JP2018066314A - Hermetic type rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic type rotary compressor that can achieve high efficiency by a simple method.SOLUTION: A hermetic type rotary compressor 1 includes an electric motor 3 including a rotor core 12 fixing a rotation shaft 5 on an inside; a stator core 11 fixed to a case 2 on an outer peripheral side of the rotor core 12; and a stator coil 13 provided in the stator core 11. The hermetic type rotary compressor satisfies a mathematical expression of ΦDc/ΦMo≤0.350 where ΦMo represents an outer diameter of the stator core 11 and ΦDc represents an inner diameter a cylinder 16 forming a compression chamber 19.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hermetic rotary compressor that compresses a fluid.

  Conventionally, for example, a hermetic rotary compressor is known as a compressor used for refrigeration and air conditioning. Such a compressor is described in Patent Document 1, for example.

  In a hermetic rotary compressor as described in Patent Document 1, a rotating shaft, a motor for rotating the rotating shaft, a piston rotor attached eccentrically to the rotating shaft, and a piston are arranged inside the sealed container. A cylinder or the like is mainly provided. In such a compressor, the refrigerant gas is sucked into the cylinder through a suction pipe connected to the side wall of the cylinder, and the refrigerant gas is compressed by the rotation of the piston rotor.

JP 2011-153526 A

  In recent years, such compressors have been required to be further improved in efficiency, but there is a problem in that it is difficult to significantly change the structure and shape of the compressor for the purpose of higher efficiency due to restrictions on installation space and the like. .

  Therefore, the present invention provides a hermetic rotary compressor that can achieve high efficiency by a simple method.

A hermetic rotary compressor according to an aspect of the present invention is provided with an electric motor, a rotary shaft that can be rotated around an axis by the electric motor, the rotary shaft, and the rotary shaft as the rotary shaft rotates. A piston rotor that rotates eccentrically with respect to the axis, a compression chamber that houses the piston rotor, a cylinder in which a supply flow path for supplying a refrigerant to the compression chamber is formed, and surrounding the cylinder Forming a discharge space for discharging the refrigerant compressed by the piston rotor between the cylinder and the case for sealing and housing the electric motor, the rotary shaft, the piston rotor, and the cylinder; A bearing that supports the rotating shaft in the case, and the electric motor includes a rotor core that fixes the rotating shaft inside, and a front side on an outer peripheral side of the rotor core. A stator core fixed to the case, and a stator coil provided on the stator core, wherein the stator core has an outer diameter of ΦMo and the cylinder has an inner diameter of ΦDc, and satisfies the following formula (1): Type rotary compressor.
ΦDc / ΦMo ≦ 0.350 (1)

As the outer diameter ΦMo of the stator core increases, iron loss (eddy current loss) in the stator core can be reduced, and the efficiency of the electric motor is improved.
Further, under the condition that the compressor obtains a predetermined compression capacity, it is necessary to increase the rotation speed of the electric motor if the cylinder exclusion volume (compression chamber volume) is reduced. The cylinder displacement volume has a correlation with the cylinder inner diameter ΦDc, and the smaller the cylinder displacement volume (compression chamber volume), the smaller the cylinder inner diameter ΦDc. Therefore, under conditions for obtaining a predetermined compression capacity, it is necessary to increase the rotational speed of the electric motor as the cylinder inner diameter ΦDc is reduced.
Here, the efficiency of the electric motor is low when it is operated in a low rotational speed region. As described above, if the inner diameter ΦDc of the cylinder is small, the number of revolutions of the electric motor is increased. As a result, the efficiency of the electric motor is improved.
Therefore, by increasing the outer diameter ΦMo of the stator core or (and) decreasing the inner diameter ΦDc of the cylinder and forming the electric motor and the cylinder so that the value of ΦDc / ΦMo is 0.350 or less, The efficiency of the hermetic rotary compressor can be improved without significantly changing the installation space or outer shape of the hermetic rotary compressor.

