JP5551644B2 - Scroll compressor - Google Patents

Description

  The present invention relates to the reliability and energy efficiency of refrigerant compressors for refrigeration and air conditioning, air and other electric scroll compressors.

  As a background art of this technical field, there is Patent Document 1. This publication states that “a non-orbiting scroll member, an orbiting scroll member that forms a suction chamber or a compression chamber by meshing with the non-orbiting scroll member and forming a suction chamber or a compression chamber; A back pressure chamber for providing fluid, back pressure chamber fluid inflow means for allowing fluid to flow into the back pressure chamber in order to maintain the back pressure, which is the pressure of the back pressure chamber, and The back pressure chamber fluid outflow means includes a back pressure control valve for controlling a differential pressure across the back pressure chamber and a throttle in a back pressure chamber fluid outflow passage connecting the back pressure chamber and the suction chamber or the compression chamber. The flow path portion and the intermittent flow path portion that intermittently communicates with each other by the orbiting motion of the orbiting scroll member are arranged in series. "

JP 2005-163655 A

  In the conventional technology, the back pressure chamber fluid outflow passage connecting the back pressure chamber and the suction chamber or the compression chamber is intermittently provided by a back pressure control valve that controls the differential pressure across the back and forth, the throttle passage, and the orbiting scroll. Stable back pressure was ensured by arranging the intermittent flow channel part to communicate, but the communication time between the back pressure chamber and the suction chamber (or compression chamber) is shortened by arranging the intermittent flow channel part. There is a possibility that the required amount of oil supply to the compression chamber cannot be obtained. Further, when the intermittent flow path portion is not disposed, the pressure pulsation in the back pressure chamber fluid outflow path is large, the back pressure control valve is abnormally opened, and the back pressure cannot be generated. That is, if both the oil supply amount and the back pressure can be ensured, a highly reliable compressor can be realized.

  Therefore, an object of the present invention is to realize a highly reliable scroll compressor.

The object of the present invention is as follows.
A fixed scroll and an orbiting scroll that stand upright with a spiral wrap on a base plate are engaged with each other, and a crankshaft that drives the orbiting scroll to rotate is provided, and suction is provided between the fixed scroll and the orbiting scroll as the crankshaft rotates. A back pressure chamber having a pressure higher than that of the suction chamber, and a back pressure chamber fluid outflow passage connecting the suction chamber or the compression chamber and the back pressure chamber. In the scroll compressor comprising back pressure control means for opening and closing the passage by a differential pressure in the middle of the back pressure chamber fluid outflow path,
This is achieved by a scroll compressor characterized in that an enlarged space having a cross-sectional area larger than the cross-sectional area of the back pressure chamber fluid outflow passage is provided in the middle of the back pressure chamber fluid outflow passage from the back pressure control means to the back pressure chamber. The

The object of the present invention is as follows.
With fixed scrolling,
A revolving scroll that receives a back pressure that is the pressure of the back pressure chamber from the back and is pressed against the fixed scroll and meshes to form a compression chamber;
A back pressure control valve that is provided in the middle of the path from the back pressure chamber to the suction space or the compression chamber and controls the back pressure by restricting the flow;
Have
In the scroll compressor that sucks the refrigerant from the suction space and compresses the refrigerant by the compression chamber,
In the middle of the path, on the back pressure chamber side of the back pressure control valve, there is an enlarged space whose cross-sectional area is 1.5 times larger than the cross-sectional area of the inlet of the path
The inlet is achieved by a scroll compressor that is always open without being blocked by the orbiting scroll.

  According to the present invention, a highly reliable scroll compressor can be realized.

The whole structure in the scroll compressor of a 1st embodiment. The detailed structure of the back pressure control means in the scroll compressor of 1st Embodiment. The detailed structure of the back pressure control means in the scroll compressor of 2nd Embodiment. The detailed structure of the back pressure control means in the conventional scroll compressor.

  Embodiments of the present invention will be described below with reference to the drawings.

