Stator, motor, compressor and refrigeration cycle system

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

Technical Field

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

Background Art

[0002] In a compressor, there is known a compressor provided with a mechanism for returning lubricating oil (hereinafter also referred to as refrigeration machine oil) separated from a refrigerant in a space above an electric motor and inside a sealed container through a passage formed between the outer peripheral surface of the stator core of the electric motor and the inner peripheral surface of the sealed container to an oil sump at the bottom of the sealed container (see, for example, Patent Document 1). In the compressor disclosed in Patent Document 1, a notch is formed on the outer peripheral surface of the stator core such that the center is located on the tooth center line, which is a virtual line at the center in the circumferential direction of the teeth, and the radial width of the passage for the refrigeration machine oil is configured to be the largest on the tooth center line.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the refrigeration machine oil separated from the refrigerant in the space above the electric motor and inside the sealed container collides with and scatters from the stator winding protruding from the upper end surface of the stator core, in the passage for the refrigeration machine oil as disclosed in Patent Document 1, it is difficult for the refrigeration machine oil that has collided with the stator winding and bounced back to enter, and there is a problem that the refrigeration machine oil cannot be efficiently captured.

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

Means for Solving the Problems

[0006] The stator of the electric motor according to this disclosure is provided on an electric motor, and a rotating rotor is disposed on its inner circumference with a gap between them, and comprises a stator core having an annular core back, a plurality of teeth arranged at intervals from each other 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 central axis extending in the vertical direction, and stator windings wound in a distributed winding on the plurality of teeth of the stator core, wherein the outer circumference of the stator core has an arc portion with respect to the central axis of the stator core, and a notch formed on the outer circumference that is located radially inward from the arc portion. The notches are provided alternately in the circumferential direction, and each of the notches corresponds to one or more of the multiple teeth. When the notches are defined as the tooth centerline, which is the imaginary line at the circumferential center of the corresponding tooth, and the slot centerlines, which are the imaginary lines at the circumferential center of the slots on both sides of the corresponding tooth, the innermost point of the notch on the upper end surface of the stator core is formed between the tooth centerline and the slot centerline on the rear side in the rotation direction of the rotor when the motor is formed.

[0007] The electric motor according to this disclosure comprises a stator and a rotor which is arranged on the inner circumference side of the stator with a gap in between, has a cylindrical shape, has an oil passage formed therein that penetrates in the vertical direction, and rotates by the magnetic field generated by the stator.

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

[0009] The refrigeration cycle device according to this disclosure comprises the above-mentioned compressor, an outdoor heat exchanger, an expansion mechanism for expanding the fluid, and an indoor heat exchanger. [Effects of the Invention]

[0010] In the stator, motor, compressor, and refrigeration cycle device of this disclosure, the innermost point of the notch on the upper end face of the stator core is positioned between the tooth centerline and the slot centerline located on the rear side in the rotor's rotation direction. Therefore, the notch is wider at the point where the refrigeration oil flows after colliding with and bouncing off the stator windings during rotor rotation. Compared to conventional designs where the widest passage is on the tooth centerline, this design allows for more efficient capture of the refrigeration oil after it has collided with and bounced off the stator windings. [Brief explanation of the drawing]

[0011] [Figure 1] This is a circuit diagram showing the refrigerant flow during cooling of a refrigeration cycle device according to Embodiment 1. [Figure 2] This is a circuit diagram showing the refrigerant flow during heating in a refrigeration cycle device according to Embodiment 1. [Figure 3] This is a longitudinal cross-sectional view of the compressor according to Embodiment 1. [Figure 4] This is a plan view of the stator of the electric motor according to Embodiment 1. [Figure 5] This is a plan view of the stator in Figure 4, excluding the coil ends. [Figure 6] This is a view along line AA in Figure 5. [Figure 7] This is a view along the line BB in Figure 5. [Figure 8] Figure 5 is a partial plan view showing a portion of the circumferential direction of the upper end surface of the stator core in the stator. [Figure 9] Figure 5 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 within the slots in the stator. [Figure 10] This 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. [Figure 11] Partial plan view showing a part of the circumferential direction of the stator winding in the slot and the upper end surface of the stator core in the stator of the motor according to Embodiment 2. [Figure 12] Simulation diagram showing the flow of refrigerant oil in the stator of the motor according to Embodiment 2. [Figure 13] Partial plan view showing a part of the circumferential direction of the stator winding in the slot and the upper end surface of the stator core in the stator of the motor according to Embodiment 3. [Figure 14] Partial view showing a part of the circumferential direction of the stator winding in the slot and the lower end surface of the stator core in the stator of the motor according to Embodiment 3, as seen from above. [Figure 15] Side view schematically showing the stator core in the stator of the motor according to Embodiment 3.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will be omitted or simplified as appropriate. Also, regarding the configuration shown in each figure, the shape, size, arrangement, etc. can be changed as appropriate.

[0013] Embodiment 1. FIG. 1 is a circuit diagram showing the refrigerant flow during cooling of the refrigeration cycle device 10 according to Embodiment 1. FIG. 2 is a circuit diagram showing the refrigerant flow during heating of the refrigeration cycle device 10 according to Embodiment 1. In FIG. 1, the connection state of the refrigerant circuit 11 during cooling is shown, and the flow direction of the refrigerant during cooling is indicated by a white arrow. In FIG. 2, the connection state of the refrigerant circuit 11 during heating is shown, and the flow direction of the refrigerant during heating is indicated by a white arrow.

[0014] As shown in FIGS. 1 and 2, the refrigeration cycle device 10 includes a refrigerant circuit 11 through which the refrigerant circulates. In the present embodiment, the refrigeration cycle device 10 is an air conditioner. Note that even if the refrigeration cycle device 10 is a device other than an air conditioner, the present embodiment can be applied.

