Stator, electric motor, compressor and refrigeration cycle device

Abstract

This stator is provided to an electric motor and has a rotating rotor disposed, via a gap, on an inner peripheral side of the stator. This electric motor, this compressor, and this refrigeration cycle device each comprise the stator. The stator comprises: a stator core that has an annular core back, a plurality of teeth arranged at intervals from each other in a circumferential direction of the core back and extending radially inward from the core back, and a slot provided between two adjacent teeth among the plurality of teeth, the stator core having a center axis extending in an up-down direction; and a stator winding that is wound, by means of distributed winding, around the plurality of teeth of the stator core. An outer periphery of the stator core is provided, alternately in the circumferential direction, with an arc section which takes the center axis of the stator core as a reference, and a cutout section, which is a notch formed on the outer periphery and which is located radially inward from the arc section. The cutout section is provided to correspond to one or more teeth among the plurality of teeth. In a case where a virtual line at the circumferential center of the corresponding tooth among the one or more teeth is defined as a tooth center line and virtual lines at the circumferential centers of the slots on both sides of the corresponding tooth are defined as slot center lines, the cutout section is formed such that an innermost point, which is a point on an upper end face of the stator core and located on the innermost side in the radial direction of the cutout section, is formed between the tooth center line in the circumferential direction and the slot center line, among the slot center lines on both sides of the corresponding tooth, located on a rear side in the direction of rotation of the rotor when the electric motor is configured.

Description

Stator, motor, compressor and refrigeration cycle device

[0001] The present disclosure relates to a stator, an electric motor, a compressor, and a refrigeration cycle device, and in particular to a structure of a stator.

[0002] There is known a compressor equipped with a mechanism for returning lubricating oil (hereinafter also referred to as refrigerating oil) separated from a refrigerant in a space within a sealed container and above an electric motor to an oil reservoir at the bottom of the sealed container via a passage formed between the outer circumferential surface of the stator core of the electric motor and the inner circumferential surface of the sealed container (see, for example, Patent Document 1). In the compressor disclosed in Patent Document 1, a notch is formed in the outer circumferential surface of the stator core so that its center is located on the tooth center line, which is an imaginary line of the circumferential center of the teeth, and the radial width of the cooling oil passage is configured to be greatest on the tooth center line.

[0003] JP 2018-57238 A

[0004] However, the refrigeration oil separated from the refrigerant in the space above the motor within the sealed container collides with the stator windings protruding from the upper end surface of the stator core and scatters, so that in the air conditioner oil passage as disclosed in Patent Document 1, the refrigeration oil that collides with the stator windings and rebounds is difficult to enter, and there is a problem that the refrigeration oil cannot be efficiently captured.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a stator, an electric motor, a compressor, and a refrigeration cycle device that can efficiently capture refrigeration oil separated from a refrigerant.

[0006] The stator of an electric motor according to the present disclosure is a stator provided in an electric motor, with a rotating rotor disposed on the inner circumferential side via a gap, the stator comprising: an annular core back; a plurality of teeth disposed at intervals in the circumferential direction of the core back, each extending radially inward from the core back; a stator core having a central axis extending in the vertical direction, the plurality of teeth having slots disposed between two adjacent teeth of the plurality of teeth; and a stator winding wound in a distributed winding manner around the plurality of teeth of the stator core, the stator core having an outer periphery provided with an arc portion based on the central axis of the stator core and a notch formed on the outer periphery and positioned radially inward from the arc portion. and portions are arranged alternately in the circumferential direction, and the notch portions are provided corresponding to each of one or more teeth among the plurality of teeth, and when an imaginary line at the circumferential center of a corresponding tooth among the one or more teeth is defined as a tooth center line, and imaginary lines at the circumferential centers of the slots on both sides of the corresponding tooth are defined as slot center lines, the innermost point of the notch portion, which is the point located most inward in the radial direction, on the upper end surface of the stator core, is formed between the tooth center line in the circumferential direction and the slot center line on both sides that is located rearward in the rotation direction of the rotor when the electric motor is constructed.

[0007] The electric motor according to the present disclosure comprises the stator described above, and a rotor arranged on the inner periphery of the stator via a gap, having a cylindrical shape, having an oil flow path penetrating in the vertical direction, and rotating due to the magnetic field generated by the stator.

[0008] The compressor according to the present disclosure includes the electric motor, a crankshaft extending in the vertical direction, a compression element driven by the electric motor via the crankshaft to compress fluid drawn in from the outside, and a sealed container accommodating the electric motor and the compression element.

[0009] A refrigeration cycle device according to the present disclosure includes the above compressor, an outdoor heat exchanger, an expansion mechanism for expanding the fluid, and an indoor heat exchanger.

[0010] In the stator, electric motor, compressor, and refrigeration cycle device of the present disclosure, the innermost point of the notch in the upper end surface of the stator core is positioned between the tooth center line and the slot center line located on the rear side in the direction of rotation of the rotor. Therefore, the notch is wide at the point where refrigeration oil flows after colliding with the stator winding and bouncing off during rotor rotation, so that refrigeration oil can be more efficiently captured after colliding with the stator winding and bouncing off, compared to conventional passages that are widest on the tooth center line.

[0011] 5 is a circuit diagram showing a refrigerant flow during cooling in the refrigeration cycle device according to embodiment 1. FIG. 6 is a circuit diagram showing a refrigerant flow during heating in the refrigeration cycle device according to embodiment 1. FIG. 7 is a longitudinal sectional view of the compressor according to embodiment 1. FIG. 8 is a plan view of the stator of the electric motor according to embodiment 1. FIG. 9 is a plan view of a portion of the stator of FIG. 4 , excluding the coil ends. FIG. 10 is a view as seen from the arrows A-A in FIG. 11. FIG. 11 is a view as seen from the arrows B-B in FIG. 12. FIG. 13 is a partial plan view showing a portion of the circumferential direction of the upper end surface of the stator core in the stator of FIG. 12. FIG. 14 is a partial plan view showing the upper end surface of the stator core and a portion of the circumferential direction of the stator windings in the slots in the stator of FIG. 13. FIG. 15 is a simulation diagram showing the flow of refrigerant oil in the upper part of the stator of the electric motor according to embodiment 1. FIG. 16 is a partial plan view showing the upper end surface of the stator core and a portion of the circumferential direction of the stator windings in the slots in the stator of the electric motor according to embodiment 1. FIG. 17 is a simulation diagram showing the flow of refrigerant oil in the stator of the electric motor according to embodiment 1. FIG. 18 is a partial plan view showing the upper end surface of the stator core and a portion of the circumferential direction of the stator windings in the slots in the stator of the electric motor according to embodiment 1. 10 is a partial view showing, from above, a lower end surface of a stator core in a stator of an electric motor according to embodiment 3 and a portion of a circumferential direction of stator windings in slots. FIG. 11 is a side view schematically showing a stator core in a stator of an electric motor according to embodiment 3.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and their description will be omitted or simplified as appropriate. Furthermore, the shape, size, arrangement, etc. of the configurations shown in each drawing may be changed as appropriate.

