JP2019019768A - Scroll compressor - Google Patents

Abstract

To inhibit pressing force between a fixed scroll and an orbiting scroll from becoming excessive even in an operation condition in which a pressure ratio becomes high.SOLUTION: A scroll compressor comprises an orbiting scroll 200, and a fixed scroll 100 meshed with the orbiting scroll to form compression chambers 4. Further, the scroll compressor comprises: a high-pressure chamber 7 in which a discharge pressure is introduced for closely contacting the orbiting scroll and the fixed scroll to each other; a back pressure chamber 6 that is divided from the high-pressure chamber via a first seal part 403 and has a pressure between a suction pressure and the discharge pressure to bring both scrolls in tight contact with each other; a seal part internal space that is a part of the high-pressure chamber divided via a second seal part 607; a communication passage 208 providing communication between the seal part internal space and the back pressure chamber; and a pressure regulation valve 600 opening and closing the communication passage by a pressure difference. When the pressure difference between the seal part internal space and the back pressure chamber becomes a predetermined value or more, the pressure regulation valve is opened to let a fluid in the seal part internal space outflow to the back pressure chamber side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a scroll compressor, and is particularly suitable for a hermetic scroll compressor used as a refrigerant compressor such as a refrigeration apparatus or an air conditioner.

  The scroll compressor forms a compression chamber by engaging both the fixed scroll and the orbiting scroll, and compresses the refrigerant gas by reducing the volume while moving the compression chamber toward the center. Due to the compression action at this time, a force (pulling force) for pulling the orbiting scroll away from the fixed scroll is generated.

  On the other hand, in the hermetic scroll compressor used in the refrigeration apparatus, the refrigerant gas compressed in the two scrolls to a high pressure is discharged into the hermetic container, and the swirling is performed by the refrigerant gas at the discharge pressure. A force for pressing the scroll against the fixed scroll (pressing force) is also generated.

If the orbiting scroll is separated from the fixed scroll, the refrigerant gas compression efficiency deteriorates, and even if the orbiting scroll is excessively pressed against the fixed scroll, sliding loss increases. Therefore, it is necessary to press the orbiting scroll in a balanced manner against the fixed scroll so that the pressing force is appropriate for the pulling force.
As this kind of prior art, there is one described in Japanese Patent Laid-Open No. 2005-307989 (Patent Document 1).

Japanese Patent Laid-Open No. 2005-307989

  In a conventional scroll compressor, the back side of the orbiting scroll is a back ring space that is a space between a discharge pressure space on the center side and an intermediate pressure (pressure between the suction pressure and the discharge pressure) on the outer peripheral side by a seal ring. Some are separated into pressure chambers. In the case of the scroll compressor configured as described above, the pressing force by the discharge pressure space is determined by the inner diameter dimension of the seal ring. On the other hand, the pulling force is also determined by the compression action in the compression chamber formed by the fixed scroll and the orbiting scroll. Depending on the operating conditions of the scroll compressor, the pressing force may be excessively larger than the pulling force.

  When the pressing force becomes excessively large with respect to the pulling force, the sliding loss (friction sliding loss) on the end plate surface between the fixed scroll and the orbiting scroll increases, and the power loss of the compressor increases. Further, when the pressing force becomes excessively large, there is a possibility that galling, seizure, or the like occurs on the scroll end plate surface.

  For such a problem, in the scroll compressor described in Patent Document 1, a communication passage that communicates the suction chamber and the back pressure chamber provided at the back of the orbiting scroll is provided, and the communication passage is opened and closed. A back pressure control valve is provided to open and close the back pressure control valve according to the difference between the pressure in the back pressure chamber and the suction pressure. Thereby, the fluctuation of the pressing force of the orbiting scroll is reduced.

  However, when the operation is performed at a low evaporation temperature even when the outside air temperature is high, that is, the operation at a so-called high pressure ratio is necessary, the suction pressure is low and the discharge pressure is high, so that the pressing force becomes excessively large. There is.

In particular, in a refrigeration system or the like where the main operating range is a high pressure ratio where the difference between the suction pressure and the discharge pressure is large, it is often operated with an excessively large pressing force, and sliding Loss increases, and the risk of galling and seizure on the scroll end plate surface increases, reducing the reliability of the scroll compressor.
However, in the thing of the said patent document 1, it is not considered with respect to the operating conditions in a high pressure ratio, and the consideration in ensuring reliability and performance improvement in a high pressure ratio operating condition is not made.

