JP4355308B2 - Scroll fluid machinery - Google Patents

Description

  The present invention relates to fluid compressors and fluid transfer machines used for refrigeration air conditioners and air compressors, and more particularly to scroll compressors.

  Conventionally, in a scroll compressor applied to a room air conditioner, a fixed scroll having a spiral wrap formed on a base plate and a orbiting scroll are meshed so that the wraps face each other to form a plurality of compression chambers, and the rear surface of the orbiting scroll By applying back pressure to the end plate of both scrolls (peripheral parts of the base plate) and bringing the anti-rotation mechanism on the back of the orbiting scroll, the orbiting scroll does not rotate, so that the compression chamber volume continues. For example, Japanese Patent Application Laid-Open No. H10-228707 discloses a device that is configured to be reduced in size and perform fluid compression.

And in patent document 1, the through-hole which penetrates the lap | wrap and baseplate of a turning scroll is provided, and the sealing property of a compression chamber is provided by supplying oil from the high pressure area | region of a bearing part to a back pressure area | region or a compression chamber through this through hole. It is shown to improve (form an oil film seal).
JP 2004-225644 A

  The problem with the scroll compressor disclosed in Patent Document 1 is that when a large amount of liquid refrigerant from the refrigeration cycle is sucked, the non-compressible liquid refrigerant is compressed to increase the hydraulic pressure (operation) in the compression chamber. This sometimes occurs when the pressure exceeds the pressure range obtained by compressing the refrigerant gas. In the scroll compressor shown in Patent Document 1, since a through-hole penetrating the orbiting scroll lap and the base plate is provided, the non-compression chamber region (back pressure region or bearing portion) passes through the through-hole from the compression chamber side. It is conceivable that the liquid refrigerant flows into When the liquid refrigerant flows in, there is a possibility that the lubricity deteriorates in the back pressure region or the bearing portion, the oil film is cut off due to the foaming of the liquid refrigerant, and the reliability is lowered.

  In addition, when the operation is stopped for a certain period of time under low temperature conditions, this phenomenon is likely to occur when the refrigerant is dissolved in the oil in the compressor (comprising the compression mechanism and motor) and the ratio of oil to oil is high. In the back pressure region, the oil in which the refrigerant is dissolved foams and the back pressure rises, increasing the pressing force of the orbiting scroll, and refrigerant gas generated by foaming (refrigerant gas having higher pressure than the refrigerant gas entering the compression chamber during normal operation) ) Flows into the compression chamber and the pressure in the compression chamber rises unexpectedly, causing a problem of reducing performance and reliability.

  An object of the present invention is to discharge a high-pressure liquid compressed when liquid refrigerant is sucked into a compression chamber to the outside without entering a back pressure region or the like via a communication flow path of the orbiting scroll and includes a large amount of refrigerant. An object of the present invention is to provide a scroll compressor that easily discharges the refrigerant that has flowed into the compression chamber through the communication flow path of the orbiting scroll when the oil foams in the back pressure region and the back pressure rises.

In order to solve the above problems, the present invention mainly adopts the following configuration.
A plurality of compression chambers are formed by meshing a fixed scroll provided with a spiral wrap and a turning scroll so that the wraps face each other, and back pressure is applied to the back of the turning scroll so that the turning scroll does not rotate. In a scroll compressor that performs fluid compression by continuously reducing the volume of the compression chamber by rotating it, the compression chamber communicates with a region other than the compression chamber, such as a back pressure region of the orbiting scroll or a bearing portion. A communication flow path is provided in the wrapping and base plate of the orbiting scroll,
A relief mechanism for opening a predetermined pressure fluid in a compression chamber connected to a communication channel provided in the wrap of the orbiting scroll to the outside is provided in the fixed scroll.

  In the scroll compressor, the flow path resistance of the relief mechanism provided in the fixed scroll is configured to be smaller than the flow path resistance of the communication flow path.