[0015] In the refrigerant circuit 11, a compressor 12, a flow path switching valve 13, an outdoor heat exchanger 14, an expansion mechanism 15, and an indoor heat exchanger 16 are connected. The compressor 12 compresses the refrigerant. The flow path switching valve 13 switches the direction in which the refrigerant flows between cooling operation and heating operation. The flow path switching valve 13 is a four-way valve in FIGS. 1 and 2, but is not particularly limited thereto, and may be configured by combining, for example, a two-way valve and a three-way valve.

[0016] The outdoor heat exchanger 14 operates as a condenser during cooling operation, and dissipates heat from the refrigerant compressed by the compressor 12. The outdoor heat exchanger 14 operates as an evaporator during heating operation, and performs heat exchange between the outdoor air and the refrigerant expanded by the expansion mechanism 15 to heat the refrigerant. The expansion mechanism 15 decompresses 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 operation, and dissipates heat from the refrigerant compressed by the compressor 12. The indoor heat exchanger 16 operates as an evaporator during cooling operation, and performs heat exchange between the indoor air and the refrigerant expanded by the expansion mechanism 15 to heat the refrigerant.

[0017] The refrigeration cycle device 10 further includes a control device 17. The control device 17 is composed of dedicated hardware or a CPU (Central Processing Unit) that executes a program stored in a memory. The CPU is also referred to as a central processing unit, a processing device, an arithmetic device, a microprocessor, a microcomputer, or a processor.

[0018] Examples of refrigerants circulating in the refrigerant circuit 11 include, for example, a single refrigerant such as R1234yf, R1234ze, R32, or R290, or a mixture of two or more of these, or a mixture of one of these with another refrigerant, a mixture containing R1132(E), or a mixture containing R1123. In addition, other examples of refrigerants circulating in the refrigerant circuit 11 include a mixture of two or more of the following: R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.

[0019] Here, the operation of the refrigeration cycle device 10 will be explained based on Figures 1 and 2. For example, in heating operation of the refrigeration cycle device 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 indoor heat exchanger 16, where it condenses and liquefies. Then, it is depressurized and expanded in the expansion mechanism 15, becoming a low-temperature, low-pressure two-phase state. The low-temperature, low-pressure two-phase refrigerant flows to the outdoor heat exchanger 14, evaporates, gasifies, and returns to the compressor 12 through the flow path switching valve 13. That is, the refrigerant circulates as shown by the white arrows in Figure 2. Through this circulation, the refrigerant and the outside air exchange heat in the outdoor heat exchanger 14, which is the evaporator. The refrigerant sent to the outdoor heat exchanger 14 absorbs heat, and the absorbed refrigerant is sent to the indoor heat exchanger 16, which is the condenser, where it exchanges heat with the indoor air and warms the indoor air.

[0020] Furthermore, during cooling operation of the refrigeration cycle device 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, liquefies, and then expands under reduced pressure in the expansion mechanism 15, becoming a low-temperature, low-pressure two-phase state. The low-temperature, low-pressure two-phase refrigerant flows to the indoor heat exchanger 16, evaporates, gasifies, and returns to the compressor 12 through the flow path switching valve 13. In other words, when switching from heating operation to cooling operation, 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. In this circulation, the indoor heat exchanger 16, which acts as an evaporator, exchanges heat between the refrigerant and the indoor air. The refrigerant cools the indoor air by absorbing heat from it, and the absorbed refrigerant is sent to the outdoor heat exchanger 14, which acts as a condenser, where it exchanges heat with the outside air and releases heat into the outside air.

[0021] Figure 3 is a longitudinal cross-sectional view of the compressor 12 according to Embodiment 1. Figure 4 is a plan view of the stator 41 of the electric motor according to Embodiment 1. Note that in Figure 3, hatching to represent the cross-section of equipment inside the sealed container 20 has been omitted. In this Embodiment 1, the compressor 12 is a single-cylinder rotary compressor. Note that this Embodiment 1 can also be applied to a multi-cylinder rotary compressor or a scroll compressor.

[0022] As shown in Figure 3, the compressor 12 comprises a sealed container 20 forming the outer casing, a compression element 30, an electric motor 40 (electric motor for the compressor), and a crankshaft 60. The sealed container 20 is also fitted with an intake pipe 21 for drawing in refrigerant and a discharge pipe 22 for discharging refrigerant.

[0023] The sealed container 20 is a bottomed cylindrical container. The sealed container 20 is composed of, for example, a cylindrical container body 20c, an upper lid portion 20a that closes the upper opening of the container body 20c, and a lower lid portion 20b that closes the lower opening of the container body 20c, as shown in Figure 1.

[0024] The compression element 30 is housed inside the sealed container 20. Specifically, the compression element 30 is installed in the lower inside of the sealed container 20. The compression element 30 compresses the refrigerant drawn in 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 where the refrigerant compressed by the compression element 30 passes before being discharged from the discharge pipe 22. That is, the electric motor 40 is installed inside the sealed container 20, 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 for storing refrigerant oil 25 to lubricate the sliding parts of the compression element 30. As the refrigerant oil 25, for example, synthetic oils such as POE (polyol ester), PVE (polyvinyl ether), or AB (alkylbenzene) can be used.

[0027] The details of the compression element 30 will be described below. The compression element 30 comprises a cylinder 31, a rolling piston 32, vanes (not shown), a main bearing 33, and a secondary bearing 34.

[0028] The cylinder 31 has a substantially cylindrical shape. The outer circumference of the cylinder 31 is substantially circular in plan view. Inside the cylinder 31, a cylinder chamber is formed, which is a substantially circular space in plan view. The cylinder 31 is open at both ends in the vertical direction (arrow Z direction). The cylinder 31 is provided with vane grooves (not shown) that communicate with the cylinder chamber and extend radially around the cylinder 31. Outside the vane grooves, a back pressure chamber is formed, which is a substantially circular space in plan view and communicates with the vane grooves.

