JP2018074890A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine capable of reducing a stress to be applied to permanent magnets while suppressing reduction of a torque.SOLUTION: A motor compressor 10 comprises: a rotor 30; a stator 40 provided outside of the rotor 30 in a radial direction R and including a stator core 41, armature coils 42u, 42v and 42w and permanent magnets 62 and 72; and a housing 11 in which the rotor 30 and the stator 40 are accommodated in a state where the stator core 41 is fixed. In the stator core 41, an inner magnet slot 61 recessed from a distal end face 53 of teeth and an outer magnet slot 71 disposed outside of the inner magnet slot 61 in the radial direction R and recessed from a core outer peripheral surface 51a are formed. The stator core 41 includes a bridge 80 that separates both the magnet slots 61 and 71. The permanent magnets 62 and 72 are then accommodated in the magnet slots 61 and 71.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a rotating electrical machine.

  An electric compressor as a rotating electrical machine includes, for example, a rotor and a stator, and a housing that houses the rotor and the stator (see, for example, Patent Document 1). In Patent Document 1, the stator has a stator core provided on the outer side in the radial direction of the rotor, an armature winding wound around the stator core, and the stator core is shrink-fitted to the housing. The fixed points are described. Patent Document 2 describes a rotating electrical machine in which a permanent magnet is provided on a stator core from the viewpoint of speeding up a rotor.

Japanese Patent Laid-Open No. 2015-1160 Japanese Patent Laid-Open No. 2002-199679

  Here, in the configuration in which the stator core is fixed to the housing as described above, if a permanent magnet is provided on the stator core, stress may be applied to the permanent magnet. If excessive stress is applied to the permanent magnet, the operation of the rotating electrical machine may be hindered. However, in order to suppress application of excessive stress to the permanent magnet, for example, if the installation space of the permanent magnet is reduced or a magnetic flux that does not contribute to torque is generated, there is a concern about a decrease in torque. .

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a rotating electrical machine capable of reducing stress applied to a permanent magnet while suppressing a decrease in torque.

  The rotating electrical machine that achieves the above object includes a rotor, a stator having a stator core provided on the outer side in the radial direction of the rotor with respect to the rotor, an armature winding, and a permanent magnet. A rotor and a housing that accommodates the stator, wherein the stator core is formed by winding a core cylinder portion having a core outer peripheral surface pressed from an inner peripheral surface of the housing, and the armature winding. A plurality of teeth projecting from the inner peripheral surface of the core cylindrical portion toward the radially inner side of the rotor and arranged in the circumferential direction of the rotor, and a tooth front end surface that is a front end surface of each of the teeth A recessed inner magnet slot, and an outer magnet slot which is disposed radially outside the rotor with respect to the inner magnet slot and is recessed from the outer peripheral surface of the core A bridge that divides the slot for the inner magnet and the slot for the outer magnet, and the permanent magnet is housed in the slot for the inner magnet and the slot for the outer magnet. An outer permanent magnet is included.

  According to such a configuration, when a current flows through the armature winding wound around the teeth, the magnetic flux generated from the armature winding and the magnetic flux of both permanent magnets interact to rotate the rotor. it can.

  Here, in the configuration in which the core outer peripheral surface is pressed from the inner peripheral surface of the housing, stress can be applied to both permanent magnets housed in both magnet slots of the stator core. On the other hand, according to the present configuration, the bridge can receive stress applied to both permanent magnets. Thereby, the stress provided to both permanent magnets can be reduced.

  In particular, because the outer magnet slot is formed so as to be recessed from the outer peripheral surface of the core, the bridge that partitions the outer magnet slot and the inner magnet slot should be disposed radially inward of the rotor from the core outer peripheral surface. It becomes. Thereby, since the stress applied to the stator core is distributed and applied to the bridge and the core tube portion, the stress applied to the bridge can be reduced. Therefore, since the strength required for the bridge can be reduced, the bridge can be thinned. Therefore, the short circuit magnetic flux which penetrates a bridge can be reduced, and the fall of the torque of the rotary electric machine resulting from a bridge can be suppressed through it. Further, by thinning the bridge, for example, the space of the slots for both magnets can be increased, and the permanent magnets can be increased through the space.

  Furthermore, according to this configuration, the stator core is integrated by the bridge without being divided into a plurality of parts. Thereby, the inconvenience caused by dividing the stator core into a plurality of parts, specifically, misalignment between the parts and complication of the mounting work to the housing can be suppressed.

  With respect to the rotating electric machine, the teeth have a pair of teeth side surfaces around which the armature winding is wound, and the stator core is provided between the pair of teeth side surfaces, and defines the inner magnet slot. And a pair of inner slot side wall surfaces facing each other and a pair of outer slot side wall surfaces defining the outer magnet slot and facing each other, wherein the bridge constitutes a bottom surface of the inner magnet slot. An inner bridge surface and an outer bridge surface that is provided on the opposite side of the inner bridge surface and forms a bottom surface of the outer magnet slot, and is a distance between the inner bridge surface and the outer bridge surface. The bridge thickness is preferably smaller than the thickness of the core tube portion.

  According to such a configuration, compared to a configuration in which the bridge thickness is equal to or greater than the thickness of the core tube portion, the slots for both magnets can be increased, so that both permanent magnets can be increased and the short-circuit magnetic flux can be decreased. Therefore, the torque of the rotating electrical machine can be improved.

  In the rotating electrical machine, a groove extending in the axial direction of the rotor and recessed from the outer slot side wall surface may be formed between the pair of outer slot side wall surfaces and the outer bridge surface.

  According to such a configuration, the stress concentration in the vicinity of the corner between the pair of outer slot side wall surfaces and the outer bridge surface can be suppressed by the groove. In particular, according to this configuration, the groove is recessed with respect to the outer slot side wall, not the outer bridge surface. Thereby, the situation where the location where bridge thickness becomes locally small resulting from a groove | channel can arise can be suppressed. Therefore, local stress concentration can be suppressed while suppressing a decrease in strength of the bridge.

  In the rotating electrical machine, the groove has an inner groove surface that is continuous with the outer bridge surface, and the inner groove surface is radially outward of the rotor as the distance from the outer bridge surface increases when viewed from the axial direction of the rotor. It is preferable to include an inner curved surface that is curved toward.

  According to such a configuration, when a stress including a component in a direction in which the outer slot side wall surfaces approach each other is applied to the vicinity of the corner between the pair of outer slot side wall surfaces and the outer bridge surface, the inner curved surface is It is easy to receive the stress. In this case, since the inner curved surface is curved, the stress can be dispersed. Thereby, the said stress can be received suitably.

  In the rotating electrical machine, the outer permanent magnet has a pair of outer magnet side surfaces that contact or face the pair of outer slot side wall surfaces, and the groove has a first end continuous with the inner groove surface and the outer side. An outer groove surface having a second end continuous with the slot side wall surface is provided, and the outer groove surface is curved so that the width of the groove gradually decreases from the first end side toward the second end side. An outer curved surface may be included.

  According to such a configuration, it is possible to suppress a decrease in the area in which the outer slot side wall surface and the outer magnet side surface abut or face each other while securing the area of the inner curved surface to some extent. As a result, it is possible to suppress a reduction in torque due to the reduction in the area caused by the formation of the grooves while achieving stress dispersion.

  For the rotating electrical machine, the teeth have a tapered shape formed so that the length in the circumferential direction of the rotor in the teeth gradually decreases toward the inner side in the radial direction of the rotor. It is provided on both sides of the slot for the inner magnet, and is composed of a pair of tip curved surfaces that extend continuously in both the teeth side surface and the inner slot side wall surface facing each other and extend in the circumferential direction of the rotor, The shortest distance between the tooth side surface and the groove is the tangent of the tip which is the length of the tangent perpendicular to the tooth side surface and in contact with the tip curved surface of the straight lines connecting the tooth side surface and the inner slot side wall surface facing each other. It is set longer than the shorter one of the length and the circumferential length of the tip curved surface.

  According to this configuration, the portion where the area through which the magnetic flux penetrates is the smallest in the tooth is the tip portion of the tooth. Thereby, it can avoid that the magnetic flux which penetrates the inside of a tooth | gear by a groove | channel is rate-limited. Therefore, the situation where the magnetic flux penetrating the teeth due to the groove can be suppressed, and the decrease in the torque due to the groove can be suppressed through it.

  In the rotating electrical machine, the outer permanent magnet has an outer magnet bottom surface facing the outer bridge surface, and the groove has an opening whose width direction is the facing direction of the outer bridge surface and the outer magnet bottom surface. The rotating electrical machine may include a support portion that supports the outer permanent magnet so that the outer bridge surface and the outer magnet bottom surface are separated at least partially.

  According to such a configuration, since the outer bridge surface and the outer magnet bottom surface are separated at least in part, a region where no outer permanent magnet is present is formed between them. Thereby, an outer permanent magnet can be made small by the area | region. Thereby, the quantity of the outer permanent magnet to be used can be reduced, and the cost can be reduced.

  Here, the region where the outer permanent magnet does not exist includes a portion facing the opening of the groove formed between the pair of outer slot side wall surfaces and the outer bridge surface. This part does not contribute to the torque of the rotating electrical machine regardless of the presence or absence of the outer permanent magnet. Therefore, even if the region where the outer permanent magnet does not exist is formed, the torque is unlikely to decrease.

  Further, since the outer permanent magnet is supported by the support portion, even when vibration or the like is applied to the rotating electrical machine, the movement of the outer permanent magnet in the direction in which the outer magnet bottom surface approaches the outer bridge surface is restricted. Has been. Thereby, the fall of the torque resulting from the position shift of an outer side permanent magnet can be suppressed.

About the said rotary electric machine, the said support part is good to support the said outer side permanent magnet in the position where the said outer side magnet bottom face was spaced apart more than the opening width of the said groove | channel with respect to the said outer side bridge surface.
According to this configuration, the region facing the opening of the groove in the outer magnet slot is all included in the region where the outer permanent magnet does not exist. Thereby, by further eliminating the portion of the outer permanent magnet that does not contribute to the torque, it is possible to further reduce the size of the outer permanent magnet while suppressing a decrease in torque.

  In the rotating electrical machine, the support portion is a protrusion provided on at least one of the pair of outer slot side wall surfaces, and the outer permanent magnet is supported by the outer magnet bottom surface contacting the protrusion. It is good to be.

  According to this configuration, if the outer permanent magnet is pressed toward the bridge by vibration or the like, the protrusion receives the pressing force. Thereby, it can suppress that the pressing force provided from an outer side permanent magnet is added to a bridge, and can suppress that an excessive stress is provided to a bridge through it.

  In the rotating electrical machine, the support portion is a protruding portion provided on the outer bridge surface and protruding from the outer bridge surface toward the outer magnet bottom surface, and the outer magnet bottom surface abuts on the protruding portion. It is good that it is supported by.

  According to this configuration, it is possible to avoid the outer permanent magnet from becoming smaller due to the provision of the protrusions on the pair of outer slot side wall surfaces. Thereby, the fall of the torque resulting from providing a support part can be avoided.

About the said rotary electric machine, the said support part is good in it being a nonmagnetic member interposed between the said outside bridge surface and the said outside magnet bottom face.
According to this configuration, since it is not necessary to provide a support portion on the outer slot side wall surface or the outer bridge surface, it is possible to suppress complication of the configuration of the stator core due to the support portion. Further, since a nonmagnetic member is employed as the support portion, a short circuit magnetic path through the nonmagnetic member is less likely to occur. Thereby, the fall of the torque resulting from a support part can be suppressed.

  For the rotating electrical machine, the magnetization direction of the inner permanent magnet coincides with the opposing direction of the pair of inner slot side wall surfaces, and the magnetization direction of the outer permanent magnet is the opposite direction of the pair of outer slot side wall surfaces. The lengths of the inner permanent magnets in the magnetization direction may be set longer than the length of the outer permanent magnet in the magnetization direction.

  The inner permanent magnet closer to the rotor tends to have a larger demagnetization amount than the outer permanent magnet, and therefore a demagnetization phenomenon is likely to occur in the inner permanent magnet. In this respect, according to the present configuration, the length of the inner permanent magnet in the magnetization direction is longer than the length of the outer permanent magnet in the magnetization direction, so that the coercivity of the inner permanent magnet is higher than the coercivity of the outer permanent magnet. It has become. Thereby, the demagnetization phenomenon which is easy to occur with the inner permanent magnet can be suppressed. Therefore, torque can be improved.