[0013] Embodiment 1. Fig. 1 is a circuit diagram showing the refrigerant flow during cooling in a refrigeration cycle apparatus 10 according to embodiment 1. Fig. 2 is a circuit diagram showing the refrigerant flow during heating in the refrigeration cycle apparatus 10 according to embodiment 1. Fig. 1 shows the connection state of the refrigerant circuit 11 during cooling, with the direction of refrigerant flow during cooling indicated by a white arrow. Fig. 2 shows the connection state of the refrigerant circuit 11 during heating, with the direction of refrigerant flow during heating indicated by a white arrow.

[0014] 1 and 2 , a refrigeration cycle apparatus 10 includes a refrigerant circuit 11 through which a refrigerant circulates. In this embodiment, the refrigeration cycle apparatus 10 is an air conditioner. Note that this embodiment can also be applied to devices other than an air conditioner as the refrigeration cycle apparatus 10.

[0015] The refrigerant circuit 11 is connected to a compressor 12, a flow path switching valve 13, an outdoor heat exchanger 14, an expansion mechanism 15, and an indoor heat exchanger 16. The compressor 12 compresses the refrigerant. The flow path switching valve 13 switches the direction of refrigerant flow between cooling and heating. While the flow path switching valve 13 is a four-way valve in Figures 1 and 2, it is not limited thereto and may be configured as a combination of a two-way valve and a three-way valve, for example.

[0016] The outdoor heat exchanger 14 operates as a condenser during cooling, dissipating heat from the refrigerant compressed by the compressor 12. The outdoor heat exchanger 14 operates as an evaporator during heating, exchanging heat between outdoor air and the refrigerant expanded by the expansion mechanism 15 to heat the refrigerant. The expansion mechanism 15 depressurizes and expands the refrigerant that has dissipated heat in the condenser. The expansion mechanism 15 is, for example, an expansion valve. The indoor heat exchanger 16 operates as a condenser during heating, dissipating heat from the refrigerant compressed by the compressor 12. The indoor heat exchanger 16 operates as an evaporator during cooling, exchanging heat between indoor air and the refrigerant expanded by the expansion mechanism 15 to heat the refrigerant.

[0017] The refrigeration cycle apparatus 10 further includes a control device 17. The control device 17 is configured with dedicated hardware or a CPU (Central Processing Unit) that executes programs stored in a memory. The CPU is also called a central processing unit, processing device, arithmetic unit, microprocessor, microcomputer, or processor.

[0018] Examples of the refrigerant circulating through the refrigerant circuit 11 include a single refrigerant selected from R1234yf, R1234ze, R32, and R290, a mixed refrigerant of two or more of these, a mixed refrigerant of any of these with another refrigerant, a mixed refrigerant containing R1132(E), and a mixed refrigerant containing R1123. Other examples of the refrigerant circulating through the refrigerant circuit 11 include a mixed refrigerant of two or more of R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.

[0019] The operation of the refrigeration cycle apparatus 10 will now be described with reference to FIGS. 1 and 2 . For example, during heating operation of the refrigeration cycle apparatus 10, the flow path switching valve 13 is connected as shown in FIG. 2 . The high-temperature, high-pressure refrigerant compressed by the compressor 12 flows to the indoor heat exchanger 16, condenses, and liquefies. The refrigerant is then decompressed and expanded by the expansion mechanism 15 to become a low-temperature, low-pressure, two-phase refrigerant. The low-temperature, low-pressure, two-phase refrigerant flows to the outdoor heat exchanger 14, evaporates, and gasifies before returning to the compressor 12 through the flow path switching valve 13. That is, the refrigerant circulates as shown by the white arrows in FIG. 2 . Through this circulation, the refrigerant exchanges heat with outside air in the outdoor heat exchanger 14, which serves as an evaporator. The refrigerant sent to the outdoor heat exchanger 14 absorbs heat. The absorbed refrigerant is then sent to the indoor heat exchanger 16, which serves as a condenser, where it exchanges heat with indoor air to warm the indoor air.

[0020] Furthermore, during cooling operation of the refrigeration cycle apparatus 10, the flow path switching valve 13 is connected as shown in Figure 2. The high-temperature, high-pressure refrigerant compressed by the compressor 12 flows to the outdoor heat exchanger 14, where it condenses and liquefies. The refrigerant is then decompressed and expanded by the expansion mechanism 15, becoming a low-temperature, low-pressure, two-phase refrigerant. The low-temperature, low-pressure, two-phase refrigerant flows to the indoor heat exchanger 16, where it evaporates and gasifies, and passes through the flow path switching valve 13 and returns to the compressor 12. In other words, when the operation mode changes from heating to cooling, the indoor heat exchanger 16 changes from a condenser to an evaporator, and the outdoor heat exchanger 14 changes from an evaporator to a condenser. Therefore, the refrigerant circulates as shown by the white arrows in Figure 1. Through this circulation, heat is exchanged between the refrigerant and the indoor air in the indoor heat exchanger 16, which serves as an evaporator, and the refrigerant cools the indoor air by absorbing heat from it. The refrigerant that has absorbed heat is sent to the outdoor heat exchanger 14, which serves as a condenser, where it exchanges heat with the outdoor air and releases heat into the outdoor air.

[0021] Fig. 3 is a longitudinal cross-sectional view of the compressor 12 according to the first embodiment. Fig. 4 is a plan view of the stator 41 of the electric motor according to the first embodiment. Note that in Fig. 3, hatching representing a cross section of the equipment inside the sealed container 20 is omitted. In the first embodiment, the compressor 12 is a single-cylinder rotary compressor. Note that the first embodiment can also be applied when the compressor 12 is a multi-cylinder rotary compressor or a scroll compressor.

[0022] 3, the compressor 12 includes a sealed container 20 that forms an outer shell, a compression element 30, an electric motor 40 (electric motor for the compressor), and a crankshaft 60. In addition, a suction pipe 21 for drawing in a refrigerant and a discharge pipe 22 for discharging the refrigerant are attached to the sealed container 20.

[0023] The sealed container 20 is a cylindrical container with a bottom. As shown in Fig. 1, the sealed container 20 is composed of a cylindrical container body 20c, an upper lid 20a that closes the upper opening of the container body 20c, and a lower lid 20b that closes the lower opening of the container body 20c.

[0024] The compression element 30 is housed inside the sealed container 20. Specifically, the compression element 30 is installed at the lower inside of the sealed container 20. The compression element 30 compresses the refrigerant sucked through the suction pipe 21.

[0025] The electric motor 40 is also housed inside the sealed container 20. Specifically, the electric motor 40 is installed inside the sealed container 20 at a position through which the refrigerant compressed by the compression element 30 passes before being discharged from the discharge pipe 22. In other words, the electric motor 40 is installed inside the sealed container 20 and above the compression element 30. The electric motor 40 drives the compression element 30.

[0026] An oil reservoir 20o is provided at the bottom of the sealed container 20 to store refrigerating machine oil 25 for lubricating the sliding parts of the compression element 30. As the refrigerating machine oil 25, for example, synthetic oil such as POE (polyol ester), PVE (polyvinyl ether), or AB (alkyl benzene) is used.

