JP6676622B2 - Brushless motor, electric pump, and brushless motor manufacturing method - Google Patents

Description

The present invention is a brushless motor, the electric pump, a method of manufacturing a contact and a brushless motor.
This application claims priority based on Japanese Patent Application No. 2015-084922 filed on April 17, 2015, the contents of which are incorporated herein by reference.

  A general brushless motor has a stator on which windings are wound, and a rotor rotatably provided radially inside the stator. The stator has a cylindrical core body, and a plurality of teeth radially projecting from the inner peripheral surface of the core body toward the inside in the radial direction. Slots each having a radially inner opening are formed between the teeth. A winding is wound around each tooth via this slot.

  It is effective to improve the space factor of the winding in order to increase the efficiency and reduce the size of the motor. However, in the case of a slot shape in which the radially inner side of the stator is opened, as in an inner rotor type brushless motor, the opening width is larger than that of a slot shape in which the radially outer side is opened, as in an outer rotor type brushless motor. small. Therefore, in the inner rotor type brushless motor, it is difficult to improve the space factor of the winding. For this reason, the core body may be divided in the circumferential direction for each tooth to form a divided core.

When forming the divided cores, for example, windings are wound around the teeth of each of the divided cores, and then the divided cores are assembled to form an annular core body. With this configuration, the winding can be wound around each tooth without considering the slot width, so that the space factor of the winding can be improved.
Here, in order to reduce the size and weight of the brushless motor, a technique of insert-molding a stator in a resin-made motor case has been proposed.

Japanese Patent Application Laid-Open No. 2012-143032

  However, the stator constituted by each of the divided cores has a slight play at the connecting portion of each of the divided cores. Therefore, when the stator is insert-molded in the motor case as it is, the roundness of the stator is deteriorated by the resin pressure when the molten resin is injected into the mold, or the stator is displaced from a predetermined insert position.

  An aspect of the present invention has been made in view of the above-described circumstances, and a brushless motor and an electric pump that can suppress deterioration of roundness even when a stator formed by combining divided cores is insert-molded in a motor case. And a method for manufacturing a brushless motor.

In order to solve the above problems, the present invention has adopted the following aspects.
A brushless motor according to one aspect of the present invention includes a resin motor case, a stator embedded in the motor case, and a rotor rotatably supported by the motor case, wherein the stator has a ring shape. Core body, and a plurality of teeth extending radially from the core body and wound around the core body, the core body includes a plurality of split cores connected via a connection portion. , wherein the bottom portion of the motor case, the gate portion of the traces of the plurality of gates of a mold for injecting the molten resin during molding, provided same number of the teeth, by the connecting portion, the core body a concave portion along the axial direction is formed on an outer peripheral surface of the position of each of the gate portion is a portion corresponding to the radially outer side of the core body is set in the circumferential center of the divided cores, and It said gate portion is arranged at equal intervals in the circumferential direction.

In this case, when insert molding the stator into the motor case, the resin pressure when the molten resin is injected into the mold acts from the radially outer side to the inner side of the core body. The core body receiving the resin pressure is displaced so as to reduce the diameter in a well-balanced manner corresponding to the play of the connecting portion of each core body. As a result, the deterioration of the roundness of the stator can be suppressed.
Also, resin pressure can be applied to each of the divided core bodies in a well-balanced manner. Therefore, the deterioration of the roundness of the stator can be reliably suppressed.
Further, resin pressure can be applied to each of the divided core bodies in a more balanced manner. For this reason, the deterioration of the roundness of the stator can be suppressed more reliably.

  In the above-mentioned brushless motor, the motor case may have traces of the resin being simultaneously injected from the plurality of gates of the mold.

  In this case, resin pressure can be simultaneously applied to each of the divided core bodies. For this reason, it is possible to reliably suppress the deterioration of the roundness of the stator due to a shift in the timing at which the resin pressure is applied.

  In the brushless motor, the trace is a weld line in which the flow of the injected resin is merged and solidified, and the plurality of weld lines are located at equal intervals along a circumferential direction, and are arranged in a circumferential direction. It may be located at substantially the center of the gate portions adjacent on both sides.

  In this case, the flow of the resin merges at a substantially central position of each of the divided core bodies. Therefore, the joining point of the resin where the resin pressure is increased is not biased and is substantially at the center in the circumferential direction with respect to each core body. Therefore, the deterioration of the roundness of the stator can be suppressed more reliably.

In the brushless motor, the motor case may include a housing for housing a control unit for controlling the energization of the windings, and a connector housing provided on one side of the housing .

  In this case, the entire brushless motor integrated with the control unit can be reduced in size.

  An electric pump according to one aspect of the present invention includes the brushless motor described above, and a pump unit driven by the brushless motor.

  In this case, a small and high-performance electric pump can be provided.

A method of manufacturing a brushless motor according to one aspect of the present invention includes a resin motor case, a stator embedded in the motor case, and a rotor rotatably supported by the motor case. A ring-shaped core body, teeth extending along the radial direction from the core body, winding the windings, and connecting the windings wound for each of the teeth to each other, the axial direction of the core body A crossover wire disposed at an end of the core main body, and a crossover presser provided along the outer diameter of the core main body on a side opposite to the core main body with the crossover wire therebetween, the plurality of divided cores is being coupled through a coupling portion, by the connecting portion, a manufacturing method of a brushless motor that recesses on the outer peripheral surface along the axial direction is formed in the core body, in the teeth Winding the winding And, fixing a winding step of forming the connecting wire, it is connected to the plurality of divided cores, and the divided core connecting step of forming the core body, the stator into a mold for forming the motor casing A stator setting step, a crossover wire pressing arrangement step of arranging the crossover presser on the crossover wire , and melting the resin into the mold so that a radially inward resin pressure acts on the core body. And a motor case forming step of injecting the obtained resin from a side opposite to the crossover in the axial direction of the stator .

  In this case, when the stator is insert-molded in the motor case, the core body receiving the resin pressure is displaced so as to reduce the diameter in a well-balanced manner corresponding to the play of the connecting portion of each core body. As a result, the deterioration of the roundness of the stator can be suppressed.

  In the method for manufacturing a brushless motor, a plurality of gates may be provided for injecting the molten resin into the mold, and the resin may be simultaneously injected from each of the gates in the motor case forming step.

  In this case, resin pressure can be simultaneously applied to each of the divided core bodies. For this reason, it is possible to reliably suppress the deterioration of the roundness of the stator due to a shift in the timing at which the resin pressure is applied.

  In the method for manufacturing a brushless motor, the teeth extend radially inward from the core body, and in the stator setting step, a core is disposed at a radial center of the stator, and in the motor case forming step, The radially inner end of the stator may contact the outer peripheral surface of the core.