The hermetic rotary compressor may further satisfy the following expression (2), where the outer diameter of the stator core is ΦMo and the inner diameter of the cylinder is ΦDc.
ΦDc / ΦMo ≦ 0.320 (2)

  According to such a hermetic rotary compressor, the outer diameter ΦMo of the stator core is further increased, or (and) the inner diameter ΦDc of the cylinder is decreased, and the electric motor is controlled so that the value of ΦDc / ΦMo becomes 0.320 or less. By forming the motor and the cylinder, it is possible to achieve further improvement in the efficiency of the hermetic rotary compressor without significantly changing the installation space, outer shape, etc. of the hermetic rotary compressor.

The hermetic rotary compressor may further satisfy the following expression (3) when the outer diameter of the stator core is ΦMo and the inner diameter of the cylinder is ΦDc.
0.200 ≦ ΦDc / ΦMo ≦ 0.320 (3)

  According to such a hermetic rotary compressor, the outer diameter ΦMo of the stator core is further increased, or (and) the inner diameter ΦDc of the cylinder is decreased, the value of ΦDc / ΦMo is 0.320 or less, and 0 By forming the electric motor and cylinder so as to be 200 or more, further improvement in efficiency of the hermetic rotary compressor can be achieved without drastically changing the installation space, outer shape, etc. of the hermetic rotary compressor. .

Further, the above-described hermetic rotary compressor may further satisfy the following expression (4) when the outer diameter of the rotating shaft is ΦLJ.
ΦLJ / ΦMo ≦ 0.140 (4)

  If the outer diameter ΦLJ of the rotating shaft is reduced, the sliding loss between the rotating shaft and the bearing can be reduced, and the mechanical efficiency in the hermetic rotary compressor can be improved. Further, if the outer diameter ΦMo of the stator core is increased as described above, iron loss (eddy current loss) in the stator core can be reduced, and the efficiency of the electric motor is improved. Therefore, by further reducing the outer diameter ΦLJ of the rotating shaft with respect to the outer diameter ΦMo of the stator core and setting the value of ΦLJ / ΦMo to 0.140 or less, further efficiency improvement of the hermetic rotary compressor can be achieved.

Further, the above-described hermetic rotary compressor may further satisfy the following formula (5) when the outer diameter of the rotating shaft is ΦLJ.
0.0800 ≦ ΦLJ / ΦMo ≦ 0.140 (5)

  If the outer diameter ΦLJ of the rotating shaft becomes smaller, the sliding loss between the rotating shaft and the bearing can be reduced. However, if the outer diameter ΦLJ of the rotating shaft becomes too small, the rotating shaft hits against the bearing. However, the sliding loss increases. Therefore, by setting the value of ΦLJ / ΦMo to be 0.0800 or more, it is possible to improve the mechanical efficiency of the hermetic rotary compressor while suppressing the per-rotation of the rotating shaft, and the hermetic rotary compression Further efficiency improvement of the machine can be achieved.

Further, the above-described hermetic rotary compressor may further satisfy the following expression (6) when the outer diameter of the rotating shaft is ΦLJ.
0.106 ≦ ΦLJ / ΦMo ≦ 0.140 (6)

  If the outer diameter ΦLJ of the rotating shaft becomes smaller, the sliding loss between the rotating shaft and the bearing can be reduced. However, if the outer diameter ΦLJ of the rotating shaft becomes too small, the rotating shaft hits against the bearing. However, the sliding loss increases. Therefore, by setting the value of ΦLJ / ΦMo to 0.106 or more, it is possible to operate in a region where the sliding loss is minimized while suppressing the per side of the rotating shaft, and the sealed rotary compression The mechanical efficiency in the machine can be improved, and further efficiency improvement of the hermetic rotary compressor can be achieved.

  According to the above-described hermetic rotary compressor, it is possible to achieve high efficiency by a simple method by forming the electric motor and the cylinder based on the simple index as described above.