  An object of the present invention is to obtain a scroll compressor capable of suppressing an excessive pressing force between a fixed scroll and an orbiting scroll even under operating conditions where a high pressure ratio is achieved.

  To achieve the above object, according to the present invention, a rotating scroll having a spiral wrap on the end plate and having a turning boss formed on the back side of the end plate, and a compression chamber formed by meshing with the turning scroll. A fixed scroll, a crankshaft having an eccentric pin portion engaged with a turning boss portion of the orbiting scroll, and a rotation shaft for driving the orbiting scroll; and a frame for accommodating the orbiting scroll and fixing the fixed scroll. A scroll compressor provided with a high-pressure chamber that is formed in the orbiting boss portion of the orbiting scroll and into which discharge pressure is introduced, and is formed on the outer peripheral side of the orbiting boss portion on the back side of the orbiting scroll, A back pressure chamber partitioned through one seal portion and a portion of the high pressure chamber separated from the interior of the seal portion partitioned through a second seal portion And a communication passage formed in the end plate of the orbiting scroll and communicating the inner space of the seal portion and the back pressure chamber, and a pressure adjusting valve that opens and closes the communication passage by a pressure difference, and the inner space of the seal portion, When the pressure difference with the back pressure chamber becomes equal to or greater than a predetermined value, the pressure regulating valve opens, and the fluid in the space in the seal portion flows out to the back pressure chamber side.

  Another feature of the present invention is that in a scroll compressor including a orbiting scroll and a fixed scroll that meshes with the orbiting scroll to form a compression chamber, a discharge pressure for bringing the orbiting scroll and the fixed scroll into close contact with each other is provided. The high-pressure chamber to be introduced and the high-pressure chamber are partitioned through a first seal portion, and a back pressure chamber serving as a pressure between the suction pressure and the discharge pressure in order to bring the orbiting scroll and the fixed scroll into close contact with each other. , A part of the high-pressure chamber, a space inside the seal part partitioned through a second seal part, a communication path communicating the space inside the seal part and the back pressure chamber, and opening and closing the communication path by pressure difference And when the pressure difference between the inner space of the seal portion and the back pressure chamber exceeds a predetermined value, the pressure adjustment valve opens to allow the fluid in the inner space of the seal portion to flow to the back pressure chamber side. There to be.

  According to the present invention, there is an effect that it is possible to obtain a scroll compressor that can suppress an excessive pressing force between the fixed scroll and the orbiting scroll even under an operating condition where the pressure ratio is high.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a first embodiment of a scroll compressor according to the present invention. FIG. 6 is a schematic diagram illustrating a state in which the fixed scroll and the orbiting scroll in the first embodiment illustrated in FIG. 1 are combined, and is a diagram illustrating a pressing force when the pressure adjustment valve is closed. FIG. 5 is a schematic diagram illustrating a state in which the fixed scroll and the orbiting scroll are combined in the first embodiment illustrated in FIG. 1, and is a diagram illustrating a pressing force when a pressure adjustment valve is open.

  Hereinafter, specific examples of the scroll compressor of the present invention will be described with reference to the drawings. In each figure, the part which attached | subjected the same code | symbol is the same part.

A scroll compressor according to a first embodiment of the present invention will be described with reference to FIGS.
First, the overall configuration of the scroll compressor according to the first embodiment will be described with reference to FIG. FIG. 1 is a longitudinal sectional view showing Embodiment 1 of the scroll compressor of the present invention.

  As shown in FIG. 1, in the sealed container 700, a compression mechanism unit 1 is provided above, an electric motor 2 is provided at the center, and an oil sump 3 is provided below. The compression mechanism unit 1 is connected to the electric motor 2 via a crankshaft 300.

The compression mechanism unit 1 includes a fixed scroll 100, a turning scroll 200, a frame 400, and the like.
The fixed scroll 100 includes an end plate 102, a spiral wrap (fixed wrap) 101 standing on one side of the end plate 102, a discharge port 103, and the like. The fixed scroll 100 is fixed to the frame 400 via bolts 402.

  The orbiting scroll 200 includes an end plate 202, a spiral wrap (orbiting wrap) 201 erected on one side of the end plate 202, and an orbiting boss portion (shaft support) formed at the center of the rear surface (non-wrap side) of the end plate. Part) 203 and the like.

  The compression chamber 4 is formed by meshing the wraps 101 and 201 of the fixed scroll 100 and the orbiting scroll 200 with each other, and the compression chamber 4 is a compression whose volume is reduced by the orbiting motion of the orbiting scroll 200. Operation is performed.

