JPH0692797B2 - Scroll compressor - Google Patents

Description

Detailed Description of the Invention

[Field of Industrial Application] The present invention relates to a compression mechanism portion of a scroll compressor, and in particular,
The present invention relates to a scroll compressor including a discharge bypass mechanism suitable for an air conditioner or a refrigerator whose operating pressure ratio changes greatly.

[Prior art]

As a method for improving the axial sealing performance of the wrap tip of the scroll compressor, there have been conventional methods such as 57-92 and 57.
-83293 etc. have been proposed.

[Problems to be Solved by the Invention]

These methods have a bidirectional sealing property and have the advantage of reducing leakage and improving efficiency during design pressure ratio operation, but on the other hand, even if the compression chamber becomes overcompressed, the compressed gas remains Since it cannot escape, the increase in power loss at a low pressure ratio cannot be eliminated, which has been a problem of the scroll compressor. As a solution to this problem, a bypass valve system disclosed in Japanese Patent Application Laid-Open No. 57-137677 has been proposed, but it is effective as a system for preventing overcompression, but this system originally requires a valve mechanism. Not only does it hinder the characteristics of the scroll compressor, but it also has a problem that the addition of a valve mechanism causes a decrease in reliability. INDUSTRIAL APPLICABILITY The present invention alleviates overcompression that occurs when operating at a design pressure ratio or less, which is a problem of a constant volume ratio scroll compressor, and at the same time, does not impair the sealability of the compression chamber other than during this overcompression, and provides a wide pressure range. An object of the present invention is to obtain a scroll compressor capable of operating efficiently in a specific range.

[Means for Solving the Problems]

A first feature of the present invention for achieving the above-mentioned object is to engage a fixed scroll member and an orbiting scroll member, which are upright spiral wraps on an end plate, with the wraps being inside each other,
The frame supports the fixed scroll member, and the orbiting scroll member is engaged with the eccentric shaft portion provided continuously with the rotating shaft supported by the frame, and the orbiting scroll member is caused to orbit with respect to the fixed scroll member without rotating, The fixed scroll member has a discharge port that opens in the center and a suction port that opens in the outer periphery. Gas is sucked in through the suction port and the volume is reduced by moving it around the enclosed space formed by both scroll members. In a scroll compressor that compresses gas and discharges compressed gas from the discharge port, a groove provided along the lap curve at the axial end of the wrap and a width smaller than the groove width provided in this groove It is configured to be movable in the radial direction inside the groove, and this radial movement prevents the flow from the inner closed space to the outer closed space between the back-to-back closed spaces with the wrap interposed. In that it comprises a and to form a passage to permit flow from the outside of the enclosed space to the inside of the sealed space unidirectional sealing means. A second feature of the present invention is that the groove provided along the lap curve at the axial tip of the wrap and the groove provided,
It has a flexible tongue that is bent from the outer closed space side to the inner closed space side at its tip, and when the pressure of the outer closed space is higher than that of the inner closed space, The tongue is deformed to allow the flow from the outer closed space to the inner closed space, and when the pressure in the inner closed space is higher than the outer closed space, the flow from the inner closed space to the outer closed space is changed. And a one-way sealing means for blocking.

[Action]

According to the present invention having the above-mentioned first feature or second feature, the following actions can be obtained. That is, during operation at or below the design pressure ratio, overcompression occurs in which the pressure in the closed space immediately before discharge is higher than the discharge pressure. When the pressure in the sealed space increases, the differential pressure causes the unidirectional sealing means to move from the outer peripheral side to the inner peripheral side, or the tongue of the unidirectional sealing means deforms from the outer peripheral side to the inner peripheral side. As a result, the compressed gas in the outer closed space can be released to the inner closed space to alleviate overcompression. Further, in a normal compressed state, the pressure in the inner closed space is higher than the pressure in the outer closed space, so the differential pressure causes the unidirectional seal means to move from the inner peripheral side to the outer peripheral side.
Alternatively, the tongue piece of the one-way sealing means is pressed against the end plate of the counterpart scroll member to prevent the flow from the inner closed space to the outer closed space, so that the sealability of the compression chamber (closed space) is not impaired. Therefore, according to the present invention, a scroll compressor having high efficiency over a wide pressure ratio range can be obtained.

