JP2009293564A - Displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise caused by a vessel or a motor. <P>SOLUTION: In the displacement compressor wherein a compressing mechanism part 1 compressing a refrigerant, and a motor 7 connected to the compressing mechanism part 1 and having a rotor 3 and a stator 5 are housed in the vessel 9, a bottomed hole 40 is formed on one end or both ends of the stator 5 in a rotating axis direction of the motor 7. In stead of the bottomed hole 40, a flow passage 65 is formed on the stator 5 along the rotating axis direction of the motor, and an enlarged part 63 having an enlarged flow passage cross section is formed in the halfway of the flow passage 65, and one end or both ends of the flow passage 65 are formed to have a cross sectional area smaller than that of the enlarged part 63. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a positive displacement compressor, and more particularly to a technique for reducing noise generated from a compressor.

  Conventionally, positive displacement compressors are known to be used in air conditioners, heat pump water heaters, and the like. As such a positive displacement compressor, a compressor in which a compressor that compresses a refrigerant and a motor that is connected to the compressor and includes a rotor and a stator are housed in a container is known (for example, Patent Document 1). .

  On the other hand, as a technology to reduce the noise of positive displacement compressors, noise caused by pulsation and vibration of compressor discharge pressure is reduced by providing an expansion silencer in the suction side piping or discharge side piping of the compressor It has been proposed (for example, Patent Document 2).

JP 2-149777 JP 2006-342708 A

  However, although the technique described in Patent Document 2 can reduce noise associated with fluctuations in the discharge pressure of the compressor, no consideration is given to reducing noise inside the container caused by vibration of the container or vibration of the motor. .

  This invention makes it a subject to reduce the noise resulting from a container and a motor.

  In order to solve the above-described problem, the positive displacement compressor according to the first aspect of the present invention includes a compressor that compresses refrigerant, and a motor that is coupled to the compressor and includes a rotor and a stator. In the positive displacement compressor, the stator has a bottomed hole formed at one end or both ends in the rotation axis direction of the motor.

  Since it did in this way, noise inside a compressor can be reduced because a bottomed hole acts as a resonance type silencer. That is, of the noise inside the compressor, the acoustic energy of noise having a frequency that resonates (resonates) in the bottomed hole can be absorbed by resonance. Therefore, the depth of the bottomed hole is preferably 1/4 of the wavelength of the noise frequency to be attenuated or an odd multiple thereof. Here, the noise frequency to be attenuated is subject to noise caused by motors, compressor containers, compressor pulsations, etc., but in particular, it should be set based on the chopping frequency of the inverter that drives the motor at a variable speed. Is more desirable.

  In order to solve the above problems, the positive displacement compressor according to the second aspect of the present invention comprises a compressor that compresses refrigerant and a motor that is connected to the compressor and has a rotor and a stator. In the positive displacement compressor, the stator has a flow path provided in the direction of the rotation axis of the motor, an enlarged portion having a flow passage cross section enlarged is provided in the middle of the flow path, and one or both ends of the flow path are enlarged portions. The cross-sectional area is further reduced.

  Since it did in this way, a flow path can act as an expansion type silencer and the noise of a compressor can be reduced. In this case, a flow path having a smaller cross-sectional area than the enlarged portion is provided in another member on one or both of the shaft ends of the stator instead of the stator, and a flow path having a smaller step area than the enlarged portion is provided in the member. It may be provided. In general, since the stator is formed by stacking stator core plates such as magnetic steel plates, the stator core plates can be processed in the same shape, and the stator can be easily manufactured.

  According to the present invention, noise caused by the container and the motor can be reduced.

  Hereinafter, the present invention will be described based on embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view showing the overall configuration of a scroll compressor according to an embodiment of the present invention. As shown in FIG. 1, the vertical scroll compressor which is a positive displacement compressor of this embodiment is provided with the compression mechanism part 1 which is a compression means which compresses refrigerant gas (for example, carbon dioxide). A motor 7 having a rotor 3, a coil 4, and a stator 5 is connected to the compression mechanism unit 1, and the compression mechanism unit 1 and the motor 7 are accommodated in a cylindrical container 9.