[0029] Furthermore, the cylinder 31 is provided with an intake port (not shown) through which gaseous refrigerant is drawn in from the refrigerant circuit 11. The intake port penetrates from the outer surface of the cylinder 31 into 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 performs eccentric motion within the cylinder chamber. The rolling piston 32 is slidably fitted onto the eccentric shaft portion 61 of the crankshaft 60.

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

[0032] The main bearing 33 is roughly T-shaped in side view. The main bearing 33 is slidably fitted onto the 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 and the upper side of the vane groove of the cylinder 31.

[0033] The sub-bearing 34 is roughly T-shaped in side view. The sub-bearing 34 is slidably fitted 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 and the lower side of the vane groove of the cylinder 31.

[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 gaseous refrigerant discharged through the discharge valve enters the discharge muffler 35 and is then released from the discharge muffler 35 into the space inside the sealed container 20. The discharge valve and discharge muffler 35 may also be provided on the sub-bearing 34, or on both the main bearing 33 and the main bearing 33.

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

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

[0037] A terminal 24 (for example, a glass terminal) for connecting to an external power source is attached to the top of the sealed container 20 (specifically, the top lid portion 20a). The terminal 24 is fixed to the sealed container 20, for example, by welding. Lead wires 45 from the electric motor 40, which will be described later, are connected to the terminal 24.

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

[0039] The upper part of the crankshaft 60 protrudes from the rotor 42 of the electric motor 40, which will be described later. An oil separation member 47 for separating the refrigerant oil 25 from the gaseous refrigerant is fixed to the upper part of the crankshaft 60. The oil separation member 47 has a flange portion 47a that protrudes radially from the center of the rotor 42.

[0040] In Figure 3, the oil separator 47 is composed of a cylindrical flange portion 47b fixed to the upper part of the crankshaft 60 and an annular plate-shaped flange portion 47a projecting radially from the upper end of the flange portion 47b. The outer diameter of the flange portion 47a is approximately the same as the outer diameter of the rotor 42 of the electric motor 40, which will be described later. Therefore, in a plan view, the flange portion 47a covers the oil passage 42a that penetrates the rotor 42, which will be described later, in approximately the vertical direction (arrow Z direction).

[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, but may be bowl-shaped. Also, although this explanation assumes that the compressor 12 has an oil separation member 47, the oil separation member 47 is not essential. However, when the compressor 12 has an oil separation member 47, compared to a compressor 12 without an oil separation member 47, it is possible to suppress the upward movement of the refrigerant oil 25 that has leaked out from the oil passage 42a of the rotor 42 (described later) into the sealed container 20, and to suppress the discharge of the refrigerant oil 25 from the discharge pipe 22.

[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 even if the electric motor 40 is a motor other than an induction motor, such as a brushless DC (Direct Current) motor.

[0043] As shown in Figure 3, the electric motor 40 comprises a stator 41 and a rotor 42. The stator 41 has a substantially 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 between them.

[0044] As shown in Figures 3 and 4, the stator 41 has a substantially cylindrical stator core 43 and stator windings 44. Hereafter, the direction in which the central axis Ax (see Figure 5 below) of the stator core 43 extends will sometimes simply be referred to as the axial direction. The stator core 43 is manufactured by stacking multiple steel plates, each punched into a predetermined shape, in the axial direction (arrow Z direction) and fixing them together by crimping or the like. The steel plates are, for example, electrical steel plates with a thickness of 0.1 to 1.5 [mm].

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

[0046] As shown in Figure 4, multiple notches 54 are formed on the outer circumference of the stator core 43 at approximately equal intervals in the circumferential direction. Each notch 54 serves as one of the passages for the gaseous refrigerant discharged from the discharge muffler 35 (see Figure 3) into the space inside the sealed container 20. Each notch 54 shown in Figure 4 also serves as a passage for the refrigerant oil 25 that returns from the top of the electric motor 40 shown in Figure 3 to the oil reservoir 20o at the bottom of the sealed container 20.

[0047] As shown in Figure 3, the rotor 42 is configured such that the upper portion of the crankshaft 60 is inserted into a roughly cylindrical rotor core 46. The rotor core 46 is constructed by laminating multiple steel plates, such as electrical steel sheets. Multiple oil passages 42a are formed in the rotor core 46, penetrating roughly in the axial direction. Each oil passage 42a, similar to the notch 54 of the stator core 43 (see Figure 4), serves as one of the passages for the gaseous refrigerant discharged from the discharge muffler 35 into the space inside the sealed container 20.

[0048] 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. For example, ferrite magnets and rare earth magnets are used as permanent magnets. To prevent the permanent magnets from coming 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 by multiple fixing rivets or the like.

[0049] The rotor 42 is configured such that the north poles and south poles are arranged alternately in the circumferential direction. In the following, the rotor 42 is defined as having 6 poles.