  In this case, the divided core bodies can be accurately positioned by the core material. For this reason, the roundness of the stator can be improved.

According to the aspect of the present invention, when insert molding the stator into the motor case, the resin pressure at the time of injecting the molten resin into the mold acts from the radially outer side to the inner side of the core body. The core body receiving the resin pressure is displaced so as to reduce the diameter in a well-balanced manner corresponding to the play of the connecting portion of each core body. As a result, the deterioration of the roundness of the stator can be suppressed.
Also, resin pressure can be applied to each of the divided core bodies in a well-balanced manner. Therefore, the deterioration of the roundness of the stator can be reliably suppressed.
Further, resin pressure can be applied to each of the divided core bodies in a more balanced manner. For this reason, the deterioration of the roundness of the stator can be suppressed more reliably.

FIG. 1 is a perspective view of an electric pump according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the electric pump according to the embodiment of the present invention. FIG. 3 is a perspective view of the motor case according to the embodiment of the present invention. FIG. 4 is a perspective view of the stator according to the embodiment of the present invention. FIG. 5 is a perspective view of a split core according to the embodiment of the present invention. FIG. 6 is a plan view of the split core according to the embodiment of the present invention as viewed from the axial direction. FIG. 7 is an explanatory diagram showing a winding order of windings on each split core in the embodiment of the present invention. FIG. 8A is an explanatory diagram illustrating a step of a method of connecting the divided cores after the winding operation of the winding according to the embodiment of the present invention is completed. FIG. 8B is an explanatory diagram illustrating a step of a method of connecting the divided cores after the winding operation of the winding according to the embodiment of the present invention is completed. FIG. 8C is an explanatory diagram illustrating a step of a method of connecting the divided cores after the winding operation of the winding according to the embodiment of the present invention is completed. FIG. 9 is an explanatory diagram showing the gate position of the mold with respect to the motor case in the embodiment of the present invention. FIG. 10 is an explanatory diagram showing the gate position of the mold with respect to the motor case in the embodiment of the present invention. FIG. 11 is an explanatory diagram showing a flow of the resin when the resin is injected into the mold according to the embodiment of the present invention. FIG. 12 is a graph showing a variation in roundness of the back yoke according to the embodiment of the present invention.

  Next, an embodiment of the present invention will be described with reference to the drawings.

(Electric pump)
FIG. 1 is a perspective view of the electric pump 1. FIG. 2 is a sectional view of the electric pump 1.
As shown in FIGS. 1 and 2, the electric pump 1 is an electric pump for supplying oil to a transmission mounted on an automobile, for example, to drive the transmission (both not shown). The electric pump 1 includes a motor unit 2, a pump unit 3 connected to the motor unit 2 and arranged coaxially with the motor unit 2, and a control unit 4. The control unit 4 is arranged between the motor unit 2 and the pump unit 3 and on the outer peripheral side of the motor unit 2 and the pump unit 3.
In the following description, the direction indicated by arrow A in FIG. 2 and the axial direction of the rotating shaft 81 of the motor unit 2 is simply referred to as the axial direction. The direction orthogonal to the axial direction and being the radial direction of the rotating shaft 81 is simply referred to as the radial direction. The circumferential direction of the rotation shaft 81 is simply referred to as a circumferential direction.

(Motor part)
The motor section 2 includes a motor case 50 formed of resin, a stator 40 insert-molded in the motor case 50, and a rotor 80 rotatably supported by the motor case 50. The motor unit 2 is a so-called brushless motor to which electric power is supplied from the control unit 4 without using a brush. Details of the motor case 50 and the stator 40 will be described later.

  The can 9 is located radially inside the stator 40. The opening 9a of the can 9 faces the pump section 3 and is engaged and fixed to a boss 96 (described later) via a first O-ring 97a and a second O-ring 97b. The can 9 is formed in a bottomed cylindrical shape from a plate material such as a nonmagnetic material (for example, stainless steel). The electric pump 1 of the present embodiment has a can structure. In the can structure of the electric pump 1 according to the present embodiment, the inside of the can 9 is filled with oil, thereby preventing oil from entering the stator 40.

  A rotor 80 is rotatably provided radially inside the stator 40 and inside the can 9. The rotor 80 includes a rotating shaft 81 and a rotor core 82 externally fitted and fixed to a position of the rotating shaft 81 corresponding to the stator 40. A plurality (four in the present embodiment) of permanent magnets 83 are embedded in the rotor core 82 at equal intervals in the circumferential direction. In addition, one end side of the rotating shaft 81 protrudes toward the pump unit 3 side, and the pump unit 3 is connected to the protruding portion.

(Pump section)
The pump section 3 includes a pump body 92 and a bracket 93. The pump body 92 is provided with a pump chamber 91 (described later) that is disposed on the motor unit 2 and that sucks and discharges oil. The bracket 93 is arranged on the pump body 92 on the side opposite to the motor unit 2.
The pump body 92 has a pump case 94 provided to close the opening 51a of the motor case 50.
The pump case 94 is formed by, for example, aluminum die casting. The pump case 94 includes, for example, a base 95 and a boss 96 integrally formed at a position corresponding to the opening 51 a of the motor case 50 in the base 95.

  The boss 96 is formed so as to be able to fit inside the opening 51 a of the motor case 50. The boss 96 is formed from a base boss 96a and a tip boss 96b. The base boss 96a corresponds to the shape of the inner peripheral surface of the opening 51a. The tip boss 96b fits inside the opening of the can 9. The boss 96 is formed so as to protrude such that the tip thereof is close to the rotor core 82 in a state where the pump case 94 is mounted on the motor case 50. Further, a first O-ring 97a for securing a sealing property with the motor case 50 is mounted on the outer peripheral surface of the base end boss portion 96a. A second O-ring 97b is mounted on the outer peripheral surface of the distal end boss portion 96b to ensure a sealing property with the inner surface of the can 9.

  At the center of the boss 96, a bearing hole 98 through which one end of the rotating shaft 81 of the motor 2 is inserted is formed in a penetrating manner. The bearing hole 98 rotatably supports the rotating shaft 81. Oil penetrates between the bearing hole 98 and the rotating shaft 81 to form an oil film. The rotating shaft 81 is rotatably supported by the thickness of the oil film. That is, the bearing hole 98 functions as a so-called journal bearing.

  One end of the rotating shaft 81 extends from the motor unit 2 through the bearing hole 98 of the pump case 94 to the end surface 93 a of the pump case 94 on the bracket 93 side. The base 95 of the pump case 94 has a substantially cylindrical pump chamber 91 at a position corresponding to the rotating shaft 81 as viewed in a plan view in the axial direction. The pump chamber 91 is a chamber for sucking oil, compressing the oil, and then discharging the oil, and is recessed so that the bracket 93 side is opened. A substantially ring-shaped outer rotor 101 is rotatably provided on the inner peripheral surface of the pump chamber 91. On the other hand, an inner rotor 102 is externally fitted and fixed to a tip portion of the rotating shaft 81 corresponding to the pump chamber 91.