  The compression mechanism unit 1 includes a fixed scroll 11 and a turning scroll 13. The fixed scroll 11 is in a cylindrical shape so as to surround the wrap 11b, the end plate 11a formed in a disc shape, a wrap 11b erected in a spiral shape on the end plate 11a, and the outer peripheral side of the end plate 11a. It is comprised from the formed support part 11d. The surface of the end plate 11a on which the wrap 11b is erected is a tooth bottom 11c. The fixed scroll 11 is fixed to the frame 15 by bolts 8 or the like at the support portion 11d, and the frame 15 is fixed to the container 9 by fixing means such as welding.

  The orbiting scroll 13 is disposed to face the fixed scroll 11 and is provided in the frame 15 so as to be orbitable. Similar to the disc-shaped end plate 13a and the fixed scroll wrap 11b, the orbiting scroll 13 is provided at the center of the rear surface of the end plate 13a and the spiral wrap 13b erected from the tooth bottom 13c that is the surface of the end plate 13a. And a boss portion 13d.

  The container 9 is formed in a hermetically sealed structure that houses a scroll portion including a fixed scroll 11 and a turning scroll 13, a motor 7, and lubricating oil. The crankshaft 17 is fixed to the rotor 3 of the motor 7 by press fitting or the like, and is coaxial with the axis of the fixed scroll 11. One end of the crankshaft 17 is rotatably provided on the frame 15 via a bearing 18, and the other end is rotatably provided on a support member 19 fixed to the lower part of the container 9 via a bearing 20. . A crank 21 is provided at the tip of the crankshaft 17, and a boss 13 d of the orbiting scroll 13 is rotatably attached to the crank 21 via a bearing 22. The crankshaft 17 is provided with a hole 23 in the axial direction, and the refrigerating machine oil at the bottom of the container 9 is supplied to the bearing 18, the bearing 22, and a back pressure chamber 33 to be described later via the hole 23. The orbiting scroll 13 is attached in a state where the axis is eccentric by a predetermined distance with respect to the axis of the fixed scroll 11.

  The wrap 13b of the orbiting scroll 13 is overlapped with the wrap 11b of the fixed scroll 11 while being shifted by a predetermined angle in the circumferential direction. An Oldham ring 24 is attached as a mechanism for making the orbiting scroll 13 relatively orbital while restraining the orbiting scroll 13 from rotating relative to the fixed scroll 11. When the orbiting scroll 13 is orbited in this state, a plurality of crescent-shaped compression chambers 25 are formed between the wraps 11b and 13b.

  The suction hole 27 is formed in the fixed scroll 11, and the suction hole 27 is formed on the outer peripheral side of the end plate 11a so as to communicate with the outermost peripheral compression chamber 25, thereby forming a suction chamber. One end of a suction pipe 28 is connected to the suction hole 27, and the other end is drawn out through the container 9. The discharge hole 29 is formed at the center of the end plate 11a of the fixed scroll 11 so as to communicate with the compression chamber 25 on the innermost peripheral side. A discharge chamber 30 is formed inside the container 9, one end of the discharge pipe 31 is opened to the discharge chamber 30 of the container 9, and the other end is drawn outside through the container 9.

  The back pressure chamber 33 is formed by a space surrounded by the compression mechanism portion 1 and the frame 15 on the back surface of the end plate 13 a of the orbiting scroll 13. The back pressure chamber 33 is compressed by a compression mechanism via a back pressure adjustment valve 35. It communicates with the suction chamber of part 1. A hole 37 for communicating the back pressure chamber 33 and the compression chamber is provided at the tooth tip of the wrap 13 b of the orbiting scroll 13.

  Next, the structure of the stator which is a characteristic part of this embodiment will be described. 2 is a view taken along the line AA in FIG. 1, FIG. 3 is a view taken along the line BB in FIG. 1, and FIG. 4 is a cross-sectional view showing a main part of the stator according to the present embodiment. The stator 5 is fixed to the container 9 by shrink fitting or the like, and is formed by stacking a plurality of stator core plates 5a and 5b. The stator core plates 5a and 5b are formed in a substantially circular shape by a processing method such as pressing a steel plate (for example, a magnetic steel plate). A bottomed hole 40 is formed in the stator 5 by combining the stator core plates 5a and 5b.