[0050] Based on Figure 3, and with reference to Figures 1, 2, and 4, the operation of the compressor 12 will be described. Power is supplied from terminal 24 to the stator 41 of the electric motor 40 via lead wire 45 (see Figure 4). This causes the rotor 42 of the electric motor 40 to rotate. The rotation of the rotor 42 causes the crankshaft 60, which is fixed to the rotor 42, to rotate. 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, drawing in refrigerant from the intake muffler 23. In the other space, the volume gradually contracts, compressing the gaseous refrigerant inside. The compressed gaseous refrigerant is discharged once from the discharge muffler 35 into the space inside the sealed container 20 (specifically, the space between the compression element 30 and the electric motor 40). The discharged gaseous refrigerant passes through the electric motor 40 and is discharged outside the sealed container 20 from the discharge pipe 22 located at the top of the sealed container 20 (specifically, the refrigerant piping connecting the compressor 12 and the condenser in the refrigerant circuit 11 in Figures 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, mainly flows out to the top of the electric motor 40 through the oil passage 42a of the rotor 42. Therefore, the refrigerant that flows out to the top of the electric motor 40 from the oil passage 42a contains refrigerant oil 25. Of the gaseous refrigerant containing refrigerant oil 25 that flows out to the top of the electric motor 40, the gaseous refrigerant itself flows to the upper discharge pipe 22, and the refrigerant oil 25 is separated from the gaseous refrigerant by centrifugal force and falls to the top of the electric motor 40, and if it falls to the top of the rotor 42, it moves to the outer circumference due to rotation. Furthermore, if an oil separation member 47 is provided on the top of the crankshaft 60, the flow direction of the refrigerant oil 25 is changed by the oil separation member 47 to radially outward, that is, towards the inner wall of the container body 20c of the sealed container 20 from the main shaft portion 62. At this time, the refrigerant oil 25 mixed with the gaseous refrigerant is efficiently separated by the centrifugal force of the oil separation member 47. The refrigerant oil 25 separated from the gaseous refrigerant passes over the stator 41, which is located on the outer circumference of the rotor 42, and adheres to or collides with the coil ends 44e of the stator 41 and the inner wall of the sealed container 20. Subsequently, the refrigerant oil 25 enters a notch 54 (see Figure 4) formed on the outer circumference of the stator core 43 of the electric motor 40, and flows from top to bottom of the electric motor 40 along the inner wall of the sealed container 20 within the notch 54. The refrigerant oil 25 that has flowed below the electric motor 40 passes through gaps between the equipment, 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] Figure 5 is a plan view of the stator 41 in Figure 4, excluding the coil end 44e. Figure 6 is a view taken along line AA in Figure 5. Figure 7 is a view taken along line BB in Figure 5. Based on Figures 5 to 7, the configuration of the stator 41 will be explained in detail with reference to Figure 3.

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

[0054] The outer circumference of the stator core 43 has an arc portion 53 based on the central axis Ax of the stator core 43, and a notch portion 54 formed on the outer circumference that is located radially inward from the arc portion 53. The arc portion 53 and the notch portion 54 are alternately arranged in the circumferential direction on the outer circumference of the stator core 43. The arc portion 53 of the stator core 43 is fitted inside the container body 20c (see Figure 3) of the sealed container 20. The notch portion 54 is formed, for example, by processing the circular outer circumference of the stator core 43, such as by making a D-cut. The notch portion 54 is a groove provided so as to extend axially (in the direction of arrow Z) from the upper end surface 43c to the lower end surface 43d of the stator core 43 in the axial direction, and the space formed between the notch portion 54 and the sealed container 20 (see Figure 3) serves as a passage for the refrigerant oil 25 described above.

[0055] In the stator core 43, slots 100 are formed between adjacent teeth 43a in the circumferential direction. The slots 100 are spaces in which the stator windings 44 are housed. The vertically extending portions of the stator windings 44 are housed within the slots 100 along the teeth 43a. The upper and lower folded portions of the stator windings 44 are positioned above and below the teeth 43a, respectively, forming coil ends 44e (see Figure 3) that protrude from the upper end face 43c and lower end face 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 and the stator windings 44 from each other. The number of slots 100 in the stator core 43 is referred to as the number of slots. The number of slots is three times the number of poles of the rotor 42. As described above, if the number of poles of the rotor 42 is 6, the number of slots is 18.

[0056] As shown in Figure 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, or more specifically, concentric winding.

[0057] In the example in Figure 5, the stator windings 44U, 44V, and 44W for each phase are all wound so that the winding pitch is 3 slots. Winding with a winding pitch of 3 slots means that the stator windings 44U, 44V, and 44W are wound so that they span three teeth 43a. Also, in the example in Figure 5, as shown in Figures 6 and 7, the U-phase stator winding 44U, the V-phase stator winding 44V, and the W-phase stator winding 44W partially overlap each other in the circumferential direction and are arranged in offset ranges.

[0058] Furthermore, the radial positions of the U-phase stator winding 44U, the V-phase stator winding 44V, and the W-phase stator winding 44W are different from each other. Specifically, the U-phase stator winding 44U is located furthest radially outward, and the W-phase stator winding 44W is located furthest radially inward. The V-phase stator winding 44V is located radially between the stator windings 44U and 44W. However, the arrangement of the stator windings 44U, 44V, and 44W of each phase is not limited to the above arrangement; it is sufficient that the radial positions of the U-phase stator winding 44U, the V-phase stator winding 44V, and the W-phase stator winding 44W are different from each other.

[0059] Figure 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 Figure 5. Also in Figure 8, the rotation direction R of the rotor 42 (see Figure 3), which is located on the inner circumference side of the stator 41, is indicated by a solid arrow. Based on Figures 5 and 8, and with reference to Figure 3, the position where the notch 54 is provided on the outer circumference 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 centerline Lt, and the imaginary line at the circumferential center of the slot 100 is defined as the slot centerline Ls. In the following, we will focus on the tooth 43a, which is provided with the corresponding notch 54. Also, in the following, for the sake of clarity, among the slot centerlines Ls of the slots 100 provided on both sides of the tooth 43a, the slot centerline Ls located on the rear side in the rotation direction R of the rotor 42 will be referred to as slot centerline Ls2, and the slot centerline Ls located on the front side in the rotation direction R of the rotor 42 will be referred to as slot centerline Ls1, and so on. Furthermore, the point located furthest inward in the radial direction of the notch 54 will be referred to as the innermost point 55.