Further, a plurality of compression chambers are formed by meshing a fixed scroll provided with a spiral wrap and a orbiting scroll so that the laps face each other, and back pressure is applied to the back of the orbiting scroll to rotate the orbiting scroll. In a scroll compressor that performs fluid compression by continuously reducing the volume of the compression chamber by swirling without making a fluid movement,
A communication channel that communicates from the compression chamber to a region other than the compression chamber, such as a back pressure region or a bearing portion of the orbiting scroll, is provided in the wrap and base plate of the orbiting scroll,
A relief mechanism for opening a predetermined pressure fluid in a compression chamber connected to a communication flow path provided in the wrap of the orbiting scroll to the outside is provided in the fixed scroll;
The communication flow path provided in the orbiting scroll is provided with a flow path resistance change mechanism in which the flow path resistance changes according to the flow direction of the fluid,
The flow path resistance changing mechanism increases a first flow path resistance in a fluid flow direction from the compression chamber to a region other than the compression chamber, and increases a fluid flow direction from the region other than the compression chamber to the compression chamber. Having a function of reducing the second flow path resistance;
The flow path resistance of the relief mechanism provided on the fixed scroll is configured to be smaller than the first flow path resistance of the flow path resistance changing mechanism.

  According to the present invention, in particular, it is possible to reduce the inflow of liquid fluid from the compression chamber side to regions other than the compression chamber (for example, the back pressure region, the orbiting scroll bearing portion, etc.), and to achieve a highly efficient and highly reliable compressor. Can be provided.

  In addition, even when oil containing a large amount of refrigerant is supplied to the back pressure region and foamed, unnecessary pressure rise in the back pressure region and the compression chamber can be suppressed, and the performance and reliability of the compressor can be improved. It becomes.

  A scroll compressor according to an embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a sectional view of a compression chamber in a scroll compressor according to an embodiment of the present invention, and is a sectional view taken along line A-A ′ of FIG. 2. FIG. 2 is a diagram showing a schematic overall configuration of the scroll compressor according to the present embodiment. FIG. 3 is a diagram illustrating an example of resistance change of the communication flow path provided in the orbiting scroll wrap in the scroll compressor according to the present embodiment. FIG. 4 is a diagram showing another example of the resistance change of the communication channel provided in the orbiting scroll lap according to the present embodiment. FIG. 5 is a diagram showing a further example of resistance change of the communication flow path provided in the orbiting scroll lap according to the present embodiment.

  In the drawings, 1 is a fluid inlet, 2 is a fluid outlet, 3 is an intermediate outlet, 5 is an orbiting scroll base plate, 6 is a fixed scroll base plate, 7 is an orbiting scroll end plate, 8 is a fixed scroll end plate, 10 is a fixed scroll, 11 Is a relief port, 12, 12a, 12b is a relief port, 15 is a turning scroll wrap, 16 is a fixed scroll wrap, 20 is a turning scroll, 21 is a through hole, 22 is a backflow reduction mechanism, 23 is a fluid diode, 30, 30a, 30b represents a compression chamber, 31 represents a back pressure region, 40 represents a gap, 50 represents a frame, 60 represents a shaft, 70 represents a rotation prevention mechanism, and 80 represents a back pressure adjustment mechanism.

  1 and 2, the scroll compressor according to the present embodiment includes a motor (not shown) mainly composed of a stator and a rotor, mainly compression chambers 30a and 30b, a fixed scroll 10, a turning scroll 20, and a back pressure region. And a compression mechanism composed of 31. When this scroll compressor is applied to a refrigeration cycle, refrigerant gas used in the refrigeration cycle is introduced into the fluid inlet 1 and compressed by passing through the compression chambers 30a and 30b, and the compressed gas is sent out from the intermediate outlet 3. Then, the fluid is output from the fluid outlet 2 through the inside of the scroll compressor.