【Example】

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. In the scroll compressor shown in FIG. 1, a compressor unit 2 and an electric motor unit 3 are housed in a closed container 1. In the compressor unit 2, a fixed scroll member 4 and an orbiting scroll member 5 are meshed with each other to form a compression chamber (closed space) 9. The fixed scroll member 4 is composed of a disk-shaped end plate 4a and a wrap 4b which stands upright on the end plate 4a and is formed in an involute curve or a curve similar to this, and has a discharge port 10 at the center thereof and a suction port 7 at the outer peripheral portion thereof. Is equipped with. The orbiting scroll member 5 is composed of a disk-shaped end plate 5a, a wrap 5b standing upright on the end plate 5a and having the same shape as the wrap of the fixed scroll, and a boss 5c formed on the non-lap surface of the end plate. The frame 11 has a bearing portion 11a formed in the center thereof, and the rotary shaft 14 is supported by the bearing portion, and the eccentric shaft 14a at the tip of the rotary shaft is inserted into the boss 5c so as to be capable of pivoting movement. The fixed scroll member 4 is fixed to the frame 11 by a plurality of bolts, the orbiting scroll member 5 is supported by the frame 11 by an Oldham mechanism 12 including an Oldham ring and an Oldham key, and the orbiting scroll member 5 is fixed to the fixed scroll member 4. Thus, it is formed so as to make a turning motion without rotating. The electric motor part 3 is directly connected to the lower part of the rotary shaft 14. A suction pipe 17 is connected to the suction port 7 of the fixed scroll member 4 through the closed container 1, and the discharge chamber 1a where the discharge port 10 is opened communicates with the lower chamber 1b through passages 18a and 18b. It communicates with a discharge pipe 19 which penetrates the closed container 1. A space (hereinafter, referred to as a back pressure chamber) 20 surrounded by the back surface of the orbiting scroll member 5 and the frame 11 has a thrust direction due to gas pressure in a plurality of compression chambers 9 formed by both orbiting and fixed scroll members. An intermediate pressure between the suction pressure (low pressure side pressure) and the discharge pressure acts in order to oppose the gas force (this force acts as a separating force for pushing down the orbiting scroll member 5). This intermediate pressure is set by the orbiting scroll 5.
The end plate 5a is provided with pores (not shown), the gas inside the scroll is guided to the back pressure chamber 20 through the pores, and the gas acts on the back surface of the orbiting scroll. The rotating shaft 14 and the eccentric shaft 14a are provided with oil supply holes (not shown) for supplying oil to the respective bearings from the oil supply pipe 14b protruding from the lower end of the rotating shaft 14 to the upper end surface of the eccentric shaft 14a. Tube 14b
Is immersed in the lubricating oil 6 at the bottom of the closed container 1. In the scroll compressor having the above structure, the eccentric shaft 14a is eccentrically rotated by the rotation of the rotary shaft 14 directly connected to the electric motor 3, and the orbiting scroll member 5 makes an orbiting motion via the boss 5c. Due to this swirling motion, the compression chamber 9 gradually moves to the center and its volume decreases. Constant temperature low pressure refrigerant gas suction pipe
From 17 through the suction port 7, it enters the suction part 8 at the outer peripheral portion in the fixed scroll, and is compressed as described above to increase the pressure and is discharged from the central discharge port 10 to the discharge chamber 1a. This high-temperature, high-pressure refrigerant gas flows into the lower chamber 1b via the passages 18a and 18b, and is then discharged from the discharge pipe 19 to the outside. A seal member 21 having the same shape is provided at the tip ends of the wrap 4b of the fixed scroll 4 and the wrap 5b of the orbiting scroll 5 in the axial direction. FIG. 2 shows an arrangement state of the seal member of the orbiting scroll. A groove 25 along the spiral wrap is provided at the tip of the wrap 5b over almost the entire range of the wrap except for the end of the wrap. A seal member 21 having a width slightly narrower than the groove width is inserted in the groove 25. The sealing member 21 is provided with a unidirectional sealing means in the range of about one turn from the start of the spiral. On the other hand, the detailed structure of the sealing member provided with the row-shaped sealing means
Shown in the figure. As shown in the figure, the spiral seal member 21 is provided with a plurality of cutout passages 21a and 21b, which communicate with each other on the inner peripheral surface and the lower surface of the spiral seal member 21, approximately one winding range from the beginning. FIG. 4 shows a seal member installed in the fixed scroll. As shown in the figure, at the tip of the wrap 4b of the fixed scroll 4 (only the inside of the suction chamber 8 is shown), there is a groove 24 along the spiral wrap, except for the winding end. The seal member 21 is provided in the range, and the groove 24 is provided with the seal member 21. Further, the figure shows a state in which it is combined with the orbiting scroll wrap 5b. The tip of the orbiting scroll wrap 5b has the same structure as described above. FIG. 5 shows a cross section of the lap portion, and FIG. 5 (a) shows a state in which back-to-back compression chambers communicate with each other via a seal member at the tip of the wrap,