  The rotating electrical machine includes a pressure receiving member that is provided on a radially outer side of the rotor than the bridge and is pressed from the pair of outer slot side wall surfaces, and the pressure receiving member is nonmagnetic and has higher strength than the stator core. It should be composed of a body.

  According to this configuration, the bridge and the pressure receiving member are dispersed and receive stress. As a result, the stress applied to the bridge can be reduced. In particular, since the pressure receiving member is disposed on the outer side in the radial direction of the rotor than the bridge, the stress is preferentially applied to the pressure receiving member rather than the bridge. In this case, since the pressure receiving member is made of a material having higher strength than the stator core, it is difficult to break. Thereby, the stress applied to both permanent magnets can be reduced while the stress applied to the bridge is reduced.

  Moreover, since the pressure receiving member is made of a non-magnetic material, it is possible to suppress the formation of a short circuit magnetic path through the pressure receiving member. Thereby, the fall of the torque resulting from the short circuit magnetic path via a pressure receiving member can be suppressed.

  In the rotating electrical machine, the pressure receiving member may be disposed on the outermost periphery of the outer magnet slot, and the outer permanent magnet may be disposed between the bridge and the pressure receiving member.

  According to such a configuration, it is possible to avoid the outer magnet slot being divided into two storage chambers by the pressure receiving member. Thereby, the complication of the structure which divides | segments an outer side permanent magnet into two and accommodates in each storage chamber can be suppressed.

  Further, the outermost periphery of the outer magnet slot is a portion that hardly contributes to the torque of the rotating electrical machine as compared with the inner periphery. For this reason, even if a pressure receiving member is disposed on the outermost periphery of the outer magnet slot instead of the outer permanent magnet, the amount of torque reduction can be small. Therefore, it is possible to suppress a decrease in torque, which is a disadvantage caused by providing the pressure receiving member.

  In the rotating electric machine, the pair of outer slot side wall surfaces are paired with a pair of first side wall surfaces facing each other and a pair of first side wall surfaces spaced apart from each other in a direction away from the pair of first side wall surfaces. And the pressure receiving member is in contact with or opposed to a pair of step surfaces formed between the pair of first side wall surfaces and the pair of second side wall surfaces. It is good to fit between the pair of second side wall surfaces.

  According to such a configuration, the movement of the pressure receiving member is regulated by the step surface. Thereby, the position shift of a pressure receiving member can be suppressed. Further, when the pressure receiving member is pressed by vibration or the like, the stepped surface receives the pressing force from the pressure receiving member, so that the pressing force can be suppressed from being applied to the outer permanent magnet.

  With respect to the rotating electrical machine, the inner permanent magnet has an inner facing surface that faces the rotor, and the inner facing surface is linear when viewed from the axial direction of the rotor, and is more than the tip end surface of the teeth. It is good to arrange | position at the radial direction outer side of a rotor.

According to this configuration, the inner permanent magnet can be easily manufactured as compared with the configuration in which the inner facing surface is curved. Moreover, it can suppress that an inner side permanent magnet collides with a rotor.
In the rotating electrical machine, the outer permanent magnet has an outer facing surface that faces the inner peripheral surface of the housing, and the outer facing surface is linear when viewed from the axial direction of the rotor, and the outer magnet It is good to arrange | position on the radial direction inner side of the said rotor on the same plane as the opening end of the slot for use, or it.

  According to such a configuration, it is possible to suppress the outer permanent magnet from preferentially contacting the inner peripheral surface of the housing, and therefore it is possible to suppress stress from being directly applied to the outer permanent magnet. Thereby, it can suppress that an excessive stress is provided to an outer side permanent magnet. Further, the outer permanent magnet can be easily manufactured as compared with the configuration in which the outer facing surface is curved.

About the said rotary electric machine, the said bridge | bridging is good to be provided in the said teeth.
According to such a configuration, the stress applied to the stator core by being pressed from the housing is more preferentially applied to the core tube portion than the configuration in which the bridge is provided in the core tube portion. Thereby, the stress given to a bridge can be reduced. Therefore, for example, since the bridge can be made thinner and the space for the slots for both magnets can be increased, the size of both permanent magnets can be increased.

In the rotating electrical machine, a depth from the core outer peripheral surface in the outer magnet slot may be larger than a depth from the teeth front end surface in the inner magnet slot.
According to this configuration, the bridge is disposed radially inward as compared with the configuration in which the depth of the outer magnet slot is equal to or less than the depth of the inner magnet slot. Thereby, the stress given to a bridge can be reduced more.

With respect to the rotating electrical machine, the bridge may have a linear shape extending in a direction intersecting with the radial direction of the rotor as viewed from the axial direction of the rotor.
According to such a configuration, the bridge can be formed relatively easily because the processing of the bridge is easier compared to the configuration in which the bridge is curved. Moreover, since a dead space is not easily generated between the bridge and both permanent magnets, it is possible to suppress a decrease in torque due to the dead space.

About the said rotary electric machine, the said inner side permanent magnet is good to be comprised with the material whose coercive force is stronger than the said outer side permanent magnet.
The inner permanent magnet closer to the rotor tends to have a larger demagnetization amount than the outer permanent magnet, and therefore a demagnetization phenomenon is likely to occur in the inner permanent magnet. In this respect, according to this configuration, the inner permanent magnet is made of a material having a stronger coercive force than the outer permanent magnet, and therefore the coercive force of the inner permanent magnet is higher than the coercive force of the outer permanent magnet. Yes. Thereby, the demagnetization phenomenon which is easy to occur with the inner permanent magnet can be suppressed. Therefore, torque can be improved.

  According to the present invention, it is possible to reduce the stress applied to the permanent magnet while suppressing a decrease in torque.

Sectional drawing which shows typically the outline | summary of the electric compressor as a rotary electric machine. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. FIG. 3 is a partially enlarged view of FIG. 2. Sectional drawing which expands and shows the periphery of an inner side permanent magnet and a groove | channel. Sectional drawing which expands and shows the periphery of an outer permanent magnet and a housing. Sectional drawing which expands and shows a groove | channel and its periphery. Sectional drawing which expands and shows the front end side of teeth. The partially expanded view which shows the cross-section of the teeth of 2nd Embodiment. The partially expanded view which shows the cross-section of the slot for outer magnets of 3rd Embodiment. The partially expanded view which shows the cross-section of the slot for outer magnets of 4th Embodiment. Sectional drawing which shows the groove | channel of another example. Sectional drawing which shows the groove | channel of another example. Sectional drawing which shows the groove | channel of another example. Sectional drawing which shows the inner side opposing surface of another example. Sectional drawing which shows the outer side opposing surface of another example. Sectional drawing which shows the support part of another example. Sectional drawing which shows the support part of another example.

(First embodiment)
Hereinafter, a first embodiment of a rotating electrical machine will be described. In this embodiment, the rotating electrical machine is an electric compressor that compresses fluid. Moreover, in this embodiment, an electric compressor is mounted, for example in a vehicle, and is used for a vehicle-mounted air conditioner. That is, the fluid to be compressed by the electric compressor in the present embodiment is a refrigerant. 2 to 7 and the like, for convenience of illustration, one of the radial directions R of the rotor 30 that coincides with the vertical direction of the drawing is shown as an example.

  As shown in FIG. 1, the electric compressor 10 includes a housing 11 in which an inlet 11 a into which refrigerant is sucked from an external refrigerant circuit constituting an in-vehicle air conditioner is formed, and a compression unit 12 accommodated in the housing 11, A rotating shaft 13 and an electric motor 14 are provided.

  The housing 11 is formed with a suction port 11a and has a bottomed cylindrical suction housing 21 opened on one side, and a discharge housing 22 formed with a discharge port 11b through which refrigerant is discharged. . The discharge housing 22 is connected to the suction housing 21 in a state where the opening portion of the suction housing 21 is closed. The suction housing 21 has a bottom wall portion 21a and a side wall portion 21b standing from the outer peripheral edge of the bottom wall portion 21a. The suction port 11 a is formed in a portion near the bottom wall portion 21 a in the side wall portion 21 b of the suction housing 21. The discharge port 11b is connected to an external refrigerant circuit.

  The housing 11 has a cylindrical shape (in detail, a cylindrical shape) as a whole and has an inner peripheral surface 11c. In the present embodiment, the inner peripheral surface 11 c of the housing 11 is circular when viewed from the axial direction of the housing 11.

  In the housing 11, the compression part 12 is arrange | positioned rather than the inlet 11a at the discharge outlet 11b side. The compressor 12 compresses the refrigerant sucked into the housing 11 from the suction port 11a by rotating the rotating shaft 13, and discharges the compressed refrigerant from the discharge port 11b. In addition, the specific structure of the compression part 12 is arbitrary, such as a scroll type, a piston type, and a vane type.

  As shown in FIG. 1, the rotary shaft 13 is supported so as to be rotatable with respect to the housing 11 in a state where one end thereof is connected to the compression portion 12. The axial direction of the rotating shaft 13 coincides with the axial direction of the cylindrical housing 11.

  The electric motor 14 is disposed in the housing 11 closer to the suction port 11 a than the compression unit 12. The electric motor 14 rotates the rotating shaft 13. The electric motor 14 of this embodiment is a reluctance motor, for example.

  As shown in FIG. 1, the electric compressor 10 includes an inverter 23 as a drive circuit that drives the electric motor 14. The inverter 23 is housed in a cylindrical cover member 24 attached to the housing 11, specifically, the bottom wall portion 21 a of the suction housing 21. The electric motor 14 (specifically, the multi-phase armature windings 42u, 42v, 42w) and the inverter 23 are electrically connected.

  Incidentally, in this embodiment, the compression part 12, the electric motor 14, and the inverter 23 are arranged in a line. However, the configuration is not limited to this, and the inverter 23 may be attached to the side wall portion 21 b of the suction housing 21.

Next, the structure of the electric motor 14 of this embodiment will be described in detail.
As shown in FIGS. 1 and 2, the electric motor 14 includes a rotor 30 and a stator 40 that is provided outside the rotor 30 in the radial direction R of the rotor 30 and is fixed to the housing 11.

  The rotor 30 is fixed to the rotating shaft 13 with the rotating shaft 13 inserted therethrough, and rotates integrally with the rotating shaft 13. The rotor 30 is configured by laminating a plurality of electromagnetic steel plates.

  The rotor 30 has a structure having saliency. Specifically, as shown in FIG. 2, the rotor 30 includes a cylindrical rotor base portion 31 and a plurality of salient pole portions 32 protruding from the outer peripheral surface of the rotor base portion 31. The plurality of salient pole portions 32 are arranged at a predetermined interval in the circumferential direction C of the rotor 30.

  As shown in FIGS. 2 and 3, the front end surface 32 a of each salient pole portion 32 is convex toward the outside in the radial direction R of the rotor 30. The tip end surface 32 a of each salient pole portion 32 is disposed on the same circumferential surface when viewed from the axial direction Z of the rotor 30. Specifically, assuming that the circumferential surface having a predetermined diameter from the center line of the rotor 30 is the virtual rotor outer circumferential surface Sx1 (see FIG. 3), the tip surface 32a of each salient pole portion 32 is on the virtual rotor outer circumferential surface Sx1. Is arranged. Note that the circumferential direction C of the rotor 30 can be said to be the circumferential direction of the rotor base portion 31 or the arrangement direction of the salient pole portions 32, or the rotational direction of the rotor 30 or the rotating shaft 13.

  The stator 40 includes a stator core 41 provided outside the rotor 30 in the radial direction R with respect to the rotor 30, a plurality of armature windings 42u, 42v, 42w wound around the stator core 41, permanent magnets 62, 72.

  The stator core 41 is a core cylinder portion 51 having a core outer peripheral surface 51 a that is in contact with an inner peripheral surface 11 c of the housing 11 (specifically, the side wall portion 21 b of the suction housing 21), and an inner peripheral surface of the core cylinder portion 51. A plurality of teeth 52 projecting inward from the core inner circumferential surface 51 b (specifically, in the radial direction R of the rotor 30) and arranged in the circumferential direction of the rotor 30 are provided.

  The core cylinder portion 51 has a cylindrical shape (in detail, a cylindrical shape) formed slightly smaller than the side wall portion 21 b of the housing 11. The core outer peripheral surface 51 a is circular when viewed from the axial direction Z of the rotor 30, and the diameter thereof is set to be the same as the diameter of the inner peripheral surface 11 c of the housing 11.