[0027] The following describes in detail the compression element 30. The compression element 30 includes a cylinder 31, a rolling piston 32, a vane (not shown), a main bearing 33, and an auxiliary bearing .

[0028] The cylinder 31 has a generally cylindrical shape. The outer periphery of the cylinder 31 is generally circular in plan view. A cylinder chamber, which is a generally circular space in plan view, is formed inside the cylinder 31. Both ends of the cylinder 31 in the vertical direction (arrow Z direction) are open. The cylinder 31 is provided with a vane groove (not shown) that communicates with the cylinder chamber and extends in the radial direction of the cylinder 31. A back pressure chamber, which is a generally circular space in plan view and communicates with the vane groove, is formed outside the vane groove.

[0029] The cylinder 31 is also provided with a suction port (not shown) through which gas refrigerant is drawn from the refrigerant circuit 11. The suction port penetrates from the outer peripheral surface of the cylinder 31 to the cylinder chamber. The cylinder 31 is also provided with a discharge port (not shown) through which compressed refrigerant is discharged from the cylinder chamber. The discharge port is formed by cutting out the upper end surface of the cylinder 31.

[0030] The rolling piston 32 has a cylindrical shape. The rolling piston 32 moves eccentrically within the cylinder chamber. The rolling piston 32 is slidably fitted onto an eccentric shaft portion 61 of the crankshaft 60.

[0031] The vane has a flat, approximately rectangular parallelepiped shape. The vane is installed in a vane groove of the cylinder 31. The vane is constantly pressed against the rolling piston 32 by a vane spring (not shown) provided in the back pressure chamber. Since the pressure inside the sealed container 20 becomes high during operation of the compressor 12, when the compressor 12 starts operating, a force due to the difference in pressure between the sealed container 20 and the cylinder chamber acts on the back surface of the vane, i.e., the surface of the vane facing the back pressure chamber. For this reason, the vane spring is used to press the vane against the rolling piston 32 mainly when the compressor 12 is started (i.e., when there is no difference in pressure between the sealed container 20 and the cylinder chamber).

[0032] The main bearing 33 has a generally inverted T-shape in side view. The main bearing 33 is slidably fitted to a main shaft portion 62, which is the portion of the crankshaft 60 above the eccentric shaft portion 61. The main bearing 33 closes the cylinder chamber of the cylinder 31 and the upper side of the vane groove.

[0033] The sub-bearing 34 has a substantially T-shape in side view. The sub-bearing 34 slidably fits onto the sub-shaft portion 63, which is the portion of the crankshaft 60 below the eccentric shaft portion 61. The sub-bearing 34 closes the cylinder chamber of the cylinder 31 and the lower side of the vane groove.

[0034] The main bearing 33 is equipped with a discharge valve (not shown). A discharge muffler 35 is attached to the outside of the main bearing 33. The high-temperature, high-pressure gas refrigerant discharged through the discharge valve enters the discharge muffler 35 and is then released from the discharge muffler 35 into the space within the sealed container 20. The discharge valve and the discharge muffler 35 may be provided in the sub-bearing 34 or in both the main bearing 33 and the main bearing 33.

[0035] The cylinder 31, main bearing 33, and sub-bearing 34 are made of gray cast iron, sintered steel, carbon steel, etc. The rolling piston 32 is made of alloy steel containing chromium, etc. The vane is made of high-speed tool steel, for example.

[0036] A suction muffler 23 is provided next to the sealed container 20. The suction muffler 23 draws low-pressure gas refrigerant from the refrigerant circuit 11 (more specifically, from the evaporator via a refrigerant pipe). The suction muffler 23 prevents the liquid refrigerant from directly entering the cylinder chamber of the cylinder 31 when the liquid refrigerant returns. The suction muffler 23 is connected to the suction port of the cylinder 31 via the suction pipe 21. The main body of the suction muffler 23 is fixed to the side of the sealed container 20 by welding or the like.

[0037] A terminal 24 (e.g., a glass terminal) for connection to an external power source is attached to the top of the sealed container 20 (specifically, the upper lid 20a). The terminal 24 is fixed to the sealed container 20 by, for example, welding. A lead wire 45 (described later) from the electric motor 40 is connected to the terminal 24.

[0038] A discharge pipe 22 having open ends is attached to an upper portion (specifically, an upper lid portion 20 a) of the sealed container 20. The gas refrigerant discharged from the compression element 30 is discharged from the space within the sealed container 20 through the discharge pipe 22 to the external refrigerant circuit 11.

[0039] An upper portion of the crankshaft 60 protrudes from a rotor 42 (described later) of the electric motor 40, and an oil separator 47 that separates refrigerating machine oil 25 from the gas refrigerant is fixed to the upper portion of the crankshaft 60. The oil separator 47 has a flange 47a that protrudes radially from the center of the rotor 42.

[0040] 3, the oil separation member 47 is composed of a cylindrical flange portion 47b fixed to the upper part of the crankshaft 60 and an annular plate-like collar portion 47a protruding radially from the upper end of the flange portion 47b. The outer diameter of the collar portion 47a is approximately the same as the outer diameter of a rotor 42 (described later) of the electric motor 40. Therefore, in a plan view, the collar portion 47a covers an oil flow path 42a that passes through the rotor 42 (described later) in the approximately vertical direction (direction of arrow Z).

[0041] The configuration of the oil separation member 47 is not limited to the above configuration. For example, the flange portion 47a does not have to be plate-shaped, and may be curved like a bowl. Here, the compressor 12 is described as having the oil separation member 47, but the oil separation member 47 is not essential. However, when the compressor 12 has the oil separation member 47, the refrigeration oil 25 that flows out from the oil flow path 42a of the rotor 42 (described later) can be prevented from moving upward within the sealed container 20, and the refrigeration oil 25 can be prevented from being discharged from the discharge pipe 22, compared to a compressor 12 without the oil separation member 47.

[0042] The following describes the details of the electric motor 40. In this embodiment, the electric motor 40 is an induction motor. However, this embodiment can also be applied to a motor other than an induction motor, such as a brushless DC (Direct Current) motor, as the electric motor 40.

[0043] As shown in Fig. 3, the electric motor 40 includes a stator 41 and a rotor 42. The stator 41 has a generally cylindrical shape. The stator 41 is fixed in contact with the inner circumferential surface of the sealed container 20. More specifically, the stator 41 is fixed in contact with the inner circumferential surface of the container body 20c of the sealed container 20. The rotor 42 is installed inside the stator 41 with a gap of about 0.3 to 1 mm therebetween.

[0044] 3 and 4, the stator 41 has a substantially cylindrical stator core 43 and a stator winding 44. Hereinafter, the direction in which the central axis Ax (see FIG. 5 described later) of the stator core 43 extends may be simply referred to as the axial direction. The stator core 43 is manufactured by stacking a plurality of steel plates, each punched into a predetermined shape, in the axial direction (the direction of the arrow Z) and fixing them together by caulking or the like. The steel plates are, for example, electromagnetic steel plates having a thickness of 0.1 to 1.5 mm.