The outer rotor 101 and the inner rotor 102 constitute a so-called trochoid pump. That is, by changing the volume of the space formed by the internal teeth (not shown) of the outer rotor 101 and the external teeth (not shown) of the inner rotor 102, the working chamber 103 that sucks oil and discharges the oil is formed.
A sub suction chamber 104 is formed in the base section 95 on the oil suction side (the right side in FIG. 2) of the pump chamber 91 and on the motor section 2 side. Further, a sub-discharge chamber 105 is formed in the base section 95 on the oil discharge side (the left side in FIG. 2) of the pump chamber 91 and on the motor section 2 side. The boss portion 96 is formed with a sub communication hole 106 for communicating the sub suction chamber 104 of the pump chamber 91 with the inside of the can 9 of the motor section 2.

A concave portion 107 that receives a part of the control unit 4 is formed on the outer peripheral portion of the base unit 95 and on the motor unit 2 side. Further, a through hole 108 through which the bolt 59 can be inserted is formed at the outer peripheral portion of the base portion 95 and at a position corresponding to the through hole 57a of the motor case 50.
An O-ring 109 is provided on an end surface 94a of the pump case 94 to ensure a sealing property between the pump case 94 and the bracket 93. The O-ring 109 is formed in an annular shape so as to surround the pump chamber 91.

The bracket 93 is formed by, for example, aluminum die casting, and is formed in a flat plate shape so as to overlap the end surface 94 a of the pump case 94. An end surface 93b of the bracket 93 opposite to the end surface 93a on the pump case 94 side is attached to a transmission (not shown), and the transmission side is connected to the oil passage.
In the following description, the end surface 93a of the bracket 93 on the pump case 94 side is referred to as a pump case side end surface 93a. An end surface 93b opposite to the pump case side end surface 93a is referred to as a mounting side end surface 93b.

In the bracket 93, a suction chamber 110a and a suction port 110b communicating with the suction chamber 110a are formed at a position corresponding to the pump chamber 91 of the pump case 94, and communicate with the discharge chamber 111a and the discharge chamber 111a. Discharge port 111b.
More specifically, the flow path from the suction chamber 110a to the suction port 110b is formed so as to penetrate the bracket 93 in a meandering manner in the thickness direction from a position corresponding to the oil suction side of the pump chamber 91. . The suction chamber 110a is formed in a stepped hole shape so that the pump case side end surface 15a is reduced in diameter by a step compared to the oil passage side end surface 15b.

On the other hand, the flow path from the discharge chamber 111a to the discharge port 111b is formed at a position corresponding to the oil discharge side of the pump chamber 91 so as to penetrate the bracket 93 in the thickness direction. Similarly to the suction chamber 110a, the discharge chamber 111a is formed in a stepped hole shape so that the pump case side end surface 15a is reduced in diameter by a step compared to the oil passage side end surface 15b.
Although detailed description and illustration are omitted, the suction chamber 110a and the sub suction chamber 104 are formed in a substantially semicircular shape having substantially the same shape as viewed in the axial direction. Further, the discharge chamber 111a and the sub-discharge chamber 105 are formed in a substantially semicircular shape having substantially the same shape as viewed in the axial direction. Thereby, in the working chamber 103, the balance of the pressure applied to both axial end surfaces of the outer rotor 101 and the inner rotor 102 is maintained.

A female screw portion 112 into which the bolt 59 is screwed is formed in the bracket 93 at a position corresponding to the through hole 108 of the pump case 94.
A bolt seat 113 for fixing the electric pump 1 to the mounting surface of the transmission is formed on the outer peripheral portion of the bracket 93 so as to extend (see FIG. 1). The bolt seat 113 has a through hole 114 through which a bolt (not shown) can be inserted.

(Control unit)
The control unit 4 controls the driving of the motor unit 2. The control unit 4 includes the board 23 housed in a housing recess 53 (described later) of the motor case 50. The substrate 23 includes a plurality of switching elements 24 such as FET (Field Effect Transistor) for controlling a current supplied to the stator 40, an IC (integrated circuit) element 25, and a capacitor 26 for smoothing a voltage applied to the substrate 23. Etc. have been implemented.
The substrate 23 is sealed in the storage recess 53 with a filler 41 having high thermal conductivity. As the filler 41, it is desirable to use a flame-retardant filler such as a filler mainly composed of an epoxy resin or a filler mainly composed of a silicone-modified polymer.

The control unit 4 includes a control unit cover 42 that closes the opening 53b of the storage recess 53. The control unit cover 42 is formed of, for example, a resin. The shape of the control section cover 42 on the pump section 3 side is formed so as to face the concave section 107 formed in the pump case 94, that is, along the concave section 107.
Further, on the inner surface of the control unit cover 42, a convex portion 43 protruding toward the IC element 25 is formed at a position corresponding to the IC element 25. Then, the surface (tip surface) of the convex portion 43 facing the IC element 25 is in a state close to the IC element 25 and is in contact with the filler 41. Further, a plurality of concave portions 44 are formed on the outer surface (back surface) of the convex portion 43. Thereby, the heat of the substrate 23 is efficiently radiated through the filler 41 and the control unit cover 42.

(Motor case)
FIG. 3 is a perspective view of the motor case 50 in which the stator 40 is insert-molded.
As shown in FIGS. 2 and 3, the motor case 50 includes a substantially bottomed cylindrical case main body 51 and a substrate storage section 52. The board storage part 52 is formed integrally with the outer peripheral surface 51 b of the case main body 51 and forms the control unit 4.
The substrate storage part 52 is formed in a substantially rectangular shape in plan view in the axial direction. A board (not shown) for supplying electric power to the stator 40 is housed in the board housing section 52, and almost the entire surface of the case body 51 on the opening 51 a side (the surface on the pump section 3 side in the axial direction) is A storage recess 53 is formed.
The substrate 23 is stored in the storage recess 53.

  In addition, a connector housing 54 is integrally formed on one side of the board storage section 52. A connector (both not shown) extending from an external device is fitted (connected) to the connector housing 54. The external device supplies power to the stator 40 via the board 23 and outputs a control signal to the board 23.

One end 55 a of the connector terminal 55 protrudes into the connector housing 54. The other end 55b of the connector terminal 55 protrudes from the bottom surface 53a of the storage recess 53. The other end 55b of the connector terminal 55 is electrically connected to the board 23.
One end 56a of a connection terminal 56 for electrically connecting a winding 5 (described later) of the stator 40 and the substrate 23 protrudes from a bottom surface 53a of the storage recess 53. The connection terminal 56 is embedded in the board storage section 52, and the other end 56 b is connected to the winding 5.