  In this embodiment, the rotating shaft 13, the rotor 30, and the core cylinder part 51 are arrange | positioned on the same axis line. The axial direction Z, the radial direction R, and the circumferential direction C of the rotor 30 can be said to be the axial direction, the radial direction, and the circumferential direction of the rotating shaft 13, and both the axial direction, the radial direction, and the circumferential direction of the stator 40 (core cylindrical portion 51). I can say that.

  Here, the stator core 41 is fitted in the housing 11. Specifically, the core cylinder portion 51 is fitted into the side wall portion 21 b of the suction housing 21 with the core outer peripheral surface 51 a and the inner peripheral surface 11 c of the housing 11 in contact with each other. For this reason, the core outer peripheral surface 51 a is pressed from the inner peripheral surface 11 c of the housing 11. That is, the stator core 41 is pressed from the housing 11 (specifically, the side wall portion 21 b of the suction housing 21) via a contact portion between the core outer peripheral surface 51 a and the inner peripheral surface 11 c of the housing 11. Therefore, stress is applied to the stator core 41.

  As a specific method for fitting the stator core 41 into the housing 11, for example, the stator core 41 is inserted into the suction housing 21 that has been thermally expanded by heating in advance, and then the suction housing 21 is cooled. A so-called shrink fitting technique is possible. As a result, the stator core 41 is fixed to the suction housing 21 by heat shrinkage accompanying cooling of the suction housing 21. However, the specific method for fitting the stator core 41 into the housing 11 is not limited to shrink fitting and is arbitrary.

  Each of the teeth 52 extends in the axial direction Z, and a cross section in a direction orthogonal to the extending direction is substantially fan-shaped. Each tooth 52 has a tapered shape formed such that the length in the circumferential direction C gradually decreases as it goes inward in the radial direction R.

  Each of the teeth 52 is opposed to the rotor 30 and has a pair of teeth wound around one of the teeth tip surface 53 extending in the circumferential direction C and the plurality of armature windings 42u, 42v, 42w. Side surfaces 54 and 55.

The tooth front end surface 53 is arcuate when viewed from the axial direction Z, and the diameter thereof is set to be larger than the virtual rotor outer peripheral surface Sx1.
As shown in FIG. 2, the pair of tooth side surfaces 54 and 55 are both end surfaces in the circumferential direction C of the tooth 52 and extend in the radial direction R. A plurality of armature windings 42u, 42v, 42v, 42v of a plurality of phases are formed by two teeth side surfaces (specifically, first tooth side surface 54 and second tooth side surface 55) facing each other in two adjacent teeth 52 and a core inner peripheral surface 51b. A winding slot 56 for accommodating 42w is formed. A plurality of winding slots 56 are arranged in the circumferential direction C.

  The multiple-phase armature windings 42u, 42v, 42w are wound around the teeth 52 by concentrated winding. Specifically, a one-phase armature winding is wound around one tooth 52, and a two-phase armature winding is accommodated in one winding slot 56. The multi-phase armature windings 42 u, 42 v, 42 w are Y-connected or delta-connected, and are electrically connected to the inverter 23.

  As shown in FIG. 3, the stator core 41 partitions the inner magnet slot 61 in which the inner permanent magnet 62 is accommodated, the outer magnet slot 71 in which the outer permanent magnet 72 is accommodated, and both the magnet slots 61, 71. And a bridge (partition wall) 80. Both magnet slots 61 and 71 are opposed to each other via a bridge 80.

  As shown in FIGS. 3 and 4, the inner magnet slot 61 is recessed from the tooth tip surface 53. Specifically, the inner magnet slot 61 has a groove shape that is recessed outwardly in the radial direction R from the tooth tip surface 53 and extends in the axial direction Z. The inner magnet slot 61 is opened toward the inside in the radial direction R. An inner magnet slot 61 is formed in each tooth 52. For this reason, the winding slots 56 and the inner magnet slots 61 are alternately arranged in the circumferential direction C.

  The outer magnet slot 71 is disposed on the outer side in the radial direction R with respect to the inner magnet slot 61. The outer magnet slot 71 is recessed from the core outer peripheral surface 51a. Specifically, the outer magnet slot 71 has a groove shape that is recessed inward in the radial direction R from the core outer peripheral surface 51 a and extends in the axial direction Z. The outer magnet slot 71 is opened outward in the radial direction R.

  As shown in FIG. 3, in the present embodiment, the magnet slots 61 and 71 are formed at positions passing through the center line M of the teeth 52 when viewed from the axial direction Z. Both the magnet slots 61 and 71 are recessed along the center line M of the tooth 52. The depth directions of the magnet slots 61 and 71 coincide with the direction along the center line M of the teeth 52. For this reason, the teeth 52 are symmetrical with respect to the center line M.

Next, the bridge 80, the magnet slots 61 and 71, and the permanent magnets 62 and 72 will be described in detail with reference to FIGS.
As shown in FIG. 3, the bridge 80 has a linear shape extending in a direction intersecting (in detail, orthogonal to) the radial direction R. The bridge 80 has an inner bridge surface 80 a that constitutes the bottom surface of the inner magnet slot 61 and an outer bridge surface 80 b that constitutes the bottom surface of the outer magnet slot 71. The outer bridge surface 80b is disposed on the opposite side to the inner bridge surface 80a, and both face each other.

  In the present embodiment, the bridge 80 is provided not on the core cylinder portion 51 but on the teeth 52. Specifically, the bridge 80 is disposed closer to the tooth tip surface 53 than the core inner peripheral surface 51 b of the tooth 52.

  Here, the distance between the bridge surfaces 80a and 80b is defined as a bridge thickness D1. The bridge thickness D1 is a length in a direction orthogonal to both the opposing direction of the magnet slots 61 and 71 in the bridge 80 and the axial direction Z. The bridge thickness D1 is set to be smaller than the thickness (length in the radial direction R) D2 of the core cylinder portion 51.

  As shown in FIGS. 3 and 4, the inner magnet slot 61 is defined by an inner bridge surface 80a and a pair of inner slot side wall surfaces 61a and 61b formed on the stator core 41 (specifically, the teeth 52). Yes. The pair of inner slot side wall surfaces 61 a and 61 b are disposed between the pair of teeth side surfaces 54 and 55. The pair of inner slot side wall surfaces 61a and 61b are opposed to each other, and in the present embodiment, the opposing direction is the opposing direction of the magnet slots 61 and 71 (in other words, the direction along the center line M of the teeth 52). ) And the axial direction Z. The pair of inner slot side wall surfaces 61 a and 61 b are continuous with both ends of the inner bridge surface 80 a when viewed in the axial direction Z, and are continuous with the tooth tip surface 53.

  Incidentally, the tooth front end surface 53 is configured by a pair of front end curved surfaces 53a and 53b extending in the circumferential direction C and continuing to both the tooth side surfaces 54 and 55 and the inner slot side wall surfaces 61a and 61b. The pair of tip curved surfaces 53 a and 53 b are provided on both sides in the circumferential direction C of the inner magnet slot 61. The first tip curved surface 53a is continuous with the first tooth side surface 54 and the first inner slot side wall surface 61a facing each other, and the second tip curved surface 53b is the second tooth side surface facing each other. 55 and the second inner slot side wall surface 61b. In the present embodiment, the pair of distal curved surfaces 53 a and 53 b are symmetrical with respect to the center line M of the tooth 52.

  The inner permanent magnet 62 is fixed to the stator core 41 while being accommodated in the inner magnet slot 61. Note that a specific method for fixing the inner permanent magnet 62 to the stator core 41 is arbitrary, but for example, an adhesive or the like can be used.

  The inner permanent magnet 62 is formed corresponding to the shape of the inner magnet slot 61 and occupies almost the entire space of the inner magnet slot 61. The inner permanent magnet 62 has a rectangular parallelepiped shape as a whole. The inner permanent magnet 62 is disposed on the opposite side of the inner magnet bottom surface 63 and is in contact with or opposed to the inner bridge surface 80 a and faces the rotor 30. An inner facing surface 64 and a pair of inner magnet side surfaces 65 and 66 that abut or face the pair of inner slot side wall surfaces 61a and 61b. Note that the abutting includes a configuration abutting via an adhesive or the like.

  One of the pair of inner magnet side surfaces 65 and 66 is an N pole, and the other is an S pole. That is, the inner permanent magnet 62 is arranged so that the magnetization direction of the inner permanent magnet 62 intersects (specifically, orthogonal) with the radial direction R. The magnetization direction of the inner permanent magnet 62 coincides with the opposing direction of the pair of inner slot side wall surfaces 61a and 61b.

As shown in FIG. 4, the inner facing surface 64 is formed in a straight line when viewed from the axial direction Z. Specifically, the inner facing surface 64 is a plane orthogonal to the center line M of the tooth 52.
The inner facing surface 64 is disposed on the outer side in the radial direction R than the tooth tip surface 53. Specifically, the inner facing surface 64 is disposed slightly closer to the inner bridge surface 80a than the inner peripheral ends that are continuous with the distal curved surfaces 53a, 53b in the pair of inner slot side wall surfaces 61a, 61b. That is, the inner facing surface 64 is disposed at a position where a step surface 67 is formed between the inner facing surface 64 and the tooth tip surface 53 (specifically, the tip curved surfaces 53a and 53b).

  Here, the same peripheral surface as the tooth front end surface 53 extending in the circumferential direction C is defined as a virtual stator inner peripheral surface Sx2. Virtual stator inner circumferential surface Sx2 is a circumferential surface having the same curvature as that of teeth tip surface 53. In this case, the inner facing surface 64 is disposed at a position in contact with the virtual stator inner circumferential surface Sx2.

  As shown in FIGS. 3 to 5, the outer magnet slot 71 is defined by an outer bridge surface 80 b and a pair of outer slot side wall surfaces 71 a and 71 b formed in the stator core 41. The pair of outer slot side wall surfaces 71a and 71b are opposed to each other. In this embodiment, the facing direction of both is the same as the facing direction of the pair of inner slot side wall surfaces 61a and 61b. The pair of outer slot side wall surfaces 71a and 71b extends from the vicinity of both ends of the outer bridge surface 80b when viewed from the axial direction Z, and is continuous with the core outer peripheral surface 51a.

  The outer permanent magnet 72 is fixed to the stator core 41 while being accommodated in the outer magnet slot 71. A specific method for fixing the outer permanent magnet 72 to the stator core 41 is arbitrary, but it is conceivable to use an adhesive or the like, for example.

  In the present embodiment, the inner permanent magnet 62 and the outer permanent magnet 72 are made of the same material. In addition, although the material which comprises both the permanent magnets 62 and 72 is arbitrary, it is a neodymium alloy etc., for example.

  The outer permanent magnet 72 is formed corresponding to the shape of the outer magnet slot 71 and occupies almost the entire space of the outer magnet slot 71. The outer permanent magnet 72 has a rectangular parallelepiped shape as a whole, and is disposed on the opposite side of the outer magnet bottom surface 73 that is in contact with the outer bridge surface 80 b and the outer magnet bottom surface 73, and the inner peripheral surface 11 c of the housing 11. And a pair of outer magnet side surfaces 75 and 76 in contact with or facing the pair of outer slot side wall surfaces 71a and 71b. Note that the abutting includes a configuration abutting via an adhesive or the like.

  Incidentally, the outer permanent magnet 72 is arranged so that the magnetization direction of the outer permanent magnet 72 intersects (in detail, orthogonal) with the radial direction R. The magnetization direction of the outer permanent magnet 72 coincides with the opposing direction of the pair of outer slot side wall surfaces 71a and 71b.

  The magnetization direction of the outer permanent magnet 72 and the magnetization direction of the inner permanent magnet 62 are the same. Specifically, for example, when the first inner magnet side surface 65 is an N pole and the second inner magnet side surface 66 is an S pole, the first outer magnet side surface 75 is an N pole, and the second outer magnet side surface 76. Is the S pole.

As shown in FIG. 5, the outer facing surface 74 is formed in a straight line when viewed from the axial direction Z. Specifically, the outer facing surface 74 is a plane orthogonal to the center line M of the tooth 52.
The outer facing surface 74 is preferably arranged on the same plane as the opening end 71c of the outer magnet slot 71 or on the inner side in the radial direction R, and in this embodiment, is the same as the opening end 71c of the outer magnet slot 71. It is arranged on a plane. The opening end 71c of the outer magnet slot 71 is a corner end between the pair of outer slot side wall surfaces 71a and 71b and the core outer peripheral surface 51a. For this reason, a gap A <b> 1 is formed between the outer facing surface 74 and the inner peripheral surface 11 c of the housing 11. In other words, the outer facing surface 74 is configured such that a gap A <b> 1 is formed between the outer facing surface 74 and the inner peripheral surface 11 c of the housing 11.

