Compressor

Abstract

The compressor (10) is provided with a sealed container (1), an electric motor (2), and a compression mechanism (3), and the circulation amount when the compressor (10) is operated at the highest rotational speed is 1000 kg / hr or more. The motor (2) is provided with a rotor (21) arranged on a rotating shaft (4) extending in the vertical direction and a stator (22) fixed in the sealed container (1). The compression mechanism (3) is arranged below the motor (2) inside the closed container (1). 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 sealed container (1). In the compressor (10), (pressure loss generated between an inlet (46a) and an outlet (46b) of the core cutout (46)) / (gas density of refrigerant-density of lubricating oil) is 1.45 or less.

Description

Technical Field

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

[0002] In the past, compressors for compressing refrigerants were known. Patent Document 1 discloses a rotary compressor. The rotary compressor contains a compression mechanism and an electric motor in a dome-shaped housing, and is configured as a fully enclosed compressor. The electric motor includes a stator fixed to the body of the housing and a rotor connected to a drive shaft and arranged inside the stator.

[0003] Prior art literature

[0004] Patent Literature

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

[0006] -Technical problem to be solved by the invention-

[0007] Patent Document 1 discloses that a core cutout is provided on the outer peripheral surface of a stator, and a refrigerant passage is formed between the outer peripheral surface of the stator and the inner wall of a housing to communicate spaces on both sides of the motor in the axial direction.

[0008] However, in order to suppress the reduction of motor performance, it is necessary to suppress the size of the core cutout. On the other hand, if the core cutout is small, the pressure loss of the refrigerant when passing through the core cutout will increase, and the oil discharge rate will increase. With the demand for larger capacity compressors in the future, it is considered difficult to balance the suppression of pressure loss and the maintenance of motor performance.

[0009] An object of the present disclosure is to suppress an increase in the oil discharge rate without degrading the performance of the motor in a compressor having a larger capacity.

[0010] -Technical solutions to solve technical problems-

[0011] The first aspect of the present disclosure is a compressor, which includes a sealed container 1, a motor 2 and a compression mechanism 3, wherein the circulation volume of the compressor 10 when operating at the maximum speed is 1000 [kg / hr] or more. The motor 2 is arranged inside the sealed container 1. The motor 2 has a rotor 21 arranged on a rotating shaft 4 extending in the up-down direction and a stator 22 fixed in the sealed container 1. The compression mechanism 3 is arranged below the motor 2 inside the sealed container 1. The compression mechanism 3 is driven by the motor 2 to compress the refrigerant. The stator 22 has a stator core 41, and a core cutout 46 that becomes a passage 13 for the refrigerant is provided between the stator core 41 and the inner wall of the sealed 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 less than 1.45.

[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 less than 1.45, the size of the core cutout 46 can be suppressed, and the pressure difference between the lower space and the upper space of the motor 2 can be suppressed. Therefore, even if the capacity of the compressor 10 is increased, the increase in the oil discharge rate can be suppressed without reducing the performance of the motor 2.

[0013] The second aspect of the present disclosure is that, based on the first aspect, the cross-sectional area of ​​the core cutout 46 is set to S[m 2 ], the circulation rate is set to F [kg / hr], wherein F [kg / hr] > 1000 [kg / hr], S ≤ 0.00215 × (F / 1000) 7 / 9 .

[0014] In the second aspect, when the circulation rate of the compressor 10 is increased (ie, when the capacity of the compressor 10 is increased), the cross-sectional area S of the core cutout 46 can be suppressed to be smaller than before, thereby suppressing the reduction in performance of the motor 2.

[0015] The third aspect of the present disclosure is that, based on the above-mentioned first or second aspect, an insulating component 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 component 51 has a surface continuous with the side wall surface 41c of the stator core 41 where the core cutout 46 is provided.

[0016] In the third aspect, since the cross-sectional area of ​​the refrigerant passage 13 can be suppressed from increasing sharply at the inlet 46a or outlet 46b of the core cutout 46, the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or outlet 46b of the core cutout 46 can be suppressed.

[0017] The fourth aspect of the present disclosure is that, based on the above-mentioned first or second aspect, the compressor is provided with an insulating component 51, and the insulating component 51 covers at least one end 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 cutout 46.