  As can be seen from the illustrated structure shown in FIG. 3, the scroll compressor according to this embodiment includes a fixed scroll 10 in which a spiral wrap 16 is formed on a fixed scroll base plate 6, and a turning scroll 20 in which a wrap 15 is formed. Are engaged with each other so that the wraps 15 and 16 face each other, and a plurality of compression chambers 30a and 30b are formed, and back pressure is applied to the back surface of the orbiting scroll 5 to bring the end plates 7 and 8 of both scrolls into contact with each other. Further, a rotation prevention mechanism 70 is provided on the rear surface of the orbiting scroll 5, and the orbiting scroll 5 is orbited without rotating, whereby the volume of the compression chamber 30 is continuously reduced and fluid compression is performed.

  Further, the wrap 15 of the orbiting scroll 20 is provided with a through hole 21 having one end opened on the wrap end surface of the orbiting scroll 20 and the other end connected to the back pressure region 31. That is, the through hole 21 is a hole that penetrates the wrap 15 and the base plate 5. Compression chambers 30a and 30b are formed across the opening of the through hole 21 (the opening on the wrap end face side) (see FIG. 1). At this time, referring to FIG. 3, a gap 40 is formed between the end face side of the wrap and the base plate 6 of the fixed scroll 10. Then, the clearance 40 and the through hole 21 are formed between the compression chamber 30 and the back pressure region 31, and the compression chamber 30 is connected to the back pressure region via the communication channel including the clearance 40 and the through hole 21. 31 is communicated.

  In the present embodiment, the compression chamber 30a has a relief port 12a provided in the fixed scroll 10, and similarly, the compression chamber 30b has a relief port 12b opened. Is one of the features of the scroll compressor according to the present embodiment. Here, the function of the relief mechanism 11 having the relief port 12 is to release the pressure to the outside when the compression chamber 30 reaches a predetermined pressure set in advance.

  Note that the back pressure in the back pressure region 31 acts on the side opposite to the compression chamber of the base plate 5 of the orbiting scroll 20 during the compressor operation, and generates a force for pressing the orbiting scroll 20 against the fixed scroll 10, so that the sealing property required for compression Is set so as to reduce sliding loss. Here, the back pressure reduces the discharge pressure into the compressor via the bearing portion and introduces it into the back pressure region. On the other hand, the refrigerant gas in the back pressure chamber is discharged from the back pressure chamber to the compression chamber having a substantially suction pressure through a back pressure adjusting mechanism 80 that combines a valve body and a spring provided in the fixed scroll 10. Further, the exhaust gas is discharged to a region closer to the back pressure in the compression chamber than the back pressure region through a through hole 21 provided in the orbiting scroll 20. Although the fluid flowing into the suction region of the compression chamber via the back pressure adjusting mechanism 80 has a higher temperature and pressure than the suction fluid, there is an influence such as re-expansion when the fluid flows in or heating the sucked fluid. By disposing the through-hole 21 so as to flow into a region where conditions such as the pressure and temperature of the fluid are close to those of the back pressure region 31, the above loss can be reduced.

  As described above, in the present embodiment, by providing the relief mechanism 11 in the compression chamber 30, the liquid refrigerant is easily discharged from the relief port when the suction of the liquid into the compression chamber due to the liquid return from the refrigeration cycle or the like occurs. By discharging the liquid refrigerant, it is possible to reduce the inflow of the liquid refrigerant to the back pressure region 31 through the through hole 21, and to further improve performance and reliability. In this way, the liquid refrigerant in the compression chamber is not introduced into the back pressure region or the bearing portion of the orbiting scroll through the communication channel.

  Next, the function and operation of the communication channel related to the relief mechanism (installed in the compression chamber 30 and the fixed scroll 10) will be described below. The orbiting scroll 20 is incorporated in a predetermined space between the fixed scroll 10 and the frame 50 together with the shaft 60 and the rotation prevention mechanism 70. During the normal operation, the orbiting scroll 20 is pushed by the fixed scroll 10 in the illustrated configuration example of FIG.