  As shown in FIG. 2, the stator core plate 5 a is provided with six circular holes 41 at equal intervals in the circumferential direction, and circular at two positions on both sides in the circumferential direction with respect to one hole 41. The hole 43 is provided therethrough. On the other hand, as shown in FIG. 3, the stator core plate 5b is provided with six circular holes 45 that are circumferentially spaced at equal intervals. The holes 45 are formed on the stator core 5a when the stator cores 5a and 5b are stacked. It is arranged at a position coaxial with the hole 41. That is, a plurality of stator core plates 5b are stacked on the upper portion of the stator 5, a plurality of stator core plates 5a are stacked and combined on the lower portion, and the holes 41 and 45 are arranged so as to be coaxial. A bottom hole 40 is formed. As shown in FIG. 4, the axial length L of the crankshaft 17 of the bottomed hole 40 is determined by the number of stacked stator core plates 5a. The length L of the bottomed hole 40 is set to, for example, 1/4 of the wavelength of the noise frequency to be attenuated or (2n-1) times (odd times). Here, n is an integer of 1 or more.

  Further, the stator 5 is provided with through holes (not shown) extending in the axial direction of the crankshaft 17 by coaxially arranging the holes 41 and 45 of the stator core plates 5a and 5b. A refrigerant containing machine oil is allowed to pass through. Notches are formed at equal intervals in the circumferential direction on the outer periphery of the stator core plates 5a and 5b, and a gap is formed between the container 9 and a refrigerant containing refrigerating machine oil. Protrusions on which the coils 4 are mounted are provided at equal intervals in the circumferential direction on the inner peripheral portions of the stator core plates 5a and 5b.

  Next, the operation of the scroll compressor configured as described above will be described. When the motor 7 is driven to rotate the crankshaft 17, the rotation of the crankshaft 17 is transmitted to the orbiting scroll 13 via the crank 21 and the bearing 22. As a result, the orbiting scroll 13 orbits around the axis of the fixed scroll 11 with an orbiting radius of a predetermined distance. It is restrained by the Oldham ring 24 so that the turning scroll 13 does not rotate during this turning motion. Then, due to the orbiting motion of the orbiting scroll 13, the compression chamber 25 formed between the laps 11b and 13b continuously moves to the center, and the volume of the compression chamber 25 is continuously reduced according to the movement. As a result, the fluid sucked from the suction pipe 28 is sequentially compressed in each compression chamber 2, and the compressed refrigerant gas is discharged from the discharge pipe. The discharged refrigerant gas is supplied to a refrigeration cycle, for example. Further, when the compression of the refrigerant is started, a part of the refrigerant gas is supplied from the hole 37 of the orbiting scroll 13 to the back pressure chamber to increase the back pressure.

  On the other hand, the refrigerating machine oil is stored in the bottom of the container 9, and the surrounding pressure is a discharge pressure. Since the pressure in the back pressure chamber 33 is lower than the discharge pressure, the refrigerating machine oil stored at the bottom of the container 9 flows into the back pressure chamber 33 through the hole 23 provided in the crankshaft 17. Specifically, a part of the refrigerating machine oil reaches the back pressure chamber 33 while lubricating the bearing 18 through a hole 51 provided in a part of the crankshaft 17. Further, the other refrigerating machine oil reaches the upper part of the crank 21 through the hole 53, lubricates the bearing 22 and enters the back pressure chamber 33. Here, when passing through the bearings 18 and 22, the refrigerating machine oil enters the back pressure chamber 33 at a pressure lower than the discharge pressure because the bearing clearance is small. When the back pressure increases, the refrigerating machine oil that has entered the back pressure chamber 33 opens the back pressure adjustment valve 35 provided in the communication path to the suction chamber and enters the suction chamber. The back pressure chamber 33 has a predetermined back pressure. Kept. The refrigerating machine oil that has entered the suction chamber passes through the compression chamber 25 and is discharged from the discharge hole 29, and a part of the refrigerating machine oil is discharged from the discharge pipe 31 to the refrigeration cycle. The remainder is separated from the refrigerant gas in the container 9 and is stored in the bottom of the container 9 through a through hole provided in the stator 5 and a gap between the stator and the container 9.