  On the outer peripheral surface 51b of the case body 51, two bolt seats 57 are integrally formed on the opening 51a side. The bolt seat 57 is for fixing the motor case 50 to an external device (not shown). The two bolt seats 57 are arranged to face each other with the radial center of the case body 51 interposed therebetween. The bolt seat 57 is formed to protrude radially outward from the outer peripheral surface 51b of the case body 51.

  In the bolt seat 57, a through hole 57a through which a bolt (not shown) can be inserted is formed along the axial direction. The through hole 57a is formed integrally with a collar 58 formed of, for example, carbon steel. A bolt 59 (see FIGS. 1 and 2) is inserted through the collar 58 through the through hole 57a. The bolt 59 is screwed into the female screw portion 112 of the bracket 93 via the through hole 108 of the pump body 92. In this manner, the motor case 50, the pump body 92, and the bracket 93 are integrally fastened and fixed.

  As shown in FIG. 9, six gate portions P1 are provided on the bottom surface 51c of the case body 51. The gate portion P1 is a mark of a gate 100 (described later) for injecting a molten resin into a mold 200 (described later) at the time of molding the motor case 50. The position of each gate portion P1 is set at a position corresponding to the radially outer side of the core body 11 on the bottom surface 51c, and is arranged at equal intervals in the circumferential direction.

  As shown by broken lines in FIG. 9, six weld lines L each extending toward the center in the radial direction are provided on the bottom surface 51c of the case body 51 at substantially the center in the circumferential direction between the adjacent gate portions P1. The weld line L is a portion where the flows of the resin injected from different gates 100 merge and solidify inside the mold 200. The six weld lines L are located at equal intervals along the circumferential direction, and also extend on the outer peripheral surface 51b of the case main body 51 (not shown).

(Stator)
FIG. 4 is a perspective view of the stator 40.
As shown in FIG. 4, the stator 40 is formed in a substantially cylindrical shape. The stator 40 is embedded in the case main body 51 in a state where the axial direction of the stator 40 matches the axial direction of the case main body 51.
The core main body 11 of the stator 40 includes a substantially cylindrical back yoke 31 and a plurality of teeth 32 formed to project radially inward from the back yoke 31. Further, the core body 11 includes an insulating insulator 33 mounted so as to cover the periphery of the tooth 32, and the winding 5 wound around the tooth 32 from above the insulator 33. Then, a plurality of coils 6 are formed by winding the winding 5 around each tooth 32.

  The stator 40 of the present embodiment is provided with six teeth 32 and has a three-phase (U-phase, V-phase, W-phase) structure. The teeth 32 of each phase are arranged in the circumferential direction in the order of U phase, V phase, and W phase. That is, the teeth 32 located on both sides with the two teeth 32 interposed therebetween become the teeth 32 in the same phase.

(Split core)
Here, the back yoke 31 of the core main body 11 employs a split core method that can be split in the circumferential direction. That is, the back yoke 31 of the core body 11 is configured by annularly connecting the divided cores 10 divided into a plurality in the circumferential direction.

FIG. 5 is a perspective view of the split core 10. FIG. 6 is a plan view of the split core 10 viewed from the axial direction. In FIG. 6, the coil 6 formed on the teeth 32 is shown in a cross section orthogonal to the axial direction for easy understanding.
As shown in FIGS. 5 and 6, the split core 10 is formed by stacking a plurality of metal plates, for example, and has a split back yoke 30 extending in the circumferential direction. The split back yoke 30 is a portion that forms an annular magnetic path of the back yoke 31 when the split cores 10 are connected in an annular shape. The divided back yoke 30 is formed to have a substantially arc-shaped cross section.

At both ends in the circumferential direction of the divided back yoke 30, connecting portions 12a and 12b which are connected to other divided back yokes 30 by press fitting are formed. One connecting portion 12a has a convex shape, and the other connecting portion 12b has a concave shape capable of receiving the connecting portion 12a.
As shown in FIG. 4, in a state where the divided cores 10 are connected via the connecting portions 12 a and the connecting portions 12 b (a state in which the back yoke 31 is formed), the outer peripheral surface 31 a of the back yoke 31 is connected in the circumferential direction. At the place where the portion 12a and the connecting portion 12b are formed, the connecting portion 12a and the connecting portion 12b form a concave portion 31b along the axial direction.

The teeth 32 are formed on the inner peripheral surface 30a of the divided back yoke 30 so as to protrude radially inward (toward the rotation center of the rotor) from substantially the center in the circumferential direction. That is, each split core 10 includes one tooth 32.
The teeth 32 include a tooth body 13 extending along a radial direction and a flange portion 14. The flange portion 14 is integrally formed with a radially inner end portion of the tooth body 13, that is, a tip portion of the tooth body 13, and extends along both circumferential sides. A slot 15 for winding the winding 5 is formed so as to be surrounded by the tooth body 13, the divided back yoke 30 and the flange portion 14. That is, each split core 10 is provided with a pair of slots 15 on both sides of the teeth 32.

The inner peripheral surface 30a of the split back yoke 30 is not orthogonal to the extending direction (radial direction) of the teeth 32 and is formed in a substantially arc shape. The arc shape of the inner peripheral surface 30a and the arc shape of the outer peripheral surface 30b of the divided back yoke 30 are slightly different.
That is, the outer peripheral surface 30b is formed in an arc shape centered on the radial center of the stator 40. On the other hand, the inner peripheral surface 30a of the divided back yoke 30 is formed in an arc shape so as to be biased (biased) radially inward (toward the teeth 32) from the outer peripheral surface 30b toward the both ends in the circumferential direction from the root of the tooth body 13. Have been. That is, the inner peripheral surface 30a of the divided back yoke 30 is so-called overhanging so as to project radially inward toward both ends in the circumferential direction. An insulator 33 is attached so as to cover the periphery of the teeth 32 formed as described above.

  The insulator 33 includes a first insulator 16 and a second insulator 17. The first insulator 16 and the second insulator 17 are mounted so that the teeth 32 are sandwiched between the ends 10a and 10b, which are both ends in the axial direction of the split core 10, respectively. The first insulator 16 and the second insulator 17 cover the insulator body 16a and the insulator body 16a, which cover the portion of the tooth 32 facing the slot 15 and the end of the tooth 32 (the end 10a and the end 10b of the split core 10). It has an insulator body 17a. The insulator main body 16a and the insulator main body 17a are formed such that the connecting portions 12a and 12b of the divided back yoke 30 are exposed.