  The pair of outer slot side wall surfaces 71 a and 71 b of the present embodiment are formed across the core tube portion 51 and the teeth 52. That is, in the present embodiment, the outer magnet slot 71 passes through the core cylinder portion 51 and reaches the teeth 52.

  As shown in FIG. 3, the depth Dp1 of the inner magnet slot 61 from the tooth tip surface 53 is different from the depth Dp2 of the outer magnet slot 71 from the core outer peripheral surface 51a. Specifically, the depth Dp2 of the outer magnet slot 71 is set to be greater than the depth Dp1 of the inner magnet slot 61.

  Correspondingly, the height H2 of the outer permanent magnet 72 is larger than the height H1 of the inner permanent magnet 62. The height H2 of the outer permanent magnet 72 is the length in the depth direction of the outer magnet slot 71 in the outer permanent magnet 72. In the present embodiment, the height H2 of the outer permanent magnet 72 is the same as the depth Dp2 of the outer magnet slot 71.

  Similarly, the height H <b> 1 of the inner permanent magnet 62 is the length in the depth direction of the inner magnet slot 61 in the inner permanent magnet 62. In the present embodiment, the height H1 of the inner permanent magnet 62 is slightly smaller (specifically, equivalent to the step surface 67) than the depth Dp1 of the inner magnet slot 61.

  As shown in FIG. 4, in this embodiment, a pair of inner side slot side wall surfaces 61a and 61b are parallel. For this reason, when the opposing distance between the pair of inner slot side wall surfaces 61a and 61b is the inner magnet slot width La1, the inner magnet slot width La1 is constant regardless of the location. The inner magnet slot width La1 is the length of the inner magnet slot 61 in a direction orthogonal to both the axial direction Z and the depth direction of the inner magnet slot 61.

  Similarly, the pair of outer slot side wall surfaces 71a and 71b are parallel. Therefore, when the opposing distance between the pair of outer slot side wall surfaces 71a and 71b is the outer magnet slot width La2, the outer magnet slot width La2 is constant regardless of the place. The outer magnet slot width La2 is the length of the outer magnet slot 71 in the direction orthogonal to both the axial direction Z and the depth direction of the outer magnet slot 71.

  In this configuration, the inner magnet slot width La1 is set larger than the outer magnet slot width La2. Correspondingly, the inner permanent magnet width Lb1 is set larger than the outer permanent magnet width Lb2.

  The inner permanent magnet width Lb1 is the length of the inner permanent magnet 62 in the magnetization direction, and specifically the length of the inner permanent magnet 62 in the opposing direction of the pair of inner slot side wall surfaces 61a and 61b. In other words, the inner permanent magnet width Lb1 is the facing distance between the pair of inner magnet side surfaces 65, 66.

  Similarly, the outer permanent magnet width Lb2 is the length of the outer permanent magnet 72 in the magnetization direction, and specifically the length of the outer permanent magnet 72 in the opposing direction of the pair of outer slot side wall surfaces 71a and 71b. In other words, the outer permanent magnet width Lb <b> 2 is a facing distance between the pair of outer magnet side surfaces 75 and 76.

  In the present embodiment, the inner magnet slot width La1 and the inner permanent magnet width Lb1 are the same, and the outer magnet slot width La2 and the outer permanent magnet width Lb2 are the same. However, the present invention is not limited to this, and both may be slightly different.

  In addition, the pair of inner slot side wall surfaces 61a and 61b and the pair of outer slot side wall surfaces 71a and 71b of the present embodiment are surfaces parallel to the axial direction Z and along the center line M of the teeth 52. However, the center line M of the teeth 52 may be crossed.

  As shown in FIG. 2, a plurality of inner permanent magnets 62 are arranged in the circumferential direction C in correspondence with the inner magnet slots 61 being arranged in the circumferential direction C via the winding slots 56. ing. The inner permanent magnets 62 are accommodated in the inner magnet slots 61 in a state where adjacent ones in the circumferential direction C face each other with the same magnetic pole. That is, each inner permanent magnet 62 is arranged such that the magnetic poles are arranged in the circumferential direction C as N, S, S, N, N, S,.

  Similarly, a plurality of outer permanent magnets 72 are arranged in the circumferential direction C. The magnetic pole (magnetization direction) of each outer permanent magnet 72 is the same as the magnetic pole of the inner permanent magnet 62 arranged inside the radial direction R of each outer permanent magnet 72.

  Here, as indicated by an arrow A in FIG. 3, stress is applied to the stator core 41 from the housing 11 toward the inside in the radial direction R. For this reason, diagonal stress is applied to both ends of the bridge 80 on the pair of teeth side surfaces 54 and 55 side. Specifically, the corner portion between the outer bridge surface 80b and the pair of outer slot side wall surfaces 71a and 71b has a component in a direction perpendicular to the pair of outer slot side wall surfaces 71a and 71b. Stress including a component in a direction in which 71a and 71b approach each other is applied. Thereby, local stress concentration may occur in the corner portion.

On the other hand, the stator core 41 of this embodiment has a configuration for suppressing the stress concentration. The configuration will be described below.
As shown in FIGS. 3 and 4, a groove 90 extending in the axial direction Z is formed between the pair of outer slot side wall surfaces 71a and 71b and the outer bridge surface 80b (specifically, a corner portion). . The grooves 90 are formed both between the first outer slot side wall surface 71a and the outer bridge surface 80b and between the second outer slot side wall surface 71b and the outer bridge surface 80b, and form a pair. .

  As shown in FIG. 6, the pair of grooves 90 are recessed with respect to the pair of outer slot side wall surfaces 71 a and 71 b, and in detail, are recessed in a direction orthogonal to the radial direction R. Both grooves 90 are open toward the outer permanent magnet 72. In other words, the groove 90 has an opening 90 a that opens toward the outer magnet slot 71. The two openings 90a of the pair of grooves 90 are opposed to each other, and a part of the outer permanent magnet 72 is present between the two openings 90a arranged to face each other. That is, a part of the outer permanent magnet 72 is opposed to the opening 90 a of the groove 90.

  For convenience of explanation, in the following explanation, the direction in which the groove 90 is recessed, specifically, the direction perpendicular to the pair of outer slot side wall surfaces 71a and 71b is defined as the depth direction of the groove 90, and the axial direction Z and The direction orthogonal to both the depth directions of the groove 90 is defined as the width direction of the groove 90. The width direction of the groove 90 is a direction in which the outer bridge surface 80 b and the outer magnet bottom surface 73 are opposed to each other.

  Both grooves 90 are the same except that they are symmetric with respect to the center line M of the teeth 52. For this reason, for convenience of explanation, in the following explanation, the groove 90 formed between the first outer slot side wall surface 71a and the outer bridge surface 80b will be described in detail.

  As shown in FIG. 6, the groove 90 of the present embodiment suppresses a reduction in the area in which the first outer magnet side surface 75 and the first outer slot side wall surface 71 a abut or face each other due to the groove 90. However, the stress concentration can be suppressed. Specifically, the groove 90 includes an inner groove surface 91 that is continuous with the outer bridge surface 80 b, and an outer groove surface 92 that is disposed outside the inner groove surface 91 in the radial direction R.

  The inner groove surface 91 has an inner curved surface 91a that is curved outward in the radial direction R as it is away from the outer bridge surface 80b when viewed from the axial direction Z. It can be said that the inner curved surface 91a is curved so as to be arranged on the outer side in the radial direction R as it is away from the first outer magnet side surface 75.

  The outer groove surface 92 faces the inner groove surface 91 and is continuous with both the inner groove surface 91 and the first outer slot side wall surface 71a. Specifically, the outer groove surface 92 has a first end 92a continuous with the inner groove surface 91 and a second end 92b continuous with the first outer slot side wall surface 71a.

  The outer groove surface 92 includes an outer curved surface 92c that is curved such that the width Dh of the groove 90 gradually decreases from the first end 92a side toward the second end 92b side. The outer curved surface 92c is curved so as to move away from the inner groove surface 91 as it goes from the second end 92b to the first end 92a, for example. As a result, the groove 90 is narrow in the vicinity of the opening and becomes wider as the distance from the outer permanent magnet 72 increases. The opening width Dhx of the groove 90 is set smaller than the maximum width Dhm of the groove 90. The opening width Dhx of the groove 90 is the length of the opening 90a in the width direction of the groove 90 (opposite direction between the outer bridge surface 80b and the outer magnet bottom surface 73).

  According to such a configuration, the groove 90 suppresses local stress concentration in the vicinity of the corner between the outer bridge surface 80b and the first outer slot side wall surface 71a. Specifically, when a stress in an oblique direction is applied near the corner, the stress is easily applied to the inner curved surface 91 a of the inner groove surface 91. Since the inner curved surface 91a is curved, the stress is dispersed.

  Further, since the opening width Dhx of the groove 90 is reduced by the outer curved surface 92c, the contact area between the first outer slot side wall surface 71a and the first outer magnet side surface 75 resulting from the formation of the groove 90 or The amount of decrease in the facing area is reduced.

  Here, as shown in FIG. 7, since the groove 90 is recessed from the first outer slot side wall surface 71 a, a portion corresponding to the groove 90 in the tooth 52, specifically, the groove 90 and the first tooth in the tooth 52. The portion existing between the side surface 54 is narrowed by the amount of the groove 90. The magnetic flux generated by the outer permanent magnet 72 and the inner permanent magnet 62 penetrates the teeth 52 in the radial direction R. For this reason, depending on the shape (specifically, depth) of the groove 90, the magnetic flux penetrating the teeth 52 can be inhibited by the groove 90.

On the other hand, in the present embodiment, the groove 90 is configured so that the influence on the magnetic flux penetrating the teeth 52 is suppressed.
Specifically, as shown in FIG. 7, the length in the circumferential direction C of the first tip curved surface 53a is defined as the tip circumferential direction length Lx1. Further, when viewed from the axial direction Z, the straight line connecting the first tooth side surface 54 and the first inner slot side wall surface 61a facing each other, orthogonal to the first tooth side surface 54 and on the first tip curved surface 53a. The length of the tangent line in contact is the tip tangent length Lx2.

  In such a configuration, the shortest distance Ly between the first tooth side surface 54 and the groove 90 is set to be longer than the shorter one of the distal circumferential length Lx1 and the distal tangent length Lx2. The shortest distance Ly is the shortest of the perpendiculars perpendicular to the first tooth side surface 54 and reaching the groove 90. Specifically, since the inner groove surface 91 and the outer groove surface 92 in the groove 90 are curved, the length of the perpendicular of the first tooth side surface 54 connecting the groove 90 and the first tooth side surface 54 depends on the location. fluctuate. In this regard, the shortest distance Ly is the minimum value of the length of the perpendicular line connecting the groove 90 and the first tooth side surface 54 that vary depending on the location.

According to this embodiment explained in full detail above, there exist the following effects.
(1) The electric compressor 10 as a rotating electric machine has a rotor 30, a stator core 41, armature windings 42 u, 42 v, 42 w and permanent magnets 62, 72 provided on the outer side in the radial direction R with respect to the rotor 30. A stator 40 and a housing 11 that accommodates the rotor 30 and the stator 40 in a state where the stator core 41 is fixed are provided. The stator core 41 includes a core cylindrical portion 51 having a core outer peripheral surface 51a pressed from the inner peripheral surface 11c of the housing 11, and a tooth 52 protruding inward in the radial direction R from the core inner peripheral surface 51b. . The teeth 52 are wound around the armature windings 42u, 42v, 42w, and a plurality of teeth 52 are arranged in the circumferential direction C.

  In such a configuration, the stator core 41 has an inner magnet slot 61 that is recessed from the tooth tip surface 53, which is the tip surface of each tooth 52, and is disposed on the outer side in the radial direction R with respect to the inner magnet slot 61 and the outer peripheral surface of the core An outer magnet slot 71 recessed from 51a is formed. The stator core 41 includes a bridge 80 that partitions both the magnet slots 61 and 71. The magnet slots 61 and 71 accommodate permanent magnets 62 and 72, respectively.

  According to such a configuration, the magnetic flux generated from the armature windings 42u, 42v, 42w by the current flowing through the armature windings 42u, 42v, 42w interacts with the magnetic fluxes of the permanent magnets 62, 72. The rotor 30 can be rotated.

