Compressor

Abstract

The compressor (10) includes a hermetic container (1), an electric motor (2), and a compression mechanism (3). The circulation amount of the compressor (10) during operation at the maximum rotational speed is 1000 [kg / hr] or more. The electric motor (2) has a rotor (21) provided on a rotating shaft (4) extending in the vertical direction and a stator (22) fixed inside the hermetic container (1). The compression mechanism (3) is arranged below the electric motor (2) inside the hermetic container (1). The stator (22) has a stator core (41), and a core cutout (46) serving as a refrigerant passage (13) is provided between the stator core (41) and the inner wall of the hermetic container (1). In the compressor (10), (pressure loss generated between the inlet (46a) and the outlet (46b) of the core cutout (46)) / (gas density of the refrigerant - density of the lubricating oil) is 1.45 or less.

Description

Technical Field

[0001] The present disclosure relates to a compressor. Background Art

[0002] Conventionally, compressors for compressing refrigerants have been known. Patent Document 1 discloses a rotary compressor. The rotary compressor houses a compression mechanism and an electric motor in a vault-shaped housing and is configured as a hermetic compressor. The electric motor includes a stator fixed to the trunk of the housing and a rotor connected to a drive shaft and disposed inside the stator.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Publication No. 2009-299663 Summary of the Invention

[0006] -Technical Problem to be Solved by the Invention-

[0007] The following is disclosed in Patent Document 1: A core cutout is provided on the outer peripheral surface of the stator, and a refrigerant passage that communicates the spaces on both axial sides of the electric motor is formed between the outer peripheral surface of the stator and the inner wall of the housing.

[0008] However, in order to suppress a decrease in the performance of the electric motor, it is necessary to suppress the size of the core cutout. On the other hand, if the core cutout is small, the pressure loss when the refrigerant passes through the core cutout becomes large, and the oil discharge rate increases. In view of the future demand for larger-capacity compressors, it is considered difficult to balance the suppression of pressure loss and the maintenance of electric motor performance.

[0009] An object of the present disclosure is to suppress an increase in the oil discharge rate in a compressor after being enlarged in capacity without reducing the performance of the electric motor.

[0010] -Technical Solution for Solving the Technical Problem-

[0011] A first aspect of the present disclosure is a compressor, which includes a hermetic container 1, an electric motor 2, and a compression mechanism 3. The circulation amount of the compressor 10 during operation at the maximum rotational speed is 1000 [kg / hr] or more. The electric motor 2 is disposed inside the hermetic container 1. The electric motor 2 has a rotor 21 provided on a rotating shaft 4 extending in the vertical direction and a stator 22 fixed inside the hermetic container 1. The compression mechanism 3 is disposed below the electric motor 2 inside the hermetic container 1. The compression mechanism 3 compresses the refrigerant driven by the electric motor 2. The stator 22 has a stator core 41, and a core cutout 46 serving as a passage 13 for the refrigerant is provided between the stator core 41 and the inner wall of the hermetic container 1. In the compressor 10, (pressure loss generated between the inlet 46a and the outlet 46b of the core cutout 46) / (gas density of the refrigerant - density of the lubricating oil) is 1.45 or less.

[0012] In the first aspect, since the ratio of the pressure loss generated in the core cutout 46 to the density difference between the refrigerant and the lubricating oil is set to 1.45 or less, the size of the core cutout 46 can be suppressed, and at the same time, the pressure difference between the lower space and the upper space of the electric motor 2 can be suppressed. Therefore, even if the compressor 10 is made larger in capacity, the increase in the oil discharge rate can be suppressed without degrading the performance of the electric motor 2.

[0013] A second aspect of the present disclosure is, based on the above first aspect, setting the cross-sectional area of the core cutout 46 as S [m 2 , setting the circulation amount as F [kg / hr], where F [kg / hr] > 1000 [kg / hr], and S ≤ 0.00215 × (F / 1000) 7 / 9 .

[0014] In the second aspect, when the circulation amount of the compressor 10 is increased (i.e., when the compressor 10 is made larger in capacity), since the cross-sectional area S of the core cutout 46 can be suppressed to be smaller than before, the degradation of the performance of the electric motor 2 can be suppressed.