  Next, noise reduction, which is a characteristic part of the present embodiment, will be described together with the operation. As shown in FIG. 4, in the bottomed hole 40 of the stator 5, among the noise, a standing wave 50 of noise having a frequency that resonates at the depth L of the bottomed hole 40 is generated. Thereby, the acoustic energy of the noise having a frequency that resonates (resonates) with the length L of the bottomed hole 40 is absorbed by the resonance. The depth L of the bottomed hole 40 is set according to the frequency of noise to be reduced. For example, when the frequency of the noise to be reduced is 3.6 kHz of the chopping frequency of the inverter that drives the motor 7 at a variable speed, the sound speed when the suction pressure is 4 MPa, the discharge pressure is 10 MPa, and the suction temperature is 13 ° C. is 260 m. Therefore, the wavelength of the chopping frequency is 72 mm. Therefore, the depth L of the bottomed hole 40 is set to 18 mm which is a quarter of the wavelength of the chopping frequency. The depth L of the bottomed hole in this case may be a length that allows the wavelength of the chopping frequency to resonate, and can be an odd multiple of 1/4 of the wavelength of the chopping frequency.

Since it did in this way, the noise inside a compressor can be reduced because the bottomed hole 40 acts as a resonance type silencer. Here, the noise frequency to be attenuated includes the motor 7, the compressor container 9, noise caused by the pulsation of the compressor, and the like. In particular, based on the chopping frequency of the inverter that drives the motor 7 at a variable speed. It is more desirable to set. Further, it is only necessary to provide the hole 43 in the stator core plate 5a, and it is not necessary to provide the noise reduction means separately from the compressor. Therefore, the manufacturing cost of the compressor can be reduced. Further, in the refrigeration cycle using CO ₂ refrigerant, heat pump type hot water heaters using midnight power are mainstream, and it is effective to apply the scroll compressor of the present embodiment to such heat pump type hot water heaters. Is.

  In the present embodiment, the bottomed hole 40 is provided at the lower end in the axial direction of the crankshaft 17 of the stator 5, but may be provided at both ends in the axial direction of the crankshaft 17. Further, the bottomed hole 40 may be provided at the upper end. However, in the case of a vertically installed compressor, since the refrigeration oil enters the inside and the noise reduction effect of the frequency to be reduced is reduced, the bottomed hole 40 is reduced. Is preferably provided at the lower end. Moreover, the length L of the bottomed hole 40 of this embodiment is the same length, but when there are a plurality of noise frequencies to be reduced, the bottomed holes having a plurality of lengths according to the noise frequency. Can be provided.

  Further, if the number of the bottomed holes 40 is large and the diameter of the holes is large, the noise reduction effect is increased, but conversely, since the efficiency of the motor 7 is reduced, the number and size of the bottomed holes 40 are It is set appropriately according to the capacity of the motor and the degree of noise reduction. Further, the bottomed hole 40 is formed by laminating the stator core plate 5a having the holes 43 previously formed. However, the bottomed hole 40 is formed by laminating the stator core plates having no holes, and then using a drill or the like. It may be formed.

  Moreover, although the bottomed hole 40 of this embodiment is provided in parallel with the axial direction of the crankshaft 17, what is necessary is just to be able to reduce noise by resonance in the bottomed hole 40. It may be provided so as to be inclined with respect to the axial direction.

  In the present embodiment, the scroll compressor has been described. However, the present invention can be applied to a positive displacement compressor, for example, a scroll compressor, a reciprocating compressor, and the like. Moreover, although the scroll compressor was demonstrated about the vertical installation type, it is applicable also to a horizontal installation type. In the case of the horizontal type, since a part of the stator is immersed in the refrigerator oil, it is preferable to provide a bottomed hole in a portion other than the portion immersed in the refrigerator oil.

(Embodiment 2)
5 is a longitudinal sectional view showing the overall configuration of a scroll compressor according to another embodiment of the present invention, FIG. 6 is a view taken along the line CC in FIG. 5, and FIG. 7 is a view taken along the line DD in FIG. 8 is a cross-sectional perspective view showing the main part of the stator of the present embodiment. As shown in the figure, this embodiment is different from the first embodiment in the configuration of the stator 5, and a flow path 65 including reduced portions 60 and 61 and an enlarged portion 63 is provided instead of the bottomed hole 40. There is. Since other configurations are the same as those in FIG. 1, detailed description thereof is omitted.