(B) The figure shows a state in which the seal member seals between the compression chambers back to back. In FIG. 4, when the compression chambers 9a and 9b are in the overcompression state, that is, when the pressure (Pc) in the compression chambers 9a and 9b is higher than the pressure (Pd) in the innermost chamber 30 communicating with the discharge port, the seal is performed. Member 21
As shown in FIG. 5 (a), is pushed from the outside to the inside and is biased toward the inner peripheral side of the groove. The gas in the compression chambers 9a and 9b passes through the grooves 25 and 24 and the cutout passages 21b and 21a of the seal member, and is the innermost chamber.
It goes out to 30, and it goes out to the discharge chamber from the discharge port 10. Therefore, the overcompression of the compression chambers 9a and 9b is mitigated, and the efficiency of the compressor at a low pressure ratio is improved. On the other hand, when the pressure (Pc) in the compression chambers 9a and 9b is lower than the pressure (Pd) in the innermost chamber 30, the seal member 21 moves to the fifth position.
As shown in Figure (b), the groove is pushed from the inside to the outside.
The outer peripheral surface of the seal member is grooved 25, 24
It adheres to the inner peripheral surface of and eliminates the gap. Therefore the compression chamber 9
The innermost chamber 30 and a and 9b are completely sealed. That is, during high pressure ratio operation, gas does not flow backward from the innermost chamber 30 to the compression chambers 9a and 9b. By forming the seal member 21 with a material having a certain degree of flexibility, the seal member can be biased toward the inner peripheral side only in the portion where the pressure in the compression chamber is higher than the discharge pressure, and only the pressure in the overcompressed portion can be set. Since it can be escaped and the sealability of other parts can be maintained, the efficiency of the compressor is not adversely affected. In the above-mentioned embodiment, the seal member 21 is provided in the almost entire length range of the scroll wrap, and the unidirectional sealing means is provided in this seal member in the range of the compression chamber where overcompression easily occurs in normal operation, that is, the wrap winding start. Although an example in which it is provided only in the range of from about 1 turn (1 turn) is shown, of course, the unidirectional sealing means may be provided over the entire length of the sealing member. FIG. 6 and FIG. 7 show another embodiment. In this embodiment, the seal member provided with the one-way sealing means shown in the above embodiment is installed in a fixed and one scroll range on the inner peripheral side of the orbiting scroll wrap. Only the wrap is provided, and the outer peripheral side is sealed with only the wrap as in the conventional case. Therefore, the gaps 4d, 5d at the tips of the wraps 4b, 5b in which the grooves 24 ', 25' for mounting the seal member 26 are provided are increased, and the gaps 4d 'at the tips of the wraps 4b', 5b 'without the seal member are made larger. , 5d 'is small. Since overcompression occurs only in the innermost chamber during normal operation, sufficient effect of preventing overcompression can be obtained in this embodiment as well. FIG. 8 shows another embodiment in which the sectional shape of the seal member is different. Similar to FIG. 5, (a) shows the sealing member in the communicating state, and (b) shows the sealing state. In the figure, the fixed scroll wrap 4b and the orbiting scroll wrap 5b are provided at their tips with grooves 24 and 25 along the wrap as in the first embodiment, and a seal member 31 is embedded in these grooves. There is. The one-way sealing means provided in the seal member 31 has a cross-sectional shape as shown in the figure, for example, and is provided with a tongue piece 31a which is easily bent on the inner peripheral side and hard to be bent on the outer peripheral side. By doing so, Pc> Pd is established in the compression chambers 9a 'and 9b' that are now overcompressed, and a force due to the differential pressure is applied to the seal member from the outer peripheral side toward the inner peripheral side. At this time, the sealing member 31 is replaced with the tongue piece 31 as shown in FIG.
As a is bent, a gap is formed at the tip, and the gas in the compression chambers 9a ', 9b' escapes to the innermost chamber 30. When the pressure in the compression chambers 9a and 9b is lower than the discharge pressure, Pc <Pd, and the tongue piece 31 of the seal member
Since a does not bend and becomes a state as shown in (b) and no gap is generated, the innermost chamber 30 and the compression chambers 9a and 9b are sealed. FIG. 9 shows still another embodiment in which the sectional shape of the seal member is different. (A) The figure shows the seal member in communication,