[0015] A third aspect of the present disclosure is, based on the above first or second aspect, an insulating member 51 is provided at at least one of the upper end 41a and the lower end 41b of the stator core 41, and the insulating member 51 has a surface continuous with the side wall surface 41c of the stator core 41 provided with the core cutout 46.

[0016] In a third aspect, since it is possible to suppress a sharp increase in the cross-sectional area of the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core notch 46, it is possible to suppress the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core notch 46.

[0017] A fourth aspect of the present disclosure is that, based on the above first or second aspect, the compressor is provided with an insulating member 51 that covers at least one of the upper end 41a and the lower end 41b of the stator core 41, and a part or all of the side wall surface 41c of the stator core 41 provided with the core notch 46.

[0018] In the fourth aspect, it is possible to fill the step of the side wall surface 41c of the stator core 41 provided with the core notch 46 with the insulating member 51. Therefore, since it is possible to suppress a sharp increase or decrease in the cross-sectional area of the refrigerant passage 13 between the side wall surface 41c of the stator core 41 and the inner wall of the hermetic container 1, it is possible to suppress the pressure loss (expansion loss or contraction loss).

[0019] A fifth aspect of the present disclosure is that, based on the above third or fourth aspect, the end position on the radially outer side of the insulating member 51 continuously retreats radially inward as it moves away from the stator core 41.

[0020] In the fifth aspect, it is possible to further suppress a sharp increase in the cross-sectional area of the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core notch 46. Therefore, it is possible to further suppress the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core notch 46. Description of the Drawings

[0021] Figure 1 is a longitudinal sectional view of the compressor according to the embodiment;

[0022] Figure 2 is a sectional view showing the arrangement structure of the hermetic container and the stator in the compressor according to the embodiment;

[0023] Figure 3 is a perspective view of the stator and the insulating member in the compressor according to the embodiment;

[0024] Figure 4 is a sectional view schematically showing the situation where the refrigerant flows through the core notch of the compressor according to the embodiment;

[0025] Figure 5A is a sectional view schematically showing the situation where the refrigerant flows through the core notch in an example of the structure in which the insulating member is provided on the side wall surface of the stator core of the compressor according to the embodiment;

[0026] Figure 5B FIG. 0 is a cross-sectional view schematically showing a case where refrigerant flows through a core notch in another example of a structure in which an insulating member is provided on a side wall surface of a stator core of a compressor according to an embodiment;

[0027] Figure 6A FIG. 5 is a cross-sectional view showing an arrangement structure of a hermetic container and a stator in a compressor of a comparative example;

[0028] Figure 6B FIG. 9 is a perspective view of a stator and an insulating member in a compressor of a comparative example;

[0029] Figure 7 FIG. 13 is a cross-sectional view schematically showing a case where refrigerant flows through a core notch of a compressor of a comparative example;

[0030] Figure 8 FIG. 17 is a graph showing the results of an investigation by the inventors of the present application on the relationship between "the ratio of the pressure loss at the core notch to the density difference between the refrigerant and the lubricating oil" and "the oil ejection rate";

[0031] Figure 9 FIG. 21 is a graph showing the results of an investigation by the inventors of the present application on the relationship between "the circulation amount of the compressor" and "the ratio of the pressure loss at the core notch to the density difference between the refrigerant and the lubricating oil". DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] (Embodiment)

[0033] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be noted that the following embodiments are only preferred examples in essence and are not intended to limit the present invention, its application object, or its usage scope.

[0034] <Structure of Compressor>

[0035] As Figure 1 shown, the compressor 10 of the present embodiment mainly includes a hermetic container 1, an electric motor 2, and a compression mechanism 3. The circulation amount of the compressor 10 when operating at the maximum rotational speed is 1000 [kg / hr] or more. In the present embodiment, a rotary compressor is exemplified as the compressor 10, but the compressor to which the technology described in the present embodiment is applied is not limited to a rotary compressor. The technology described in the present embodiment can also be applied to compressors other than rotary compressors.

[0036] The electric motor 2 is disposed inside the hermetic container 1. The electric motor 2 has a rotor 21 provided on a rotating shaft 4 extending in the vertical direction and a stator 22 fixed inside the hermetic container 1.

