JP6851851B2 - Stator and brushless motor - Google Patents

Description

The techniques disclosed herein relate to stators and brushless motors used in brushless motors.

When the electric power for controlling the motor is supplied to the motor, electromagnetic noise is generated from the motor. Patent Document 1 discloses a technique for reducing electromagnetic noise of a brushed motor. The motor of Patent Document 1 is used for a fuel pump. A shield structure is arranged at one end of the motor. The shield structure includes an outer cover attached to the fuel outlet of the fuel pump and a conductive outer coating layer covering the outer surface of the outer cover. The outer cover is pierced by a conductive pin that is electrically connected to the brush of the motor. That is, the conductive pin is exposed to the outside from the outer cover.

Japanese Unexamined Patent Publication No. 2003-42030

In a brushless motor, when power is supplied to the stator via an external terminal connected to the energized terminal, electromagnetic noise generated by switching is emitted from the energized terminal to the outside.

The present specification provides a technique capable of suppressing transmission of electromagnetic noise from an energized terminal to the outside.

The techniques disclosed herein relate to stators used in brushless motors. The stator is arranged on the core, the energizing terminal protruding from the core, on the peripheral side of the stator from the energizing terminal, at least on the side opposite to the core from the tip of the energizing terminal, and near the tip of the energizing terminal. It is provided with a conductive shielding wall to be formed.

According to this configuration, it is possible to suppress the electromagnetic noise radiated from the energizing terminal from being transmitted over the shielding wall.

The stator may further include a resin partition wall arranged between the energizing terminal and the shielding wall. According to this configuration, the electrical path between the energizing terminal and the shielding wall can be lengthened. As a result, electrolytic corrosion of the energizing terminal can be suppressed.

The stator further includes a resin outer wall located at the end of the core, and the partition wall may be integrally formed with the outer wall. According to this configuration, when the outer wall of the stator is manufactured by molding, the shielding wall can be manufactured integrally with the outer wall.

The partition wall may have a shape along the connector of the external terminal to be connected to the energizing terminal. According to this configuration, the partition wall can guide the external terminal when connecting the external terminal and the energizing terminal. As a result, when connecting the external terminal and the energizing terminal, the force applied to the energizing terminal can be reduced.

The stator may further include a ground terminal. The shielding wall may be manufactured integrally with the ground terminal. According to this configuration, the barrier wall can be easily arranged.

The ground terminal may be arranged on the opposite side of the energizing terminal to the shielding wall. According to this configuration, it is possible to suppress the radiation of electromagnetic noise from the energized terminal to the side where the blocking wall is not arranged by the ground terminal.

A brushless motor comprising the above-mentioned stator, that is, a brushless motor including any of the above-mentioned stators and a rotor housed in the stator and rotatably arranged with respect to the stator is also new and useful. ..

The vertical sectional view of the fuel pump of this Example is shown. The front view of the stator of an Example is shown. The perspective view of the stator of an Example is shown. The cross-sectional view of the vicinity of the shielding wall of the IV-IV cross section of FIG. 3 is shown. The cross-sectional view of the VV cross section of FIG. 2 is shown. A perspective view showing a state in which the outer wall and the partition wall of the stator of the embodiment are removed is shown. The perspective view of the energizing terminal of an Example is shown. The perspective view of the state where the fixed part is attached to the energizing terminal of an Example is shown. The perspective view of the ground terminal part of an Example is shown. The perspective view of the terminal part of an Example is shown. A front view of the vicinity of the terminal portion in a state where the outer wall and the partition wall of the stator of the embodiment are removed is shown. A vertical cross-sectional view of a modified fuel pump is shown. A vertical cross-sectional view of a modified fuel pump is shown. A cross-sectional view of a portion corresponding to the VV cross section of FIG. 2 in the fuel pump of the modified example is shown.

The stator 60 of this embodiment is used for the fuel pump 10. The fuel pump 10 is arranged in a fuel tank (not shown) and supplies fuel (for example, gasoline or the like) to an engine (not shown) of a vehicle such as an automobile. As shown in FIG. 1, the fuel pump 10 includes a motor unit 50 and a pump unit 30. The motor unit 50 and the pump unit 30 are arranged in the housing 2. The housing 2 has a cylindrical shape with both ends open.

The pump unit 30 includes a casing 32 and an impeller 34. The casing 32 closes the opening at the lower end of the housing 2. A suction port 38 is provided at the lower end of the casing 32. At the upper end of the casing 32, a communication hole (not shown) for communicating the inside of the casing 32 and the motor portion 50 is provided. The impeller 34 is housed in the casing 32.

The motor unit 50 is located above the pump unit 30. The motor unit 50 is a brushless motor and is a three-phase motor. The motor unit 50 includes a rotor 54 and a stator 60. The rotor 54 includes a permanent magnet. A shaft 52 penetrates and is fixed to the center of the rotor 54. The lower end of the shaft 52 is inserted into and penetrates the central portion of the impeller 34. The rotor 54 is rotatably supported around the shaft 52 by bearings arranged at both ends of the shaft 52. In the embodiment, the upper and lower parts are defined in the state of FIG. That is, the pump unit 30 is located "lower" when viewed from the motor unit 50, and the motor unit 50 is located "upper" when viewed from the pump unit 30.