  The frame 400 is fixed in the sealed container 700 and is provided with a rolling bearing (main bearing) 401 that rotatably supports the crankshaft 300. The crankshaft 300 is supported by the rolling bearing 401 provided at the upper part of the electric motor 2 and the auxiliary bearing 500 provided at the lower part of the electric motor 2. The sub-bearing 500 is provided in a sub-bearing housing 503, and the sub-bearing housing 503 is attached to a lower frame 501 attached to the lower part in the hermetic container 700.

  The crankshaft 300 is integrally coupled to the rotor of the electric motor 2. An eccentric pin portion (crank pin) 301 is provided on the upper end side of the crankshaft 300, and the eccentric pin portion 301 is formed to project from the rear surface of the end plate 202 of the orbiting scroll 200 of the compression mechanism unit 1. It is inserted into the boss portion 203 and engaged. A turning bearing 205 is provided in the turning boss portion 203 and forms a sliding surface with the eccentric pin portion 301.

  An Oldham joint 502 is disposed on the rear surface of the orbiting scroll 200. This Oldham joint 502 is a joint as an anti-rotation mechanism that causes the orbiting scroll 200 to orbit with respect to the fixed scroll 100 when the eccentric pin portion 301 rotates eccentrically by the rotation of the crankshaft 300.

  A back pressure chamber 6 formed by the frame 400, the fixed scroll 100, and the orbiting scroll 200 is provided on the back side of the end plate 202 of the orbiting scroll 200. Further, the end plate 202 of the orbiting scroll 200 is formed with a back pressure hole 206 for communicating the compression chamber 4 and the back pressure chamber 6 formed by combining the laps 101 and 201. The back pressure hole 206 is communicated with the compression chamber 4a immediately after being closed, that is, a compression chamber having a pressure slightly higher than the suction pressure, whereby the pressure in the back pressure chamber 206 is intermediate between the suction pressure and the discharge pressure. Pressure (intermediate pressure) is maintained.

  On the other hand, in the space in the orbiting boss portion 203 of the orbiting scroll 200, high pressure oil is supplied from the oil reservoir 3 through an oil passage 303 formed in the crankshaft 300 in the axial direction. A chamber (discharge pressure space) 7 is formed.

  An annular seal groove 404 is formed in the portion of the frame 400 facing the orbiting boss portion end surface 204 of the orbiting scroll 200, and a seal ring 403 is disposed in the seal groove 404. The seal part is configured. The seal ring (first seal portion) 403 seals the back pressure chamber 6 in which the intermediate pressure on the back surface of the orbiting scroll 200 acts and the discharge pressure space 7 serving as the discharge pressure inside the seal ring 403. Thus, refrigerant gas or oil having a discharge pressure is prevented from flowing into the back pressure chamber 6 from the high pressure chamber 7. Thus, in this embodiment, the seal ring 403 forms the high-pressure chamber (discharge pressure space) 7 on the back center side of the orbiting scroll 200 and the back pressure chamber (intermediate pressure space) 6 on the outside thereof. doing.

  As described above, since the back pressure chamber 6 and the high pressure chamber 7 are formed on the back surface of the orbiting scroll 200, the orbiting scroll 200 includes the intermediate pressure of the back pressure chamber 206 and the high pressure chamber. 7 is pressed against the fixed scroll 100 from the back side with a resultant force of the discharge pressure of 7, and the orbiting scroll and the fixed scroll are configured such that their end plate surfaces come into contact with each other and slide.

  When the electric motor 2 is driven and the orbiting scroll 200 is orbited, a working fluid (refrigerant gas) flowing through a refrigeration cycle such as a refrigeration apparatus passes through a suction pipe 702 attached so as to penetrate the upper part of the hermetic container 700. The suction chamber 104 formed on the outer peripheral side of the fixed scroll 100 is sucked. From here, the working fluid is taken into the compression chamber 4, and as the compression chamber 4 moves to the center, the volume is reduced to compress the gas, and the compressed gas is discharged from the discharge port 103 to the discharge chamber 5. Discharged.

  The gas discharged into the discharge chamber 5 passes through a passage (not shown) on the outer peripheral side of the compression mechanism portion 1 and flows into the space where the electric motor 2 is disposed, and a part of the gas is discharged from the electric motor 2. After the motor 2 is circulated through the surroundings and cooled, it is sent out to a refrigeration cycle outside the compressor from a discharge pipe 701 attached to the side portion of the closed container 700. Since the scroll compressor is configured in this way, the space in the hermetic container 700 is maintained at the discharge pressure.