[0045] As shown in Fig. 4, the stator winding 44 is wound around the stator core 43, and lead wires 45 are connected to the stator winding 44. In Fig. 4, the stator winding 44 is wound around the stator core 43 in a distributed manner, and three lead wires 45 are connected to the stator winding 44. Each lead wire 45 connects the stator winding 44 to a terminal 24 (see Fig. 3) attached to the sealed container 20 (see Fig. 3).

[0046] As shown in Fig. 4, a plurality of notches 54 are formed at approximately equal intervals in the circumferential direction on the outer periphery of the stator core 43. Each notch 54 serves as one of the passages for the gas refrigerant discharged from the discharge muffler 35 (see Fig. 3) to the space within the sealed container 20. Each notch 54 shown in Fig. 4 also serves as a passage for refrigeration oil 25 returning from above the motor 40 shown in Fig. 3 to the oil reservoir 20o at the bottom of the sealed container 20.

[0047] As shown in Fig. 3, the rotor 42 is configured such that the upper portion of the crankshaft 60 is inserted into a substantially cylindrical rotor core 46. The rotor core 46 is configured by laminating multiple steel plates, such as electromagnetic steel plates. Multiple oil flow paths 42a are formed in the rotor core 46, penetrating it in the substantially axial direction. Similar to the notches 54 of the stator core 43 (see Fig. 4), each oil flow path 42a serves as a passage for the gas refrigerant discharged from the discharge muffler 35 into the space within the sealed container 20.

[0048] In addition, when the electric motor 40 is configured as a brushless DC motor (not shown), permanent magnets are inserted into multiple insertion holes formed in the rotor core 46. Ferrite magnets or rare earth magnets, for example, are used as the permanent magnets. To prevent the permanent magnets from slipping out in the vertical direction (arrow Z direction), upper and lower end plates are provided at the upper and lower ends of the rotor 42, respectively. The upper and lower end plates also serve as rotational balancers. The upper and lower end plates are fixed to the rotor core 46 with multiple fixing rivets or the like.

[0049] The rotor 42 is provided so that N poles and S poles are arranged alternately in the circumferential direction. In the following, the number of poles of the rotor 42 is defined as six.

[0050] The operation of the compressor 12 will be described based on Fig. 3 and with reference to Figs. 1, 2, and 4. Electric power is supplied from the terminals 24 to the stator 41 of the electric motor 40 via lead wires 45 (see Fig. 4). This rotates the rotor 42 of the electric motor 40. The rotation of the rotor 42 rotates the crankshaft 60 fixed to the rotor 42. As the crankshaft 60 rotates, the rolling piston 32 of the compression element 30 rotates eccentrically within the cylinder chamber of the cylinder 31 of the compression element 30. The space between the cylinder 31 and the rolling piston 32 is divided into two by the vanes of the compression element 30. As the crankshaft 60 rotates, the volumes of these two spaces change. In one space, the volume gradually expands, and refrigerant is drawn in through the suction muffler 23. In the other space, the volume gradually contracts, and the gas refrigerant therein is compressed. The compressed gas refrigerant is first discharged from the discharge muffler 35 into the space within the sealed container 20 (more specifically, the space between the compression element 30 and the electric motor 40). The discharged gas refrigerant passes through the electric motor 40 and is discharged from the discharge pipe 22 at the top of the sealed container 20 to the outside of the sealed container 20 (more specifically, the refrigerant piping that connects the compressor 12 and the condenser in the refrigerant circuit 11 in FIGS. 1 and 2 ).

[0051] The refrigerant compressed by the compression element 30 and discharged from the discharge muffler 35 into the space between the compression element 30 and the electric motor 40 in the sealed container 20 flows mainly through the oil flow path 42a of the rotor 42 to the upper part of the electric motor 40. Therefore, the refrigerant flowing from the oil flow path 42a to the upper part of the electric motor 40 contains refrigerant oil 25. Of the gas refrigerant containing refrigerant oil 25 that flows to the upper part of the electric motor 40, the gas refrigerant itself flows upward to the discharge pipe 22, and the refrigerant oil 25 is separated from the gas refrigerant by centrifugal force and falls to the upper part of the electric motor 40. If the refrigerant falls to the upper part of the rotor 42, it moves to the outer periphery due to rotation. Furthermore, if an oil separator 47 is provided on the upper part of the crankshaft 60, the oil separator 47 changes the flow direction of the refrigerant oil 25 radially outward, i.e., from the main shaft portion 62 toward the inner wall of the container body 20c of the sealed container 20. At this time, the refrigeration oil 25 mixed in the gas refrigerant is efficiently separated by the centrifugal separation effect of the oil separator 47. The refrigeration oil 25 separated from the gas refrigerant passes above the stator 41 arranged on the outer periphery of the rotor 42, and adheres to or collides with the coil end 44e of the stator 41 and the inner wall of the sealed container 20, etc. The refrigeration oil 25 then enters a notch 54 (see FIG. 4 ) formed on the outer periphery of the stator core 43 of the electric motor 40, and flows within the notch 54 from top to bottom of the electric motor 40 along the inner wall of the sealed container 20. The refrigeration oil 25 that has flowed below the electric motor 40 passes through gaps between devices, such as the gap between the compression element 30 and the inner wall of the sealed container 20, and flows into the oil reservoir 20o at the bottom of the sealed container 20, where it is returned.

[0052] Fig. 5 is a plan view of the stator 41 in Fig. 4 excluding the coil end 44e. Fig. 6 is a view taken along the line A-A in Fig. 5. Fig. 7 is a view taken along the line B-B in Fig. 5. The configuration of the stator 41 will be described in detail based on Figs. 5 to 7 and with reference to Fig. 3.

[0053] 5, the stator core 43 has an annular core back 43b extending in the circumferential direction and a plurality of teeth 43a each extending radially inward from the core back 43b. The plurality of teeth 43a are spaced apart from one another in the circumferential direction. The stator winding 44 (see FIG. 4) is wound around the plurality of teeth 43a formed on the stator core 43.

[0054] The stator core 43 has an outer periphery formed with arc portions 53 based on the central axis Ax of the stator core 43, and cutout portions 54 formed on the outer periphery and positioned radially inward of the arc portions 53. The arc portions 53 and the cutout portions 54 are alternately arranged in the circumferential direction on the outer periphery of the stator core 43. The arc portions 53 of the stator core 43 are fitted inside the container body 20c (see FIG. 3) of the sealed container 20. The cutout portions 54 are formed, for example, by processing the circular outer periphery of the stator core 43 with a D-cut or the like. The cutout portions 54 are grooves extending in the axial direction (direction of arrow Z) from the upper end surface 43c to the lower end surface 43d of the stator core 43. The space formed between the cutout portions 54 and the sealed container 20 (see FIG. 3) serves as a passage for the refrigerating machine oil 25.

[0055] Slots 100 are formed between circumferentially adjacent teeth 43a in the stator core 43. The slots 100 are spaces that accommodate the stator windings 44. The vertically extending portions of the stator windings 44 are accommodated in the slots 100 along the teeth 43a. The upper and lower folded portions of the stator windings 44 are respectively positioned above and below the teeth 43a, and form coil ends 44e (see FIG. 3 ) that protrude from the upper end surface 43c and the lower end surface 43d of the stator core 43. Although not shown, an insulating portion is provided between the slots 100 and the stator windings 44 to insulate the stator core 43 from the stator windings 44. The number of slots 100 in the stator core 43 is referred to as the slot count. The slot count is three times the number of poles of the rotor 42. If the rotor 42 has six poles as described above, the number of slots is 18.