However, in the case of compression of the liquid refrigerant due to the inflow of the liquid refrigerant into the compression chamber (causes an unexpected pressure increase in the compression chamber), the orbiting scroll 20 is separated from the fixed scroll 10 by this increased pressure and is below. In some cases, the vehicle is operated while being in contact with the frame 50. Then, the through-hole 21 that penetrates the wrap 15 of the orbiting scroll 20, the clearance in the floating state (gap 40) during normal operation, and the clearance (gap 40) in the state separated downward during liquid compression In consideration of the above, the flow resistance of the relief mechanism 11 is defined as a communication flow path that connects the compression chamber 30 and the back pressure region 31 (through hole 21 + gap 40 passing through the base plate 5 and the wrap 15 of the orbiting scroll 20). It is desirable to set it smaller than the flow path resistance. In other words, when the pressure in the compression chamber 30 rises, it is desirable to discharge the liquid refrigerant in the compression chamber through the relief mechanism 11 instead of communicating with the back pressure region 31 or the bearing portion via the communication channel. It becomes.
For this reason, as the size of the clearance 40 and the size and shape of the through hole 21 which are influenced by the arrangement relationship of the frame 50, the cross-sectional area of the flow path is appropriately reduced, or the cross-sectional area is stepwise as shown in FIG. (The flow path resistance can be easily changed as appropriate during actual processing) or a shape that continuously changes.

  Next, another configuration example for changing the channel resistance of the communication channel will be described below with reference to FIGS. 4 and 5. FIG. 4 shows an example in which a reverse flow reduction mechanism is provided in the orbiting scroll 20. When the orbiting scroll 20 is provided with the backflow reduction mechanism 22 and flows into the compression chamber 30 from the back pressure region 31, the resistance is small, and the flow path resistance during backflow (a flow at an unexpected pressure increase due to liquid medium compression). To increase the backflow. As can be seen from the upper diagram of FIG. 4, the spring-biased slider moves to the right against the spring by the pressure from the back pressure region, and the fluid from the back pressure region is sent to the compression chamber with less resistance ( Ensuring sealing performance of the compression chamber). On the other hand, the structure shown in the lower diagram of FIG. 4 functions so that the spring-biased slider blocks the communication flow path and the resistance of the liquid refrigerant flow path from the compressor increases.

  Other backflow reduction mechanisms include a combination of a valve body and an elastic body, and a mechanism based on temperature sensitivity in response to a temperature drop of the liquid refrigerant, and the flow path resistance changes depending on the flow direction as shown in FIG. A so-called fluidic diode 23 may be used. In particular, when the orbiting scroll 20 has a large gap that moves up and down in the direction of the rotation axis, the back flow of the liquid refrigerant is more likely to occur, so the above-described back flow reduction mechanism is more effective. Of course, a structure that can not only reduce the backflow but also suppress the backflow is acceptable.

  As described above, the scroll compressor according to the embodiment of the present invention can reduce the liquid refrigerant in the compression chamber while reducing loss due to re-expansion and heating through the communication flow path between the back pressure region and the compression chamber. The main feature is that a relief mechanism is provided in the compression chamber and the fixed scroll so that the refrigerant does not enter the back pressure region through the communication channel when the pressure rises due to compression.

  As a specific configuration and action, the orbiting scroll wrap is provided with a communication channel (a through hole in a specific example) that communicates between the compression chamber and other than the compression chamber, and the compression chamber communicates with the opening on the compression chamber side of the communication channel. By disposing the relief mechanism on the fixed scroll so that the relief mechanism can be opened, the liquid refrigerant can be prevented from entering other than the compression chamber while being easily discharged when the liquid refrigerant is sucked. In addition, when oil containing a large amount of refrigerant in the back pressure region other than the compression chamber or in the bearing portion is foamed, it is not only discharged to the compression chamber through the flow path of the orbiting scroll, but also discharged from the fixed scroll. Thus, unnecessary pressure rises in the back pressure region and the compression chamber are also reduced. Although the description has been given of the compressor communicating with the compression chamber and the back pressure region as an example, the same effect can be obtained with a compressor provided with a through-hole communicating with the orbiting scroll between the compression chamber and the bearing portion. In the above description, the scroll compressor has been described as an example, but the present invention is not limited to this and is a technique applicable to a fluid compressor and a fluid transport machine.