[0018] In the fourth aspect, the step of the side wall surface 41c of the stator core 41 provided with the core cutout 46 can be buried by the insulating member 51. Therefore, since the cross-sectional area of ​​the refrigerant passage 13 can be suppressed from increasing or decreasing sharply between the side wall surface 41c of the stator core 41 and the inner wall of the closed container 1, the pressure loss (expansion loss or contraction loss) can be suppressed.

[0019] According to a fifth aspect of the present disclosure, based on the third or fourth aspect, a radially outer end portion of the insulating member 51 continuously retreats radially inwardly as it moves away from the stator core 41 .

[0020] In the fifth aspect, the rapid increase in the cross-sectional area of ​​the refrigerant passage 13 at the inlet 46a or outlet 46b of the core cutout 46 can be further suppressed, thereby further suppressing the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or outlet 46b of the core cutout 46. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 2 is a cross-sectional view showing an arrangement structure of a closed container and a stator in a compressor according to an embodiment;

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

[0024] Figure 4 is a cross-sectional view schematically showing a state where a refrigerant flows through a core cutout of a compressor according to an embodiment;

[0025] Figure 5A is a cross-sectional view schematically showing a state in which a refrigerant flows through a core cutout in an 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;

[0026] Figure 5B is a cross-sectional view schematically showing a state where a refrigerant flows through a core cutout 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] Fig. 6A is a cross-sectional view showing the arrangement structure of a closed container and a stator in a compressor of a comparative example;

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

[0029] Figure 7 is a cross-sectional view schematically showing a state where a refrigerant flows through a core cutout of a compressor of a comparative example;

[0030] Figure 8 This is a diagram showing the results of an investigation conducted by the inventors of the present application on the relationship between "the ratio of the pressure loss at the core cutout to the density difference between the refrigerant and the lubricating oil" and "the oil discharge rate";

[0031] Fig. 9 This is a diagram showing the results of an investigation conducted 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 cutout to the density difference between the refrigerant and the lubricant oil”. DETAILED DESCRIPTION

[0032] (Implementation Method)

[0033] The following embodiments of the present disclosure are described with reference to the accompanying drawings. It should be noted that the following embodiments are merely preferred examples in nature and are not intended to limit the present invention, its application objects or its scope of use.

[0034] <Compressor Structure>

[0035] like Figure 1 As shown, the compressor 10 of the present embodiment mainly includes a closed container 1, a motor 2 and a compression mechanism 3. The circulation amount of the compressor 10 when operating at the maximum speed is more than 1000 [kg / hr]. 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 the rotary compressor. The technology described in the present embodiment can also be applied to compressors other than the rotary compressor.

[0036] The motor 2 is arranged inside the sealed container 1. The motor 2 has a rotor 21 provided on a rotating shaft 4 extending in the up-down direction and a stator 22 fixed inside the sealed container 1.

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

[0038] At the lower side of the closed 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 accumulator 15, and the accumulator 15 is arranged adjacent to the closed container 1. The refrigerant gas (low-pressure refrigerant) supplied from the suction pipe 11 to the compressor 10 through the accumulator 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 is provided with two suction pipes 11 connected to the cylinders of each stage.

[0039] A discharge pipe 12 is connected to the upper space of the motor 2 in the closed container 1. The refrigerant gas (high-pressure refrigerant) compressed in the compression mechanism 3 is discharged from the discharge pipe 12. The suction pipe 11 and the discharge pipe 12 penetrate the closed container 1 and are fixed to the closed container 1 in a manner to ensure the airtightness of the closed container 1. The closed container 1 is formed as an airtight container except that the suction pipe 11 and the discharge pipe 12 are connected to the outside of the closed container 1.

[0040] An oil reservoir for lubricating oil for lubricating a driving portion of the compression mechanism 3 is formed in the lower space of the compression mechanism 3 in the closed container 1. The lubricating oil is refrigeration oil used to improve the lubricity of sliding portions in the internal space of the closed container 1.