It is a longitudinal section showing a closed type rotary compressor of an embodiment of the present invention. It is a graph which shows the relationship between the outer diameter (PHI) Mo of a stator core, and the motor efficiency of an electric motor. It is a graph which shows the relationship between the internal diameter (PHI) Dc of a cylinder in the state which exhibits the predetermined compression capability with a sealed rotary compressor, and the rotation speed of an electric motor. It is a graph which shows the relationship between the rotation speed of an electric motor, and the motor efficiency of an electric motor. It is a graph which shows the relationship between the internal diameter (PHI) Dc of a cylinder, and the motor efficiency of an electric motor. It is a graph which shows the relationship between outer diameter (PHI) LJ of a rotating shaft, and mechanical efficiency. It is a graph which shows the relationship between (PHI) LJ / (PHI) Mo which is ratio of the outer diameter (PHI) LJ of a rotating shaft, and outer diameter (PHI) Mo of a stator core, and the sliding loss in a bearing.

Hereinafter, a hermetic rotary compressor 1 (hereinafter simply referred to as a compressor 1) according to an embodiment of the present invention will be described.
As shown in FIG. 1, the compressor 1 includes a cylindrical case 2, an electric motor 3 accommodated in the case 2, a rotating shaft 5 driven by the electric motor 3 in the case 2, and the case 2. Bearings 17 and 18 (upper bearing 17 and lower bearing 18) for supporting the rotating shaft 5, a piston rotor 15 attached to the rotating shaft 5 in the case 2, and a piston rotor 15 provided in the case 2 to accommodate the piston rotor 15. And a cylinder 16 to be operated.
The compressor 1 is connected to a refrigerant circuit (not shown). That is, the compressor 1 is a device that is incorporated in a refrigerant circuit having a condenser, an expansion valve, an evaporator, and the like, and compresses the refrigerant flowing in the piping of the refrigerant circuit.

  The case 2 has a cylindrical body 7, an upper lid 8 welded to the upper end of the body 7, and a bottom lid 9 welded to the lower end of the body 7. The electric motor 3, the piston rotor 15, and the cylinder 16 are sealed inside the case 2. The body 7 is provided with a suction pipe 10 connected to the cylinder 16. The suction pipe 10 is a pipe that sucks the refrigerant gas G into the cylinder 16 through, for example, an accumulator (not shown). Case 2 forms a discharge space in which refrigerant gas G compressed from cylinder 16 is discharged. Then, the refrigerant gas G filled in the discharge space is discharged to the refrigerant circuit through the discharge pipe 14 penetrating the upper lid 8.

  The electric motor 3 includes a rotor core 12, and a stator core 11 and a stator coil 13 disposed on the outer peripheral side of the rotor core 12.

The stator core 11 is formed of an electromagnetic steel plate and has a cylindrical shape centered on the axis O. The stator core 11 is fixed to the inner peripheral surface of the case 2.
The stator coil 13 is wound around the stator core 11.

  Here, the outer diameter of the stator core 11 is ΦMo.

  The rotor core 12 is formed of a magnetic steel plate and a magnet, and has a cylindrical shape with the axis O as the center. The rotor core 12 is rotatable about the axis O by energization of the stator 11. Further, the rotor core 12 is formed in a columnar shape with the axis O as the center, and a through hole 12a penetrating the rotor core 12 in the direction of the axis O is formed. A balance weight 25 (counter weight) is attached to the rotor core 12 in order to suppress the runout of the rotor core 12 when the electric motor 3 is driven. The balance weight 25 is attached to the lower part of the rotor core 12. The balance weight 25 is made of stainless steel. The balance weight 25 does not need to be formed of stainless steel, and any nonmagnetic material such as copper alloy or steel can be used.

  The rotating shaft 5 has a cylindrical shape centered on the axis O, and extends in the direction of the axis O along the vertical direction. The rotating shaft 5 is fixed in the rotor core 12 by being inserted into the through hole 12 a of the rotor core 12. Thereby, the rotational driving force by the electric motor 3 is output from the rotor core 12 to the rotating shaft 5.

  Here, the outer diameter of the rotating shaft 5 (≈the diameter of the through hole 12a) is ΦLJ.