(B) The figure shows a sealed state. At the ends of the fixed scroll wrap 4b and the orbiting scroll wrap 5b, grooves are formed along the wraps as in the first embodiment.
24 and 25 are provided, and the seal member 41 and
42 is inserted. The one-way sealing means provided on the seal member 42 is triangular and is solidified at the bottom of the groove, and the seal member 41 is movable in the radial direction on the slope of the seal member 42. In the compression chamber 9a'9b 'which is now overcompressed, Pc> Pd, and a force due to the differential pressure is applied to the seal member 41 from the outer peripheral side toward the inner peripheral side. At this time, the seal member 41 is biased toward the inner peripheral side as shown in FIG. 4A, and a gap is formed between the seal member 41 and the end plate, and the gas in the compression chambers 6a, 6b escapes to the innermost chamber 30.
When the pressure in the compression chambers 9a, 9b is lower than the discharge pressure, Pc> Pd, the seal member 41 is biased toward the outer peripheral side and the gap between the tips is very small as shown in FIG. And the compression types 9a and 9b are sealed. In the embodiment shown in FIG. 9, a slight gap is provided at the tip even in the sealed state in order to prevent the seal member from being caught. Fifth
Even in the illustrated embodiment, it is possible to provide a slight gap at the tip of the seal member so as not to impair the sealing property, and the effect of preventing overcompression does not change. That is, if only prevention of overcompression is achieved, the tip clearance of the seal member may be the same as that of a conventional scroll compressor without a seal member, and if improvement of the sealability is also achieved, the clearance of the tip should be small. Good. In the embodiment shown in FIG. 9, the seal member is used during overcompression.
41 is pushed inside the grooves 24, 25, but at this time the sealing member 41
When the seal member 41 is provided with a cutout passage 41a as shown in FIG. 10 when it does not descend along the slope of the bottom seal member 42 and rises above the slope, the gap between the slopes is increased during overcompression. The gas is formed so as to escape through the floating gap and the notch passage 41a. In the embodiment shown in FIGS. 8 and 9, the seal member is provided in a substantially full length range excluding the winding end portion of the wrap, and the unidirectional sealing means is provided in the range of about 1 winding from the beginning of the wrap. Although shown, unidirectional sealing means may be provided over the entire length of the sealing member. Further, as shown in FIG. 6 and FIG. 7, the unidirectional sealing means is provided with the sealing member only in the range of approximately one turn on the inner peripheral side of the fixed and orbiting scroll, and the outer peripheral side thereof is the same as the conventional one. You may make it the structure which seals only. [Effects of the Invention] According to the present invention as described above, compressed gas is released from the compression chamber in which overcompression occurs to the discharge side to mitigate overcompression, and the compression chamber in a normal compression state is There is an effect that a scroll compressor having a high efficiency can be obtained over a wide pressure ratio range without impairing the sealing property.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a scroll compressor showing an embodiment of the present invention, FIG. 2 is a top view of an orbiting scroll equipped with the seal member of the embodiment of FIG. 1, and FIG. 3 is a part of the seal member. FIG. 4 is a perspective view, FIG. 4 is a cross-sectional view showing a meshing state of a fixed scroll equipped with the seal member of FIG. 1 and both scrolls,
FIG. 5 is a partial cross-sectional view showing the detailed structure of the seal member. FIG. 5 (a) is a state diagram of the seal member during overcompression, and FIG. 5 (b) is a normal seal state diagram. FIG. 6 is a cross sectional view showing another embodiment of the seal member, and FIG.
FIG. 7 is a sectional view taken along the line VII-VII of FIG. 6, and FIGS. 8 and 9 are partial sectional views showing the detailed structure of the seal member showing still another embodiment, respectively, and FIG. The state diagram of the seal member at the time of compression, (b) figure shows a normal seal state diagram. First
FIG. 10 is a perspective view showing a partly modified example of the seal member of the embodiment shown in FIG. 4 ... Fixed scroll, 4b ... Wrap, 5 ... Orbiting scroll, 5b ... Wrap, 9a, 9b ... Compression chamber, 10 ... Discharge port, 21 ... Sealing member, 24, 25 ... Groove, 30 The innermost room, 3
1 …… Seal member, 41, 42 …… Seal member, 41a …… Notch passage, 21a, 21b …… Notch passage, 31a …… Tongue piece.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masao Shibayashi, 390 Muramatsu, Shimizu City, Shizuoka Prefecture, Hitachi, Ltd., Mechanical Research Laboratory (72) Inventor, Akira Murayama, 390, Muramatsu, Shimizu City, Shizuoka, Hitachi, Ltd., Shimizu Plant, Hitachi, Ltd.