  Further, the stator core 41 is integrated without being divided into a plurality of parts by a bridge 80 that partitions both the magnet slots 61 and 71. Thereby, the inconvenience caused by dividing the stator core 41 into a plurality of parts can be suppressed.

  More specifically, for example, when the stator core 41 is formed with a magnet slot penetrating both the teeth 52 and the core tube portion 51 in and out, the stator core 41 is divided into a plurality of parts by the magnet slot. Then, since the position shift occurs between the divided parts, the shape of the magnet slot formed between the divided parts is not stable, and the operation of housing the permanent magnet in the magnet slot can be complicated. . Moreover, the operation | work which fits the stator core which consists of a several division | segmentation part in the housing 11 becomes easy to become complicated. On the other hand, in the present embodiment, since the stator core 41 is integrated by the bridge 80, it is possible to suppress complications of the above operations.

  (2) The stator core 41 is pressed from the housing 11 because the stator core 41 is fixed to the housing 11. In this case, the bridge 80 receives stress applied to the permanent magnets 62 and 72. Thereby, the stress given to the permanent magnets 62 and 72 is reduced. That is, the bridge 80 functions to relieve stress applied to the permanent magnets 62 and 72.

  Further, because the outer magnet slot 71 is recessed inward in the radial direction R from the core outer peripheral surface 51a, the bridge 80 that partitions the outer magnet slot 71 and the inner magnet slot 61 is more inward than the core outer peripheral surface 51a. It arrange | positions (radial direction R inner side). As a result, the space occupied by the slots for both magnets 61 and 71 can be increased while ensuring the strength required for the bridge 80.

  More specifically, the bridge 80 needs to have a predetermined strength because of the stress. In this case, the strength of the bridge 80 increases as the bridge thickness D1, which is the distance between the slots 61 and 71 for both magnets, increases. On the other hand, as the bridge thickness D1 is increased, the space occupied by the slots 61 and 71 for both magnets is reduced, and the sizes of the permanent magnets 62 and 72 are likely to be reduced. Then, the magnetic flux generated from both permanent magnets 62 and 72 becomes small, and there is a problem that the torque is lowered. However, if the space occupied by the slots 61 and 71 for both magnets is increased while securing the bridge thickness D1, the outer diameter of the stator core 41 needs to be increased, and the electric compressor 10 becomes larger. easy.

  In contrast, the inventors of the present application have a case where the bridge 80 is disposed on the inner side in the radial direction R from the core outer peripheral surface 51a than when the bridge 80 is provided on the outermost periphery of the stator core 41. It has been found that the stress from the housing 11 is dispersed by the bridge 80 and the core cylinder portion 51, and the stress applied to the bridge 80 is reduced. The case where the bridge 80 is provided on the outermost periphery of the stator core 41 is a case where the bridge 80 is provided so as to be continuous with the core outer peripheral surface 51a.

  Focusing on this knowledge, in the present embodiment, the bridge 80 is arranged on the inner side in the radial direction R from the core outer peripheral surface 51a, so that the bridge 80 is compared with the configuration in which the bridge 80 is formed on the outermost periphery. The stress applied to is reduced. Thereby, since the strength required for the bridge 80 can be reduced, the bridge thickness D1 can be reduced. Therefore, the space occupied by the slots 61 and 71 for both magnets can be expanded, and the size of the permanent magnets 62 and 72 can be increased through the space. Therefore, stress applied to both permanent magnets 62 and 72 can be reduced while suppressing a decrease in torque of the electric compressor 10 (electric motor 14).

  (3) In particular, in the configuration in which the bridge 80 is provided, a part of the magnetic flux generated by the permanent magnets 62 and 72 becomes a short-circuit magnetic flux penetrating the bridge 80. The short-circuit magnetic flux does not contribute to the torque of the electric compressor 10 and tends to increase as the bridge thickness D1 increases. In this respect, according to the present embodiment, the bridge thickness D1 can be reduced as described above, so that the short-circuit magnetic flux can be reduced. Thereby, the fall of the torque resulting from the bridge | bridging 80 can be suppressed.

  That is, in this embodiment, as described above, the bridge 80 is provided to integrate the stator core 41 and reduce the stress applied to the permanent magnets (both permanent magnets 62 and 72) provided on the stator core 41. . For this reason, compared with the case where one permanent magnet is fitted in the magnet slot penetrating both the teeth 52 and the core cylindrical portion 51 in and out, the permanent magnet is easily reduced by the amount of the bridge 80. Since the short-circuit magnetic flux resulting from this occurs, the torque tends to decrease. On the other hand, in the present embodiment, the bridge 80 is provided so as to partition both the magnet slots 61 and 71, so that the bridge 80 is disposed on the inner side in the radial direction R from the core outer peripheral surface 51a. The length D1 can be reduced. Therefore, integration of the stator core 41 and reduction of stress applied to both the permanent magnets 62 and 72 can be achieved while suppressing a decrease in torque.

  (4) The bridge 80 is provided not on the core cylinder portion 51 but on the teeth 52. Thereby, the stress applied to the stator core 41 by being pressed from the housing 11 is more preferentially applied to the core tube portion 51, and the stress applied to the bridge 80 can be reduced. Therefore, the bridge thickness D1 can be further reduced, and the space in the radial direction R of the slots 61 and 71 for both magnets can be increased. Therefore, both permanent magnets 62 and 72 can be enlarged in the radial direction R.

  (5) The depth Dp2 of the outer magnet slot 71 is set to be greater than the depth Dp1 of the inner magnet slot 61. According to this configuration, the bridge 80 is disposed on the inner side in the radial direction R as compared with the configuration in which the depth Dp2 of the outer magnet slot 71 is equal to or less than the depth Dp1 of the inner magnet slot 61. Thereby, the stress applied to the bridge 80 can be further reduced.

  (6) Each tooth 52 has a pair of tooth side surfaces 54 and 55 around which any one of the armature windings 42u, 42v, and 42w is wound. The stator core 41 is provided between the pair of teeth side surfaces 54 and 55, and defines the inner magnet slot 61. The stator core 41 defines the pair of inner slot side wall surfaces 61a and 61b facing each other and the outer magnet slot 71. And a pair of outer slot side wall surfaces 71a and 71b opposed to each other. The bridge 80 includes an inner bridge surface 80a that constitutes the bottom surface of the inner magnet slot 61, and an outer bridge surface 80b that is provided on the opposite side of the inner bridge surface 80a and constitutes the bottom surface of the outer magnet slot 71. ing. That is, the inner magnet slot 61 is partitioned by the inner bridge surface 80a and the pair of inner slot side wall surfaces 61a and 61b, and the outer magnet slot 71 is formed by the outer bridge surface 80b and the pair of outer slot side wall surfaces 71a and 71b. It is divided by.

  In such a configuration, the bridge thickness D1, which is the distance between the bridge surfaces 80a and 80b, is smaller than the thickness D2 of the core cylinder portion 51. Thereby, compared with the structure whose bridge thickness D1 is the same as or more than the thickness D2 of the core cylinder part 51, the slots 61 and 71 for both magnets can be ensured large, and both permanent magnets 62 and 72 can be enlarged. . Therefore, the torque of the electric compressor 10 can be improved.

  (7) A groove 90 extending in the axial direction Z and recessed from the outer slot side wall surfaces 71a and 71b is formed between the pair of outer slot side wall surfaces 71a and 71b and the outer bridge surface 80b. According to such a configuration, the groove 90 can suppress local stress concentration in the vicinity of the corner between the pair of outer slot side wall surfaces 71a and 71b and the outer bridge surface 80b.

  Here, if the groove is recessed with respect to the outer bridge surface 80b, that is, if the groove is recessed inward in the radial direction R, the bridge 80 has a portion where the bridge thickness D1 is locally reduced. As a result, the strength of the bridge 80 decreases.

  On the other hand, in this embodiment, the groove 90 is recessed with respect to the outer slot side wall surfaces 71a and 71b. Thereby, the situation where the location where bridge thickness D1 becomes locally small resulting from groove | channel 90 becomes small can be suppressed. Therefore, local stress concentration can be suppressed while suppressing the strength reduction of the bridge 80.

  (8) The groove 90 has an inner groove surface 91 continuous with the outer bridge surface 80b. The inner groove surface 91 has an inner curved surface 91a that is curved outward in the radial direction R as it is away from the outer bridge surface 80b when viewed in the axial direction Z. According to such a configuration, when stress including a component in a direction in which the outer slot side wall surfaces 71a and 71b approach each other is applied in the vicinity of the corner between the pair of outer slot side wall surfaces 71a and 71b and the outer bridge surface 80b. The inner curved surface 91a is easily subjected to the stress. In this case, since the inner curved surface 91a is curved, the stress can be dispersed. Thereby, local stress concentration can be suppressed.

  (9) The outer permanent magnet 72 has a pair of outer magnet side surfaces 75 and 76 that abut or face the pair of outer slot side wall surfaces 71a and 71b. The groove 90 includes an outer groove surface 92 having a first end 92a continuous with the inner groove surface 91 and a second end 92b continuous with the first outer slot sidewall surface 71a (or the second outer slot sidewall surface 71b). . The outer groove surface 92 includes an outer curved surface 92c that is curved such that the width Dh of the groove 90 gradually decreases from the first end 92a side toward the second end 92b side. According to such a configuration, a decrease in torque due to a decrease in the contact area or the opposed area between the outer slot side wall surfaces 71a and 71b and the outer magnet side surfaces 75 and 76 is suppressed while securing the area of the inner curved surface 91a to some extent. it can.

  More specifically, for example, if the groove 90 has a semicircular shape when viewed from the axial direction Z, the area of the inner curved surface 91a (specifically, the inner curved surface 91a viewed from the axial direction Z) is used in order to distribute stress. When an attempt is made to increase the arc length), the opening width Dhx of the groove 90 also increases, and the contact area or the opposing area decreases. Then, the magnetic flux penetrating the teeth 52 becomes small, and the torque decreases.

  In contrast, in the present embodiment, the outer curved surface 92c can reduce the opening width Dhx of the groove 90 while increasing the area of the inner curved surface 91a. Thereby, the fall of the said contact area or opposing area accompanying enlarging the area of the inner side curved surface 91a can be suppressed. Therefore, both suppression of stress concentration and suppression of torque reduction due to the groove 90 can be achieved.

  (10) The teeth 52 have a tapered shape formed so that the length in the circumferential direction C of the teeth 52 is gradually shortened toward the inside in the radial direction R. The teeth front end surface 53 includes a pair of front end curved surfaces 53 a and 53 b provided on both sides of the inner magnet slot 61. The distal curved surfaces 53a and 53b are continuous with both the tooth side surfaces 54 and 55 and the inner slot side wall surfaces 61a and 61b facing each other, and extend in the circumferential direction C.

  In such a configuration, the shortest distance Ly between the tooth side surfaces 54 and 55 and the groove 90 is the tip tangent length Lx2 and the tip circumferential direction length Lx1 that is the length in the circumferential direction C of the tip curved surfaces 53a and 53b. It is set longer than the shorter one. The tip tangent length Lx2 is a straight line connecting the tooth side surfaces 54, 55 and the inner slot side wall surfaces 61a, 61b facing each other, and is perpendicular to the tooth side surfaces 54, 55 and is in contact with the tip curved surfaces 53a, 53b. Length. According to such a configuration, the portion where the area through which the magnetic flux passes is minimized in the tooth 52 is the tip portion of the tooth 52. As a result, the magnetic flux penetrating through the teeth 52 is limited by the tip portion of the teeth 52, not the portion corresponding to the groove 90. Therefore, the situation in which the magnetic flux decreases due to the groove 90 can be suppressed, and the decrease in torque due to the groove 90 can be suppressed through it.

  (11) The inner permanent magnet 62 has an inner facing surface 64 that faces the rotor 30. The inner facing surface 64 is linear when viewed in the axial direction Z, and is disposed on the outer side in the radial direction R with respect to the tooth tip surface 53. According to this configuration, the inner permanent magnet 62 can be easily manufactured as compared with the configuration in which the inner facing surface 64 is curved. In addition, it is possible to suppress the inner permanent magnet 62 from colliding with the rotor 30 due to the inner facing surface 64 protruding beyond the tooth tip surface 53.

  (12) The inner facing surface 64 is in contact with the virtual rotor outer circumferential surface Sx1 on the same circumferential surface as the tooth tip surface 53. According to this configuration, it is possible to improve the volume of the inner permanent magnet 62 while avoiding a collision between the inner permanent magnet 62 and the rotor 30.