[0056] 5, the stator winding 44 has a U-phase stator winding 44U, a V-phase stator winding 44V, and a W-phase stator winding 44W. The U-phase stator winding 44U, the V-phase stator winding 44V, and the W-phase stator winding 44W are wound around the stator core 43 by distributed winding, more specifically, by concentric winding.

[0057] In the example of Fig. 5, the stator windings 44U, 44V, and 44W of each phase are all wound so that the winding pitch is three slots. "Wound so that the winding pitch is three slots" means that the stator windings 44U, 44V, and 44W are wound so that they straddle three teeth 43a. Also, in the example of Fig. 5, the U-phase stator winding 44U, the V-phase stator winding 44V, and the W-phase stator winding 44W are arranged in offset ranges so that they partially overlap each other in the circumferential direction, as shown in Figs. 6 and 7.

[0058] Furthermore, the U-phase stator winding 44U, the V-phase stator winding 44V, and the W-phase stator winding 44W are located at different radial positions. Specifically, the U-phase stator winding 44U is located at the outermost radial position, and the W-phase stator winding 44W is located at the innermost radial position. The V-phase stator winding 44V is located between the stator windings 44U and 44W in the radial direction. However, the arrangement of the stator windings 44U, 44V, and 44W of each phase is not limited to the above arrangement, as long as the U-phase stator winding 44U, the V-phase stator winding 44V, and the W-phase stator winding 44W are located at different radial positions.

[0059] Fig. 8 is a partial plan view showing a portion of the circumferential direction of the upper end surface 43c of the stator core 43 in the stator 41 of Fig. 5. Also, in Fig. 8, the rotation direction R of the rotor 42 (see Fig. 3) arranged on the inner circumferential side of the stator 41 is indicated by a solid arrow. Based on Fig. 5 and Fig. 8, and with reference to Fig. 3, the positions at which the cutout portions 54 are provided on the outer periphery of the stator core 43 will be described.

[0060] In the following, the imaginary line at the circumferential center of the tooth 43a is defined as the tooth center line Lt, and the imaginary line at the circumferential center of the slot 100 is defined as the slot center line Ls. The following description focuses on the tooth 43a on which the corresponding cutout 54 is provided. To facilitate the description, the slot center line Ls of the slots 100 provided on both sides of the tooth 43a may be distinguished as follows: the slot center line Ls2 is the rearmost slot center line in the rotation direction R of the rotor 42, and the slot center line Ls1 is the frontmost slot center line in the rotation direction R of the rotor 42. The radially innermost point of the cutout 54 is referred to as the innermost point 55.

[0061] 8 , the cutouts 54 are provided in the circumferential direction of the stator core 43 such that their innermost points 55 are located between the tooth center line Lt and, of the slot center lines Ls1 and Ls2 of the slots 100 provided on both sides thereof, the rearmost slot center line Ls2 in the rotation direction R of the rotor 42. Here, the position of the innermost point 55 as described above only needs to be specified so that the refrigerating machine oil 25 is filled at the inlet of the cutouts 54, i.e., at the upper end of the cutouts 54. In other words, the cutouts 54 are provided on the outer peripheral surface of the stator core 43 so as to extend in the axial direction, and it is only necessary that the innermost points 55 of the cutouts 54 are located between the tooth center line Lt and the rearmost slot center line Ls2 on the upper end surface 43 c of the stator core 43. The notch 54 may be arranged so that the cross-sectional shape of the passage for the refrigerating oil 25 formed by the notch 54 and the inner wall of the sealed container 20 (see Figure 3) changes in the axial direction (direction of arrow Z), or may be arranged at an angle so that the position of the innermost point 55 changes in the axial direction (direction of arrow Z).

[0062] In the first embodiment, the notches 54 are symmetrical on both sides in the circumferential direction with respect to the innermost point 55. The cross-sectional shape of the passage for the refrigeration oil 25, i.e., the cross-sectional shape of the passage perpendicular to the axial direction, is symmetrical on both sides in the circumferential direction with respect to an imaginary line Li that extends radially from the center axis Ax of the stator core 43 and passes through the innermost point 55.

[0063] In Fig. 8 , the cross-sectional shape of the passage for refrigerating machine oil 25 is a substantial triangle, and in particular a substantial isosceles triangle. Here, if a connection point between notch 54 and arc portion 53 located on the front side in the rotation direction R of rotor 42 is defined as a first connection point 58, and a connection point between notch 54 and arc portion 53 located on the rear side in the rotation direction R of rotor 42 is defined as a second connection point 59, notch 54 in Fig. 8 forms a substantial isosceles triangle in which the distance between innermost point 55 and first connection point 58 is equal to the distance between innermost point 55 and second connection point 59. The corner of notch 54 at innermost point 55 may be rounded as shown in Fig. 8 .

[0064] As described above, the innermost point 55 of the notch 54 may be located between the tooth center line Lt and the slot center line Ls2. The cross-sectional shape of the passage for the refrigerating oil 25 is not limited to a substantially triangular shape and may be, for example, a rectangular shape. Furthermore, the cross-sectional shape of the passage for the refrigerating oil 25 does not have to be symmetrical with respect to the imaginary line Li passing through the innermost point 55, and may be asymmetrical.

[0065] 5, the number of notches 54 provided in the stator core 43 is eight, which is fewer than the number of teeth 43a (18 in FIG. 5). The number of notches 54 is not limited to the above number and may be, for example, the same number as the number of teeth 43a.

[0066] The more notches 54 provided in the stator core 43, or the larger the cross-sectional area of ​​the passage for the refrigerating machine oil 25, the more difficult it is to ensure the rigidity of the stator 41. Furthermore, the more notches 54 provided in the stator core 43, or the wider the circumferential width of the notches 54, the more difficult it is to ensure the area of ​​the joint that fixes the stator 41 (particularly the arc portions 53) to the inner wall of the sealed container 20.

[0067] FIG. 9 is a partial plan view showing the upper end surface 43c of the stator core 43 in the stator 41 of FIG. 5 and a portion of the circumferential direction of the stator windings 44 in the slots 100. In FIG. 9, the flow of refrigerant oil 25 at the upper end surface 43c of the stator core 43 is indicated by outline arrows. FIG. 10 is a simulation diagram showing the flow of refrigerant oil 25 in the upper part of the stator 41 of the electric motor according to embodiment 1. In FIGS. 9 and 10, the rotation direction R of the rotor 42 (see FIG. 3) disposed on the inner circumferential side of the stator 41 is indicated by solid arrows. FIG. 10 also illustrates the position of the notch 54 when a passage for refrigerant oil 25 is provided for each tooth 43a. The flow of refrigerant oil 25 in the stator 41 of embodiment 1 will be described with reference to FIGS. 3, 6, 7, 9, and 10.