[0037] The compression mechanism 3 is arranged below the electric motor 2 inside the sealed container 1. The compression mechanism 3 is driven by the electric motor 2 to compress the refrigerant.

[0038] On the lower side and side of the sealed container 1, one end of the suction pipe 11 is connected to the compression mechanism 3. The other end of the suction pipe 11 is connected to the liquid reservoir 15, and the liquid reservoir 15 is arranged adjacent to the sealed container 1. The refrigerant gas (low-pressure refrigerant) supplied from the suction pipe 11 to the compressor 10 through the liquid reservoir 15 is introduced into the suction side of the compression mechanism 3. In this example, the compression mechanism 3 has a two-stage structure, and two suction pipes 11 connected to the cylinders of each stage are provided.

[0039] An ejection pipe 12 is connected to the upper space of the electric motor 2 in the sealed container 1. The refrigerant gas (high-pressure refrigerant) compressed in the compression mechanism 3 is ejected from the ejection pipe 12. The suction pipe 11 and the ejection pipe 12 penetrate the sealed container 1 and are fixed to the sealed container 1 in a manner that ensures the airtightness of the sealed container 1. Except for the suction pipe 11 and the ejection pipe 12 communicating with the outside of the sealed container 1, the sealed container 1 is formed as an airtight container.

[0040] An oil storage part for the lubricating oil that lubricates the driving part of the compression mechanism 3 is formed in the lower space of the compression mechanism 3 in the sealed container 1. The lubricating oil is the refrigeration oil used to improve the lubricity of the sliding parts in the internal space of the sealed container 1.

[0041] The compression mechanism 3 includes a cylindrical main body part 31. The rotating shaft 4 is inserted into the inside of the main body part 31. The rotating shaft 4 is supported by bearings respectively provided at the upper end and the lower end of the compression mechanism 3 to rotate freely. A crank pin 32 is provided on the rotating shaft 4 inside the main body part 31. In the compression mechanism 3, a compression chamber 34 for compressing the refrigerant is formed between the piston 33 driven by fitting onto the crank pin 32 and the main body part 31. The piston 33 rotates or revolves in a state eccentric to the axis of the rotating shaft 4, thereby changing the volume of the compression chamber 34. Thus, the refrigerant gas is compressed.

[0042] The electric motor 2 drives the compression mechanism 3 via the rotating shaft 4. The electric motor 2 is arranged in the high-pressure area inside the sealed container 1 filled with the high-pressure refrigerant gas ejected from the compression mechanism 3. The electric motor 3 includes a cylindrical rotor 21 fixed to the rotating shaft 4 and a stator 22 arranged to face the rotor 21 across an air gap in the radial direction of the rotor 21. The rotor 21 has a rotor core composed of a plurality of metal plates laminated in the vertical direction, and magnets are embedded in the rotor core. The stator 22 is a cylindrical component fixed to the inner wall of the sealed container 1.

[0043] <Stator>

[0044] As Figure 2 and Figure 3As shown, the stator 22 mainly includes a stator core 41 and an insulating member 51. The stator core 41 is fixed, for example, by press-fitting on the inner circumferential surface of the sealed container 1. The stator core 41 is made of electromagnetic steel, for example. The insulating member 51 is mounted on both end faces (upper end face and lower end face) of the stator core 41 in the vertical direction. The insulating member 51 is made of resin, for example. It should be noted that in Figure 3 the stator 22 is shown with a part of the stator core 41 and the insulating member 51 cut off.

[0045] The stator core 41 has an annular portion 42 and a plurality of (nine in this example) teeth 43. The annular portion 42 has a substantially cylindrical shape. The teeth 43 project radially inward from the inner circumferential surface of the annular portion 42. The teeth 43 are arranged at equal intervals in the circumferential direction of the annular portion 42. A slot 44 is formed between the teeth 43 adjacent to each other in the circumferential direction of the annular portion 42. A wire is wound around the teeth 43 with an insulating sheet interposed therebetween, thereby forming a coil 45. The insulating sheet may also be provided integrally with the insulating member 51. The insulating member 51 has vertical walls 51a that cover the upper and lower ends (coil ends) of the coil 45 and prevent the coil ends from shifting radially.