[0041] The compression mechanism 3 includes a cylinder-shaped main body 31. The rotating shaft 4 is inserted into the interior of the main body 31. The rotating shaft 4 is supported by bearings provided at the upper end and the lower end of the compression mechanism 3 so as to rotate freely. A crank pin 32 is provided on the rotating shaft 4 in the main body 31. In the compression mechanism 3, a compression chamber 34 for compressing refrigerant is formed between a piston 33 driven by being engaged with the crank pin 32 and the main body 31. The piston 33 rotates or revolves in an eccentric state relative to the axis of the rotating shaft 4, thereby changing the volume of the compression chamber 34. As a result, the refrigerant gas is compressed.

[0042] The motor 2 drives the compression mechanism 3 via the rotating shaft 4. The motor 2 is arranged in a high-pressure area in the sealed container 1 filled with high-pressure refrigerant gas ejected from the compression mechanism 3. The motor 3 includes a cylindrical rotor 21 fixed to the rotating shaft 4 and a stator 22 arranged to face the rotor 21 with 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 stacked in the up-down direction, and a magnet is 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] like Figure 2 and Figure 3As shown, the stator 22 mainly includes a stator core 41 and an insulating component 51. The stator core 41 is fixed to the inner circumference of the sealed container 1 by, for example, heat press fitting. The stator core 41 is made of, for example, electromagnetic steel. The insulating component 51 is installed on both end surfaces (upper end surface and lower end surface) of the stator core 41 in the vertical direction. The insulating component 51 is made of, for example, resin. It should be noted that Figure 3 In FIG. 2 , the stator 22 is shown with a portion of the stator core 41 and the insulating member 51 cut away.

[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 protrude radially inward from the inner circumferential surface of the annular portion 42. The teeth 43 are arranged at equal intervals along the circumference of the annular portion 42. Slots 44 are formed between adjacent teeth 43 in the circumferential direction of the annular portion 42. A conductive wire is wound around the teeth 43 via an insulating sheet, thereby forming a coil 45. The insulating sheet may also be provided integrally with the insulating component 51. The insulating component 51 has a vertical wall 51a that covers the upper and lower ends (coil ends) of the coil 45 and prevents the coil ends from shifting radially.

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

[0047] The outer peripheral surface of the stator core 41 (annular portion 42) is provided with core cutouts 46 which are grooves extending in the up-down direction. The core cutouts 46 are arranged at equal intervals on the outer peripheral surface of the stator core 41. The core cutouts 46 form passages 13 (hereinafter also referred to as refrigerant passages 13) for the refrigerant gas (high-pressure refrigerant) compressed in the compression mechanism 3 to move toward the discharge pipe 12.

[0048] <Insulation parts>

[0049] like Figure 2 to Figure 4 As shown, the insulating component 51 provided at the upper end 41a and the lower end 41b of the stator core 41 has a surface that is continuous with the side wall surface 41c of the stator core 41 provided with the core cutout 46. In other words, the insulating component 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 component 51 is smoothly connected to the side wall surface 41c of the stator core 41 in a manner that does not produce steps. Thereby, it is possible to suppress the rapid increase in the cross-sectional area of ​​the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core cutout 46, thereby suppressing 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 2A cross-sectional view of the a-a line. Figure 4 In FIG. 1 , the refrigerant flowing in the refrigerant passage 13 is indicated by arrows.

[0050] like Figure 5A As shown in the figure, the insulating member 51 may also have a covering portion 51b, which covers the side wall surface 41c of the stator core 41 provided with the core cutout 46. In this example, the covering portion 51b connects the insulating members 51 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 cutout 46 in the up-down direction. However, the covering portion 51b may be connected to only one of the insulating members 51 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 portion of the side wall surface 41c of the stator core 41 provided with the core cutout 46 in the up-down direction.

[0051] exist Figure 5A In the insulating member 51 shown in the figure, as long as the surface of the insulating member 51 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 play the role of Figure 4 The insulating member 51 shown has the same effect.

[0052] like Figure 5B As shown, in the case where there is a step 41d on the side wall surface 41c of the stator core 41 provided with the core cutout 46, the covering portion 51b may be provided in a manner of filling the step 41d. Thus, between the side wall surface 41c of the stator core 41 and the inner wall of the sealed container 1, the change in the cross-sectional area of ​​the refrigerant passage 13 caused by the step 41d can be suppressed, thereby suppressing the pressure loss (expansion loss or contraction loss).