[0061] As shown in Figure 8, the notch 54 is provided such that its innermost point 55 is located between the tooth centerline Lt and the rear slot centerline Ls2 of the slots 100 provided on both sides of the tooth centerline Lt in the rotation direction R of the rotor 42, in the circumferential direction of the stator core 43. Here, the position of the innermost point 55 as described above is defined by the fact that it is filled at the inlet of the refrigerant oil 25 in the notch 54, i.e., at the upper end of the notch 54. In other words, the notch 54 is provided extending axially from the outer circumferential surface of the stator core 43, but the innermost point 55 of the notch 54 is located between the tooth centerline Lt and the rear slot centerline Ls2 on the upper end surface 43c of the stator core 43. The notch 54 may be provided such that the cross-sectional shape of the passage for the refrigerant 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 it may be provided at an angle such that the position of the innermost point 55 changes in the axial direction (direction of arrow Z).

[0062] In this embodiment 1, the notch 54 is symmetrical on both sides in the circumferential direction with respect to the innermost point 55. The cross-sectional shape of the passage for the refrigerant oil 25, that is, the cross-sectional shape of the passage perpendicular to the axial direction, is symmetrical on both sides in the circumferential direction with respect to a virtual line Li that extends radially from the central axis Ax of the stator core 43 and passes through the innermost point 55.

[0063] In Figure 8, the cross-sectional shape of the passage for the refrigerant oil 25 is approximately triangular, and more specifically, approximately isosceles. Here, if we define the connection point between the notch 54 and the arc portion 53 located on the front side in the rotation direction R of the rotor 42 as the first connection point 58, and the connection point between the notch 154 and the arc portion 53 located on the rear side in the rotation direction R of the rotor 42 as the second connection point 59, then the notch 54 in Figure 8 exhibits an approximately isosceles triangle in which the distance between the innermost point 55 and the first connection point 58 is equal to the distance between the innermost point 55 and the second connection point 59. The corner provided at the innermost point 55 of the notch 54 may be a rounded corner, as shown in Figure 8.

[0064] As described above, the notch 54 only needs to have its innermost point 55 between the tooth centerline Lt and the slot centerline Ls2. The cross-sectional shape of the passage for the refrigerant oil 25 is not limited to a roughly triangular shape, but may be rectangular, for example. Also, the cross-sectional shape of the passage for the refrigerant oil 25 does not have to be symmetrical with respect to the imaginary line Li passing through the innermost point 55, but may be asymmetrical.

[0065] In Figure 5, the number of notches 54 provided in the stator core 43 is less than the number of teeth 43a (18 in Figure 5), which is 8. Note that the number of notches 54 is not limited to the above number; for example, it could be the same number as the number of teeth 43a.

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

[0067] Figure 9 is a partial plan view showing the upper end surface 43c of the stator core 43 and a portion of the circumferential direction of the stator winding 44 in the slot 100 in the stator 41 of Figure 5. In Figure 9, the flow of refrigerant oil 25 on the upper end surface 43c of the stator core 43 is indicated by white arrows. Figure 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 Figures 9 and 10, the rotation direction R of the rotor 42 (see Figure 3) arranged on the inner circumference side of the stator 41 is indicated by solid arrows. Also in Figure 10, the position of the notch 54 when a passage for refrigerant oil 25 is provided for each tooth 43a is shown. Based on Figures 3, 6, 7, 9 and 10, the flow of refrigerant oil 25 in the stator 41 of Embodiment 1 will be explained.

[0068] In the electric motor 40 shown in Figure 3, the refrigerant oil 25 adhering to the upper part of the rotor 42, or the refrigerant oil 25 that flows out from the oil passage 42a to the upper part of the rotor 42 and is separated from the refrigerant, flows to the upper part of the stator 41 located on the outer circumference of the rotor 42, having a radially outward velocity component and a forward velocity component in the rotation direction R of the rotor 42, as shown in Figure 9 (see the shorter white arrow in Figure 9). This refrigerant oil 25 from the upper part of the rotor 42 flows over the teeth 43a between the stator windings 44U, 44V, and 44W of the coil end 44e shown in Figures 6 and 7, and flows into the notch 54.

[0069] As shown in Figures 9 and 10, the refrigerant oil 25 does not flow radially (i.e., outward along the radial direction) over the teeth 43a from the inner circumference to the outer circumference of the stator 41. Instead, on the inner circumference side, it first flows from the radial direction toward the front in the rotational direction R of the rotor 42. Subsequently, the refrigerant oil 25 collides with the stator windings 44 protruding from the slots 100 in the direction of travel, bounces back, and flows over the teeth 43a from the radial direction toward the rear in the rotational direction R of the rotor 42 (see the longer white arrow in Figure 9). In other words, the refrigerant oil 25 from the top of the rotor 42 first flows on the teeth 43a with a radially outward velocity component and a forward velocity component in the rotational direction R of the rotor 42. After colliding with and bouncing off the stator windings 44 protruding from the slot 100, it flows with a radially outward velocity component and a backward velocity component in the rotational direction R of the rotor 42.

[0070] As explained with reference to Figure 8, the notch 54 of this disclosure has a configuration in which the innermost point 55 is positioned between the tooth centerline Lt and the slot centerline Ls2, which is on the rear side in the rotor rotation direction R, of the two slot centerlines Ls1 and Ls2 on either side of the tooth centerline Lt. Therefore, compared to a conventional notch 54 in which the innermost point 55 is positioned on the tooth centerline Lt, the innermost point 55 of the notch 54 is provided at the point where the refrigerant oil 25 flows after colliding with the stator winding 44 and bouncing back, so that the refrigerant oil 25 can be efficiently captured and guided into the passage for the refrigerant oil 25.

[0071] In the electric motor 40, if the rotational speed of the rotor 42 is high, the flow velocity of the refrigerant oil 25 flowing from the top of the rotor 42 to the top of the stator 41 increases. And if the flow velocity of the refrigerant oil 25 is high, the angle of the rebound of the refrigerant oil 25 that collides with the stator windings 44 also increases. Therefore, it is preferable to set the circumferential width of the notch 54 to be wider for electric motors 40 with high rotor rotational speeds.