  Example 1 will be described with reference to FIGS.

  First, the overall structure of the scroll compressor according to the first embodiment will be described with reference to FIG. The scroll compressor 1 is configured by storing a compression unit 2 and a drive unit 3 in a sealed container 4.

  In the compression unit 2, the compression operation is performed by reducing the volume of the mechanically configured compression chamber 2 a by meshing the fixed scroll 18 and the orbiting scroll 19 by the rotating action of the drive unit 3. With this compression operation, the working fluid is sucked into the compression chamber via the suction port 5 and the suction space, and the sucked working fluid is discharged to the discharge space in the sealed container 4 through the compression stroke, and further the discharge port. 6 is discharged from the sealed container 4 via 6.

  In the compression operation, an intermediate pressure between the discharge pressure and the suction pressure (hereinafter referred to as back pressure) is applied to the rear surface of the orbiting scroll 19 in order to keep the orbiting scroll 19 pressed against the fixed scroll 18 and keep the compression chamber 2a hermetically sealed. It acts on a space (hereinafter referred to as a back pressure chamber 21). By maintaining the back pressure appropriately by the back pressure control means 30, it is possible to reduce energy loss due to refrigerant leakage during the compression operation and to ensure good reliability with respect to the pressing scroll of the orbiting scroll.

  The drive unit 3 includes an electric motor 9 including a stator 7 and a rotor 8, a crankshaft 10, a frame 11, a sub frame 12, and a sub bearing housing 15 as basic elements. Here, the electric motor 9 is driven by an electric input from an inverter (not shown) via the electric terminal 16 and imparts a rotating action to the crankshaft 10. The crankshaft 10 includes a main shaft portion 10a, a sub shaft portion 10b, and an eccentric pin portion 10c. The shaft support portion 13 disposed on the frame 11 and the shaft support portion 14 disposed on the auxiliary bearing housing 15 constitute a shaft support portion that rotatably engages the main shaft portion 10 a and the sub shaft portion 10 b of the crankshaft 10. . Further, oil 17 for lubricating the shaft support portions 13 and 14 is stored in the sealed container 4, and the sub-frame 12 engaged with the frame 11 and the sub-bearing housing 15 is fixed to the sealed container 4.

  Next, the configuration of the back pressure control means 30 will be described with reference to FIG. FIG. 2 shows the back pressure control means 30 shown in FIG. 1 in detail. The illustrated back pressure control means 30 includes a seal member 31, a spring 32, a valve body 33, an inlet passage 34, an outlet passage 35, and an enlarged space 36 between the valve body 33 and the inlet passage 34.

  The inlet passage 34 communicates with the back pressure chamber 21, and the inlet portion of the inlet passage 34 is always open without being blocked by the orbiting scroll 19. The outlet passage 35 communicates with a suction space (not shown) that is in communication with the suction port 5 and has a suction pressure, or a compression chamber (not shown) that is being compressed. That is, a path from the back pressure chamber 21 to the suction space or the compression chamber is formed, and the back pressure control means 30 is disposed in the middle.

  In the valve body 33 of the back pressure control means 30, the valve body 33 is opened when the load acting on the pressure in the back pressure chamber 21 becomes larger than the load acting on the spring 32 and the pressure on the outlet passage side. The predetermined back pressure can be maintained by releasing the pressure in the back pressure chamber 21.

  FIG. 4 shows the detailed structure of the back pressure control means in the conventional scroll compressor.

  The conventional back pressure control means includes a seal member 51, a spring 52, a valve body 53, an inlet passage 54, and an outlet passage 55. The expansion space 36 in the present embodiment is between the valve body 53 and the inlet passage 54. It does not exist, and the inlet portion of the inlet passage 54 is intermittently opened and closed as the orbiting scroll 19 is compressed (illustration shows a closed state). In the conventional back pressure control means, unless the inlet passage 54 is intermittently opened, the valve body 53 may open at an unintended timing (occurrence of abnormal valve opening).

