compression chamber on the innermost peripheral side and the gap. (2) A patent claim characterized in that the communication groove is one or more vertical grooves formed on the side surface of the fine adjustment element attached to the fixed scroll and the oscillating scroll, respectively, in contact with the side surface of the concave groove. Scroll compressor according to the scope of item (1) (3) The fine adjustment element has a thickness substantially equal to the depth of the concave groove, and is formed between the end face of the spiral side plate and the mating scroll base plate when the fixed scroll and the oscillating scroll are combined with each other. A scroll compressor characterized in that the fine adjustment element is made to protrude from the end surface of the spiral side plate by a minute gap. (4) The groove forms a stepped part in the middle of the depth direction,
The groove width of the opening above the stepped part is larger than the bottom bottom groove width, and the width of the fine adjustment element is smaller than the opening groove width above the stepped part, and the width of the bottom bottom groove is smaller than the width of the bottom bottom groove. Claim No. 3 characterized in that it is larger than
Scroll compressor described in ). (5) A patent characterized in that the communication groove is one or more vertical grooves formed on the side surface of the fine adjustment element attached to the fixed scroll and the oscillating scroll, respectively, in contact with the side surface of the concave groove. Scroll compressor according to claims (3) and (4)