[0072] As described above, the stator 41 according to Embodiment 1 is a stator 41 provided on an electric motor 40, on which a rotating rotor 42 is arranged with a gap between them on the inner circumference side. The stator 41 comprises a stator core 43 having a central axis Ax extending in the vertical direction (arrow Z direction). The stator core 43 has an annular core back 43b, a plurality of teeth 43a arranged at intervals from each other in the circumferential direction of the core back 43b, each extending radially inward from the core back 43b, and a slot 100 provided between two adjacent teeth of the plurality of teeth 43a. The stator 41 also comprises stator windings 44 wound in a distributed winding manner on the plurality of teeth 43a of the stator core 43. Furthermore, the outer circumference of the stator core 43 is alternately provided in the circumferential direction with arc portions 53 based on the central axis Ax of the stator core 43 and notches 54 formed on the outer circumference and located radially inward from the arc portions 53. The notches 54 are provided corresponding to one or more of the multiple teeth 43a. The imaginary line at the circumferential center of a corresponding tooth 43a is defined as the tooth centerline Lt, and the imaginary lines at the circumferential centers of the slots 100 on both sides of the corresponding tooth 43a are defined as slot centerlines Ls1 and 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 point located radially inward in the notch 54, being formed in the circumferential direction between the tooth center line Lt and the slot center line Ls2, which is located on the rear side in the rotor rotation direction R when the electric motor 40 is formed from the slot center lines Ls1 and Ls2 on both sides.

[0073] Thus, on the upper end surface 43c of the stator core 43, the innermost point 55 of the notch 54 is positioned between the tooth centerline Lt and the slot centerline Ls2 located on the rear side in the rotation direction R of the rotor 42. Therefore, since the notch 54 is wider at the point where the refrigerant oil 25 flows after colliding with the stator windings 44 and bouncing back, it is possible to efficiently capture the refrigerant oil 25 after colliding with the stator windings 44 and bouncing back, compared to the conventional method where the widest passage is on the tooth centerline.

[0074] Furthermore, the electric motor 40 comprises the stator 41 and a rotor 42 positioned on the inner circumference side of the stator 41 with a gap in between, and rotating due to the magnetic field generated by the stator 41. The rotor 42 has a cylindrical shape and has an oil passage 42a that penetrates in the vertical direction.

[0075] Even when an oil passage 42a is formed in the rotor 42 in this way, the refrigeration oil 25 that flows upward from the oil 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's rotation direction R. Therefore, the effect of efficiently capturing the refrigeration oil 25 can be obtained in a similar manner.

[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 driven by the electric motor 40 via the crankshaft 60 to compress fluid drawn in from the outside, and a sealed container 20 housing the electric motor 40 and the compression element 30.

[0077] Since the compressor 12 is equipped with an electric motor 40 that efficiently captures the refrigerant oil 25, the refrigerant oil 25 is efficiently returned to the oil reservoir 20o in the compressor 12. Therefore, depletion of the refrigerant oil 25 is less likely to occur, and a highly reliable compressor 12 can be provided.

[0078] Furthermore, in the compressor 12, the crankshaft 60 is positioned at the center of the rotor 42 such that the upper part of the crankshaft 60 protrudes from the rotor 42, and is fixed to the rotor 42. An oil separation member 47 is provided on the upper part of the crankshaft 60, which has a flange portion 47a that protrudes radially from the rotor 42.

[0079] As a result, the flow direction of the refrigerant (fluid) containing the refrigerant oil 25 that has leaked out from the oil passage 42a is changed to the radial direction by the oil separation member 47, thereby suppressing the upward movement of the refrigerant oil 25 that has leaked out from the oil passage 42a into the sealed container 20. Consequently, the leakage of the refrigerant oil 25 out of the sealed container 20 from the discharge pipe 22 along with the refrigerant is suppressed, and the refrigerant oil 25 remains in the sealed container 20, making depletion of the refrigerant oil 25 less likely, thus further improving reliability.

[0080] Furthermore, the refrigeration cycle system 10 includes the compressor 12, an outdoor heat exchanger 14, an expansion mechanism 15 for expanding the fluid (refrigerant), and an indoor heat exchanger 16. Since the refrigeration cycle system 10 is equipped with a highly reliable compressor 12 that is less prone to depletion of the refrigerant oil 25, the compressor 12 is less likely to malfunction in the refrigeration cycle system 10, improving its reliability.

[0081] Embodiment 2. Figure 11 is a partial plan view showing the upper end surface 143c of the stator core 143 and a portion of the circumferential direction of the stator winding 44 in the slot 100 in the stator 141 of the electric motor according to Embodiment 2. In the stator 141 of Embodiment 2, the shape of the notch 154 provided on the outer circumference of the stator core 143 differs from that of Embodiment 1. Hereinafter, the differences between the stator 141 of Embodiment 2 and that of Embodiment 1 will be described based on Figure 11 and with reference to Figure 3. Note that components in the stator 141 of Embodiment 2 that are the same as those in Embodiment 1 will be denoted by the same reference numerals and their explanations will be omitted.

[0082] In the following, the point located furthest inward in the radial direction within the notch 154 will be referred to as the innermost point 155. Furthermore, a hypothetical 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 the hypothetical line Li.

[0083] In Embodiment 1, the notch 54 is formed 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 refrigerant oil 25 is symmetrical on both sides in the circumferential direction with respect to a virtual line Li passing through the innermost point 55. In Embodiment 2, the notch 154 is formed 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 refrigerant oil 25 is asymmetrical on both sides in the circumferential direction with respect to a virtual line Li passing through the innermost point 155.