  The abnormal opening of the valve body 53 is caused by pressure pulsation in the back pressure chamber 21 communicating with the inlet passage 54, and causes a phenomenon that the back pressure cannot be generated. The back pressure chamber 21 is subjected to a local compression action by the orbiting motion of the orbiting scroll, so that pressure pulsation is generated. Since the back pressure chamber 21 is also a part of the oil supply path to the compression chamber, the pressure pulsation propagates to the valve body 53. Therefore, the propagation of pressure pulsation is blocked by the intermittent opening of the inlet passage 54 to suppress the abnormal opening of the valve body 53. However, due to the intermittent opening, the oil supply to the compression chamber is not sufficient, and in the air conditioner, the improvement in energy efficiency under intermediate conditions that have become important in recent years is hindered.

  The present embodiment corresponds to the above points. The relationship with the orbiting scroll 19 is defined so that the entrance passage 34 is always opened. Further, an enlarged space 36 is provided on the back pressure chamber 21 side of the back pressure control means 30 in the middle of the path. More specifically, an enlarged space 36 is provided between the valve body 33 and the inlet passage 34. The enlarged space 36 is formed by processing the fixed scroll 18, and has a cross-sectional area 1.5 times larger than the cross-sectional area of the inlet passage 34, so that the dynamic pressure is half that of the inlet passage 34. The following is preferable. The propagation of the pressure pulsation is attenuated by the expansion space 36 to prevent the valve body 33 from opening abnormally.

  In this way, the inlet passage 34 can always be opened to the back pressure chamber 21 and sufficient oil can be supplied to the compression chamber, so that leakage loss during compression can be reduced and intermediate conditions can be achieved. Energy efficiency can be improved.

  As a result, it is possible to reliably press the orbiting scroll 19 against the fixed scroll 18 and to reliably supply the oil to the compression chamber 2a. Energy efficiency can be improved. In addition, since it is possible to optimize the back pressure, it is possible to ensure reliability related to the sliding of the orbiting scroll 19. Therefore, a scroll compressor suitable for realizing high reliability and high energy efficiency can be realized.

  Next, Example 2 will be described with reference to FIG. Note that differences from the first embodiment will be mainly described.

  The back pressure control means is configured by inserting a piece member 46 separate from the fixed scroll 18 into the fixed scroll 18 and disposing a seal member 41, a spring 42, and a valve body 43 therein.

  The piece member 46 includes an inlet passage 44 and an outlet passage 45 that communicate with each other inside, and these passages communicate with an inlet passage 47 and an outlet passage 48 disposed in the fixed scroll 18, respectively. Therefore, in order from the back pressure chamber 21, “21 → 47 → 44 → (valve element 43) → 45 → 48 → suction space or compression chamber 2 a” is communicated to form a path from the back pressure chamber to the suction space or compression chamber. Is done. The inlet passage 47 disposed in the fixed scroll 18 communicates with the back pressure chamber 21, and the inlet portion of the inlet passage 47 is always open without being blocked by the orbiting scroll 19 as in the first embodiment. is there.

In addition to the effect of the first embodiment, the effect of the present embodiment uses the piece member 46 that is a separate body from the fixed scroll 18, and thus has an effect that the valve body 43 can be easily checked for leakage.
Furthermore, since the enlarged space 36 according to the first embodiment can be configured by the inlet passage 44 of the piece member 46, the processing can be easily performed, and the cost can be reduced.

  As described above, according to each embodiment, an enlarged space having a cross-sectional area larger than the cross-sectional area of the back pressure chamber fluid outflow path is provided in the middle of the back pressure chamber fluid outflow path from the back pressure control means to the back pressure chamber. Further, in the middle of the path from the back pressure chamber to the suction space or the compression chamber, an expanded space having a cross-sectional area three times or more larger than the cross-sectional area of the inlet of the path is provided.