  The upper bearing 17 and the lower bearing 18 are disposed in the case 2 so as to be separated from each other in the direction of the axis O, that is, in the vertical direction. The upper bearing 17 and the lower bearing 18 rotate so as to be rotatable around the axis O with respect to the case 2 so that the first end (upper in FIG. 1) of the rotating shaft 5 is on the free end side. The shaft 5 is cantilevered. More specifically, the rotating shaft 5 extends downward from the rotor core 12, and only the second end (downward in FIG. 1) opposite to the first end is supported by the upper bearing 17 and the lower bearing 18. It is supported.

  The piston rotor 15 is eccentrically attached to the second end portion of the rotating shaft 5 with respect to the axis O, so that the piston rotor 15 rotates eccentrically with the rotation of the rotating shaft 5.

In the cylinder 16, a sealed compression chamber 19 in which the piston rotor 15 is accommodated is formed between the upper bearing 17 and the lower bearing 18. Further, the suction pipe 10 is connected to the cylinder 16, and a supply flow path 20 for supplying the refrigerant gas G into the compression chamber 19 is formed. Then, the piston rotor 15 is rotated by the rotation of the rotating shaft 5, whereby the volume of the compression chamber 19 in the cylinder 16 is gradually reduced to compress the refrigerant gas G. The cylinder 16 has a cylindrical inner peripheral surface 16 a that has a minute gap at one place on the outer periphery of the piston rotor 15 and is in sliding contact. The axis of the inner peripheral surface 16a of the cylinder 16 coincides with the axis O. The diameter of the inner peripheral surface 16 a is the inner diameter ΦDc of the cylinder 16.
Here, the volume of the compression chamber 19 of the cylinder 16 is a volume obtained by subtracting the volume of the piston rotor 15 in the compression chamber 19 from the volume of the space having the inside diameter ΦDc of the cylinder 16 as a diameter. The volume of the compression chamber 19 is a so-called cylinder exclusion volume. Therefore, this cylinder excluded volume is correlated with the inner diameter ΦDc of the cylinder 16, and the cylinder excluded volume decreases as the inner diameter ΦDc of the cylinder 16 decreases.

Here, in the present embodiment, the outer diameter ΦMo of the stator core 11 and the inner diameter ΦDc of the cylinder 16 satisfy the following expression (1).
ΦDc / ΦMo ≦ 0.350 (1)

Furthermore, in the present embodiment, the outer diameter ΦMo of the stator core 11 and the inner diameter ΦDc of the cylinder 16 may satisfy the following expression (2).
ΦDc / ΦMo ≦ 0.320 (2)

Furthermore, in the present embodiment, the outer diameter ΦMo of the stator core 11 and the inner diameter ΦDc of the cylinder 16 may satisfy the following expression (3).
0.200 ≦ ΦDc / ΦMo ≦ 0.320 (3)

Furthermore, in the present embodiment, the outer diameter ΦLJ of the rotating shaft 5 and the outer diameter ΦMo of the stator core 11 may satisfy the following expression (4).
ΦLJ / ΦMo ≦ 0.140 (4)

Furthermore, in the present embodiment, the outer diameter ΦLJ of the rotating shaft 5 and the outer diameter ΦMo of the stator core 11 may satisfy the following expression (5).
0.0800 ≦ ΦLJ / ΦMo ≦ 0.140 (5)

Furthermore, in the present embodiment, the outer diameter ΦLJ of the rotating shaft 5 and the outer diameter ΦMo of the stator core 11 may satisfy the following expression (6).
0.106 ≦ ΦLJ / ΦMo ≦ 0.140 (6)

  Here, as shown in FIG. 2, it is known that as the outer diameter ΦMo of the stator core 11 increases, the iron loss (eddy current loss) in the stator core 11 can be reduced. Therefore, the efficiency of the electric motor 3 is improved by increasing the outer diameter ΦMo of the stator core 11.

Further, as shown in FIG. 3, under the condition that the compressor 1 obtains a predetermined compression capacity, the rotational speed of the electric motor 3 increases when the inner diameter ΦDc of the cylinder 16 (a value that correlates with the cylinder exclusion volume) is reduced. It is known that there is a need to do. That is, if the inner diameter of the cylinder 16 is Dc ₁ <Dc ₂ , the rotational speed of the electric motor 3 is rps ₂ <rps ₁ .