  The flow path 65 of the stator 5 is provided across the axial direction of the crankshaft 17, and an enlarged portion 63 having an enlarged flow path cross section is provided in the middle of the flow path 65. At both ends of the flow path 65, reduced portions 60 and 61 are provided so that the cross-sectional area is smaller than that of the enlarged portion 63. The flow path 65 is formed by stacking the stator core plates 5c and 5d. The stator core plate 5c is provided with six circular holes 67 at equal intervals in the circumferential direction, and the stator core plate 5d has a circumferential direction. In addition, oval holes 69 are provided at six equal intervals. That is, a plurality of stator core plates 5 c are stacked on the upper and lower portions of the stator 5 to form the reduced portions 60 and 61 of the flow path 65, and a plurality of stator core plates 5 d are stacked on the center portion of the stator 5. An enlarged portion 63 is formed. Since it did in this way, since the flow path 65 acts as an expansion type silencer, the noise of a compressor can be reduced.

  In the stator 5 of the present embodiment, the reduced portions 60 and 61 are provided at both ends of the flow path 65, but the reduced portion may be provided only at one end of the flow path 65 without being limited to the present embodiment.

(Embodiment 3)
FIG. 9 is a cross-sectional perspective view showing a main part of a stator according to another embodiment of the present invention. As shown in the drawing, this embodiment is different from the second embodiment in the configuration of the stator 5, in which a plurality of stator core plates 5 d are stacked and a flow path 70 is provided in the axial direction of the crankshaft 17. Another annular member 71 is provided at both axial ends of the crankshaft 17 of the stator 5, and the member 71 is provided with a hole 72 having a smaller cross-sectional area than the enlarged portion 71. Since other configurations are the same as those in FIGS. 5 and 7, detailed description thereof is omitted. If it does in this way, stator core board 7d can be processed in the same shape, and manufacture of a stator can be made easy.

  In the stator 5 of the present embodiment, the members 71 are provided at both ends of the stator 5, but the members 71 may be provided only at one end in the axial direction of the crankshaft 17 of the stator 5.

It is a longitudinal section showing the whole scroll compressor composition of one embodiment of the present invention. It is an AA arrow line view of FIG. It is a BB arrow line view of FIG. It is sectional drawing which shows the principal part of the stator of this embodiment. It is a longitudinal cross-sectional view which shows the whole structure of the scroll compressor of other embodiment of this invention. It is CC arrow line view of FIG. FIG. 6 is a DD arrow view of FIG. 5. It is a cross-sectional perspective view which shows the principal part of the stator of other embodiment of this invention. It is a cross-sectional perspective view which shows the principal part of the stator of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compression mechanism part 3 Rotor 4 Coil 5 Stator 5a, 5b, 5c, 5d Stator core board 7 Motor 9 Container 11 Fixed scroll 13 Orbiting scroll 15 Frame 17 Crankshaft 21 Crank 23, 41, 43, 45, 67, 69, 72 Hole 27 Suction hole 28 Suction pipe 29 Discharge hole 31 Discharge pipe 33 Back pressure chamber 40 Bottomed hole 60, 61 Reduced part 63 Expanded part 65, 70 Flow path 71 Member

Claims (5)

In a positive displacement compressor in which a compression means for compressing a refrigerant and a motor connected to the compression means and having a rotor and a stator are housed in a container,
A positive displacement compressor, wherein the stator is formed with a bottomed hole at one end or both ends in the rotation axis direction of the motor. The positive displacement compressor according to claim 1, wherein
The depth of the bottomed hole is 1/4 of the wavelength of the noise frequency to be attenuated, or an odd multiple thereof, characterized in that it is a positive displacement compressor. The positive displacement compressor according to claim 2,
The positive displacement compressor according to claim 1, wherein the noise frequency is set based on a chopping frequency of an inverter that drives the motor at a variable speed. In a positive displacement compressor in which a compression means for compressing a refrigerant and a motor connected to the compression means and having a rotor and a stator are housed in a container,
The stator has a flow path provided over the rotation axis direction of the motor, and in the middle of the flow path, an enlarged portion in which a cross section of the flow path is enlarged is provided, and one end or both ends of the flow path are A positive displacement compressor having a smaller cross-sectional area than the enlarged portion. In a positive displacement compressor in which a compression means for compressing a refrigerant and a motor connected to the compression means and having a rotor and a stator are housed in a container,
The stator has a flow path provided over the rotation axis direction of the motor, and the flow path is provided with an enlarged portion in which a cross section of the flow path is enlarged, at one end or both ends of the flow path of the stator. Is a positive displacement compressor to which a member having a flow path having a smaller cross-sectional area than the enlarged portion is attached.

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