  (13) The outer permanent magnet 72 has an outer facing surface 74 that faces the inner peripheral surface 11 c of the housing 11. The outer facing surface 74 is linear when viewed from the axial direction Z. The outer facing surface 74 is disposed on the same plane as the opening end 71c of the outer magnet slot 71 or on the inner side in the radial direction R. According to such a configuration, it is possible to suppress the outer permanent magnet 72 from preferentially contacting the inner peripheral surface 11 c of the housing 11, and thus it is possible to suppress stress from being directly applied to the outer permanent magnet 72. Thereby, it is possible to suppress application of excessive stress to the outer permanent magnet 72. Further, the outer permanent magnet 72 can be easily manufactured as compared with the configuration in which the outer facing surface 74 is curved.

  (14) The bridge 80 has a linear shape extending in a direction intersecting with the radial direction R (specifically, a direction orthogonal to the radial direction R) when viewed from the axial direction Z. According to such a configuration, the bridge 80 can be formed relatively easily because the processing of the bridge 80 is easier compared to the configuration in which the bridge 80 is curved. In addition, since a dead space is unlikely to be generated between the bridge 80 and both the permanent magnets 62 and 72, a reduction in torque of the electric compressor 10 due to the dead space can be suppressed.

  (15) The inner magnet slot width La1 is set larger than the outer magnet slot width La2. Correspondingly, the inner permanent magnet width Lb1 is set larger than the outer permanent magnet width Lb2. Thereby, since the coercive force of the inner permanent magnet 62 can be increased, the demagnetization phenomenon that is likely to occur in the inner permanent magnet 62 can be suppressed.

  More specifically, a reverse magnetic field is applied to the inner permanent magnet 62 and the outer permanent magnet 72 during driving of the electric motor 14 in which current flows through the multiple-phase armature windings 42u, 42v, 42w. The reverse magnetic field is likely to be larger in the inner permanent magnet 62 having a relatively small distance from the rotor 30 than in the outer permanent magnet 72 having a relatively large distance from the rotor 30. For this reason, the amount of demagnetization tends to increase in the inner permanent magnet 62.

  In contrast, in the present embodiment, the inner permanent magnet width Lb1 that is the length in the magnetization direction of the inner permanent magnet 62 is made larger than the outer permanent magnet width Lb2 that is the length in the magnetization direction of the outer permanent magnet 72. As a result, the coercive force of the inner permanent magnet 62 is increased. Thereby, the amount of demagnetization in the inner permanent magnet 62 can be reduced. Therefore, it is possible to suppress a decrease in torque due to the reverse magnetic field.

  Further, by reducing the outer permanent magnet width Lb2 in which the applied reverse magnetic field is likely to be reduced, the outer permanent magnet 72 can be reduced in size, thereby reducing the cost.

(Second Embodiment)
As shown in FIG. 8, the slot widths La1 and La2 for both magnets of this embodiment are set to be the same, and the corresponding permanent magnet widths Lb1 and Lb2 are also set to be the same.

  In the present embodiment, the materials of the permanent magnets 101 and 102 are different. Specifically, the inner permanent magnet 101 is made of a material having a stronger coercive force than the outer permanent magnet 102. In addition, although the specific material of both the permanent magnets 101 and 102 is arbitrary as long as the coercive force is different, for example, the outer permanent magnet 102 is composed of an alnico magnet, and the inner permanent magnet 101 is composed of a neodymium magnet. It may be the case. Moreover, when both the permanent magnets 101 and 102 are comprised with the neodymium magnet, the composition ratio of both the permanent magnets 101 and 102 may differ.

  In addition, the inner facing surface 103 of the present embodiment is curved so as to protrude outward in the radial direction R, and is disposed on the same circumferential surface as the tooth tip surface 53. The outer facing surface 104 of the present embodiment is curved so as to be convex outward in the radial direction R, and is disposed on the same peripheral surface as the core outer peripheral surface 51a. The outer facing surface 104 is in contact with the inner peripheral surface 11 c of the housing 11.

  As shown in FIG. 8, the bridge 105 according to the present embodiment is not a straight line but a curved line when viewed from the axial direction Z. Specifically, the bridge 105 is curved so as to be convex outward in the radial direction R.

  Correspondingly, the inner permanent magnet 101 has an inner magnet bottom surface 106 opposite to the inner facing surface 103 and an outer permanent magnet 102 has an outer magnet bottom surface 107 opposite to the outer facing surface 104 in the radial direction R. It is curved to be convex toward the outside. In the present embodiment, the groove 90 is omitted.

According to this embodiment explained in full detail above, in addition to the effect of (1)-(6), there exist the following effects.
(16) When viewed from the axial direction Z, the bridge 105 is not linear but curved. According to such a configuration, the stress applied to the bridge 105 is easily dispersed compared to a configuration in which the bridge is linear. Thereby, the bridge 105 can receive stress more suitably.

  In particular, an external force in an oblique direction that is a direction intersecting the thickness direction of the bridge 105 can be applied to the bridge 105. In this case, since the bridge 105 has a curved shape, the pressure receiving surface of the bridge 105 can be brought close to perpendicular to the stress in the oblique direction. Thereby, the stress of the said diagonal direction can be received suitably.

  (17) The inner permanent magnet 101 is made of a material having a stronger coercive force than the outer permanent magnet 102. According to such a configuration, even if both permanent magnet widths Lb1 and Lb2 are set to be the same, the same effect as in (15) can be obtained.

(Third embodiment)
In the present embodiment, the electric compressor 10 includes the outer permanent magnet 110 such that the outer bridge surface 80b and the outer magnet bottom surface 111 arranged to face the outer bridge surface 80b of the outer permanent magnet 110 are at least partially separated from each other. The point which is provided with the support part which supports is different from 1st Embodiment. The support part will be described in detail.

  As shown in FIG. 9, the electric compressor 10 includes a protrusion 112 provided on at least one of the pair of outer slot side wall surfaces 71 a and 71 b in the outer magnet slot 71 as a support portion. In this embodiment, the protrusion 112 is provided on both of the pair of outer slot side wall surfaces 71a and 71b to form a pair. The pair of protrusions 112 protrude in a direction approaching the pair of outer slot side wall surfaces 71a and 71b, and are arranged to face each other in the same direction as the opposing direction of both outer slot side wall surfaces 71a and 71b. However, the pair of protrusions 112 are not in contact with each other, and a gap is formed between them.

  The pair of protrusions 112 are formed at the end portions near the groove 90 (in other words, the bridge 80) in the outer side slot side wall surfaces 71a and 71b. In the present embodiment, it can be said that the groove 90 and the protrusion 112 are provided adjacent to each other in the vicinity of the corner between the outer side slot side wall surfaces 71 a and 71 b and the bridge 80.

The outer magnet slot 71 is partitioned into a first chamber 113 arranged radially outside the protrusion 112 and a second chamber 114 arranged radially inside the protrusion 112.
The outer permanent magnet 110 of this embodiment is accommodated in the first chamber 113. The outer permanent magnet 110 is supported at a position separated from the outer bridge surface 80 b by the contact between the outer magnet bottom surface 111 and the protrusion 112. In this case, the movement of the outer permanent magnet 110 toward the bridge 80 is restricted by the protrusion 112.

  As shown in FIG. 9, the second chamber 114 is a space between the first chamber 113 and the bridge 80 and between the pair of grooves 90. The second chamber 114 is opposed to the opening 90 a of the groove 90. The outer permanent magnet 110 is not present in the second chamber 114. It can be said that the second chamber 114 is a region where the outer permanent magnet 110 formed by separating the outer magnet bottom surface 111 and the outer bridge surface 80b does not exist.

  In the present embodiment, the outer magnet bottom surface 111 and the outer bridge surface 80 b are separated from each other by a distance larger than the opening width Dhx of the groove 90. That is, the protrusion 112 of the present embodiment supports the outer permanent magnet 110 at a position where the outer magnet bottom surface 111 is separated from the outer bridge surface 80b by a distance larger than the opening width Dhx of the groove 90. .

  Correspondingly, the height of the outer permanent magnet 110 of the present embodiment is smaller than the height H2 of the outer permanent magnet 72 of the first embodiment. For this reason, the outer permanent magnet 110 of this embodiment is smaller than the outer permanent magnet 72 of the first embodiment.

  The outer permanent magnet 110 may be attached in any manner in the present embodiment. For example, the outer permanent magnet 110 may be inserted into the outer magnet slot 71 from the outside in the radial direction R or from the axial direction Z. It may be inserted.

  In the present embodiment, the projection thickness D11 that is the length of the projection 112 in the facing direction of the outer magnet bottom surface 111 and the outer bridge surface 80b is smaller than the bridge thickness D1. However, the present invention is not limited to this, and the protrusion thickness D11 may be the same as the bridge thickness D1, or may be larger than the bridge thickness D1.

According to this embodiment explained in full detail above, in addition to the effect of (1)-(15), there exist the following effects.
(18) The electric compressor 10 includes a protrusion 112 as a support portion that supports the outer permanent magnet 110 so that the outer bridge surface 80b and the outer magnet bottom surface 111 are separated from each other. Thereby, size reduction of the outer permanent magnet 110 can be achieved while suppressing a decrease in torque.

  More specifically, since the outer bridge surface 80b and the outer magnet bottom surface 111 are separated from each other, the second chamber 114, which is a region where the outer permanent magnet 110 does not exist, is formed between them. Thereby, the outer permanent magnet 110 can be made small by the second chamber 114, and the amount of the outer permanent magnet 110 to be used can be reduced. Therefore, the cost can be reduced by reducing the number of permanent magnets that are particularly expensive in the electric motor 14.

  Here, at least a part of the second chamber 114 is opposed to the opening 90a of the groove 90 formed between the pair of outer slot side wall surfaces 71a and 71b and the outer bridge surface 80b. A portion of the second chamber 114 facing the opening 90 a of the groove 90 does not contribute to the torque of the electric compressor 10 regardless of the presence or absence of the outer permanent magnet 110. That is, the second chamber 114 includes a portion that does not contribute to torque. Therefore, even when the outer bridge surface 80b and the outer magnet bottom surface 111 are separated from each other, the torque is unlikely to decrease.

  Further, since the outer permanent magnet 110 is supported by the protrusions 112, the outer permanent magnet is arranged so that the outer magnet bottom surface 111 approaches the outer bridge surface 80b even when vibration or the like is applied to the electric compressor 10. 110 is restricted from moving. Thereby, the fall of the torque resulting from the position shift of the outer permanent magnet 110 can be suppressed.

  (19) The protrusion 112 supports the outer permanent magnet 110 at a position where the outer magnet bottom surface 111 is separated from the outer bridge surface 80b by the opening width Dhx of the groove 90 or more. According to such a configuration, the outer permanent magnet 110 can be downsized as compared with a configuration in which a part of the outer permanent magnet 110 is opposed to the opening 90a of the groove 90. Therefore, the usage amount of the outer permanent magnet 110 is reduced. Further reduction can be achieved.

  (20) The protrusion 112 is provided on the pair of outer slot side wall surfaces 71a and 71b. The outer permanent magnet 110 is supported by the outer magnet bottom surface 111 coming into contact with the protrusion 112. According to such a configuration, the protrusion 112 receives a pressing force applied from the outer permanent magnet 110. Accordingly, it is possible to suppress application of excessive stress to the bridge 80 due to the pressing force applied from the outer permanent magnet 110 being applied to the bridge 80.

  More specifically, the outer permanent magnet 110 may be pressed inward in the radial direction R due to vibration or the like. In this case, if the outer permanent magnet 110 is supported by a protruding portion protruding from the bridge 80 or a support member in contact with the bridge 80, the bridge 80 from the outer permanent magnet 110 via the protruding portion and the supporting member. Stress can be applied to the.

  On the other hand, in this embodiment, the outer permanent magnet 110 is supported not by the bridge 80 but by the protrusion 112 protruding from the pair of outer slot side wall surfaces 71a and 71b. Thereby, since the pressing force applied from the outer permanent magnet 110 is difficult to be transmitted to the bridge 80, it is possible to suppress application of excessive stress to the bridge 80.

  In addition, if it demonstrates just in case, the stress provided from the housing 11 is preferentially provided with respect to the radial direction R inner part (specifically inner groove surface 91) in the groove | channel 90. FIG. For this reason, the situation that the protrusion 112 is broken due to the stress from the stator core 41 hardly occurs.

(Fourth embodiment)
As shown in FIG. 10, in this embodiment, the structure of the outer magnet slot 120 is different. The different points will be described in detail below.