Claims (3)

[Claims] 1. A fixed scroll member and an orbiting scroll member, each of which has a spiral wrap standing upright on an end plate, are meshed with the wrap inside each other, and the fixed scroll member is supported by a frame, and the orbiting scroll member is supported by the frame. The rotary scroll member is engaged with an eccentric shaft portion continuously provided, and the orbiting scroll member is orbitally interlocked with the fixed scroll member without rotating, and the fixed scroll member has a discharge port opening at the center and an outer peripheral portion. A scroll compressor that has an open suction port, sucks gas from the suction port, moves it around a closed space formed by both scroll members to reduce the volume and compresses the gas, and discharges compressed gas from the discharge port. In the machine, a groove provided along the lap curve at the axial tip of the wrap,
This groove is provided in this groove and has a width smaller than the groove width so that it can be moved in the groove in the radial direction. A scroll compressor, comprising: a one-way sealing means that forms a passage that blocks a flow to an enclosed space and allows a flow from an outside enclosed space to an inside enclosed space. 2. The passage defined in claim 1, wherein the passage formed in the one-way sealing means is formed by cutting out an inner peripheral surface side and a bottom surface side of the sealing means. A scroll compressor characterized by being a cutout passage that communicates with the outer peripheral surface side. 3. A fixed scroll member and an orbiting scroll member, which stand upright with a spiral wrap on an end plate, are engaged with each other with the wraps inside each other, and the fixed scroll member is supported by a frame, and the orbiting scroll member is supported by the frame. The rotating scroll member is engaged with the eccentric shaft portion, and the orbiting scroll member is caused to orbit with respect to the fixed scroll member without rotating, and the fixed scroll member has a discharge port opening at the center and an outer peripheral portion. A scroll compressor that has an open suction port, sucks gas from the suction port, moves it around a closed space formed by both scroll members to reduce the volume and compresses the gas, and discharges compressed gas from the discharge port. In the machine, a groove provided along the lap curve at the axial tip of the wrap,
This groove is provided with a flexible tongue at its tip that is bent from the outer closed space side to the inner closed space side. When the pressure is high, the tongue is deformed by the differential pressure to allow the flow from the outer closed space to the inner closed space, and when the pressure of the inner closed space is higher than the outer closed space, the outside of the inner closed space is increased. And a unidirectional sealing means for blocking the flow of the scroll compressor into the closed space of the scroll compressor.