Next, the oil supply path will be described.
A pump portion 504 is provided at the lower end of the auxiliary bearing housing 503, and the pump portion 504 is configured to be driven by the crankshaft 300. When the crankshaft 300 rotates, the pump portion 504 also rotates, sucking up the oil in the oil reservoir 3 and sending it to the oil passage 303 in the crankshaft 300. A part of this oil flows to the auxiliary bearing 500 through a lateral hole 304 communicating with the oil passage 303 and then returns to the oil sump 3.

  The oil that has reached the eccentric pin portion 301 through the oil passage 303 is sent to the high-pressure chamber 7 in the swivel boss portion 203 via the crank pin portion lateral hole 305 communicating with the oil passage 303. After lubrication of the slewing bearing 205 provided in the bearing, it flows to the rolling bearing 401 and lubricates it. Thereafter, the oil after lubrication of the bearing passes through the oil drain pipe 405 and returns to the oil reservoir 3.

  Further, a refueling pocket 207 is provided on the end surface 204 of the revolving boss 200 of the orbiting scroll 200, and the revolving pocket 200 reciprocates between the outer side and the inner side of the seal ring 403 by the revolving motion of the revolving scroll 200, Part of the oil between the slewing bearing 205 and the rolling bearing 401 is conveyed to the back pressure chamber 6. The oil transported to the back pressure chamber 6 lubricates the Oldham coupling 502 and the like, and then lubricates the sliding surfaces of the end plate 102 of the fixed scroll 100 and the end plate 202 of the orbiting scroll 200 and the suction chamber 104. Flow into. A part of the oil in the back pressure chamber 6 flows through the back pressure hole 206 and flows into the compression chamber 4a immediately after the closing.

  In the present embodiment, a ring-shaped (annular) seal groove 608 and an annular seal member 607 disposed in the seal groove 608 are formed on the end face of the eccentric pin portion 301 in the high-pressure chamber 7. A configured second seal portion is provided, and a part of the high-pressure chamber 7 is provided with a seal portion inner space 7a that is partitioned via the second seal portion. Further, a communication path 208 that communicates between the seal portion inner space 7 a and the back pressure chamber 6 is formed in the end plate 202 of the orbiting scroll 200. Further, a pressure adjusting valve 600 is provided that opens and closes the communication passage 208 by a pressure difference between the pressure in the seal portion inner space 7 a and the pressure in the back pressure chamber 6.

  The pressure regulating valve 600 is closed when the pressure difference between the seal portion inner space 7a and the back pressure chamber 6 is less than a predetermined value, and the pressure difference between the seal portion inner space 7a and the back pressure chamber 6 is reduced. It opens so that the fluid in the seal portion inner space 7a flows out to the back pressure chamber 6 side when a predetermined value or more is reached.

  Next, the axial load applied to the orbiting scroll 200 will be described with reference to FIG. FIG. 2 is a schematic diagram showing a state in which the fixed scroll and the orbiting scroll in the first embodiment shown in FIG. 1 are combined, and is a diagram for explaining the pressing force applied to the orbiting scroll when the pressure regulating valve 600 is closed. For example, when the engine is operated at a low pressure ratio in which the pressure difference between the suction pressure and the discharge pressure is small, such as during startup, the pressure difference between the seal portion inner space 7a and the back pressure chamber 6 becomes smaller than a predetermined value, The pressure regulating valve 600 is closed.

FIG. 2 shows the pressing force (pressing load) applied to the back side (the opposite lap side) of the orbiting scroll 200 when the pressure regulating valve 600 is closed by an arrow.
Here, the load acting in the axial direction of the orbiting scroll 200 is defined as follows. The load in the direction in which the orbiting scroll 200 moves away from the fixed scroll 100 is referred to as a pulling force (pressing force), and the load in the direction in which the orbiting scroll 200 is pressed against the fixed scroll 100 is referred to as a pressing force (pushing force). The resultant force of the pulling force and the pressing force finally becomes a force for pressing the orbiting scroll 200 against the fixed scroll 100.

  During normal operation, the orbiting scroll 200 is pressed against the fixed scroll 100 by the pressing force acting on the back surface of the end plate 202, and the end plates of the fixed scroll 100 and the orbiting scroll 200 are in close contact with each other. When the pulling force of the orbiting scroll 200 is large with respect to the fixed scroll 100, the phenomenon of separation of the orbiting scroll 200 occurs, resulting in a large efficiency reduction due to gas leakage in the compression chamber. For this reason, it is necessary to make the pressing force larger than the pulling force in the entire operating range of the scroll compressor, that is, in all operating pressure conditions.