[0068] In the electric motor 40 shown in Fig. 3, the refrigeration oil 25 adhering to the upper part of the rotor 42, or the refrigeration oil 25 that has flowed out from the oil flow paths 42a to the upper part of the rotor 42 and separated from the refrigerant, flows to the upper part of the stator 41 disposed on the outer periphery of the rotor 42 as the rotor 42 rotates, as shown in Fig. 9 (see the shorter hollow arrows in Fig. 9), with a radially outward speed component and a forward speed component in the rotation direction R of the rotor 42. Such refrigeration oil 25 from the upper part of the rotor 42 flows over the teeth 43a between the stator windings 44U, 44V, 44W of the coil end 44e shown in Figs. 6 and 7, at the upper part of the stator 41, and flows into the cutouts 54.

[0069] 9 and 10 , refrigeration oil 25 does not flow radially (i.e., radially outward) on teeth 43 a from the inner periphery side to the outer periphery side of stator 41, but first flows from the radial direction on the inner periphery side toward the front in the rotation direction R of rotor 42. Then, refrigeration oil 25 collides with stator windings 44 protruding from slots 100 in the forward direction, bounces off, and flows on teeth 43 a from the radial direction toward the rear in the rotation direction R of rotor 42 (see the longer hollow arrow in FIG. 9 ). That is, the refrigerant oil 25 from the top of the rotor 42 first flows over the teeth 43a with a radially outward velocity component and a forward velocity component in the rotation direction R of the rotor 42, but after colliding with the stator windings 44 protruding from the slots 100 and bouncing off, it flows with a radially outward velocity component and a backward velocity component in the rotation direction R of the rotor 42.

[0070] 8 , notch 54 of the present disclosure is configured so that its innermost point 55 is located between tooth center line Lt and, of two slot center lines Ls1, Ls2 on either side of tooth center line Lt, the slot center line Ls2 that is rearward in the direction of rotor rotation R. Therefore, compared to conventional notch 54 in which innermost point 55 is located on tooth center line Lt, notch 54 has innermost point 55 located at the location where refrigerant oil 25 flows after hitting stator winding 44 and bouncing off, and therefore can efficiently capture refrigerant oil 25 and guide it into the refrigerant oil 25 passage.

[0071] In electric motor 40, when the rotation speed of rotor 42 is high, the flow rate of refrigerating oil 25 flowing from the top of rotor 42 to the top of stator 41 increases. Furthermore, when the flow rate of refrigerating oil 25 is high, the angle of rebound of refrigerating oil 25 that collides with stator winding 44 and rebounds also increases. Therefore, it is preferable to set the circumferential width of notch 54 wider for electric motor 40 with a higher rotation speed of rotor 42.

[0072] As described above, the stator 41 according to the first embodiment is provided in the electric motor 40, and has a rotating rotor 42 disposed on its inner periphery with a gap therebetween. The stator 41 includes a stator core 43 having a central axis Ax extending in the vertical direction (the direction of the arrow Z). The stator core 43 includes an annular core back 43b, a plurality of teeth 43a spaced apart from one another in the circumferential direction of the core back 43b, each extending radially inward from the core back 43b, and slots 100 between two adjacent teeth of the plurality of teeth 43a. The stator 41 also includes a stator winding 44 wound in a distributed manner around the plurality of teeth 43a of the stator core 43. Arc portions 53 based on the central axis Ax of the stator core 43 and notches 54 formed on the outer periphery and positioned radially inward from the arc portions 53 are alternately provided in the circumferential direction on the outer periphery of the stator core 43. The notches 54 are provided corresponding to one or more of the multiple teeth 43 a. An imaginary line at the circumferential center of a corresponding tooth 43 a among the one or more teeth 43 a is defined as a tooth center line Lt, and imaginary lines at the circumferential centers of the slots 100 on both sides of the corresponding tooth 43 a are defined as slot center lines Ls1, Ls2. In this case, the notch 54 is formed on the upper end surface 43c of the stator core 43, with the innermost point 55, which is the radially innermost point of the notch 54, being between the tooth center line Lt in the circumferential direction and the slot center line Ls2, of the slot center lines Ls1 and Ls2 on both sides, which is located rearward in the rotation direction R of the rotor when the electric motor 40 is constructed.

[0073] In this way, the innermost point 55 of the notch 54 on the upper end surface 43c of the stator core 43 is located between the tooth center line Lt and the slot center line Ls2 located on the rear side in the rotation direction R of the rotor 42. Therefore, the notch 54 is wide at the location where the refrigerant oil 25 flows after colliding with the stator winding 44 and bouncing off, and therefore, compared to a conventional passage that is widest on the tooth center line, the refrigerant oil 25 after colliding with the stator winding 44 and bouncing off can be captured more efficiently.

[0074] The electric motor 40 includes the stator 41 and a rotor 42 that is disposed on the inner circumferential side of the stator 41 via a gap and rotates due to the magnetic field generated by the stator 41. The rotor 42 has a cylindrical shape and is formed with an oil flow path 42a that penetrates in the vertical direction.

[0075] Even when the oil flow passage 42a is formed in the rotor 42 in this way, the refrigeration oil 25 flowing upward from the oil flow passage 42a flows from the rotor 42 to the stator 41 with a radially outward velocity component and a forward velocity component in the rotor rotation direction R. Therefore, the effect of efficiently capturing the refrigeration oil 25 can be similarly obtained.

[0076] The compressor 12 also includes the electric motor 40, a crankshaft 60 extending in the vertical direction (arrow Z direction), a compression element 30 that is driven by the electric motor 40 via the crankshaft 60 and compresses fluid drawn in from the outside, and a sealed container 20 that houses the electric motor 40 and the compression element 30.

[0077] The compressor 12 is provided with the electric motor 40 that efficiently captures the refrigerating machine oil 25, and therefore the refrigerating machine oil 25 is efficiently returned to the oil reservoir 20o in the compressor 12. Therefore, the refrigerating machine oil 25 is less likely to run out, and a highly reliable compressor 12 can be provided.

[0078] In the compressor 12, the crankshaft 60 is disposed at the center of the rotor 42 so that the upper portion of the crankshaft 60 protrudes from the rotor 42, and is fixed to the rotor 42. An oil separating member 47 having a flange 47a protruding in the radial direction of the rotor 42 is provided on the upper portion of the crankshaft 60.

[0079] As a result, the flow direction of the refrigerant (fluid) containing refrigerating machine oil 25 that has flowed out of the oil flow path 42a is changed to the radial direction by the oil separation member 47, and the refrigerating machine oil 25 that has flowed out of the oil flow path 42a is prevented from moving upward within the sealed container 20. As a result, the refrigerating machine oil 25 is prevented from flowing out of the sealed container 20 from the discharge pipe 22 together with the refrigerant, and the refrigerating machine oil 25 remains within the sealed container 20, making it less likely that the refrigerating machine oil 25 will run out, thereby further improving reliability.

[0080] The refrigeration cycle device 10 also includes the compressor 12, an outdoor heat exchanger 14, an expansion mechanism 15 that expands the fluid (refrigerant), and an indoor heat exchanger 16. The refrigeration cycle device 10 includes the highly reliable compressor 12 that is less likely to run out of refrigerating machine oil 25, so that errors in the compressor 12 are less likely to occur in the refrigeration cycle device 10, improving reliability.