[0046] It should be noted that in the present disclosure, "radial direction" refers to the direction orthogonal to the rotation axis 4, "circumferential direction" refers to the circumferential direction of a circle centered on the rotation axis 4, and "axial direction" refers to the extending direction of the rotation axis 4, that is, the "vertical direction".

[0047] On the outer circumferential surface of the stator core 41 (annular portion 42), a groove extending in the vertical direction, that is, a core cutout 46, is formed. The core cutouts 46 are arranged at equal intervals on the outer circumferential surface of the stator core 41. The core cutout 46 serves as a passage 13 (hereinafter, also referred to as refrigerant passage 13) for the refrigerant gas (high-pressure refrigerant) compressed in the compression mechanism 3 to move toward the ejection pipe 12.

[0048] <Insulating Member>

[0049] As Figures 2 to 4 shown, the insulating member 51 provided at the upper end 41a and the lower end 41b of the stator core 41 has a surface continuous with the side wall surface 41c of the stator core 41 provided with the core cutout 46. In other words, the insulating member 51 extends from the vertical wall 51a to the radially outer end of the stator core 41, and the surface of the radially outer end of the insulating member 51 is smoothly connected to the side wall surface 41c of the stator core 41 without generating a step. Thereby, it is possible to suppress a sharp increase in the cross-sectional area of the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core cutout 46, and thus it is possible to suppress the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core cutout 46. It should be noted that Figure 4 is along Figure 2Cross-sectional view taken along line a-a. Additionally, in Figure 4 the refrigerant flowing in the refrigerant passage 13 is indicated by an arrow.

[0050] As Figure 5A shown, the insulating member 51 may also have a covering portion 51b that covers the side wall surface 41c of the stator core 41 provided with the core notch 46. In this example, the covering portion 51b connects the insulating members 51 respectively provided at the upper end 41a and the lower end 41b of the stator core 41. In other words, the covering portion 51b covers the entire side wall surface 41c of the stator core 41 provided with the core notch 46 in the vertical direction. However, the covering portion 51b may also be connected to only one of the insulating members 51 respectively provided at the upper end 41a and the lower end 41b of the stator core 41. In other words, the covering portion 51b may also cover a part of the side wall surface 41c of the stator core 41 provided with the core notch 46 in the vertical direction.

[0051] In Figure 5A the insulating member 51 shown, as long as the surface of the insulating member 51 at the part located at the upper end 41a or the lower end 41b of the stator core 41 is continuous with the surface of the covering portion 51b, it can achieve the same effect as the insulating member 51 shown in Figure 4 shown.

[0052] As Figure 5B shown, when there is a step 41d on the side wall surface 41c of the stator core 41 provided with the core notch 46, the covering portion 51b may also be provided in a manner that fills the step 41d. Thereby, between the side wall surface 41c of the stator core 41 and the inner wall of the sealed container 1, it is possible to suppress the change in the cross-sectional area of the refrigerant passage 13 caused by the step 41d, and thus it is possible to suppress the pressure loss (expansion loss or contraction loss).

[0053] It should be noted that in the insulating member 51 shown in any of Figure 4 , Figure 5A , Figure 5B in order to suppress the sharp change in the cross-sectional area of the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core notch 46, it is also preferable that the position of the radially outer end (outer peripheral end) of the insulating member 51 continuously retreats radially inward as it moves away from the stator core 41. Specifically, at the inlet 46a or the outlet 46b of the core notch 46, the outer peripheral end of the insulating member 51 preferably has an R shape or a chamfered shape. Thereby, it is possible to further suppress the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core notch 46.

[0054] <Comparative Example>

[0055] In the compressor according to the comparative example, as Figure 6A , Figure 6B , Figure 7 shows, the shape of the insulating member 51 is different from that of Figures 2 to 4 , Figure 5A , Figure 5B shown in the above-described embodiment. It should be noted that in Figure 6A , Figure 6B , Figure 7 , the same reference numerals are given to the components identical to those of the compressor 10 in the above-described embodiment.