In addition, the insulator body 16a and the insulator body 17a are integrally formed with an outer wall portion 18a and an inner wall portion 18b which stand along the axial direction at locations corresponding to the ends 10a and 10b of the split core 10, respectively. I have.
The outer wall portion 18a is arranged at a position corresponding to the root portion of the tooth 32, and is formed to have an arc-shaped cross section so as to extend along the circumferential direction. Two slits 19 (a first slit 19a and a second slit 19b) are formed at equal intervals in the circumferential direction on the outer wall portion 18a.
These slits 19a and 19b are for drawing the winding 5 wound around the teeth 32 radially outward. An engaging claw 33a that engages with the floating prevention ring 7 (described later) is formed substantially at the center in the circumferential direction of the outer wall portion 18a so as to protrude radially outward.

On the other hand, the inner wall portion 18b is arranged at a portion corresponding to the radially inner end face of the flange portion 14, and is formed so as to have an arc-shaped cross section so as to extend along the circumferential direction. That is, the circumferential length of the outer wall portion 18a is set longer than the circumferential length of the inner wall portion 18b. A concave portion 20 is formed in a large part at the center in the circumferential direction of the inner wall portion 18b. The depth of the recess 20 is set to be smaller than the depth of the slits 19a and 19b of the outer wall portion 18a.
Further, between the outer wall portion 18a and the inner wall portion 18b, a teeth covering portion 18c that covers the teeth body 13 is integrally formed.

(Operation of electric pump)
Next, the operation of the electric pump 1 configured as described above will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the current supplied to the board 23 via the connector terminal 55 of the connector housing 54 is selectively wound around the stator 40 by the IC element 25 and each switching element 24. It is supplied to the coil 6. In this way, a desired magnetic flux is formed on the stator 40. Magnetic attraction or repulsion occurs between the magnetic flux and the permanent magnet 83 of the rotor 80, and the rotor 80 rotates.

When the rotor 80 rotates, the inner rotor 102 of the pump unit 3 also rotates.
Then, the volume of the working chamber 103 formed by the inner rotor 102 and the outer rotor 101 changes, so that oil is sucked into the pump chamber 91 via the suction port 110b, and is discharged through the discharge port 111b. At this time, the oil sucked into the pump chamber 91 through the suction port 110b also flows into the can 9 through the sub suction chamber 104 and the sub communication hole 106.

(Structure of stator winding)
Next, the structure of the winding 5 (coil 6) around which the stator 40 is wound will be described with reference to FIG.
As shown in FIG. 6, the windings 5 are wound around the stator 40 from above the teeth covering portions 18c of the insulators 16 and the insulators 17 of the teeth main body 13 of each of the split cores 10 by a concentrated winding method. , The coil 6 is formed. The winding 5 is wound in a plurality of layers, and is arranged and wound in a bale shape. Here, the bale shape means a state in which the windings 5 of adjacent layers are stacked with a displacement corresponding to a radius of the thickness of the windings 5.

The inner surface 14a of the flange 32 of the tooth 32 on the slot 15 side is formed so as to be inclined so that the windings 5 of each layer are stacked in a bale shape. The insulator 16 and the insulator 17 are also formed along the inner side surface 14 a of the flange portion 14. Therefore, the windings 5 are reliably stacked in a bale shape.
Here, when winding the winding 5 around each divided core 10, the winding work of the winding 5 is continuously performed by arranging the divided cores 10 in a horizontal line. Thereafter, the stator 40 is assembled by connecting the divided cores 10 in an annular shape. These operations will be described in detail below.

(How to wind the winding around each split core)
FIG. 7 is an explanatory diagram showing the winding order of the windings 5 on each of the split cores 10.
The stator 40 of the present embodiment has three phases (U phase, V phase, and W phase). Since each of the split cores 10 is allocated in the order of the U-phase, the V-phase, and the W-phase, the winding cores 5 are also arranged in this order. That is, in FIG. 7, from the left, in order from the left, the first U-phase, the first V-phase, and the first W-phase split cores 10 (U1), 10 (V1), 10 (W1), and then 2 The split cores 10 (U2), 10 (V2), and 10 (W2) of the first U phase, the second V phase, and the second W phase are arranged.

  In this state, the winding 5 is first drawn into and wound around the first W-phase split core 10 (W1) to form the W-phase coil 6. Subsequently, the winding 5 drawn from the first W-phase split core 10 (W1) is passed to the second W-phase split core 10 (W2) to form the in-phase crossover 61. Subsequently, the winding 5 is drawn into and wound around the second W-phase split core 10 (W2) to form the W-phase coil 6.

Next, the winding 5 drawn from the second W-phase split core 10 (W2) is passed to the first V-phase split core 10 (V1) to form a different-phase crossover 62.
Subsequently, the winding 5 is drawn and wound around the first V-phase split core 10 (V1) to form the V-phase coil 6. Subsequently, the winding 5 drawn from the first V-phase split core 10 (V1) is passed to the second V-phase split core 10 (V2) to form an in-phase crossover 61. Subsequently, the winding 5 is drawn into and wound around the second V-phase split core 10 (V2) to form the V-phase coil 6.

Next, the winding 5 drawn from the second V-phase split core 10 (V2) is passed to the first U-phase split core 10 (U1) to form a different-phase crossover 62.
Subsequently, the winding 5 is drawn into and wound around the first U-phase split core 10 (U1) to form the U-phase coil 6. Subsequently, the winding 5 drawn from the first U-phase split core 10 (U1) is passed to the second U-phase split core 10 (U2) to form the in-phase crossover 61. Then, the winding 5 is pulled out from the second U-phase split core 10 (U2). Thus, the operation of winding the winding 5 around each of the divided cores 10 is completed.

  Here, each out-of-phase bridging wire 62 is finally cut, and each end and the start line end and the end line end of the winding 5 are swaged and fixed to the swaged portion 56c (described later) of the corresponding connection terminal 56. . The different-phase crossover 62 may be cut each time the different-phase crossover 62 is formed, or after the winding operation of all the windings 5 is completed, the different-phase crossover 62 is put together. May be cut.

(Method of Connecting Each Divided Core) FIGS. 8A, 8B, and 8C are explanatory views showing one process of a method of connecting each divided core 10 after the winding operation of the winding 5 is completed.
As shown in FIGS. 8A and 8B, at the time when the winding operation of the windings 5 on each of the divided cores 10 is completed, each of the divided cores 10 is held in a horizontal line by the clamp jig 63. Has become. From this state, these divided cores 10 are wound up using a cylindrical assembly jig 64. Specifically, each split core 10 is wound so that the inner circumferential surface of the flange 14 of each split core 10 contacts the outer circumferential surface of the assembly jig 64. The diameter of the assembly jig 64 is set to be the same as the diameter (inner diameter of the stator 40) along the circle connecting the radially inner peripheral surfaces of the flanges 14 of the teeth 32 of the divided cores 10 constituting the stator 40. .
Here, the roundness of the assembly jig 64 is set as high as possible.