[0053] It should be noted that in Figure 4 , Figure 5A , Figure 5B In the insulating member 51 shown in any of the figures, in order to suppress a sharp change in the cross-sectional area of ​​the refrigerant passage 13 at the inlet 46a or the outlet 46b of the core cutout 46, it is also preferred 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 cutout 46, the outer peripheral end of the insulating member 51 preferably has an R shape or a chamfered shape. As a result, the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core cutout 46 can be further suppressed.

[0054] <Comparative Example>

[0055] In the compressor involved in the comparative example, Fig. 6A , Figure 6B , Figure 7 As shown, the shape of the insulating member 51 is similar to Figure 2 to Figure 4 , Figure 5A , Figure 5B It should be noted that in Fig. 6A , Figure 6B , Figure 7 In the drawings, the same components as those of the compressor 10 of the above-described embodiment are denoted by the same reference numerals.

[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) occurs at the inlet 46a or the outlet 46b of the core cutout 46.

[0057] Below, refer to Figure 7 The mechanism of the increase in the oil discharge rate 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 of the core cutout 46 to the outlet 46b.

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

[0059] Since the lubricating oil is affected by gravity (self-weight) when it is transported to the upper space of the motor through the refrigerant passage 13 along with the flow of the refrigerant, if the pressure difference ΔP is small, the lubricating oil returns to the lower space of the motor and is used to lubricate the sliding parts of the compression mechanism 3.

[0060] However, when the pressure difference ΔP increases due to pressure loss, the pressure difference force pushing the lubricating oil upward becomes greater than the weight of the lubricating oil, and the oil return performance to the lower space of the motor is reduced, and the oil discharge rate increases. On the other hand, when the core cutout 46 is increased to suppress pressure loss, the problem of motor performance reduction occurs.

[0061] <Evaluation index of pressure loss>

[0062] The magnitude of the pressure loss generated at the core cutout 46 can be calculated using, for example, the formula (ζ1+ζ2+ζ3+ζ4+ζ5)·(ρd·v 2 / 2). Here, ζ1 is the pressure loss coefficient between the core cutout and the stacking thickness, 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~ζ5 are calculated through experiments.

[0063] Re is the Reynolds number, which can be calculated using the formula Re = ρd·v·L / μ. v is the refrigerant gas flow rate [m / s], which 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 core cutout stacking thickness (the length of the core cutout in the vertical direction) [m], D is the core cutout hydraulic diameter [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 (maximum speed) [1 / s], ρs is the suction gas density [kg / m 3 ], S is the cross-sectional area of ​​the core cutout [m 2 ]. The core cut cross-sectional area S is the sum of the cross-sectional areas of all the core cuts. When the cross-sectional area of ​​the core cut varies in the up-down direction, the cross-sectional area S of the core cut is the average cross-sectional area.

[0064] The density of the discharged refrigerant gas ρd[kg / m 3 ] uses the value calculated by REFPROP (Refrigerant Property Query Software) using the high-pressure side pressure and the ejected refrigerant gas temperature, where the high-pressure side pressure and the ejected refrigerant gas temperature are determined by the operating conditions (Tc: condensing temperature, Te: evaporating temperature, Sh: superheat, Sc: subcooling, etc.). It should be noted that REFPROP is a software developed by the National Institute of Standards and Technology (National Institute of Standards and Technology) in the United States that calculates the thermal and transport properties of fluids.

[0065] The gas flow rate v[m / s] is calculated based on the refrigerant circulation rate (circulation rate when operating at the maximum operating speed) F[kg / hr], the ejected refrigerant gas density ρd[kg / m 3 ]、Core cut section area S[m 2 ], calculated using the formula v = F / 3600 / ρd / S.

[0066] The refrigerant circulation rate F[kg / hr] is determined by the maximum operating speed rps[1 / s], displacement (the cylinder volume of the compression mechanism [m 3 ]Convert units [cm 3])Vcc[cm 3 ]、Inhaled gas density ρs[kg / m 3 ], calculated using the formula F = rps·3600·Vcc / 1000000·ρs.

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

[0068] As with the discharged refrigerant gas density ρd, the refrigerant viscosity μ [kg / m·s] uses a value calculated by REFPROP using the high-pressure side pressure and the discharged refrigerant gas temperature.