  Among the plurality of compression chambers 4 formed by the meshing of the fixed scroll 100 and the orbiting scroll 200, the inner compression chamber 4 has a higher pressure, and the radial direction from the inner compression chamber 4 toward the outer compression chamber increases. Pressure is applied. Accordingly, the pulling force acts not only on the axial load but also on the moment load due to the pressure acting in the radial direction.

  The pressing force is a pressing force (thick white arrow shown in FIG. 2) due to the discharge pressure of the high-pressure chamber 7 formed inside the inner diameter portion of the seal ring 403 shown in FIG. This is the resultant force with the pressing force (thin arrow shown in FIG. 2) due to the intermediate pressure of the back pressure chamber 6 formed outside the inner diameter portion. Any pressing force is determined by the suction pressure and the discharge pressure which are pressure conditions of the scroll compressor.

  Further, when the inner diameter of the seal ring 403 is relatively larger than the diameter of the end plate 202 of the orbiting scroll 200, the pressing force due to the discharge pressure of the high-pressure chamber 7 inside the seal ring 403 becomes dominant. In such a case, when the temperature on the evaporator side of the refrigeration cycle becomes very low, the suction pressure decreases, and the operating condition has a high pressure ratio in which the difference from the discharge pressure becomes large, the separating force due to the pressure in the compression chamber 4 On the other hand, the pressing force due to the discharge pressure of the high pressure chamber 7 inside the seal ring 403 tends to be excessive. Therefore, in the conventional scroll compressor, when the operating condition is a high pressure ratio, the pressing force of the orbiting scroll 200 tends to be excessive, sliding loss increases, and galling or seizure occurs on the scroll end plate surface. There was a problem that the risk of doing so increased.

  In order to solve this problem, in the scroll compressor of the present embodiment, as shown in FIGS. 1 and 2, a ring-shaped seal groove 608 is arranged on the end surface of the eccentric pin portion 301 and the seal groove 608 is arranged. A second seal portion constituted by the provided ring-shaped seal member 607 is provided. The seal member 607 seals between the end surface of the eccentric pin portion 301 and the back surface of the orbiting scroll 200. As a result, a seal portion inner space 7 a is formed inside the second seal portion in the high pressure chamber 7.

  Further, a communication path 208 that communicates the seal portion inner space 7 a with the back pressure chamber 6 that is an intermediate pressure space is formed in the end plate 202 of the orbiting scroll 200. That is, in the end plate 202, the communication path 208 is formed in the radial direction so as to communicate the seal portion inner space 7a and the side surface portion of the end plate 202.

  Further, a pressure regulating valve 600 is provided on the side of the communication passage 208 that is open toward the back pressure chamber 6. The pressure adjusting valve 600 is configured to open and close by a pressure difference between the pressure in the seal portion inner space 7 a and the pressure in the back pressure chamber 6.

The pressure regulating valve 600 includes a valve plate 602 provided in the communication passage 208, a valve spring 603 that presses the valve plate 602 in a closing direction, and a valve presser that fixes the counter valve plate side of the valve spring 603. 604 and the like.
In addition, the portion of the communication passage 208 that accommodates the pressure regulating valve 600 is a valve housing portion 208a that has a diameter larger than the diameter of the communication passage 208 on the seal portion inner space 7a side.

  The valve presser 604 is fixed by press-fitting into the communication path 208 from the side surface side of the end plate 202 of the orbiting scroll 200, and the load that presses the valve plate 602 by the pressure in the seal portion inner space 7a is: It acts toward the valve presser 604 side via the valve spring 603.

  The valve plate 602 is configured to partition the pressure in the seal portion inner space 7 a and the pressure in the back pressure chamber 6 on the side surface and the back surface of the end plate 202. A load in the direction of opening the valve plate 602, that is, a load in the direction of opening the communication path 208 is applied to the valve plate 602 by the discharge pressure from the inside of the seal portion inner space 7a.

  The valve retainer 604 is formed with a hole 605 communicating with both sides of the valve retainer 604 at the center thereof, and the pressure of the back pressure chamber 6 is introduced to the valve plate 602 side through the hole 605. Thus, the valve plate 602 acts in the closing direction. Therefore, a load obtained by adding the pressing force by the valve spring 603 and the pressing force by the pressure of the back pressure chamber 6 to the valve plate 602 is a load in a direction in which the valve plate 602 is closed, that is, a direction in which the communication path 202 is closed. Acts as a load.