  Thereby, even when the intermittent flow path portion is not provided, a stable back pressure can be secured, and an appropriate turning scroll push-up force and a necessary oil supply amount can be obtained. Therefore, a highly reliable scroll compressor can be realized. In actual operation, there are a number of different operating conditions, but under almost any operating condition, it is possible to secure an appropriate orbiting scroll push-up force and to suppress refrigerant leakage during the compression operation, thereby improving reliability. be able to.

DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Compression part 2a Compression chamber 3 Drive part 4 Airtight container 5 Suction port 6 Discharge port 7 Stator 8 Rotor 9 Electric motor 10 Crankshaft 11 Frame 12 Subframes 13 and 14 Shaft support part 15 Subbearing housing 16 Electricity Terminal 17 Oil 18 Fixed scroll 19 Orbiting scroll 21 Back pressure chamber 30 Back pressure control means 31, 41, 51 Seal members 32, 42, 52 Spring 33, 43, 53 Valve elements 34, 44, 54, 47 Inlet passages 35, 45 , 55, 48 Outlet passage 36 Expansion space 46 Piece member.

Claims (5)

A fixed scroll and an orbiting scroll that stand upright with a spiral wrap on a base plate are engaged with each other, and a crankshaft that drives the orbiting scroll to rotate is provided, and suction is provided between the fixed scroll and the orbiting scroll as the crankshaft rotates. A back pressure chamber having a pressure higher than that of the suction chamber, and a back pressure chamber fluid outflow passage connecting the suction chamber or the compression chamber and the back pressure chamber. The passage is opened and closed by the differential pressure between the suction chamber or the compression chamber and the back pressure chamber in the middle of the back pressure chamber fluid outflow passage, and the fluid in the back pressure chamber flows out to the suction chamber or the compression chamber. In the scroll compressor provided with the back pressure control means,
A scroll compressor characterized in that an enlarged space having a cross-sectional area larger than the cross-sectional area of the back pressure chamber fluid outflow passage is provided in the middle of the back pressure chamber fluid outflow passage from the back pressure control means to the back pressure chamber. The scroll compressor according to claim 1.
A scroll compressor comprising the back pressure chamber fluid outflow passage, the back pressure control means, and the expansion space in a fixed scroll. The scroll compressor according to claim 1 or 2,
The back pressure control means includes a valve body in a cylindrical space having a connection opening between the suction chamber side or the compression chamber side and the back pressure chamber fluid outflow passage on the suction chamber side and a connection opening between the back pressure chamber fluid outflow passage on the expansion space side. A scroll compressor comprising a spring, wherein the valve body opens and closes a connection opening with a back pressure chamber fluid outflow passage on the enlarged space side by a differential pressure. The scroll compressor according to claim 3,
The cylindrical space of the back pressure control means is composed of a cylindrical member separate from the fixed scroll, the fixed scroll provided with a back pressure chamber fluid outflow passage is provided with an assembly hole for the cylindrical member, and the connection of the cylindrical space A cylindrical member is combined with the assembly hole so that the opening is connected to the back pressure chamber fluid outflow passage on the suction chamber side or the compression chamber side, and an enlarged space is configured between the cylindrical member and the assembly hole. A featured scroll compressor. A fixed scroll, a revolving scroll that receives a back pressure that is the pressure of the back pressure chamber from the back and is pressed against and engaged with the fixed scroll to form a compression chamber, and a path from the back pressure chamber to the suction space or the compression chamber The back pressure is provided by passing the fluid in the back pressure chamber to the suction space or the compression chamber by opening and closing a passage by a differential pressure between the suction space or the compression chamber and the back pressure chamber. A scroll compressor that has a back pressure control valve to control, sucks the refrigerant from the suction space, and compresses the refrigerant by the compression chamber,
In the middle of the path, on the back pressure chamber side of the back pressure control valve, there is an enlarged space whose cross-sectional area is 1.5 times larger than the cross-sectional area of the inlet of the path
The scroll compressor characterized in that the inlet is always open without being blocked by the orbiting scroll.

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