  Furthermore, as shown in FIG. 4, it is known that the rate of decrease in motor efficiency increases as the rotational speed of the electric motor 3 moves toward the low rotational speed region. For this reason, when the electric motor 3 is operated in the low rotation speed region, the motor efficiency is lowered.

  Therefore, under the condition that the compressor 1 obtains a predetermined compression capacity, if the inner diameter ΦDc of the cylinder 16 is reduced, the number of revolutions of the electric motor 3 is increased. As a result, as shown in FIG. Efficiency is improved.

  Then, by setting the outer diameter ΦMo of the stator core 11 to be large or (and) setting the inner diameter ΦDc of the cylinder to be small, the value of ΦDc / ΦMo is set to 0.350 or less as shown in the above equation (1). The knowledge that sufficient efficiency of the electric motor 3 can be obtained even when considering application to an actual machine was obtained.

  In the compressor 1 of the present embodiment, the outer diameter ΦMo of the stator core 11 and the inner diameter ΦDc of the cylinder 16 satisfy the above formula (1): ΦDc / ΦMo ≦ 0.350. In the compressor 1 of this embodiment, the installation space and outer shape of the compressor 1 are significantly changed by forming the electric motor 3 and the cylinder 16 so that the value of ΦDc / ΦMo is 0.350 or less. The efficiency of the electric motor 3 can be improved by a simple method based on the simple index such as the above formula (1), and the efficiency of the compressor 1 can be increased.

  Furthermore, if the outer diameter ΦMo of the stator core 11 and the inner diameter ΦDc of the cylinder 16 satisfy the above formula (2): ΦDc / ΦMo ≦ 0.320, the efficiency of the electric motor 3 can be further improved, and the compressor 1 The knowledge that further efficiency improvement can be achieved was obtained. For this reason, in the compressor 1 of the present embodiment, the electric motor 3 and the cylinder 16 are formed so that the value of ΦDc / ΦMo is 0.320 or less, thereby greatly increasing the installation space and outer shape of the compressor 1. Further improvement in efficiency of the compressor 1 can be achieved without changing to.

  Furthermore, when the specifications in the actual machine are taken into consideration, if the outer diameter ΦMo of the stator core 11 and the inner diameter ΦDc of the cylinder 16 satisfy the above expression (3): 0.200 ≦ ΦDc / ΦMo ≦ 0.320, The knowledge that the efficiency of the electric motor 3 can be further improved and further efficiency improvement of the compressor 1 can be achieved was obtained. For this reason, in the compressor 1 of this embodiment, by forming the electric motor 3 and the cylinder 16 so that the value of ΦDc / ΦMo is 0.320 or less and 0.200 or more, the compressor 1 Further efficiency improvement of the compressor 1 can be achieved without significantly changing the installation space and the outer shape of the compressor 1.

  Here, as shown in FIG. 6, if the outer diameter ΦLJ of the rotating shaft 5 is reduced, the sliding loss between the rotating shaft 5 and the upper bearing 17, the lower bearing 18 and the like can be reduced. Are known.

  Therefore, the mechanical efficiency can be improved by setting the outer diameter ΦLJ of the rotating shaft 5 small. Further, by setting the outer diameter ΦMo of the stator core 11 large as described above, iron loss (eddy current loss) in the stator core 11 can be reduced, and the efficiency of the electric motor 3 can be improved. Therefore, the outer diameter ΦLJ of the rotating shaft 5 is made smaller than the outer diameter ΦMo of the stator core 11, and the value of ΦLJ / ΦMo is set to 0.140 or less as shown in the above equation (4), so that it can be applied to an actual machine. In consideration of the above, it was found that the compressor 1 can obtain sufficient efficiency.

  Therefore, in the compressor 1 of the present embodiment, the electric motor 3 is set so that the outer diameter ΦLJ of the rotating shaft 5 and the outer diameter ΦMo of the stator core 11 further satisfy the above-described expression (4): ΦLJ / ΦMo ≦ 0.140. In addition, by forming the rotary shaft 5, the electric motor can be obtained by a simple method based on a simple index such as the above formula (4) without significantly changing the shape or installation space of the compressor 1. Therefore, the efficiency of the compressor 1 can be increased.