FIG. 3 is a cross-sectional view taken along line A-A ′ of FIG. 2, showing a cross section of a compression chamber in the scroll compressor according to the embodiment of the present invention. It is a figure which shows the schematic whole structure in the scroll compressor which concerns on this embodiment. It is a figure which shows an example of resistance change of the communication flow path provided in the wrap of the turning scroll in the scroll compressor which concerns on this embodiment. It is a figure which shows the other example of resistance change of the communication flow path provided in the wrap of the turning scroll regarding this embodiment. It is a figure which shows the further example of resistance change of the communication flow path provided in the wrap of the turning scroll regarding this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluid inlet 2 Fluid outlet 3 Intermediate outlet 5 Orbiting scroll base plate 6 Fixed scroll base plate 7 Orbiting scroll end plate 8 Fixed scroll end plate 10 Fixed scroll 11 Relief mechanism 12, 12a, 12b Relief port 15 Orbiting scroll wrap 16 Fixed scroll wrap 20 Orbit Scroll 21 Through-hole 22 Backflow reduction mechanism 23 Fluid diode 30, 30a, 30b Compression chamber 31 Back pressure region 40 Clearance 50 Frame 60 Shaft 70 Rotation prevention mechanism 80 Back pressure adjustment mechanism

Claims (7)

A plurality of compression chambers are formed by meshing a fixed scroll provided with a spiral wrap and a turning scroll so that the wraps face each other, and back pressure is applied to the back of the turning scroll so that the turning scroll does not rotate. In a scroll compressor that performs fluid compression by continuously reducing the volume of the compression chamber by revolving to
A communication channel that communicates from the compression chamber to a region other than the compression chamber, such as a back pressure region or a bearing portion of the orbiting scroll, is provided in the wrap and base plate of the orbiting scroll,
A scroll compressor characterized in that a relief mechanism for opening a predetermined pressure fluid in a compression chamber connected to a communication channel provided in a lap of the orbiting scroll to the outside is provided in the fixed scroll. In claim 1,
The communication flow path is composed of a through-hole penetrating the wrap and base plate of the orbiting scroll, and a gap between the wrap end surface of the orbiting scroll and the base plate of the fixed scroll. Machine. In claim 1 or 2,
A scroll compressor characterized in that the relief mechanism is provided in a plurality of compression chambers connected adjacent to an opening of a communication flow path provided in a lap of the orbiting scroll. In claim 1, 2 or 3,
A scroll compressor characterized in that a channel resistance of a relief mechanism provided in the fixed scroll is made smaller than a channel resistance of the communication channel. In claim 2,
Changing the cross-sectional area of the through hole provided in the orbiting scroll stepwise or continuously,
A scroll compressor characterized in that a channel resistance of a relief mechanism provided in the fixed scroll is made smaller than a channel resistance of the communication channel. A plurality of compression chambers are formed by meshing a fixed scroll provided with a spiral wrap and a turning scroll so that the wraps face each other, and back pressure is applied to the back of the turning scroll so that the turning scroll does not rotate. In a scroll compressor that performs fluid compression by continuously reducing the volume of the compression chamber by revolving to
A communication channel that communicates from the compression chamber to a region other than the compression chamber, such as a back pressure region or a bearing portion of the orbiting scroll, is provided in the wrap and base plate of the orbiting scroll,
A relief mechanism for opening a predetermined pressure fluid in a compression chamber connected to a communication flow path provided in the wrap of the orbiting scroll to the outside is provided in the fixed scroll;
The communication flow path provided in the orbiting scroll is provided with a flow path resistance change mechanism in which the flow path resistance changes according to the flow direction of the fluid,
The flow path resistance changing mechanism increases a first flow path resistance in a fluid flow direction from the compression chamber to a region other than the compression chamber, and increases a fluid flow direction from the region other than the compression chamber to the compression chamber. Having a function of reducing the second flow path resistance;
A scroll compressor characterized in that a flow path resistance of a relief mechanism provided on the fixed scroll is made smaller than the first flow path resistance of the flow path resistance changing mechanism. In claim 6,
The scroll compressor, wherein the flow path resistance change mechanism is a fluid diode.

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