  As shown in FIG. 8C, each of the divided cores 10 wound by using the assembly jig 64 has a substantially annular shape. In this state, pressure is applied radially inward from the outer peripheral surface 30b of the split back yoke 30 of each split core 10 (see arrow F1 in FIG. 8C).

  Then, as shown in FIG. 10, the connecting portions 12a and 12b formed at both ends in the circumferential direction of the divided back yoke 30 are respectively connected, and the divided back yoke 30 forms an annular back yoke 31. The in-phase crossover wires 61 are respectively wired along the outer peripheral surface of the outer wall portion 18a of the first insulator 16.

Here, the outer wall portion 18a is arranged at a position corresponding to the root portion of the tooth 32. For this reason, the in-phase crossover 61 and the cut out-of-phase crossover 62 are accommodated in the connection portion (corner) between the axial end of the insulator main body 16a of the first insulator 16 and the outer wall portion 18a.
Also, by winding each of the divided cores 10 in a substantially annular shape, the in-phase crossover wires 61 located between the adjacent divided cores 10 will be loosened. Press inward in the radial direction. By doing so, the floating prevention ring 7 (described later) can be easily mounted on the first insulator 16 of the stator 40.
And finally, the assembly of the stator 40 is completed by extracting the assembly jig 64.

(Floating prevention ring)
Returning to FIG. 4, the stator 40 assembled in this manner is placed on the first insulator 16 around which the in-phase crossover 61 and the cut out-of-phase crossover 62 are routed (to the upper end in the axial direction in FIG. 4). ), A floating prevention ring 7 is provided. The floating prevention ring 7 is for preventing the coils 6, the in-phase crossover wires 61, and the cut out-of-phase crossover wires 62 from floating when insert molding the stator 40 into the motor case 50. The floating prevention ring 7 is formed of resin.

  In addition, the floating prevention ring 7 can be attached to the second insulator 17. However, in this embodiment, since the in-phase crossover 61 and the cut out-of-phase crossover 62 are routed on the first insulator 16, they are mounted on the first insulator 16. When the in-phase crossover 61 and the cut out-of-phase crossover 62 are routed on the second insulator 17, the floating prevention ring 7 is mounted on the second insulator 17.

  The floating prevention ring 7 is formed in a ring shape so as to surround the outer wall portion 18 a of the first insulator 16 and the second insulator 17. The outer diameter of the floating prevention ring 7 is set substantially equal to the outer diameter of the back yoke 31. That is, the in-phase crossover 61 wired on the first insulator 16 and the cut out-of-phase crossover 62 are covered with the floating prevention ring 7 from above in the axial direction. This prevents the in-phase crossover 61 and the cut out-of-phase crossover 62 from rising.

Further, a crossover wire retainer 73 is integrally formed on the inner peripheral surface of the floating prevention ring 7 at a position corresponding to a position between the adjacent divided cores 10. The crossover wire presser 73 is for regulating the lifting (displacement) of the in-phase crossover wire 61 located between the adjacent divided cores 10.
The crossover wire retainer 73 is formed so as to protrude from the floating prevention ring 7. The crossover wire presser 73 is formed in a triangular shape so as to taper toward the end of the stator 40 in the axial direction, and presses the in-phase crossover wire 61 at one side 73a inclined with respect to the axial direction. For this reason, the displacement of the in-phase crossover 61 is regulated by the crossover presser 73 while being pressed radially inward and in the axial direction on the opposite side (the lower side in the axial direction in FIG. 1) from the floating prevention ring 7.

  Here, the in-phase crossover wires 61 located between the adjacent divided cores 10 are pushed inward in the radial direction corresponding to the slack when the divided cores 10 are connected. Therefore, when the floating prevention ring 7 is mounted on the first insulator 16, the floating prevention ring 7 can be easily mounted without forcibly pushing the in-phase crossover 61 by the crossover presser 73.

Further, the crossover wire presser 73 is formed such that when the floating prevention ring 7 is placed on the first insulator 16, the distal end abuts on the connecting portions 12 a and 12 b of the split core 10. Thereby, a predetermined gap S is formed between the floating prevention ring 7 and each of the divided cores 10. That is, the crossover wire presser 73 not only presses the in-phase crossover wire 61 but also has a function of positioning the floating prevention ring 7 with respect to the first insulator 16.
Further, an engagement recess 7 a is formed in the floating prevention ring 7 at a position corresponding to the engagement claw 33 a formed to protrude from the outer wall portion 18 a of the first insulator 16. The engaging recess 7a is capable of engaging with the engaging claw 33a. Thereby, the floating prevention ring 7 is snap-fitted and fixed on the first insulator 16.

  In addition, a substantially rectangular parallelepiped connection base portion 75 is integrally formed on one side of the floating prevention ring 7. The connection terminals 56 are embedded in the connection base 75 so as to correspond to three phases. The connection terminal 56 is formed to have a substantially L-shaped cross section, and is arranged so that one end 56a side extends along the axial direction and the other end 56b (see FIG. 2) side extends along the radial direction. One end 56a of the connection terminal 56 projects from the bottom surface 53a of the housing recess 53 of the motor case 50 (see FIGS. 2 and 3).

The other ends 56b of the connection terminals 56 are electrically connected to the ends of the corresponding windings 5 (a total of six ends, namely, a starting end and an end of the windings and ends of the cut out-of-phase crossover 62). Connected to.
Specifically, each of the cut out-of-phase crossover wires 62 extends along the gap S formed between the floating prevention ring 7 and each of the split cores 10 and in the radial direction of the crossover presser 73 of the floating prevention ring 7. It is led to the connection base 75 so as to bypass the outside. Each of these out-of-phase connecting wires 62 is electrically connected to the other end 56b of the corresponding connection terminal 56. The coils 6 (U1 to W2) of each phase are delta-connected.

(Motor case injection molding method)
Next, the motor case 50 and insert molding of the stator 40 into the motor case 50 will be described.
First, the stator 40 to which the floating prevention ring 7 is attached, the collar 58, the connection terminals 56, and the like are fixed in the mold 200 (stator setting step). At this time, the connection terminals 56 of the floating prevention ring 7 and the ends of the windings 5 corresponding to the respective connection terminals 56 (the start and end ends of the winding, and the ends of the cut out-of-phase connecting wires 62). Are connected in advance. At the radial center of the stator 40 in the mold 200, a core mold 65 (see FIGS. 8A and 8B) having an increased roundness is set similarly to the assembly jig 64. This is because the winding process of each split core 10 and the injection process of the motor case 50 are performed by independent processing machines, and the durability of the assembling jig 64 and the core mold 65 for the original intended use is improved. Is considered.