As a result, a load in the direction of opening the valve plate 602 and a load in the direction of closing the valve plate 602 act on the valve plate 602, and the valve plate 602 is opened and closed by the resultant force of these loads.
The pressing force by the valve spring 603 is determined by the amount of deflection of the valve spring in a state in which the valve spring is assembled, and is a constant amount. Therefore, the pressure difference between the pressure in the seal portion inner space 7 a and the pressure in the back pressure chamber 6. The valve plate 602 is opened and closed by (differential pressure).

  As the scroll compressor starts and the suction pressure decreases, the pressure ratio increases. When the operation condition shifts to a high pressure ratio, the pressure in the back pressure chamber 6 decreases as the suction pressure decreases, so the load pressing the valve plate 602 in the closing direction becomes small. On the other hand, the pressure in the high-pressure chamber 7 is the discharge pressure, and the pressure in the seal portion inner space 7a is also the discharge pressure. For this reason, the load which presses the said valve plate 602 in the direction to open remains large.

  Accordingly, the pressure difference between the seal portion inner space 7a and the back pressure chamber 6 gradually increases, and when the suction pressure is stabilized, the pressure difference is also stabilized. However, when the operation is performed at a high pressure ratio in which the suction pressure is low and the discharge pressure is high, and the pressure difference becomes equal to or greater than a predetermined value, the valve plate 602 is opened. That is, since the pressure regulating valve 600 is opened, the high-pressure fluid in the seal portion inner space 7a flows out to the back pressure chamber 6 side.

  In the case where the valve plate 602 is a disk-shaped member having a diameter substantially the same as the hole diameter of the valve accommodating portion 208a, the communication path 208 is not moved even if the valve plate 602 moves to the outer peripheral side of the end plate 202. The valve plate 602 remains blocked. For this reason, in this embodiment, several notches are formed in the circumferential direction on the outer peripheral side of the valve plate 602. This notch is formed only on the outer peripheral side of the valve plate 602 so that the communication path 208 can be completely closed when the valve plate 602 is closed. That is, the notch is formed only in the valve plate 602 that is on the outer diameter side of the diameter of the communication passage 208 on the seal portion inner space 7a side.

  An outer peripheral portion of the valve plate 602 other than the notch is formed to be slightly smaller than an inner diameter of the valve housing portion 208a in the communication path 208 so that the valve plate 602 can be guided and moved by the inner surface of the valve housing portion 208a. It is configured. With this configuration, when the valve plate 602 is opened, the communication path 208 that has been blocked by the valve plate 602 is opened, and the notch formed in the valve plate 602 and the valve plate 602 and the valve housing portion are opened. The high pressure gas from the seal portion inner space 7a flows out to the back pressure chamber 6 side through the gap with the inner surface of 208a and further passing through the hole 605 formed in the valve presser 604.

  Accordingly, the pressure in the seal portion inner space 7a is reduced by opening the valve plate 602, and the seal member 607 receives a force corresponding to a pressure difference from the outside to the inside. As a result, the inner peripheral surface of the seal member 607 and the inner peripheral surface of the seal groove 608 are pressed and sealed, and the pressure difference between the pressure in the seal portion inner space 7a and the pressure in the back pressure chamber 6 is greater than the predetermined value. Until the pressure becomes smaller, the pressure in the inner space 7a of the seal portion decreases. When the pressure in the seal portion inner space 7a is thus reduced and the pressure difference becomes smaller than the predetermined value, the valve plate 602 is closed again.

  FIG. 3 is a schematic diagram showing a state in which the fixed scroll and the orbiting scroll in the first embodiment shown in FIG. 1 are combined, and is a diagram for explaining the pressing force of the orbiting scroll when the pressure regulating valve is open. That is, it shows a state in which the pressure regulating valve is open under the operating condition of the high pressure ratio.

  When the operation condition of the high pressure ratio is reached and the pressure regulating valve 600 is opened, the load applied to the back side (the non-lap side) of the orbiting scroll 200 is as shown in FIG. That is, of the load applied to the back side of the orbiting scroll 200, the pressing force (indicated by a thin arrow) due to the intermediate pressure of the back pressure chamber 6 formed outside the inner diameter portion of the seal ring 403 (see FIG. 1). Is the same as in FIG.

  Further, in the high pressure chamber 7 formed on the inner side of the inner diameter portion of the seal ring 403, the portion outside the seal portion inner space 7a indicated by A is pressed by the discharge pressure as indicated by a thick white arrow. Since force acts, it is the same as in FIG.