[0069] As can be seen from the calculation formula for pressure loss described above, when the capacity of the compressor is increased, the stacking thickness L and the cylinder volume Vcc are increased, the pressure loss increases even if other conditions remain the same.

[0070] Based on the above-described pressure loss calculation formula, the inventors of the present application calculated the ratio of pressure loss (pressure loss generated between the inlet and outlet of the core cutout) 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 for pressure loss. The results are shown in Figure 8 In. Figure 8 In the figure, ▲ represents the evaluation result of the existing single-cylinder compressor, □ represents the evaluation result of the existing two-cylinder compressor, and * represents the evaluation result of the hypothetical large-capacity compressor. In addition, the gas density of the refrigerant refers to the above-mentioned ejected refrigerant gas density ρd, and the density of the lubricating oil d [kg / m 3 ] is calculated by setting the ejected refrigerant gas temperature to T[℃] using the calculation formula d=0.93-0.00073·(T-15)·1000. In addition, the oil discharge rate refers to the proportion of the total amount of lubricating oil that does not return from the upper space of the motor. It should be noted that carbon dioxide is used as the refrigerant in any compressor. In addition, for the hypothetical large-capacity compressor, in the structure of the above-mentioned comparative example, a trial calculation was performed on the assumption that the cross-sectional area of ​​the core cutout that serves as the refrigerant passage remains unchanged from the inlet to the outlet.

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

[0072] Next, the inventor of the present application investigated Figure 8 The relationship between the circulation volume and "pressure loss / density difference" of various compressors shown in FIG. Fig. 9 In. Fig. 9 As shown, it can be seen that in the structure of the comparative example, the "pressure loss / density difference" increases as the circulation rate F becomes larger than 1000 [kg / hr].

[0073] according to Figure 8 and Fig. 9 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 the "pressure loss / density difference" can be suppressed to less than 1.45 as in the conventional compressor, the increase in oil discharge rate with increasing capacity can also be suppressed. Figure 2 to Figure 4 , Figure 5A , Figure 5B As in the above-described embodiment shown, for example, if the pressure loss is suppressed by devising an improvement in the shape of the insulating member 51, the “pressure loss / density difference” can also be suppressed.

[0074] In addition, the inventors of the present application have found that: when the cross-sectional area of ​​the core cutout is set to S[m 2 ], set the circulation rate to F [kg / hr] (> 1000 [kg / hr]), and satisfy S ≤ 0.00215 × (F / 1000) 7 / 9 The core cut cross-sectional area S is set in a manner to suppress the reduction in motor performance. Here, the coefficient 0.00215 is the core cut cross-sectional area when the "pressure loss / density difference" is 1.45 in an actual device with a circulation volume of 1000 [kg / hr]. In other words, the reduction in motor performance can also be suppressed by suppressing the increase rate of the core cut cross-sectional area S 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 closed container 1, a motor 2, and a compression mechanism 3, and the circulation volume of the compressor 10 when operating at the maximum speed is more than 1000 kg / hr. The motor 2 is arranged inside the closed container 1. The motor 2 has a rotor 21 arranged on a rotating shaft 4 extending in the up-down direction and a stator 22 fixed in the closed container 1. The compression mechanism 3 is arranged below the motor 2 inside the closed container 1. The compression mechanism 3 is driven by the motor 2 to compress the refrigerant. 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 closed 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 cutout 46) / (gas density of the refrigerant-density of the lubricating oil), that is, "pressure loss / density difference" is set to be less than 1.45. Therefore, the size of the core cutout 46 can be suppressed, and 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 can easily return to the lower space of the motor 2, thereby suppressing the increase in the oil discharge rate without reducing the performance of the motor 2.

[0078] In the compressor 10 of the present embodiment, the cross-sectional area of ​​the core cutout 46 may be set to S[m 2 ], set the circulation rate to F [kg / hr] (>1000 [kg / hr]), S ≤ 0.00215 × (F / 1000) 7 / 9 In this way, when the circulation volume F of the compressor 10 is increased (i.e., when the capacity of the compressor 10 is increased), the increase rate of the cross-sectional area S of the core cutout 46 can be suppressed to be smaller than the increase rate of the circulation volume F, thereby suppressing the reduction in the performance of the motor 2. In addition, the amount of cutting of the stator core 41 to form the core cutout 46 can be reduced, thereby facilitating processing.