  Moreover, the rotating shaft 5 which is not an electromagnetic steel plate is inserted and provided in the rotor core 12 formed with the electromagnetic steel plate. In the present embodiment, by reducing the outer diameter ΦLJ of the rotating shaft 5, the diameter of the through hole 12 a of the rotor core 12 can be reduced, and the amount of electromagnetic steel sheets in the rotor core 12 can be increased. Therefore, the magnetic resistance in the rotor core 12 can be reduced, the efficiency of the electric motor 3 can be improved, and the high efficiency of the compressor 1 can be achieved.

  Here, if the outer diameter ΦLJ of the rotating shaft 5 becomes too small, the possibility of a single contact between the upper bearing 17 and the lower bearing 18 and the rotating shaft 5 increases. Therefore, in the region where ΦLJ is smaller than the predetermined value, the sliding loss increases, and as shown in FIG. 7, the value of ΦLJ / ΦMo includes the sliding between the upper bearing 17 and the lower bearing 18 and the rotating shaft 5. It was found that there is a local minimum that reduces the dynamic loss. And the knowledge that the minimum value of this ΦLJ / ΦMo is 0.0800 or more, 0.0106 or more, and 0.140 or less was obtained.

  Therefore, in the present embodiment, when the specifications in the actual machine are taken into consideration, the outer diameter ΦLJ of the rotating shaft 5 and the outer diameter ΦMo of the stator core 11 are the above-mentioned formula (5): 0.0800 ≦ ΦLJ / ΦMo ≦ 0.140 By forming the rotary shaft 5 and the electric motor 3 so as to further satisfy the above, it is possible to reduce sliding loss, and further improve the efficiency of the compressor 1 without significantly changing the installation space and outer shape of the compressor 1. Improvement can be achieved.

  Further, in the present embodiment, the rotating shaft 5 and the stator core 11 have an outer diameter ΦLJ and an outer diameter ΦMo of the stator core 11 satisfying the above expression (6): 0.0106 ≦ ΦLJ / ΦMo ≦ 0.140. 5 and the formation of the electric motor 3 can further reduce the sliding loss, and can further improve the efficiency of the compressor 1 without significantly changing the installation space of the compressor 1 or the like.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.
For example, although the sealed rotary compressor 1 has been described above, the above-described configuration may be applied to a sealed two-stage compressor that further includes a scroll compression mechanism in the upper portion of the case 2.

DESCRIPTION OF SYMBOLS 1 ... Sealed rotary compressor 2 ... Case 3 ... Electric motor 5 ... Rotating shaft 7 ... Body 8 ... Top lid 9 ... Bottom lid 10 ... Suction pipe 11 ... Stator core 12 ... Rotor core 12a ... Through-hole 13 ... Stator coil 14 ... Discharge pipe DESCRIPTION OF SYMBOLS 15 ... Piston rotor 16 ... Cylinder 16a ... Inner peripheral surface 17 ... Upper bearing 18 ... Lower bearing 19 ... Compression chamber 20 ... Supply flow path 25 ... Balance weight O ... Axis line G ... Refrigerant gas

A hermetic rotary compressor according to an aspect of the present invention is provided with an electric motor, a rotary shaft that can be rotated around an axis by the electric motor, the rotary shaft, and the rotary shaft as the rotary shaft rotates. A piston rotor that rotates eccentrically with respect to the axis, a compression chamber that houses the piston rotor, a cylinder in which a supply flow path for supplying a refrigerant to the compression chamber is formed, and surrounding the cylinder Forming a discharge space for discharging the refrigerant compressed by the piston rotor between the cylinder and the case for sealing and housing the electric motor, the rotary shaft, the piston rotor, and the cylinder; A bearing that supports the rotating shaft in the case, and the electric motor includes a rotor core that fixes the rotating shaft inside, and a front side on an outer peripheral side of the rotor core. It has a stator core fixed to the case, and a stator coil provided on the stator core, the outer diameter of the stator core and FaiMo, when the inner diameter of the cylinder was .phi.DC1, Shi satisfy the following equation (1) When the outer diameter of the rotating shaft is ΦLJ, the following expression (4) is further satisfied .
ΦDc / ΦMo ≦ 0.350 (1)
ΦLJ / ΦMo ≦ 0.140 (4)