  However, the pressure in the seal portion inner space 7a indicated by A (the space on the inner side of the inner diameter of the seal member 607) is pressed by the discharge pressure in the state of FIG. 2 in which the pressure regulating valve 600 is closed. However, in the state of FIG. 3, the pressing force is small. That is, in the state of FIG. 3, since the pressure regulating valve 600 is open, the pressure in the seal inner space 7a is reduced to be smaller than the discharge pressure, and the pressing force is reduced as shown by the thick filled arrows. ing.

  As described above, in this embodiment, the pressure regulating valve 600 is opened and the pressure in the seal portion inner space 7a is reduced when the operating condition is a high pressure ratio with a low suction pressure and a high discharge pressure. Therefore, even under operating conditions with a high pressure ratio, the pressing load of the orbiting scroll 200 can be reduced to an appropriate pressing force. Therefore, the sliding friction loss on the end plate surfaces of both scrolls can be reduced, and the end plate surface can be prevented from galling and seizure, so that the efficiency and reliability of the scroll compressor can be improved.

  As described above, according to the embodiment of the scroll compressor of the present invention, a part of the high-pressure chamber (discharge pressure space) 7 is formed in the seal portion partitioned by the second seal portion having the seal member 607. Since the space 7a, the communication passage 208 that communicates the seal portion inner space 7a and the back pressure chamber 6, and the pressure adjusting valve 600 that opens and closes the communication passage with a pressure difference are provided, even under operating conditions with a high pressure ratio. The force for pressing the orbiting scroll due to the discharge pressure can be relaxed. Therefore, since the orbiting scroll can be pressed against the fixed scroll with an appropriate pressing force, the sliding loss can be reduced, the performance can be improved, and the reliability can be improved.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, in the above-described embodiment, the case where the high-pressure chamber and the back-pressure chamber are formed on the back side of the orbiting scroll and the orbiting scroll is pressed against the fixed scroll has been described. The present invention is also applicable to a scroll compressor in which a high-pressure chamber and a back-pressure chamber are formed on the back side of the fixed scroll and the fixed scroll is pressed against the orbiting scroll.

That is, according to the present invention, in a scroll compressor including a orbiting scroll and a fixed scroll that meshes with the orbiting scroll to form a compression chamber, a discharge pressure for bringing the orbiting scroll and the fixed scroll into close contact with each other is introduced. The high pressure chamber and the high pressure chamber are partitioned via a first seal portion, and in order to bring the orbiting scroll and the fixed scroll into close contact, a back pressure chamber serving as a pressure between suction pressure and discharge pressure, A part of the high-pressure chamber, a seal part internal space partitioned through a second seal part, a communication path communicating the seal part internal space and the back pressure chamber, and pressure for opening and closing the communication path by a pressure difference An adjustment valve, and when the pressure difference between the seal portion inner space and the back pressure chamber becomes equal to or greater than a predetermined value, the pressure adjustment valve opens and the fluid in the seal portion space flows out to the back pressure chamber side. As long as having a structure in which.
The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

1: compression mechanism, 2: electric motor, 3: oil sump,
4: compression chamber, 4a: compression chamber immediately after closing, 5: discharge chamber,
6: Back pressure chamber (intermediate pressure space),
7: high pressure chamber (discharge pressure space), 7a: space in the seal part,
100: fixed scroll, 101: fixed lap, 201: turning lap,
102, 202: End plate, 103: Discharge port, 104: Suction chamber,
200: turning scroll, 203: turning boss part (shaft support part), 204: turning boss part end face,
205: slewing bearing,
206: Back pressure hole, 207: Refueling pocket, 208: Communication path, 208a: Valve housing part,
300: Rotating shaft 301: Eccentric pin part 303: Oil passage 304: Side hole
305: crankpin side hole,
400: Frame, 401: Rolling bearing (main bearing),
402: Bolt, 403: Seal ring (first seal part), 404: Seal groove,
405: Oil drain pipe,
500: Secondary bearing, 501: Lower frame,
502: Oldham coupling, 503: Sub-bearing housing, 504: Pump part,
600: pressure adjusting valve, 602: valve plate (valve), 603: valve spring, 604: valve retainer,
605: hole passage, 607: seal member (second seal portion), 608: seal groove,
700: closed container, 701: discharge pipe, 702: suction pipe.