Next, the molten resin is poured into the mold shown in FIG. 11 to form the motor case 50, and the stator 40 is insert-molded into the motor case 50 (motor case forming step). Thereafter, the motor case 50 is removed from the mold 200, and the injection molding of the motor case 50 (insert molding of the stator 40) is completed.
As shown in FIG. 4, the stator 40 insert-molded in the motor case 50 is in a state where only the radially inner peripheral surface of the flange portion 14 of each tooth 32 is exposed. For this reason, the air gap between the stator 40 and the rotor 80 can be reduced to the minimum necessary, so that the magnetic flux can be effectively transferred and the waterproofness of the stator 40 can be secured.

  In the mold 200 used here, a total of six gates 100 for injecting molten resin into the cavity corresponding to the case body 51 of the motor case 50 are arranged at equal intervals in the circumferential direction. ing. The six gates 100 are mounted on the mold 200 such that the positions of the six gate portions P1 on the bottom surface 51c of the molded case main body 51 are set at positions corresponding to the radial outside of the core main body 11. Are located.

  Therefore, on the bottom surface 51c of the case main body 51 of the motor case 50 taken out of the mold 200, a total of six gate portions P1 are arranged at positions corresponding to the radially outer side of the core main body 11 at equal intervals in the circumferential direction. ing.

Here, the resin pressure acting on the stator 40 during insert molding will be described in detail with reference to FIGS.
FIG. 9 is an explanatory diagram showing a gate position P1 of the mold 200 with respect to the motor case 50 (a gate portion P1 as a trace of a gate). FIG. 10 is an explanatory diagram showing a gate position P1 of the mold 200 with respect to the stator 40. FIG. 11 is an explanatory diagram showing a flow of the resin when the resin is injected into the mold 200.
As shown in FIG. 9, six gate positions P1 are set at equal intervals in the circumferential direction near the connection portion (corner) between the outer peripheral surface 51b and the bottom surface 51c of the case body 51. When this gate position P1 is viewed in terms of the positional relationship with the stator 40, as shown in FIG. 10, the gate position P1 is located on one axial end side of the stator 40 and is radially outside of each of the divided back yokes 30. And at the center in the circumferential direction.

In this state, the molten resin is simultaneously injected into the mold 200 from each gate position P1. The injected resin passes through the outer peripheral side of the stator 40 as shown by an arrow Y1 in FIG. 4 and FIG. 11, from the end opposite to the side where the respective crossover wires 61 and 62 of the stator 40 are wired. It flows to the side where the crossovers 61 and 62 are wired. That is, the resin flows in a direction in which the crossover wires 61 and the crossover wires 62 rise from the axial end 10a of the split core 10.
However, since the floating prevention ring 7 is attached to the stator 40, the floating is restricted even when each of the crossover wires 61 and 62 is subjected to the resin pressure at the time of resin injection. Moreover, the floating prevention ring 7 is fixed to the first insulator 16 of the stator 40 by snap fitting. For this reason, the floating of the crossover 61 and the crossover 62 is reliably restricted by the floating prevention ring 7.
Since the concave portion 31b is formed at a position corresponding to the connecting portion 12a and the connecting portion 12b of the back yoke 31, the resin injected from each gate P1 flows easily.

Also, the flow of the resin simultaneously injected into the mold 200 from the position of the gate 100 corresponding to each gate portion P1 is filled into the cavity corresponding to the case main body portion 51 at the same speed and spreads. Here, the flow of the resin injected from each gate 100 spreads in the cavity at the same speed as the flow of the resin injected from the position of the gate 100 adjacent on both sides, and is formed at a position where the flows merge. The weld line L is formed substantially at the center between the gate portions P1. Further, since the gate portions P1 are located at equal intervals along the circumferential direction, the weld lines L formed substantially at the center between the gate portions P1 are also located at equal intervals along the circumferential direction.
In this manner, the weld line L located substantially at the center in the circumferential direction between the adjacent gate portions P1 is formed on the bottom surface 51c (see FIG. 9) and the outer peripheral surface 51b of the case main body 51 where the resin flows merge. .

  As shown in FIG. 10, each split core 10 is pressed from the radially outer side to the radially inner side by the resin pressure (arrow F2 in FIG. 10). Therefore, the split cores 10 are displaced so as to reduce the diameter in a well-balanced manner corresponding to the play of the connecting portions 12a and the connecting portions 12b. At this time, since the core mold 65 having an increased roundness is set on the radially inner side of the stator 40, the radial inner circumferential surface of the flange portion 14 of the teeth 32 is formed on the outer peripheral surface of the core mold 65. The faces abut. Accordingly, the roundness of the back yoke 31 of the stator 40 is increased, and the molten resin can be prevented from flowing around the inner peripheral surface of the flange portion 14 during resin molding.

This will be described more specifically with reference to FIG.
FIG. 12 is a graph showing the variation in the roundness of the back yoke 31 when the horizontal axis is the number of measurement samples of the stator 40 and the vertical axis is the numerical value of the roundness of the back yoke 31.
As shown in FIG. 12, the roundness of the back yoke 31 of the stator 40 is smaller (roundness) after the insert molding of the motor case 50 than before the insert molding of the motor case 50. (High degree) and small variation.

  As described above, in the above-described embodiment, when the stator 40 including the plurality of (for example, six in the present embodiment) divided cores 10 is insert-molded into the motor case 50, the gate position P1 is set to the divided back yoke 30. Are arranged at equal intervals in the circumferential direction on the outer side in the radial direction. Thereby, each split core 10 is pressed from the radial outside to the radial inside by the resin pressure (arrow F2 in FIG. 10). For this reason, since the displacement is performed so as to reduce the diameter in a well-balanced manner corresponding to the play of the connecting portion 12a and the connecting portion 12b of each split core 10, deterioration of the roundness of the stator 40 can be suppressed.

The number of gate positions P1 is set to the same number (six) as the number of split cores 10. In other words, the number of the gate positions P1 is set to be the same as the number of the teeth 32.
Therefore, the resin pressure can be applied to each of the divided cores 10 in a well-balanced manner, and the deterioration of the roundness of the stator 40 can be reliably suppressed.
Further, each gate position P1 is set at the center of each divided back yoke 30 in the circumferential direction.
Therefore, resin pressure can be applied to each of the divided core bodies in a more balanced manner. For this reason, the deterioration of the roundness of the stator 40 can be suppressed more reliably.

Further, since the resin is simultaneously injected into the mold 200 from each gate position P1, the resin pressure can be applied to each of the divided cores 10 at the same time. For this reason, the deterioration of the roundness of the stator 40 due to a shift in the timing at which the resin pressure is applied can be reliably suppressed.
Furthermore, when insert molding the stator 40 into the motor case 50, a core mold 65 having an increased roundness is set inside the stator 40 in the radial direction. For this reason, due to the resin pressure, the inner peripheral surface of the flange portion 14 of the teeth 32 abuts on the outer peripheral surface of the core die 65, and the roundness of the stator 40 can be improved.