As the outer diameter ΦMo of the stator core increases, iron loss (eddy current loss) in the stator core can be reduced, and the efficiency of the electric motor is improved.
Further, under the condition that the compressor obtains a predetermined compression capacity, it is necessary to increase the rotation speed of the electric motor if the cylinder exclusion volume (compression chamber volume) is reduced. The cylinder displacement volume has a correlation with the cylinder inner diameter ΦDc, and the smaller the cylinder displacement volume (compression chamber volume), the smaller the cylinder inner diameter ΦDc. Therefore, under conditions for obtaining a predetermined compression capacity, it is necessary to increase the rotational speed of the electric motor as the cylinder inner diameter ΦDc is reduced.
Here, the efficiency of the electric motor is low when it is operated in a low rotational speed region. As described above, if the inner diameter ΦDc of the cylinder is small, the number of revolutions of the electric motor is increased. As a result, the efficiency of the electric motor is improved.
Therefore, by increasing the outer diameter ΦMo of the stator core or (and) decreasing the inner diameter ΦDc of the cylinder and forming the electric motor and the cylinder so that the value of ΦDc / ΦMo is 0.350 or less, The efficiency of the hermetic rotary compressor can be improved without significantly changing the installation space or outer shape of the hermetic rotary compressor.
Further, if the outer diameter ΦLJ of the rotating shaft is reduced, the sliding loss between the rotating shaft and the bearing can be reduced, and the mechanical efficiency in the hermetic rotary compressor can be improved. Further, if the outer diameter ΦMo of the stator core is increased as described above, iron loss (eddy current loss) in the stator core can be reduced, and the efficiency of the electric motor is improved. Therefore, by further reducing the outer diameter ΦLJ of the rotating shaft with respect to the outer diameter ΦMo of the stator core and setting the value of ΦLJ / ΦMo to 0.140 or less, further efficiency improvement of the hermetic rotary compressor can be achieved.

A hermetic rotary compressor according to an aspect of the present invention is provided with an electric motor, a rotary shaft that can be rotated around an axis by the electric motor, the rotary shaft, and the rotary shaft as the rotary shaft rotates. A piston rotor that rotates eccentrically with respect to the axis, a compression chamber that houses the piston rotor, a cylinder in which a supply flow path for supplying a refrigerant to the compression chamber is formed, and surrounding the cylinder Forming a discharge space for discharging the refrigerant compressed by the piston rotor between the cylinder and the case for sealing and housing the electric motor, the rotary shaft, the piston rotor, and the cylinder; A bearing that supports the rotating shaft in the case, and the electric motor includes a rotor core that fixes the rotating shaft inside, and a front side on an outer peripheral side of the rotor core. Has a stator core fixed to the case, and a stator coil provided on the stator core, the outer diameter of the stator core and FaiMo, the inner diameter of the cylinder when the .phi.DC1, satisfies the following equation (3), When the outer diameter of the rotating shaft is ΦLJ, the following expression (6) is further satisfied.
0.200 ≦ ΦDc / ΦMo ≦ 0.320 (3)
0.106 ≦ ΦLJ / ΦMo ≦ 0.140 (6)