  As shown in FIG. 10, a portion of the outer magnet slot 120 of this embodiment is formed wide. Specifically, the outer magnet slot 120 of the present embodiment has a pair of outer slot side wall surfaces 121 and 131 facing each other. The pair of outer slot side wall surfaces 121 and 131 have a pair of first side wall surfaces 122 and 132 that face each other, and a pair of second side wall surfaces 123 and 133 that face each other. In the present embodiment, the second side wall surfaces 123 and 133 are disposed on the outer side in the radial direction R with respect to the first side wall surfaces 122 and 132, and are disposed on the outermost periphery of the outer magnet slot 120.

  The pair of second side wall surfaces 123 and 133 are arranged to be separated from each other in a direction away from the pair of first side wall surfaces 122 and 132. Therefore, the second outer magnet slot width La22, which is the facing distance between the pair of second side wall surfaces 123, 133, is greater than the first outer magnet slot width La21, which is the facing distance between the pair of first side wall surfaces 122, 132. Is also getting bigger. Step surfaces 124 and 134 are formed between the first side wall surfaces 122 and 132 and the second side wall surfaces 123 and 133. The step surfaces 124 and 134 intersect with the radial direction R.

  The electric compressor 10 includes a pressure receiving member 140 that is provided on the outer side in the radial direction R from the bridge 80 and is pressed from both outer side wall surfaces 121 and 131. The pressure receiving member 140 is made of a nonmagnetic material having higher strength (specifically, compressive strength) than the stator core 41, and is made of, for example, stainless steel.

  The pressure receiving member 140 has, for example, a flat plate shape. The pressure receiving member 140 is fitted between the second side wall surfaces 123 and 133 while being in contact with or opposed to the step surfaces 124 and 134 in the radial direction R. In this case, the pressure receiving member 140 is in close contact with both the second side wall surfaces 123 and 133. In other words, it can be said that the pressure receiving member 140 is fitted into a region defined by the second side wall surfaces 123 and 133, the step surfaces 124 and 134, and the inner peripheral surface 11 c of the housing 11. The pressure receiving member 140 is sandwiched between the second side wall surfaces 123 and 133 and is pressed from the second side wall surfaces 123 and 133.

  Incidentally, in the present embodiment, the pair of second side wall surfaces 123 and 133 are disposed on the outermost periphery of the outer magnet slot 120, and therefore the pressure receiving member 140 is disposed on the outermost periphery of the outer magnet slot 120. Has been. The outer permanent magnet 141 of this embodiment is accommodated between the pressure receiving member 140 and the bridge 80 in the outer magnet slot 120.

  As shown in FIG. 10, in the present embodiment, the thickness D12 of the pressure receiving member 140 is larger than the bridge thickness D1. However, the present invention is not limited to this, and the thickness D12 of the pressure receiving member 140 may be the same as the bridge thickness D1 or may be smaller than the bridge thickness D1.

  Further, the combined dimension of the pressure receiving member 140 with the thickness D12 and the bridge thickness D1 is smaller than the thickness D2 of the core tube portion 51. For this reason, it replaces with the bridge | bridging 80 and the slot 120 for outer magnets, and compared with the structure by which the core cylinder part 51 is formed over the perimeter, the space which a permanent magnet occupies in detail, both the permanent magnets 62 and 141 The combined space of both is growing.

According to this embodiment explained in full detail above, in addition to the effect of (1)-(15), there exist the following effects.
(21) The electric compressor 10 is provided on the outer side in the radial direction R from the bridge 80 and is made of a nonmagnetic material having a strength higher than that of the stator core 41. From the pair of outer slot side wall surfaces 121 and 131, A pressure receiving member 140 that is pressed is provided. According to this configuration, the stress applied from the housing 11 is preferentially applied to the bridge 80 and the pressure receiving member 140 over both the permanent magnets 62 and 141. Thereby, the stress applied to both permanent magnets 62 and 141 can be reduced.

  Further, since the stress is distributed and applied by the bridge 80 and the pressure receiving member 140, the stress applied to the bridge 80 can be reduced as compared with the case of the bridge 80 alone. In particular, since the pressure receiving member 140 is disposed on the outer side in the radial direction R with respect to the bridge 80, stress is preferentially applied to the pressure receiving member 140 rather than the bridge 80. And since the pressure receiving member 140 is comprised with the material whose intensity | strength is higher than the stator core 41, it is hard to fracture | rupture. Thereby, it is possible to reduce the stress applied to both the permanent magnets 62 and 141 while reducing the stress applied to the bridge 80. Therefore, the shape of the groove 90 can be reduced, the position of the bridge 80 can be disposed on the outer side in the radial direction R, and the bridge thickness D1 can be reduced, so that the degree of freedom in design can be improved.

  Further, since the pressure receiving member 140 is made of a non-magnetic material, the pressure receiving member 140 does not form a magnetic path. Thereby, since it can suppress that the short circuit magnetic path through the pressure receiving member 140 is formed, the short circuit magnetic flux which penetrates the pressure receiving member 140 can be suppressed, and the fall of the torque resulting from a short circuit magnetic path can be suppressed through it.

  (22) The pressure receiving member 140 is disposed on the outermost periphery of the outer magnet slot 120, and the outer permanent magnet 141 is disposed between the bridge 80 and the pressure receiving member 140. If the pressure receiving member 140 is provided in the middle of the outer magnet slot 120, the outer magnet slot 120 is divided into two storage chambers by the pressure receiving member 140. In this case, it is necessary to divide the outer permanent magnet 141 into two, and there is a concern that the configuration is complicated. On the other hand, in this embodiment, since the pressure receiving member 140 is disposed on the outermost periphery of the outer magnet slot 120, the outer permanent magnet 141 is disposed only between the bridge 80 and the pressure receiving member 140. There is no need to divide into two. Thereby, the said inconvenience can be suppressed.

  Here, if the pressure receiving member 140 is provided in the outer magnet slot 120, the outer permanent magnet 141 becomes smaller corresponding to this, and there is a concern about a decrease in torque. In this regard, the outermost periphery of the outer magnet slot 120 is less likely to contribute to torque than the inner periphery. For this reason, even if the pressure receiving member 140 is arranged on the outermost periphery of the outer magnet slot 120 instead of the outer permanent magnet 141, the amount of torque reduction is small. Therefore, it is possible to suppress a decrease in torque that is a disadvantage due to the provision of the pressure receiving member 140.

  (23) The outer slot side wall surfaces 121 and 131 have first side wall surfaces 122 and 132 that face each other, and second side wall surfaces 123 and 133 that face each other. The second side wall surfaces 123 and 133 are spaced apart from each other in a direction away from the first side wall surfaces 122 and 132. Thereby, step surfaces 124 and 134 are formed between the first side wall surfaces 122 and 132 and the second side wall surfaces 123 and 133. The pressure receiving member 140 is fitted between the second side wall surfaces 123 and 133 in a state where the pressure receiving member 140 is in contact with or opposed to the step surfaces 124 and 134. According to this configuration, the movement of the pressure receiving member 140 in the radial direction R is restricted by the step surfaces 124 and 134. Thereby, the position shift of the pressure receiving member 140 can be suppressed.

  Further, when the pressure receiving member 140 is pressed inward in the radial direction R due to vibration or the like, the stepped surfaces 124 and 134 receive the pressing force from the pressure receiving member 140, and thus the pressing force is applied to the outer permanent magnet 141. Can be suppressed.

In addition, you may change each said embodiment as follows.
As shown in FIGS. 11 to 13, the shape of the groove 90 may be changed. Specifically, as shown in FIG. 11, the groove 211 may be rectangular when viewed from the axial direction Z, or as shown in FIG. 12, the groove 212 may be elliptical when viewed from the axial direction Z. As shown in FIG. 13, the groove 213 may be circular when viewed from the axial direction Z. However, from the viewpoint of relaxation of stress concentration, the groove is preferably curved as shown in the first embodiment and FIGS. 12 and 13. Furthermore, the groove 90 as in the first embodiment is preferable when focusing on the reduction of the contact area or the facing area between the first outer magnet side surface 75 and the first outer slot side wall surface 71a due to the groove. . In the first embodiment, the groove 90 may be omitted.

  The shortest distance Ly may be set equal to or shorter than the shorter one of the tip circumferential direction length Lx1 and the tip tangent length Lx2. In this case, since the inner curved surface 91a of the inner groove surface 91 can be secured widely, the stress can be more preferably dispersed.

As shown in FIG. 14, the inner facing surface 221 may be on the outer side in the radial direction R from the position in contact with the virtual stator inner peripheral surface Sx2.
Similarly, as shown in FIG. 15, the outer facing surface 222 may be in a position recessed inward in the radial direction R from the open end 71c of the outer magnet slot 71 (in other words, the core outer peripheral surface 51a).

  The bridges 80 and 105 may be formed not on the teeth 52 but on the core cylinder portion 51. In other words, the depth Dp2 of the outer magnet slot 71 may be smaller than the thickness D2 of the core cylinder portion 51.

In the second embodiment, the bridge 105 may be curved so as to be convex inward in the radial direction R.
The slot width La1 for the inner magnet may vary depending on the radial direction R. Similarly, the slot width La2 for the outer magnet may vary according to the radial direction R. In this case, the inner permanent magnet width Lb1 and the outer permanent magnet width Lb2 may vary according to the radial direction R. In such a configuration, the minimum value of the inner magnet slot width La1 is larger than the minimum value of the outer magnet slot width La2, and the minimum value of the inner permanent magnet width Lb1 is larger than the minimum value of the outer permanent magnet width Lb2. .

  The depth direction of the inner magnet slot 61 and the depth direction of the outer magnet slot 71 coincided with the radial direction R. However, the present invention is not limited to this, and may intersect the radial direction R. . Further, the depth direction of the inner magnet slot 61 may be different from the depth direction of the outer magnet slot 71. For example, the inner magnet slot 61 and the outer magnet slot 71 may have a “<” shape when viewed from the axial direction Z.

  In the configuration in which the slot widths La1 and La2 for both magnets are the same, the outer permanent magnet width Lb2 may be smaller than the inner permanent magnet width Lb1. Even in this case, the inner permanent magnet width Lb1 is larger than the outer permanent magnet width Lb2. In such a configuration, it is preferable to separately provide a spacer for filling a gap formed between the outer permanent magnet 72 and the pair of outer slot side wall surfaces 71a and 71b.

  As shown in FIG. 16, the electric compressor 10 may have a protruding portion 231 that protrudes from the outer bridge surface 80 b toward the outer magnet bottom surface 230 a as a support portion instead of the protrusion 112. The protruding portion 231 protrudes outward in the radial direction R from the outer bridge surface 80b. The tip end surface of the protruding portion 231 is in contact with the outer magnet bottom surface 230a. The outer permanent magnet 230 is supported by the protrusion 231. The height of the outer permanent magnet 230 is larger by the projection thickness D11 than the height of the outer permanent magnet 110 of the third embodiment, and smaller by the opening width Dhx than the height H2 of the outer permanent magnet 72 of the first embodiment.

  The protruding portion 231 is provided at a part of the outer bridge surface 80b, specifically, at the central portion of the outer bridge surface 80b when viewed from the axial direction Z, and at both end portions closer to the groove 90 than the central portion. not exist. For this reason, except the part in which the protrusion part 231 is provided in the outer side bridge surface 80b, it is spaced apart by the protrusion dimension of the protrusion part 231 with respect to the outer magnet bottom face 230a. The projecting dimension is set to the opening width Dhx of the groove 90. Even in this case, the effects (18) and (19) are obtained. In particular, according to this different example, a magnet can be arranged at a portion corresponding to the protrusion 112. Specifically, when the shape of the groove 90 is the same, the outer permanent magnet 230 that is larger than the outer permanent magnet 110 of the third embodiment by the protrusion thickness D11 can be used. Thereby, the fall of the torque resulting from providing the processus | protrusion 112 as a support part can be suppressed. However, the projection 112 is preferable in consideration of the complicated structure of the bridge 80 and the point that the bridge 80 can be pressed from the outer permanent magnet 230. Note that the protruding dimension of the protruding portion 231 may be larger than the opening width Dhx of the groove 90.