Claims (10)

An orbiting scroll having a spiral wrap on the end plate and having a revolving boss formed on the back side of the end plate, a fixed scroll engaged with the orbiting scroll to form a compression chamber, and an orbiting boss portion of the orbiting scroll In a scroll compressor comprising: an eccentric pin portion engaged with the crankshaft for rotating the orbiting scroll; and a frame for accommodating the orbiting scroll and fixing the fixed scroll.
A high-pressure chamber formed in the orbiting boss portion of the orbiting scroll and into which discharge pressure is introduced; and
A back pressure chamber formed on the outer peripheral side of the orbiting boss portion on the back side of the orbiting scroll, the high pressure chamber being partitioned via a first seal portion;
A part of the high-pressure chamber, and a space inside the seal part partitioned through a second seal part;
A communication path formed on the end plate of the orbiting scroll, and communicating the space in the seal portion and the back pressure chamber;
A pressure adjustment valve that opens and closes the communication path by a pressure difference,
When the pressure difference between the space inside the seal part and the back pressure chamber becomes a predetermined value or more, the pressure adjusting valve opens, and the fluid in the space inside the seal part flows out to the back pressure chamber side.   2. The scroll compressor according to claim 1, wherein the second seal portion for separating a part of the high-pressure chamber to form the inner space of the seal portion is an end surface on the orbiting scroll side of the eccentric pin portion of the crankshaft. And a ring-shaped seal groove formed in the seal groove, and a ring-shaped seal member that is disposed in the seal groove and seals between the end surface of the eccentric pin portion and the orbiting scroll. Machine.   2. The scroll compressor according to claim 1, wherein the communication path is formed in a radial direction on a head plate of the orbiting scroll, the pressure adjusting valve is provided on an opening side of the communication path on a back pressure chamber, and The pressure adjusting valve opens and closes by a pressure difference between the pressure in the space in the seal portion and the pressure in the back pressure chamber.   4. The scroll compressor according to claim 3, wherein the pressure regulating valve includes a valve plate provided in the communication path, a valve spring that presses the valve plate in a closing direction, and a valve plate side of the valve spring. A scroll compressor comprising a valve presser for fixing the valve.   5. The scroll compressor according to claim 4, wherein the portion of the communication passage that houses the pressure regulating valve is a valve housing portion that is formed to have a diameter larger than the diameter of the communication passage on the inner space side of the seal portion. A scroll compressor characterized by that.   5. The scroll compressor according to claim 4, wherein the valve presser is press-fitted and fixed into the communication path from the side surface side of the end plate of the orbiting scroll, and presses the valve plate by the pressure in the space in the seal portion. A scroll compressor characterized in that a load acts on the valve presser via the valve spring.   6. The scroll compressor according to claim 5, wherein the valve presser has a hole formed in the center thereof so as to communicate with both sides of the valve presser, and the pressure of the back pressure chamber is transmitted through the hole. It is introduced to the valve plate side and acts in the direction of closing the valve plate, and the valve plate is configured so that a load that is the sum of the pressing force by the valve spring and the pressing force by the pressure of the back pressure chamber acts on the valve plate. A scroll compressor characterized by that.   The scroll compressor according to claim 7, wherein a plurality of notches are formed in a circumferential direction on an outer peripheral side of the valve plate, and the notches close the communication passage when the valve plate is closed. The scroll compressor is formed in a portion of the valve plate which is on the outer diameter side than the diameter of the communication path on the inner space side of the seal portion.   9. The scroll compressor according to claim 8, wherein an outer peripheral portion of the valve plate other than the notch is formed smaller than an inner diameter of the valve housing portion in the communication path, and the valve plate is formed on an inner surface of the valve housing portion. A scroll compressor characterized by being guided and moved. In a scroll compressor comprising a orbiting scroll and a fixed scroll meshed with the orbiting scroll to form a compression chamber,
A high-pressure chamber into which discharge pressure for bringing the orbiting scroll and the fixed scroll into close contact with each other is introduced;
The high-pressure chamber is partitioned through a first seal portion, and a back pressure chamber serving as a pressure between the suction pressure and the discharge pressure in order to closely contact the orbiting scroll and the fixed scroll;
A part of the high-pressure chamber, and a space inside the seal part partitioned through a second seal part;
A communication path communicating the inner space of the seal portion and the back pressure chamber;
A pressure adjustment valve that opens and closes the communication path by a pressure difference,
When the pressure difference between the space inside the seal part and the back pressure chamber becomes a predetermined value or more, the pressure adjusting valve opens, and the fluid in the space inside the seal part flows out to the back pressure chamber side.

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