  In addition, a board storage part 52 constituting a part of the control unit 4 is integrally formed with the motor case 50. Therefore, the entire motor unit 2 can be reduced in size, and furthermore, a small and high-performance electric pump 1 can be provided.

Note that aspects of the present invention are not limited to the above-described embodiments, and include various modifications of the above-described embodiments without departing from the spirit of the aspects of the present invention.
For example, in the above-described embodiment, a case has been described in which the electric pump 1 is an electric pump for supplying oil to a transmission mounted on an automobile (all of which are not shown) in order to drive the transmission. However, the present invention is not limited to this, and the electric pump 1 can be used for various purposes.

In addition, the case where the gate position P1 is set at six positions when insert molding the stator 40 into the motor case 50 has been described. However, the present invention is not limited to this, and at least three gate positions P1 may be set. Then, the gate positions P1 may be arranged at equal intervals. With this configuration, resin pressure can be applied to the outer peripheral surface of the stator 40 in a well-balanced manner.
More preferably, the gate position P1 may be set to a multiple of the number of phases of the stator 40 (that is, three phases (U phase, V phase, W phase) in the present embodiment). With this setting, it is possible to arrange the gate position P1 at the center of each divided back yoke 30 in the circumferential direction. Therefore, the resin pressure can be applied to the outer peripheral surface of each divided back yoke 30 with good balance.

  In the above-described embodiment, the case where the gate position P <b> 1 is located at one axial end of the stator 40, and is located radially outside of each divided back yoke 30 and at the center in the circumferential direction is described. did. However, the gate position P1 does not necessarily have to be set at one axial end of the stator 40, and it is sufficient that the gate positions P1 are arranged radially outward of each divided back yoke 30 at equal intervals in the circumferential direction.

Further, in the above embodiment, the rotor 80 has four permanent magnets 83, the stator 40 has six teeth 32 (split cores 10), and the stator 40 has a three-phase structure. explained. However, the present invention is not limited to this, and the number of permanent magnets 83 and the number of teeth 32 can be arbitrarily set.
In the above-described embodiment, in addition to the assembling jig 64 used to connect the divided cores 10, when inserting the stator 40 into the motor case 50, another core mold 65 is used. The case has been described. However, the present invention is not limited to this. The assembly jig 64 used for connecting the divided cores 10 can be used to insert the stator 40 into the motor case 50 by modifying the assembly process and durability. Can also be used.

1: Electric pump 2: Motor part (brushless motor)
3 ... Pump part 5 ... Winding 6 ... Coil 10 ... Split core 11 ... Core body
12a, 12b ... Connecting part 14 ... Flange part (radial inner end of stator)
30: split back yoke 31: back yoke (core body)
31a ... outer peripheral surface
31b ... recess 32 ... teeth 40 ... stator 50 ... motor case
51c ... Bottom (bottom)
52: board storage unit (storage room)
54… Connector housing
61 ... In-phase crossover (crossover)
62: Out-of-phase crossover (crossover)
64: Assembly jig (core material)
73 crossover wire holder 80 rotor P1 gate part (gate position)
100: gate 200: mold

Claims (9)

A resin motor case,
A stator embedded in the motor case;
A rotor rotatably supported by the motor case,
With
The stator is
A ring-shaped core body,
A plurality of teeth extending in a radial direction from the core main body, around which a winding is wound;
With
The core body includes a plurality of split cores connected via a connection portion,
At the bottom of the motor case , gates as traces of a plurality of gates of a mold for injecting a resin melted during molding are provided as many as the number of the teeth,
A recess along the axial direction is formed on the outer peripheral surface of the core body by the connecting portion,
The position of each of the gate portions is a location corresponding to the radially outer side of the core body, is set at the center in the circumferential direction of the divided core , and the gate portions are arranged at equal intervals in the circumferential direction. Brushless motor. The brushless motor according to claim 1, wherein
A crossover wire that is arranged at an end of the core body opposite to the gate portion and that connects the windings of the plurality of teeth to each other;
A crossover wire presser disposed on the opposite side to the core body with the crossover wire therebetween and provided along the outer periphery of the core main body,
Brushless motor with The brushless motor according to claim 1 or 2 , wherein
The motor case is a brushless motor having traces of the resin being simultaneously injected from the plurality of gates of the mold, respectively. The brushless motor according to claim 3 , wherein
The trace is a weld line in which the flow of the injected resin is merged and solidified, and the plurality of weld lines are located at equal intervals along the circumferential direction, and are adjacent to both sides in the circumferential direction. A brushless motor located approximately at the center between gates. The brushless motor according to any one of claims 1 to 4 , wherein
A brushless motor in which a storage chamber that stores a control unit that controls the energization of the windings and a connector housing provided on one side of the storage chamber are integrally formed in the motor case. A brushless motor according to any one of claims 1 to 5 ,
A pump unit driven by the brushless motor,
Electric pump with. A resin motor case,
A stator embedded in the motor case;
A rotor rotatably supported by the motor case,
With
The stator is
A ring-shaped core body,
Teeth extending radially from the core body and winding the winding,
A crossover wire that connects the windings wound for each of the teeth and is arranged at an axial end of the core body,
A crossover wire presser provided along the outer diameter of the core body, on the opposite side of the crossover wire from the core body;
With
The core body includes a plurality of split cores connected via a connection portion,
A method of manufacturing a brushless motor in which a concave portion along an axial direction is formed on an outer peripheral surface of the core body by the connecting portion ,
A winding step of winding the winding around the teeth to form the crossover,
Connecting the plurality of split cores, a split core connecting step of forming the core body,
A stator setting step of fixing the stator in a mold for forming the motor case,
A crossover wire press arranging step of arranging the crossover presser on the crossover,
A motor case forming step of injecting the resin melted in the mold from the side opposite to the crossover in the axial direction of the stator, so that the core body is acted upon by a resin pressure directed radially inward,
A method for manufacturing a brushless motor having: It is a manufacturing method of the brushless motor of Claim 7 , Comprising:
Providing a plurality of gates for injecting the molten resin into the mold,
In the motor case forming step, a method of manufacturing a brushless motor that simultaneously injects the resin from each of the gates. It is a manufacturing method of the brushless motor of Claim 7 or Claim 8 , Comprising:
The teeth extend radially inward from the core body,
In the stator setting step, a core is arranged at a radial center of the stator,
In the motor case forming step, a method of manufacturing a brushless motor in which a radially inner end of the stator abuts on an outer peripheral surface of the core material.

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