[0056] Specifically, in the comparative example, the outer peripheral end of the insulating member 51 provided at the upper end 41a or the lower end 41b of the stator core 41 is separated from the side wall surface 41c of the stator core 41. Therefore, in the comparative example, since the cross-sectional area of the refrigerant passage 13 changes sharply at the inlet 46a or the outlet 46b of the core cutout 46, a large pressure loss (inlet loss or outlet loss) is generated at the inlet 46a or the outlet 46b of the core cutout 46.

[0057] Next, with reference to Figure 7 the mechanism by which the oil discharge rate increases due to the pressure loss in the comparative example will be described. It should be noted that in the comparative example, the compression mechanism is also arranged in the lower space of the motor, and the refrigerant also flows from the inlet 46a to the outlet 46b of the core cutout 46.

[0058] If the pressure at the inlet 46a of the core cutout 46 (inlet pressure) is set as Pin and the pressure at the outlet 46b of the core cutout 46 (outlet pressure) is set as Pout, the outlet pressure Pout decreases due to the pressure loss, thereby generating a pressure difference ΔP = Pin - Pout.

[0059] Since the lubricating oil is transported to the upper space of the motor together with the refrigerant as it flows, and is affected by gravity (self-weight), if the pressure difference ΔP is small, the lubricating oil returns to the lower space of the motor to lubricate the sliding portion of the compression mechanism 3.

[0060] However, when the pressure difference ΔP increases due to the pressure loss, the pressure difference force pushing the lubricating oil upward is greater than the self-weight of the lubricating oil, and the oil return performance to the lower space of the motor decreases, and the oil discharge rate increases. On the other hand, when the core cutout 46 is enlarged to suppress the pressure loss, there arises a problem of deterioration of the motor performance.

[0061] <Evaluation Index of Pressure Loss>

[0062] The magnitude of the pressure loss generated at the core cutout 46 can be obtained, for example, using the calculation formula (ζ1 + ζ2 + ζ3 + ζ4 + ζ5)·(ρd·v 2It is calculated by (ζ1 + ζ2 + ζ3 + ζ4 + ζ5) / 2. Here, ζ1 is the pressure loss coefficient between the laminated thicknesses of the core cut, ζ2 is the inlet loss coefficient, ζ3 is the outlet loss coefficient, ζ4 is the expansion loss coefficient, and ζ5 is the contraction loss coefficient. ζ1 can be calculated using the formula 0.3164 / Re －0.25 ·L / D. ζ2 to ζ5 are calculated through experiments.

[0063] Re is the Reynolds number and can be calculated using the formula Re = ρd·v·L / μ. v is the refrigerant gas flow velocity [m / s] and can be calculated using the formula v = Vcc·rps·ρs / S. It should be noted that ρd is the density of the ejected refrigerant gas [kg / m 3 , L is the laminated thickness of the core cut (the length in the vertical direction of the core cut) [m], D is the hydraulic diameter of the core cut [m], μ is the refrigerant viscosity [kg / m·s], Vcc is the cylinder volume of the compression mechanism [m 3 , rps is the maximum operating speed (highest speed) [1 / s], ρs is the density of the suction gas [kg / m 3 , and S is the cross-sectional area of the core cut [m 2 . The cross-sectional area S of the core cut is the sum of the cross-sectional areas of all core cuts. When the cross-sectional area of the core cut varies in the vertical direction, the cross-sectional area S of the core cut is the average cross-sectional area.

[0064] The density ρd of the ejected refrigerant gas [kg / m 3 uses the value calculated by REFPROP (refrigerant property query software) using the high-pressure side pressure and the temperature of the ejected refrigerant gas, where the high-pressure side pressure and the temperature of the ejected refrigerant gas are determined by the operating conditions (Tc: condensation temperature, Te: evaporation temperature, Sh: superheat degree, Sc: subcooling degree, etc.). It should be noted that REFPROP is software developed by the National Institute of Standards and Technology of the United States to calculate the thermal properties and transport properties of fluids.

[0065] The gas flow velocity v [m / s] is calculated according to the refrigerant circulation amount (the circulation amount during operation at the maximum operating speed) F [kg / hr], the density ρd of the ejected refrigerant gas [kg / m 3 , and the cross-sectional area S of the core cut [m 2 using the formula v = F / 3600 / ρd / S.