  As shown in FIG. 17, the electric compressor 10 may include a nonmagnetic member 232 interposed between the outer bridge surface 80 b and the outer magnet bottom surface 230 a as a support portion instead of the protrusion 112. The nonmagnetic member 232 is made of, for example, a nonmagnetic material having higher strength (compressive strength) than the stator core 41, and is made of, for example, stainless steel. The nonmagnetic member 232 has a plate shape having a thickness corresponding to the opening width Dhx of the groove 90. The nonmagnetic member 232 is placed on the outer bridge surface 80b, and the outer permanent magnet 230 is supported by the nonmagnetic member 232. In this case, one plate surface of the nonmagnetic member 232 is in contact with the outer magnet bottom surface 230a, and the other plate surface of the nonmagnetic member 232 is in contact with the outer bridge surface 80b. That is, the nonmagnetic member 232 is sandwiched between the outer permanent magnet 230 and the bridge 80. Even in this case, the effects (18) and (19) are obtained. In particular, according to this example, since it is not necessary to provide the protrusion 112 of the pair of outer slot side wall surfaces 71a and 71b and the protruding portion 231 of the bridge 80, the configuration of the stator core 41 due to the support portion can be prevented from being complicated. Further, since the nonmagnetic member 232 is employed as the support portion, a short circuit magnetic path through the nonmagnetic member 232 is unlikely to occur. Thereby, the fall of the torque resulting from a support part can be suppressed. The thickness of the nonmagnetic member 232 may be larger than the opening width Dhx of the groove 90.

  In the third embodiment, the outer magnet bottom surface 111 and the outer bridge surface 80b are separated from each other as a whole. For example, a protrusion that protrudes toward the outer bridge surface 80b may be provided at the center of the outer magnet bottom surface 111, and the tip of the protrusion may be in contact with the outer bridge surface 80b. Even in this case, the region other than the protruding portion on the outer magnet bottom surface 111 is separated from the outer bridge surface 80b. In short, it is only necessary that the outer magnet bottom surface 111 and the outer bridge surface 80b are separated at least partially.

In the third embodiment, the separation distance between the outer magnet bottom surface 111 and the outer bridge surface 80b may be smaller than the opening width Dhx of the groove 90.
In 4th Embodiment, the pressure receiving member 140 may be provided in radial direction R inner side from the said outermost periphery other than the outermost periphery of the slot 120 for outer magnets, for example. In this case, the outer permanent magnet 141 may be accommodated in the outer magnet slot 120 in a state of being divided into two.

  In the fourth embodiment, the second side wall surfaces 123 and 133 may be disposed at positions closer to each other than the first side wall surfaces 122 and 132. In this case, the width of the pressure receiving member 140 is smaller than the outer permanent magnet width Lb2. In this example, the pressure receiving member 140 may be inserted into the outer magnet slot 120 from the axial direction Z.

In the fourth embodiment, the step surfaces 124 and 134 are not essential. For example, the pressure receiving member 140 may be fitted into the outer magnet slot 71 of the first embodiment.
In each embodiment, the rotating electrical machine is the electric compressor 10 in which the compression unit 12 and the electric motor 14 are integrated, but is not limited thereto. The rotating electrical machine may be configured to have another drive unit instead of the compression unit 12. In addition, the rotating electrical machine may not include a driving unit such as the rotating shaft 13 or the compression unit 12. In short, the rotating electrical machine only needs to include the electric motor 14 having the rotor 30 and the stator 40 and the housing 11 that houses the electric motor 14.

  O You may combine each embodiment and each other example suitably. For example, in the second embodiment, the groove 90 may be provided, or the first inner facing surface 64 of the first embodiment may be replaced with the second inner facing surface 103 of the second embodiment.

  In addition to the configuration in which the permanent magnet widths Lb1 and Lb2 are different as in the first embodiment, the inner permanent magnet 62 may be made of a material having a coercive force stronger than that of the outer permanent magnet 72. Thereby, the coercive force of the inner permanent magnet 62 can be further improved.

  DESCRIPTION OF SYMBOLS 10 ... Electric compressor (rotary electric machine), 11 ... Housing, 11c ... Inner peripheral surface of housing, 13 ... Rotating shaft, 14 ... Electric motor, 30 ... Rotor, 40 ... Stator, 41 ... Stator core, 42u, 42v, 42w ... Armature winding 51... Core tube portion 51 a. Core outer peripheral surface 51 b. Core inner peripheral surface 52. Teeth 53. Teeth distal end surface 53 a and 53 b distal end curved surface 54 and 55 Teeth side surface 56 ... winding slot, 61 ... inner magnet slot, 61a, 61b ... inner slot side wall surface, 62, 101 ... inner permanent magnet, 64, 103, 221 ... inner facing surface, 71, 120 ... outer magnet slot, 71a , 71b, 121, 131 ... outer slot side wall surface, 71c ... open end of outer magnet slot, 72, 102, 110, 141, 230 ... outer permanent magnet, 73 107, 111, 230a ... outer magnet bottom surface, 74,104,222 ... outer facing surface, 80,105 ... bridge, 80a ... inner bridge surface, 80b ... outer bridge surface, 90, 211-213 ... groove, 90a ... groove Opening 91, inner groove surface, 91a ... inner curved surface, 92 ... outer groove surface, 92a ... first end of outer groove surface, 92b ... second end of outer groove surface, 92c ... outer curved surface, 112 ... projection, 122, 132: first side wall surface, 123, 133: second side wall surface, 124, 134: step surface, 140: pressure receiving member, 231: protrusion, 232: nonmagnetic member, D1: bridge thickness, D2: core Thickness of cylinder part, Dp1 ... depth of slot for inner magnet, Dp2 ... depth of slot for outer magnet, Dh ... width of groove, Dhx ... opening width, La1 ... slot width for inner magnet, La2 ... for outer magnet Slot width, L 1 ... inner permanent magnet width Lb2 ... outer permanent magnet width, the shortest distance between Ly ... tooth sides and grooves, Lx1 ... tip circumferential length, Lx2 ... tip tangential length.

Claims (21)

A rotor,
A stator having a stator core, an armature winding, and a permanent magnet provided radially outside the rotor with respect to the rotor;
A housing for housing the rotor and the stator in a state where the stator core is fixed;
With
The stator core is
A core cylinder portion having a core outer peripheral surface pressed from an inner peripheral surface of the housing;
The armature winding is wound, a plurality of teeth protruding from the inner peripheral surface of the core cylindrical portion toward the radially inner side of the rotor and arranged in the circumferential direction of the rotor;
A slot for an inner magnet recessed from the tooth tip surface which is the tip surface of each of the teeth;
An outer magnet slot which is disposed radially outside the rotor with respect to the inner magnet slot and is recessed from the outer peripheral surface of the core;
A bridge that partitions the inner magnet slot and the outer magnet slot;
With
The rotating electric machine, wherein the permanent magnet includes an inner permanent magnet accommodated in the inner magnet slot and an outer permanent magnet accommodated in the outer magnet slot. The teeth have a pair of teeth side surfaces around which the armature winding is wound,
The stator core is
A pair of inner slot side wall surfaces provided between the pair of teeth side surfaces and defining the inner magnet slot and facing each other;
A pair of outer slot sidewall surfaces defining the outer magnet slot and facing each other;
Have
The bridge is
An inner bridge surface constituting the bottom surface of the inner magnet slot;
An outer bridge surface provided on the opposite side of the inner bridge surface and constituting a bottom surface of the outer magnet slot;
Have
The rotating electrical machine according to claim 1, wherein a bridge thickness, which is a distance between the inner bridge surface and the outer bridge surface, is smaller than a thickness of the core tube portion.   The rotating electrical machine according to claim 2, wherein a groove extending in an axial direction of the rotor and recessed from the outer slot side wall surface is formed between the pair of outer slot side wall surfaces and the outer bridge surface. The groove has an inner groove surface continuous with the outer bridge surface;
4. The rotating electrical machine according to claim 3, wherein the inner groove surface includes an inner curved surface that is curved toward a radially outer side of the rotor as it is separated from the outer bridge surface when viewed from the axial direction of the rotor. The outer permanent magnet has a pair of outer magnet side surfaces that contact or face the pair of outer slot side wall surfaces,
The groove includes an outer groove surface having a first end continuous with the inner groove surface and a second end continuous with the outer slot side wall surface,
5. The rotating electrical machine according to claim 4, wherein the outer groove surface includes an outer curved surface that is curved so that the width of the groove gradually decreases from the first end side toward the second end side. The teeth have a tapered shape formed such that the circumferential length of the rotor in the teeth gradually decreases as it goes inward in the radial direction of the rotor,
The teeth front end surfaces are a pair of front end curved surfaces provided on both sides of the inner magnet slot, continuous to both the teeth side surface and the inner slot side wall surface facing each other and extending in the circumferential direction of the rotor. Configured,
The shortest distance between the tooth side surface and the groove is a tip that is a length of a tangent line perpendicular to the tooth side surface and in contact with the tip curved surface among straight lines connecting the tooth side surface and the inner slot side wall surface facing each other. The rotating electrical machine according to any one of claims 3 to 5, wherein the rotating electrical machine is set to be longer than a shorter one of a tangential length and a circumferential length of the tip curved surface. The outer permanent magnet has an outer magnet bottom surface facing the outer bridge surface;
The groove has an opening whose width direction is an opposing direction of the outer bridge surface and the outer magnet bottom surface,
7. The rotating electrical machine includes a support portion that supports the outer permanent magnet such that the outer bridge surface and the outer magnet bottom surface are separated at least in part. The rotating electrical machine described.   8. The rotating electrical machine according to claim 7, wherein the support portion supports the outer permanent magnet at a position where the bottom surface of the outer magnet is separated from the outer bridge surface by at least the opening width of the groove. The support portion is a protrusion provided on at least one of the pair of outer slot side wall surfaces,
The rotating electric machine according to claim 7 or 8, wherein the outer permanent magnet is supported by the bottom surface of the outer magnet being in contact with the protrusion. The support portion is a protrusion provided on the outer bridge surface and protruding from the outer bridge surface toward the outer magnet bottom surface,
The rotary electric machine according to claim 7 or 8, wherein the bottom surface of the outer magnet is supported by contacting the protruding portion.   The rotating electrical machine according to claim 7 or 8, wherein the support portion is a nonmagnetic member interposed between the outer bridge surface and the outer magnet bottom surface. The magnetization direction of the inner permanent magnet coincides with the opposing direction of the pair of inner slot side wall surfaces,
The magnetization direction of the outer permanent magnet coincides with the opposing direction of the pair of outer slot side wall surfaces,
The rotating electrical machine according to any one of claims 2 to 11, wherein a length in the magnetization direction of the inner permanent magnet is set longer than a length in the magnetization direction of the outer permanent magnet. A pressure receiving member that is provided on a radially outer side of the rotor than the bridge and is pressed from the pair of outer slot side wall surfaces;
The rotating electrical machine according to any one of claims 2 to 12, wherein the pressure-receiving member is made of a nonmagnetic material having a higher strength than the stator core. The pressure receiving member is disposed on the outermost periphery of the outer magnet slot,
The rotating electrical machine according to claim 13, wherein the outer permanent magnet is disposed between the bridge and the pressure receiving member. The pair of outer slot side wall surfaces are
A pair of first side wall surfaces facing each other;
A pair of second side wall surfaces spaced apart from each other in a direction away from each other than the pair of first side wall surfaces;
Have
The pressure receiving member is in contact with or opposed to a pair of step surfaces formed between the pair of first sidewall surfaces and the pair of second sidewall surfaces. The rotating electrical machine according to claim 13 or 14, which is fitted in between. The inner permanent magnet has an inner facing surface facing the rotor;
The said inner side opposing surface is linear shape seeing from the axial direction of the said rotor, Comprising: It arrange | positions in the radial direction outer side of the said rotor rather than the said teeth front end surface. Rotating electric machine. The outer permanent magnet has an outer facing surface facing the inner peripheral surface of the housing,
The outer facing surface is linear when viewed from the axial direction of the rotor, and is disposed on the same plane as the opening end of the outer magnet slot or on the radially inner side of the rotor. The rotating electrical machine according to any one of?   The rotating electrical machine according to any one of claims 1 to 17, wherein the bridge is provided in the teeth.   19. The rotating electrical machine according to claim 1, wherein a depth of the outer magnet slot from the core outer peripheral surface is greater than a depth of the inner magnet slot from the teeth tip surface.   The rotating electrical machine according to any one of claims 1 to 19, wherein the bridge has a linear shape extending in a direction intersecting with a radial direction of the rotor as viewed from an axial direction of the rotor.   21. The rotating electrical machine according to claim 1, wherein the inner permanent magnet is made of a material having a coercive force stronger than that of the outer permanent magnet.

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