[0084] In Figure 11, the cross-sectional shape of the passage for the refrigerant oil 25 is approximately triangular. More specifically, if we define the connection point between the notch 154 and the arc portion 53 located on the front side in the rotor's rotation direction R as the first connection point 158, and the connection point between the notch 154 and the arc portion 53 located on the rear side in the rotor's rotation direction R as the second connection point 159, then the notch 154 in Figure 8 exhibits an asymmetrical 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 55 and the second connection point 159. The corner provided at the innermost point 155 of the notch 154 may be a rounded corner, as shown in Figure 11.

[0085] In the stator core 143 of Embodiment 2, the position where the notch 154 is provided in the circumferential direction is the same as in Embodiment 1. That is, as shown in Figure 11, the notch 154 is provided such that the innermost point 155 is located between the tooth centerline Lt and the slot centerline Ls2, which is the rear slot centerline in the rotor rotation direction R, of the slots 100 provided on both sides thereof, Ls1 and Ls2.

[0086] Furthermore, in Embodiment 2, the notch 154 on the upper end surface 43c of the stator core 43 has a first connection point 158, which is the connection point with an arc portion 53 located in front of the notch 154 in the rotational direction R, and a second connection point 159, which is the connection point with an arc portion 53 located in rear of the notch 154 in the rotational direction R. The triangle formed by the innermost point 155, the first connection point 158, and the second connection point 159 is an asymmetrical 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 the refrigerant oil 25 is approximately an isosceles triangle as in Embodiment 1, the cross-sectional shape of the passage for the refrigerant oil 25 is shaped to follow the flow of the refrigerant oil 25 after it collides with the stator winding 44 and bounces back (indicated by the white arrow in Figure 11), allowing for more efficient capture and guidance into the passage for the refrigerant oil 25.

[0088] Figure 12 is a simulation diagram showing the flow of refrigerant oil 25 at the top of the stator 141 of the electric motor according to Embodiment 2. The flow of refrigerant oil 25 shown in Figure 12 is generally the same as the flow of refrigerant oil 25 shown in Figure 11. That is, the refrigerant oil 25 from the top of the rotor 42 (see Figure 3) first flows on the teeth 43a with a radially outward velocity component and a forward velocity component in the rotor rotation direction R. After colliding with and bouncing off the stator windings 44 (see Figure 11) protruding from the slot 100 (see Figure 11), it flows with a radially outward velocity component and a backward velocity component in the rotor rotation direction R. As described above, in Embodiment 2, the cross-sectional shape of the passage for refrigerant oil 25 formed by the notch 154 and the inner wall of the sealed container 20 is not a substantially isosceles triangle, but an asymmetrical triangle in which its innermost point 155 is shifted towards the tooth centerline Lt. In other words, in Embodiment 2, the cross-sectional shape of the passage for the refrigerant oil 25 is shaped to follow the flow of the refrigerant oil 25 after it has collided with and bounced off the stator winding 44. In the notch 154, the distance between the side of the tooth centerline Lt (i.e., the line connecting the innermost point 155 and the first connection point 158) and the stator winding 44, which is positioned in front of the tooth centerline Lt in the rotor's rotation direction R, becomes shorter. Therefore, in Embodiment 2, the refrigerant oil 25 after it has collided with and bounced off the stator winding 44 enters the notch 154 more easily.

[0089] Embodiment 3. Figure 13 is a partial plan view showing the upper end surface 243c of the stator core 243 and a portion of the circumferential direction of the stator winding 44 in the slot 100 in the stator 241 of the electric motor according to Embodiment 3. Figure 14 is a partial view from above showing the lower end surface 243d of the stator core 243 and a portion of the circumferential direction of the stator winding 44 in the slot 100 in the stator 241 of the electric motor according to Embodiment 3. In Figure 14, the outline of the notch 254 on the upper end surface 243c of the stator core 243 is shown by a dashed line. Figure 15 is a schematic side view showing the stator core 243 in the stator 241 of the electric motor according to Embodiment 3. The stator 241 of Embodiment 3 differs from that of Embodiment 1 in that the area of ​​the cross-sectional surface of the passage for the refrigerant oil 25 formed by the notch 254 and the inner wall of the sealed container 20 changes in the axial direction. The following explanation will describe the differences between the stator 241 of Embodiment 3 and that of Embodiment 1, based on Figures 13 to 15 and with reference to Figure 3. Note that components of the stator 241 of Embodiment 3 that are the same as those in Embodiment 1 are denoted by the same reference numerals, and their explanations will be omitted.

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

[0091] In the examples shown in Figures 13 to 15, the notch 254 is defined as being provided on the outer circumferential surface of the stator core 243 along the axial direction (arrow Z direction) from the upper end surface 243c to the lower end surface 243d. That is, in a plan view of the electric motor 40 (see Figure 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. Also, in the examples shown in Figures 13 to 15, the passage for the refrigerant oil 25 formed by the notch 254 and the inner wall of the sealed container 20 has a cross-sectional shape of approximately an isosceles triangle.

[0092] As shown in Figure 13, in the stator core 243 of Embodiment 3, the position where the notch 254 is provided in the circumferential direction is the same as in Embodiment 1. That is, the notch 254 is provided such that in the circumferential direction of the stator core 243, the innermost point 255 is located between the tooth center line Lt and the slot center line Ls2, which is the rear slot center line in the rotor rotation direction R of the slots 100 provided on both sides thereof, Ls1 and Ls2.