[0066] The refrigerant circulation amount F [kg / hr] is based on the maximum operating speed rps [1 / s], the displacement (converting the cylinder volume of the compression mechanism [m 3 to the unit [cm 3The Vcc[cm obtained thereby 3 , the density ρs of the suction gas [kg / m 3 , and is calculated using the formula F = rps·3600·Vcc / 1000000·ρs.

[0067] The density ρs of the suction refrigerant gas [kg / m 3 is the value calculated by REFPROP using the low-pressure side pressure and the suction refrigerant gas temperature determined by the above operating conditions.

[0068] Similar to the density ρd of the discharged refrigerant gas, the refrigerant viscosity μ [kg / m·s] is the value calculated by REFPROP using the high-pressure side pressure and the discharged refrigerant gas temperature.

[0069] From the above-described pressure loss calculation formula, it can be seen that when the compressor is enlarged in capacity, the stack thickness L, and the cylinder volume Vcc increase, the pressure loss increases even if other conditions are the same.

[0070] Based on the above-described pressure loss calculation formula, the present inventors calculated the ratio of the pressure loss (the pressure loss generated between the inlet and the outlet of the core notch) to the "difference between the gas density of the refrigerant and the density of the lubricating oil" for various existing compressors and a hypothetical large-capacity compressor, and investigated the relationship between this ratio and the oil discharge rate as an evaluation index of the pressure loss. The results are shown in Figure 8 In Figure 8 , ▲ represents the evaluation result of an existing single-cylinder compressor, □ represents the evaluation result of an existing double-cylinder compressor, and * represents the evaluation result of a hypothetical large-capacity compressor. In addition, the gas density of the refrigerant refers to the above-described density ρd of the discharged refrigerant gas, and the density d of the lubricating oil [kg / m 3 is calculated using the formula d = 0.93 - 0.00073·(T - 15)·1000 with the discharged refrigerant gas temperature set to T [°C]. In addition, the oil discharge rate represents the ratio of the lubricating oil that has not returned from the upper space of the motor in the total amount of the lubricating oil. It should be noted that in any compressor, carbon dioxide is used as the refrigerant. In addition, for the hypothetical large-capacity compressor, in the structure of the above comparative example, the calculation was performed on the premise that the cross-sectional area of the core notch that becomes the refrigerant passage remains unchanged from the inlet to the outlet.

[0071] As Figure 8 shows, when the above ratio (hereinafter referred to as "pressure loss / density difference") increases, the oil discharge rate increases, and a linear relationship was found between the "pressure loss / density difference" and the oil discharge rate, including the evaluation results of the hypothetical large-capacity compressor.

[0072] Next, the present inventors investigatedFigure 8 The relationship between the circulation volume of various compressors shown and "pressure loss / density difference". The results are shown in Figure 9 . As Figure 9 shown, it can be seen that in the structure of the above comparative example, "pressure loss / density difference" increases as the circulation volume F increases to a large capacity of 1000 [kg / hr] or more.

[0073] According to Figure 8 and Figure 9 the results shown, the inventors of the present application found that: in a large-capacity compressor with a circulation volume F of 1000 [kg / hr] or more, if "pressure loss / density difference" can be suppressed to 1.45 or less as in existing compressors, it is also possible to suppress the increase in the oil discharge rate as the capacity increases. It should be noted that as Figures 2 to 4 , Figure 5A , Figure 5B shown in the above-described embodiments, for example, if the pressure loss is suppressed by paying attention to the shape of the insulating member 51, "pressure loss / density difference" can also be suppressed.

[0074] In addition, the inventors of the present application found that: when the cross-sectional area of the core notch is set to S [m 2 , and the circulation volume is set to F [kg / hr] (>1000 [kg / hr]), by setting the cross-sectional area S of the core notch so as to satisfy S ≤ 0.00215 × (F / 1000) 7 / 9 , it is possible to suppress the reduction of the motor performance. Here, the coefficient 0.00215 is the cross-sectional area of the core notch when "pressure loss / density difference" is 1.45 in an actual device with a circulation volume of 1000 [kg / hr]. That is to say, it is also possible to suppress the reduction of the motor performance by suppressing the increase rate of the cross-sectional area S of the core notch to be smaller than the increase rate of the circulation volume F.