[0081] Second Embodiment Fig. 11 is a partial plan view showing an upper end surface 143c of a stator core 143 in a stator 141 of an electric motor according to a second embodiment, and a portion of the circumferential direction of the stator windings 44 in the slots 100. In the stator 141 of the second embodiment, the shape of the notches 154 provided on the outer periphery of the stator core 143 is different from that in the first embodiment. Below, based on Fig. 11 and with reference to Fig. 3, differences between the stator 141 of the second embodiment and that in the first embodiment will be described. Note that the same components of the stator 141 of the second embodiment as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

[0082] Hereinafter, the point located most inward in the radial direction in the cutout portion 154 will be referred to as an innermost point 155. Furthermore, an imaginary line extending radially from the central axis Ax of the stator core 143 and passing through the innermost point 155 will be referred to as an imaginary line Li.

[0083] The cutout 54 in the first embodiment is formed so as to be symmetrical on both sides in the circumferential direction with respect to the innermost point 55, and as a result, the cross-sectional shape of the passage for the refrigeration oil 25 is symmetrical on both sides in the circumferential direction with respect to the imaginary line Li passing through the innermost point 55. The cutout 154 in the second embodiment is formed so as to be asymmetrical on both sides in the circumferential direction with respect to the innermost point 155, and as a result, the cross-sectional shape of the passage for the refrigeration oil 25 is asymmetrical on both sides in the circumferential direction with respect to the imaginary line Li passing through the innermost point 155.

[0084] 11 , the cross-sectional shape of the passage for refrigerant oil 25 is approximately triangular. More specifically, if the connection point of notch 154 between notch 154 and arc portion 53 located on the front side in the rotation direction R of the rotor is defined as first connection point 158, and the connection point of notch 154 between notch 154 and arc portion 53 located on the rear side in the rotation direction R of the rotor is defined as second connection point 159, notch 154 in FIG. 8 presents an asymmetrical triangle in which the distance between innermost point 155 and first connection point 158 ​​is shorter than the distance between innermost point 55 and second connection point 159. The corner provided at innermost point 155 of notch 154 may be rounded as shown in FIG. 11 .

[0085] In stator core 143 of embodiment 2, the positions at which notches 154 are provided in the circumferential direction are the same as in embodiment 1. That is, as shown in Fig. 11 , notches 154 are provided in the circumferential direction of stator core 143 so that their innermost points 155 are located between tooth center line Lt and, of slot center lines Ls1 and Ls2 of slots 100 provided on both sides thereof, the slot center line Ls2 that is rearward in the direction of rotation R of the rotor.

[0086] In the second embodiment, the notch 154 in the upper end surface 43 c of the stator core 43 has a first connection point 158 ​​which is a connection point with the arc portion 53 located in front of the notch 154 in the rotation direction R, and a second connection point 159 which is a connection point with the arc portion 53 located in rear of the notch 154 in the rotation direction R. The triangle formed by the innermost point 155, the first connection point 158, and the second connection point 159 is an asymmetric triangle in which the distance between the innermost point 155 and the first connection point 158 ​​is shorter than the distance between the innermost point 155 and the second connection point 159.

[0087] With this configuration, compared to the case where the cross-sectional shape of the passage for refrigerating oil 25 is approximately an isosceles triangle as in embodiment 1, the cross-sectional shape of the passage for refrigerating oil 25 is shaped to follow the flow of refrigerating oil 25 after it collides with and rebounds from the stator winding 44 (indicated by the white arrows in Figure 11), and the refrigerating oil can be captured and guided into the passage for refrigerating oil 25 more efficiently.

[0088] FIG. 12 is a simulation diagram showing the flow of refrigerant oil 25 above stator 141 of the electric motor according to the second embodiment. The flow of refrigerant oil 25 shown in FIG. 12 is generally similar to the flow of refrigerant oil 25 shown in FIG. 11 . That is, refrigerant oil 25 from above rotor 42 (see FIG. 3 ) first flows over teeth 43 a with a radially outward velocity component and a forward velocity component in the rotation direction R of the rotor. However, after colliding with stator windings 44 (see FIG. 11 ) protruding from slots 100 (see FIG. 11 ) and bouncing off, it flows with a radially outward velocity component and a backward velocity component in the rotation direction R of the rotor. As described above, in the second embodiment, the cross-sectional shape of the passage for refrigerant oil 25 formed by cutouts 154 and the inner wall of sealed container 20 is not a substantially isosceles triangle, but an asymmetric triangle with its innermost point 155 closer to the tooth center line Lt. That is, in the second embodiment, the cross-sectional shape of the passage for refrigerant oil 25 is shaped to follow the flow of refrigerant oil 25 after it collides with and rebounds from stator winding 44. Then, the distance between the side of notch 154 on the side of tooth center line Lt (i.e., the line connecting innermost point 155 and first connection point 158) and stator winding 44, which is disposed forward of tooth center line Lt in the direction of rotation R of the rotor, is shortened. Therefore, in the second embodiment, refrigerant oil 25 after it collides with and rebounds from stator winding 44 can more easily enter notch 154.

[0089] Embodiment 3. Fig. 13 is a partial plan view showing an upper end surface 243c of a stator core 243 in a stator 241 of an electric motor according to embodiment 3 and a portion of the circumferential direction of the stator windings 44 in the slots 100. Fig. 14 is a partial view showing a lower end surface 243d of a stator core 243 in a stator 241 of an electric motor according to embodiment 3 and a portion of the circumferential direction of the stator windings 44 in the slots 100, as viewed from above. In Fig. 14, the outline of a notch 254 in the upper end surface 243c of the stator core 243 is indicated by a dashed line. Fig. 15 is a side view schematically showing the stator core 243 in the stator 241 of an electric motor according to embodiment 3. The stator 241 of embodiment 3 differs from embodiment 1 in that the cross-sectional area of ​​the passage for refrigerating machine oil 25 formed by the notch 254 and the inner wall of the sealed container 20 changes in the axial direction. 13 to 15, and with reference to Fig. 3, differences between stator 241 of embodiment 3 and embodiment 1 will be described below. Note that the same components of stator 241 of embodiment 3 as those of embodiment 1 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0090] Hereinafter, the point located radially inward in the cutout portion 254 on the upper end surface 243c of the stator core 243 will be referred to as the innermost point 255, and the point located radially inward in the cutout portion 254 on the lower end surface 243d of the stator core 243 will be referred to as the innermost point 255d.

[0091] 13 to 15, the notch 254 is defined as being provided on the outer peripheral surface of the stator core 243 along the axial direction (direction of arrow Z) from the upper end surface 243c to the lower end surface 243d. That is, in a plan view of the electric motor 40 (see FIG. 3), the innermost point 255 of the notch 254 on the upper end surface 243c of the stator core 243 coincides with the innermost point 255d of the notch 254 on the lower end surface 243d of the stator core 243. In addition, in the examples of FIGS. 13 to 15, the passage for the refrigerating machine oil 25 formed by the notch 254 and the inner wall of the sealed container 20 has a substantially isosceles triangular cross section.