[0093] Furthermore, as shown in Figures 13 and 14, in Embodiment 3, the notch 254 is formed such that the area of ​​the cross-sectional surface of the passage for the refrigerant oil 25, formed by the notch 254 and the inner wall of the sealed container 20, decreases as it goes downwards. That is, the notch 254 is formed such that the area of ​​the cross-sectional surface of the portion cut out by the notch 254 in the stator core 243 decreases as it goes downwards. Here, the cross-section is a cross-section perpendicular to the axial direction (arrow Z direction) to which the central axis Ax of the stator core 243 extends. As shown in Figures 14 and 15, at the lower end surface 243d of the stator core 243, the distance between the first connection point 258d and the second connection point 259d of the notch 254 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 to have a large cross-sectional area of ​​the passage for the refrigerant oil 25 in order to efficiently guide the refrigerant oil 25 into the notch 254. On the other hand, in the lower part of the stator 241, it is not necessary to guide the refrigerant oil 25 into the notch 254, and it is preferable to have a smaller cross-sectional area of ​​the passage for the refrigerant oil 25 in order to increase the rigidity of the stator 241. Therefore, in the stator 241 of Embodiment 3, the notch 254 is formed such that the area of ​​the cross-sectional area of ​​the passage decreases as it goes downwards, as described above. As a result, in the upper part of the stator 241, dispersed refrigerant oil 25 after colliding with the stator winding 44 and bouncing off can be captured over a wide area, and the rigidity of the lower part of the stator 241 can be increased.

[0095] Furthermore, each embodiment can be modified or omitted as appropriate. For example, the compressor 12 in Embodiment 1 is equipped with an oil separation member 47, but the oil separation member 47 may be omitted. [Explanation of Symbols]

[0096] 10 Refrigeration cycle unit, 11 Refrigerant circuit, 12 Compressor, 13 Flow path switching valve, 14 Outdoor heat exchanger, 15 Expansion mechanism, 16 Indoor heat exchanger, 17 Control device, 20 Sealed container, 20a Top cover, 20b Bottom cover, 20c Container body, 20o Oil reservoir, 21 Suction pipe, 22 Discharge pipe, 23 Suction muffler, 24 Terminals, 25 Refrigerant oil, 30 Compression element, 31 Cylinder, 32 Rolling piston, 33 Main bearing, 34 Sub-bearing, 35 Discharge muffler, 40 Electric motor, 41 Stator, 42 Rotor, 42a Oil flow path, 43 Stator core, 43a Teeth, 43b Core back, 43c Upper end face, 43d Lower end face, 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, 47b Flange section, 53 Arc section, 54 Notch, 55 Innermost point, 58 First connection point, 59 Second connection point, 60 Crankshaft, 61 Eccentric shaft section, 62 Main shaft section, 63 Sub-shaft section, 100 Slot, 141 Stator, 143 Stator core, 143c Upper end face, 154 Notch, 155 Innermost point, 158 First connection point, 159 Second connection point, 241 Stator, 243 Stator core, 243c Upper end face, 243d Lower end face, 254 Notch, 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 centerline, Ls1; Slot centerline, Ls2; Slot centerline, Lt; Teeth centerline, R; Direction of rotation.

Claims

1. A stator provided on an electric motor, wherein a rotating rotor is positioned on its inner circumference with a gap between them, A stator core having an annular core back, a plurality of teeth arranged circumferentially around the core back at intervals from each other and each extending radially inward from the core back, and a slot provided between two adjacent teeth of the plurality of teeth, and a central axis extending in the vertical direction, The stator core comprises a stator winding wound in a distributed winding on the plurality of teeth of the stator core, On the outer circumference of the stator core, arc portions with respect to the central axis of the stator core and notches formed on the outer circumference and located radially inward from the arc portions are alternately provided in the circumferential direction. The notches are provided corresponding to one or more of the multiple teeth, The notch is defined as such when the imaginary line at the circumferential center of a corresponding tooth among the one or more teeth is defined as the tooth centerline, and the imaginary lines at the circumferential center of the slots on both sides of the corresponding tooth are defined as slot centerlines, and the innermost point of the notch, which is the point located furthest inward in the radial direction of the notch, is formed in the circumferential direction between the tooth centerline and the slot centerline on the rear side in the rotational direction of the rotor when the electric motor is formed. stator.

2. The notch in the upper end face of the stator core is A first connection point is the connection point between the notch and the arc portion located on the front side in the rotational direction, It has a second connection point which is the connection point between the notch and the arc portion located on the rear side in the rotational direction, The triangle formed by the innermost point, the first connection point, and the second connection point is an asymmetrical 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. The stator according to claim 1.

3. The notch is formed such that the area of ​​the cross-sectional surface of the portion cut out by the notch in the stator core decreases as it goes downwards. The stator according to claim 1 or 2.

4. A stator according to claim 1 or 2, A rotor is positioned on the inner circumference side of the stator with a gap in between, has a cylindrical shape, has an oil passage formed through it in the vertical direction, and rotates due to the magnetic field generated by the stator, An electric motor equipped with [a specific feature].

5. The electric motor according to claim 4, The aforementioned crankshaft extending in the vertical direction, A compression element, driven by the electric motor via the crankshaft, compresses a fluid drawn in from the outside, A sealed container housing the electric motor and the compression element, A compressor equipped with a compressor.

6. The crankshaft is positioned at the center of the rotor such that the upper part of the crankshaft protrudes from the rotor, and is fixed to the rotor. An oil separator member having a flange that protrudes radially from the rotor is provided on the upper part of the crankshaft. The compressor according to claim 5.

7. The fluid is a refrigerant, The refrigerant is a single refrigerant of any of R1234yf, R1234ze, R32, and R290, or a mixture of two or more of these, or a mixture of any one of these with another refrigerant, a mixture containing R1132(E), a mixture containing R1123, or a mixture of two or more of R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A. The compressor according to claim 5.

8. The compressor according to claim 5, An outdoor heat exchanger, an expansion mechanism for expanding the fluid, and an indoor heat exchanger, A refrigeration cycle device equipped with a refrigeration cycle system.

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