[0075] <Features of the Embodiment>

[0076] As described above, the compressor 10 of the present embodiment includes a hermetic container 1, a motor 2, and a compression mechanism 3. The circulation volume of the compressor 10 when operating at the maximum rotational speed is 1000 kg / hr or more. The motor 2 is disposed inside the hermetic container 1. The motor 2 has a rotor 21 provided on a rotating shaft 4 extending in the vertical direction and a stator 22 fixed inside the hermetic container 1. The compression mechanism 3 is disposed below the motor 2 inside the hermetic container 1. The compression mechanism 3 compresses the refrigerant by being driven by the motor 2. The stator 22 has a stator core 41, and a core notch 46 serving as a passage 13 for the refrigerant is provided between the stator core 41 and the inner wall of the hermetic container 1.

[0077] In the compressor 10 of the present embodiment, (pressure loss generated between the inlet 46a and the outlet 46b of the core notch 46) / (gas density of the refrigerant - density of the lubricating oil), that is, "pressure loss / density difference" is set to 1.45 or less. Therefore, the size of the core notch 46 can be suppressed, and at the same time, the pressure difference between the lower space and the upper space of the motor 2 can be suppressed. Therefore, even when the capacity of the compressor 10 is increased, the lubricating oil easily returns to the lower space of the motor 2, so that an increase in the oil discharge rate can be suppressed without degrading the performance of the motor 2.

[0078] In the compressor 10 of the present embodiment, it is also possible to set the cross-sectional area of the core notch 46 to S [m 2 , set the circulation amount to F [kg / hr] (>1000 [kg / hr]), and S ≤ 0.00215 × (F / 1000) 7 / 9 . In this way, when the circulation amount F of the compressor 10 is increased (that is, when the capacity of the compressor 10 is increased), the increase rate of the cross-sectional area S of the core notch 46 can be suppressed to be smaller than the increase rate of the circulation amount F. Therefore, a decrease in the performance of the motor 2 can be suppressed. In addition, the amount of cutting the stator core 41 to form the core notch 46 can be reduced, making the processing easier.

[0079] In the compressor 10 of the present embodiment, it is also possible to provide an insulating member 51 at at least one of the upper end 41a and the lower end 41b of the stator core 41, and the insulating member 51 has a surface continuous with the side wall surface 41c of the stator core 41 provided with the core notch 46. In this way, since a sharp increase in the cross-sectional area of the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core notch 46 can be suppressed, the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core notch 46 can be suppressed.

[0080] In the compressor 10 of the present embodiment, it is also possible to provide an insulating member 51 on the compressor 10, and the insulating member 51 covers at least one of the upper end 41a and the lower end 41b of the stator core 41 and a part or all of the side wall surface 41c of the stator core 41 provided with the core notch 46. In this way, the insulating member 51 can be used to fill the step of the side wall surface 41c of the stator core 41 provided with the core notch 46. Therefore, a change in the cross-sectional area of the refrigerant passage 13 between the side wall surface 41c of the stator core 41 and the inner wall of the closed container 1 can be suppressed, and thus the pressure loss (expansion loss or contraction loss) can be suppressed.

[0081] In the compressor 10 of the present embodiment, it is also possible that the end position on the radially outer side of the insulating member 51 continuously retreats radially inward as it moves away from the stator core 41. In this way, it is possible to further suppress the sharp increase in the cross-sectional area of the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core notch 46, and thus it is possible to further suppress the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core notch 46.

[0082] (Other embodiments)

[0083] In the above embodiment, the rotary compressor 10 shown Figure 1 is exemplified as the compressor, and the motor 2 shown Figure 2 and Figure 3 is exemplified as the motor. However, it is not limited thereto, and as long as it is a compressor with a circulation volume of 1000 [kg / hr] or more when operating at the maximum rotational speed, and a compressor in which a compression mechanism is arranged below the motor inside a sealed container and has a stator core with a core notch that forms a refrigerant passage between the inner wall of the sealed container, the technology described in the above embodiment can be applied.