[0092] 13 , in the stator core 243 of the third embodiment, the positions at which the notches 254 are provided in the circumferential direction are the same as in the case of the first embodiment. That is, the notches 254 are provided in the circumferential direction of the stator core 243 so that their innermost points 255 are located between the tooth center line Lt and, of the slot center lines Ls1 and Ls2 of the slots 100 provided on both sides thereof, the slot center line Ls2 that is on the rear side in the direction of rotation R of the rotor.

[0093] 13 and 14 , in the third embodiment, the notch 254 is formed so that the cross-sectional area of ​​the passage for the refrigerating machine oil 25 formed by the notch 254 and the inner wall of the sealed container 20 decreases downward. That is, the notch 254 is formed so that the cross-sectional area of ​​the portion of the stator core 243 cut out by the notch 254 decreases downward. Here, the cross-sectional area refers to a cross section perpendicular to the axial direction (direction of arrow Z) along which the central axis Ax of the stator core 243 extends. As shown in FIGS. 14 and 15 , the distance between the first connection point 258d and the second connection point 259d of the notch 254 at the lower end surface 243d of the stator core 243 is smaller than the distance between the first connection point 258 and the second connection point 259 of the notch 254 at the upper end surface 243c of the stator core 243.

[0094] Incidentally, in the upper part of the stator 241, it is preferable that the cross-sectional area of ​​the passage for the refrigerating oil 25 is large in order to efficiently guide the refrigerating oil 25 into the notches 254. On the other hand, in the lower part of the stator 241, it is not necessary to guide the refrigerating oil 25 into the notches 254, and it is preferable that the cross-sectional area of ​​the passage for the refrigerating oil 25 is small in order to increase the rigidity of the stator 241. Therefore, in the stator 241 of embodiment 3, as described above, the notches 254 are formed so that the cross-sectional area of ​​the passage becomes smaller toward the bottom. As a result, in the upper part of the stator 241, it is possible to capture the dispersed refrigerating oil 25 after colliding with the stator windings 44 and bouncing off over a wide area, and it is possible to increase the rigidity of the lower part of the stator 241.

[0095] It should be noted that each embodiment may be modified or omitted as appropriate. For example, although the compressor 12 of the first embodiment is provided with the oil separating member 47, the oil separating member 47 may be omitted.

[0096] REFRIGERATION CYCLE DEVICE, 11 REFRIGERATOR CIRCUIT, 12 COMPRESSOR, 13 FLOW CHANNEL SWITCHING VALVE, 14 OUTDOOR HEAT EXCHANGER, 15 EXPANSION MECHANISM, 16 INDOOR HEAT EXCHANGER, 17 CONTROL DEVICE, 20 SEALED CONTAINER, 20a UPPER lid, 20b LOWER lid, 20c CONTAINER BODY, 20o OIL SUMP, 21 SUCTION PIPE, 22 DISCHARGE PIPE, 23 SUCTION MUFFLER, 24 TERMINAL, 25 REFRIGERATOR OIL, 30 COMPRESSION ELEMENT, 31 CYLINDER, 32 ROLLING PISTON, 33 MAIN BEARING, 34 AUXILIARY BEARING, 35 DISCHARGE MUFFLER, 40 ELECTRIC MOTOR, 41 STATOR, 42 ROTOR, 42a OIL CHANNEL, 43 STATOR CORE, 43a TEETH, 43b CORE BACK, 43c UPPER END SURFACE, 43d LOWER END SURFACE, 44 STATOR WINDING, 44U STATOR WINDING, 44V Stator winding, 44W Stator winding, 44e Coil end, 45 Lead wire, 46 Rotor core, 47 Oil separator, 47a Flange portion, 47b Flange portion, 53 Arc portion, 54 Notch portion, 55 Innermost point, 58 First connection point, 59 Second connection point, 60 Crankshaft, 61 Eccentric shaft portion, 62 Main shaft portion, 63 Countershaft portion, 100 Slot, 141 Stator, 143 Stator core, 143c Upper end surface, 154 Notch portion, 155 Innermost point, 158 First connection point, 159 Second connection point, 241 Stator, 243 Stator core, 243c Upper end surface, 243d Lower end surface, 254 Notch portion, 255 Innermost point, 255d Innermost point, 258 first connection point, 258d first connection point, 259 second connection point, 259d second connection point, Ax central axis, Li virtual line, Ls slot center line, Ls1 slot center line, Ls2 slot center line, Lt tooth center line, R rotation direction.

Claims

1. A stator provided in an electric motor, with a rotating rotor disposed on its inner periphery via a gap, comprising: an annular core back; a stator core having a central axis extending in the vertical direction, the stator core having a plurality of teeth disposed at intervals from one another in the circumferential direction of the core back, each extending radially inward from the core back, and a slot provided between two adjacent teeth of the plurality of teeth; and a stator winding wound in a distributed winding manner around the plurality of teeth of the stator core, the outer periphery of the stator core having an arc portion based on the central axis of the stator core and a notch formed on the outer periphery and positioned radially inward from the arc portion, alternately provided in the circumferential direction, the notch being provided corresponding to each of one or more of the plurality of teeth, When an imaginary line at the circumferential center of a corresponding tooth among the one or more teeth is defined as a tooth center line, and an imaginary line at the circumferential center of the slot on both sides of the corresponding tooth is defined as a slot center line, the innermost point, which is the point located most inward in the radial direction in the cutout, on the upper end surface of the stator core is formed between the tooth center line in the circumferential direction and the slot center line on both sides that is located rearward in the rotation direction of the rotor when the electric motor is constructed. Stator.

2. A stator as described in claim 1, wherein the cutout on the upper end surface of the stator core has a first connection point which is a connection point with the arc portion located on the front side of the cutout in the rotational direction, and a second connection point which is a connection point with the arc portion located on the rear side of the cutout in the rotational direction, and a triangle formed by the innermost point, the first connection point, and the second connection point is an asymmetric triangle in which the distance between the innermost point and the first connection point is shorter than the distance between the innermost point and the second connection point.

3. A stator according to claim 1 or 2, wherein the cutouts are formed so that the cross-sectional area of ​​the portion of the stator core cut out by the cutouts decreases downward.

4. An electric motor comprising: a stator according to any one of claims 1 to 3; and a rotor arranged on the inner periphery of the stator with a gap therebetween, having a cylindrical shape, having an oil flow path penetrating in the vertical direction, and rotated by a magnetic field generated by the stator.

5. A compressor comprising: an electric motor as claimed in claim 4; a crankshaft extending in the vertical direction; a compression element driven by the electric motor via the crankshaft and compressing fluid drawn in from the outside; and a sealed container accommodating the electric motor and the compression element.

6. The compressor according to claim 5, wherein the crankshaft is disposed at the center of the rotor and fixed to the rotor so that an upper portion of the crankshaft protrudes from the rotor, and an oil separating member having a flange protruding in the radial direction of the rotor is provided on the upper portion of the crankshaft.

7. A refrigeration cycle device comprising: a compressor according to claim 5 or 6; an outdoor heat exchanger; an expansion mechanism for expanding the fluid; and an indoor heat exchanger.

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