As the outer diameter ΦMo of the stator core increases, iron loss (eddy current loss) in the stator core can be reduced, and the efficiency of the electric motor is improved.
Further, under the condition that the compressor obtains a predetermined compression capacity, it is necessary to increase the rotation speed of the electric motor if the cylinder exclusion volume (compression chamber volume) is reduced. The cylinder displacement volume has a correlation with the cylinder inner diameter ΦDc, and the smaller the cylinder displacement volume (compression chamber volume), the smaller the cylinder inner diameter ΦDc. Therefore, under conditions for obtaining a predetermined compression capacity, it is necessary to increase the rotational speed of the electric motor as the cylinder inner diameter ΦDc is reduced.
Here, the efficiency of the electric motor is low when it is operated in a low rotational speed region. As described above, if the inner diameter ΦDc of the cylinder is small, the number of revolutions of the electric motor is increased. As a result, the efficiency of the electric motor is improved.
Accordingly, the outer diameter ΦMo of the stator core is increased or (and) the inner diameter ΦDc of the cylinder is decreased , and the electric motor is set so that the value of ΦDc / ΦMo is 0.320 or less and 0.200 or more . By forming the cylinder, the efficiency of the hermetic rotary compressor can be improved without significantly changing the installation space, outer shape, etc. of the hermetic rotary compressor.
Further, if the outer diameter ΦLJ of the rotating shaft is reduced, the sliding loss between the rotating shaft and the bearing can be reduced, and the mechanical efficiency in the hermetic rotary compressor can be improved. Further, if the outer diameter ΦMo of the stator core is increased as described above, iron loss (eddy current loss) in the stator core can be reduced, and the efficiency of the electric motor is improved. Therefore, by further reducing the outer diameter ΦLJ of the rotating shaft with respect to the outer diameter ΦMo of the stator core and setting the value of ΦLJ / ΦMo to 0.140 or less, further efficiency improvement of the hermetic rotary compressor can be achieved.
Furthermore, if the outer diameter ΦLJ of the rotating shaft is reduced, the sliding loss between the rotating shaft and the bearing can be reduced. However, if the outer diameter ΦLJ of the rotating shaft is too small, the rotating shaft is separated from the bearing. It becomes easy to hit and the sliding loss increases. Therefore, by setting the value of ΦLJ / ΦMo to 0.106 or more, it is possible to operate in a region where the sliding loss is minimized while suppressing the per side of the rotating shaft, and the sealed rotary compression The mechanical efficiency in the machine can be improved, and further efficiency improvement of the hermetic rotary compressor can be achieved.

Claims (6)

An electric motor;
A rotating shaft rotatable around an axis by the electric motor;
A piston rotor provided on the rotating shaft and rotating eccentrically with respect to the axis along with the rotation of the rotating shaft;
A compression chamber for accommodating the piston rotor is formed inside, and a cylinder in which a supply flow path for supplying a refrigerant to the compression chamber is formed;
A discharge space for discharging the refrigerant compressed by the piston rotor is formed between the cylinder and the cylinder, and the electric motor, the rotating shaft, the piston rotor, and the cylinder are sealed. A housing case,
A bearing that supports the rotating shaft in the case;
With
The electric motor is
A rotor core that fixes the rotating shaft inside;
A stator core fixed to the case on the outer peripheral side of the rotor core;
A stator coil provided in the stator core;
Have
A hermetic rotary compressor that satisfies the following formula (1) when the outer diameter of the stator core is ΦMo and the inner diameter of the cylinder is ΦDc.
ΦDc / ΦMo ≦ 0.350 (1) 2. The hermetic rotary compressor according to claim 1, wherein when the outer diameter of the stator core is ΦMo and the inner diameter of the cylinder is ΦDc, the following expression (2) is further satisfied.
ΦDc / ΦMo ≦ 0.320 (2) 3. The hermetic rotary compressor according to claim 2, wherein when the outer diameter of the stator core is ΦMo and the inner diameter of the cylinder is ΦDc, the following expression (3) is further satisfied.
0.200 ≦ ΦDc / ΦMo ≦ 0.320 (3) The hermetic rotary compressor according to any one of claims 1 to 3, further satisfying the following expression (4), where ΦLJ is an outer diameter of the rotating shaft.
ΦLJ / ΦMo ≦ 0.140 (4) The hermetic rotary compressor according to claim 4, further satisfying the following expression (5), where ΦLJ is an outer diameter of the rotating shaft.
0.0800 ≦ ΦLJ / ΦMo ≦ 0.140 (5) The hermetic rotary compressor according to claim 5, further satisfying the following expression (6), where ΦLJ is an outer diameter of the rotating shaft.
0.106 ≦ ΦLJ / ΦMo ≦ 0.140 (6)

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