[0084] In addition, in the above embodiment, the insulating member 51 is used to form a gentle shape that suppresses the sharp change in the cross-sectional area of the refrigerant passage 13 at both the inlet 46a and the outlet 46b of the core notch 46. However, such a gentle shape may be provided only at one of the inlet 46a and the outlet 46b of the core notch 46. In addition, such a gentle shape may also be achieved by other units other than the insulating member 51, for example, by the shape of the stator core 41 itself.

[0085] The above describes the embodiment, but it should be understood that various changes in the manner and details can be made without departing from the gist and scope of the claims. In addition, the above embodiments and modification examples can be appropriately combined or replaced.

[0086] -Industrial applicability-

[0087] In summary, the present disclosure is useful for compressors, especially compressors with a circulation volume of 1000 [kg / hr] or more when operating at the maximum rotational speed.

[0088] -Symbol description-

[0089] 1 Sealed container

[0090] 2 Motor

[0091] 3 Compression mechanism

[0092] 4 Rotating shaft

[0093] 10 Compressor

[0094] 13 Refrigerant passage (passage)

[0095] 21 Rotor

[0096] 22 Stator

[0097] 41 Stator core

[0098] 41a Upper end

[0099] 41b Lower end

[0100] 41c Side wall surface

[0101] 46 Core notch

[0102] 46a Inlet

[0103] 46b Outlet

[0104] 51 Insulating component

Claims

1. A compressor, which comprises a hermetic container (1), an electric motor (2) and a compression mechanism (3). The electric motor (2) is arranged inside the hermetic container (1). The electric motor (2) has a rotor (21) provided on a rotating shaft (4) extending in the vertical direction and a stator (22) fixed inside the hermetic container (1). The compression mechanism (3) is arranged below the electric motor (2) inside the hermetic container (1). The compression mechanism (3) is driven by the electric motor (2) to compress the refrigerant. The circulation amount of the compressor (10) during operation at the maximum rotational speed is 1000 [kg / hr] or more. The compressor is characterized in that: The stator (22) has a stator core (41). A core cutout (46) serving as a passage (13) for the refrigerant is provided between the stator core (41) and the inner wall of the hermetic container (1). (The pressure loss generated between the inlet (46a) and the outlet (46b) of the core cutout (46)) / (the gas density of the refrigerant - the density of the lubricating oil) is 1.45 or less. An insulating member (51) is provided at at least one of the upper end (41a) and the lower end (41b) of the stator core (41). The insulating member (51) has a surface continuous with the side wall surface (41c) of the stator core (41) provided with the core cutout (46).

2. A compressor, which comprises a hermetic container (1), an electric motor (2) and a compression mechanism (3). The electric motor (2) is arranged inside the hermetic container (1). The electric motor (2) has a rotor (21) provided on a rotating shaft (4) extending in the vertical direction and a stator (22) fixed inside the hermetic container (1). The compression mechanism (3) is arranged below the electric motor (2) inside the hermetic container (1). The compression mechanism (3) is driven by the electric motor (2) to compress the refrigerant. The circulation amount of the compressor (10) during operation at the maximum rotational speed is 1000 [kg / hr] or more. The compressor is characterized in that: The stator (22) has a stator core (41). A core cutout (46) serving as a passage (13) for the refrigerant is provided between the stator core (41) and the inner wall of the hermetic container (1). (The pressure loss generated between the inlet (46a) and the outlet (46b) of the iron core cutout (46)) / (the gas density of the refrigerant - the density of the lubricating oil) is 1.45 or less. The compressor is provided with an insulating member (51), and the insulating member (51) covers at least one of the upper end (41a) and the lower end (41b) of the stator core (41), and a part or all of the side wall surface (41c) of the stator core (41) provided with the iron core cutout (46).

3. The compressor according to claim 1 or 2, characterized in that: Set the cross-sectional area of the iron core cut (46) as S [m 2 , and set the circulation amount as F [kg / hr], where F [kg / hr] > 1000 [kg / hr]. S ≤ 0.00215 × (F / 1000) 7 / 9 .

4. The compressor according to claim 1 or 2, characterized in that: The end position on the radially outer side of the insulating member (51) continuously retreats radially inward as it moves away from the stator core (41).

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