[0079] In the compressor 10 of the present embodiment, an insulating member 51 may be 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 may have a surface continuous with the side wall surface 41c of the stator core 41 provided with the core cutout 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 cutout 46 can be suppressed, the pressure loss (inlet loss or outlet loss) generated at the inlet 46a or the outlet 46b of the core cutout 46 can be suppressed.

[0080] In the compressor 10 of the present embodiment, the compressor 10 may be provided with an insulating member 51, which 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 cutout 46. In this way, the step of the side wall surface 41c of the stator core 41 provided with the core cutout 46 can be buried by the insulating member 51. Therefore, the 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, so that the pressure loss (expansion loss or contraction loss) can be suppressed.

[0081] In the compressor 10 of the present embodiment, the radially outer end position of the insulating member 51 may be continuously retreated radially inward as it moves away from the stator core 41. In this way, 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 cutout 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 cutout 46.

[0082] (Other embodiments)

[0083] In the above-mentioned embodiment, the Figure 1 The rotary compressor 10 shown is used as a compressor, and an example Figure 2 and Figure 3 The motor 2 shown is used as the motor. However, this is not limited to this, and the technology described in the above embodiment can be applied to any compressor having a circulation volume of 1000 [kg / hr] or more when operating at the maximum speed, a compression mechanism arranged below the motor inside a sealed container, and a stator core having a core cutout that serves as a refrigerant passage between the stator core and the inner wall of the sealed container.

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

[0085] Although the embodiments are described above, it should be understood that various changes in form and details can be made without departing from the spirit and scope of the claims. In addition, the above embodiments and modifications can be appropriately combined or replaced.

[0086] - Industrial Applicability -

[0087] In summary, the present disclosure is useful for compressors, particularly compressors having a circulation rate of 1000 [kg / hr] or more when operating at the maximum rotation speed.

[0088] - Explanation of symbols -

[0089] 1 airtight container

[0090] 2 Electric motor

[0091] 3 Compression mechanism

[0092] 4 Rotation axes

[0093] 10. Compressor

[0094] 13 Refrigerant passage (passage)

[0095] 21 Rotor

[0096] 22 Stator

[0097] 41 stator core

[0098] 41a Upper

[0099] 41b Lower end

[0100] 41c Side wall

[0101] 46 Core cut

[0102] 46a Entrance

[0103] 46b Exit

[0104] 51 Insulation parts

Claims

1. A compressor comprising a closed container (1), a motor (2) and a compression mechanism (3), The motor (2) is arranged inside the sealed container (1), and comprises a rotor (21) arranged on a rotating shaft (4) extending in the vertical direction and a stator (22) fixed in the sealed container (1). The compression mechanism (3) is arranged below the motor (2) inside the closed container (1), and the compression mechanism (3) is driven by the motor (2) to compress the refrigerant. The circulation rate of the compressor (10) when operating at the maximum speed is 1000 [kg / hr] or more, The compressor is characterized in that: 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 sealed container (1). (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 less than 1.

45.

2. The compressor according to claim 1, characterized in that: The cross-sectional area of ​​the core cutout (46) is set to S[m 2 ], the circulation rate is set to F [kg / hr], F [kg / hr] > 1000 [kg / hr], S≤0.00215×(F / 1000) 7 / 9 。 3. The compressor according to claim 1 or 2, characterized in that: An insulating component (51) is provided at at least one of an upper end (41a) and a lower end (41b) of the stator core (41), and the insulating component (51) has a surface continuous with a side wall surface (41c) of the stator core (41) provided with the core cutout (46).

4. The compressor according to claim 1 or 2, characterized in that: The compressor is provided with an insulating component (51), and the insulating component (51) covers at least one of the upper end (41a) and the lower end (41b) of the stator core (41) and a part or the whole of the side wall surface (41c) of the stator core (41) provided with the core cutout (46).

5. The compressor according to claim 3 or 4, characterized in that: The radially outer end position of the insulating member (51) continuously retreats radially inward as it moves away from the stator core (41).

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