The stator 60 includes a resin layer 66, a core 90, a plurality of (six in this embodiment) coils 96 arranged on the core 90, and a terminal group 70. The core 90 has a cylindrical shape. The core 90 is composed of a core plate group (92, 92, ...) And an insulator 94 provided on the surface of the core plate group (92, 92, ...). The core plate group (92, 92, ...) Is composed of a plurality of core plates 92. In FIG. 1, hatching showing the cross sections of the plurality of core plates 92 is omitted in order to give priority to visibility. Further, the core plate group (92, 92, ...) Is exposed on the side surface of the core 90, but in FIG. 2 and the like, each core plate 92 of the core plate group (92, 92, ...) Is described. Is omitted. A plurality of core plates 92 are laminated in the vertical direction, and each core plate 92 is formed of a magnetic material. A plurality of core plate groups (92, 92, ...) Extend from the inner peripheral surface of the stator yoke 93 toward the central axis of the stator yoke 93, and the cylindrical stator yoke 93 forming the side wall of the stator 60 (this implementation). In the example, 6) teeth 91 and. The insulator 94 is made of an insulating resin material. The insulator 94 covers the surface of a core plate group (92, 92, ...) Consisting of a plurality of laminated core plates 92.

A bobbin 99 formed by an insulator 94 is arranged in each of the plurality of teeth 91. A coil 96 is arranged on the bobbin 99. The coil 96 is manufactured by winding the lead wire 97 around the bobbin 99. The coil 96 is electrically connected to the terminal group 70. Further, the coil 96 is electrically connected to the common terminal 77 at the lower end of the stator 60. The common terminal 77 is electrically connected to the six coils 96.

Next, the connection state between the coil 96 and the terminal group 70 will be described. FIG. 6 is a perspective view showing a configuration of the stator 60 excluding the resin layer 66. The lead wires 97 of each of the three-phase coils 96 are arranged in the circumferential direction of the core 90 at the upper end of the core 90. The terminal group 70 is electrically connected to the coil 96 by being connected to the lead wire 97 at the upper end of the core 90.

The terminal group 70 includes a plurality of (three in this embodiment) energizing terminal portions 72 and a ground terminal portion 74. The energizing terminal portion 72 is a terminal for supplying each of the U phase, the V phase, and the W phase to the coil 96. FIG. 7 shows a perspective view of the three energizing terminals 72U, 72V, and 72W. As shown in FIG. 7, the energizing terminal portion 72 includes three energizing terminals 72U, 72V, 72W corresponding to each phase of the U phase, the V phase, and the W phase, and a connecting portion 72a. The energizing terminals 72U, 72V, 72W are made of a conductive material. The energizing terminals 72U, 72V, and 72W extend parallel to the axial direction of the stator 60.

The connecting portion 72a extends perpendicularly to the axial direction of the stator 60 from the lower ends of the energizing terminals 72U, 72V, and 72W. The U-phase terminal 72U is electrically connected to the lead wire 97 of the U-phase coil 96 via the connecting portion 72a. Similarly, the V-phase terminal 72V is electrically connected to the lead wire of the V-phase coil 96 via the connecting portion 72a, and the W-phase terminal 72W is electrically connected to the lead wire of the W-phase coil 96 via the connecting portion 72a. Has been done. Each of the three energizing terminals 72U, 72V, and 72W includes a contact portion 72b that contacts the lead wire 97.

As shown in FIG. 8, the three energizing terminals 72U, 72V, and 72W are connected to each other by the fixing portion 73. The fixing portion 73 is made of resin. The fixing portion 73 covers the connecting portion 72a of the three energizing terminals 72U, 72V, and 72W. As shown in FIG. 10, a ground terminal portion 74 is attached to the fixed portion 73. The ground terminal portion 74 is electrically insulated from the energizing terminal portion 72 with the fixed portion 73 interposed therebetween.

FIG. 9 shows a perspective view of the ground terminal portion 74. The ground terminal portion 74 includes a ground terminal 76, a shielding portion 78, and a connecting portion 79. The ground terminal 76, the shielding portion 78, and the connecting portion 79 are integrally manufactured. Here, "integrally manufactured" means that the ground terminal 76 and the shielding portion 78 are connected, and there is no joint such as welding between the ground terminal 76 and the shielding portion 78, for example, 1. It means that it is formed from a single metal plate.

The ground terminal 76 extends parallel to the axial direction of the stator 60. That is, the ground terminal 76 is arranged in parallel with the energizing terminals 72U, 72V, and 72W. The ground terminal 76 is arranged on the side opposite to the shielding portion 78 of the energizing terminals 72U, 72V, 72W, and is arranged closer to the central axis of the stator 60 than the energizing terminals 72U, 72V, 72W. A connecting portion 79 is arranged at the lower end of the ground terminal 76. The connecting portion 79 extends vertically from the lower end of the ground terminal 76 in the axial direction of the stator 60. The connecting portion 79 makes a round at the upper end of the core 90 in the circumferential direction of the core 90. As shown in FIG. 6, the connecting portion 79 is arranged above the plurality of coils 96.

As shown in FIG. 10, the ground terminal 76 is connected to the shielding portion 78 via the connecting portion 79. The shielding portion 78 includes shielding walls 78a, 78b, and 78c. As shown in FIGS. 10 and 11, in a state where the energizing terminal portion 72 and the grounding terminal portion 74 are assembled to the fixed portion 73, the shielding wall 78a is arranged around the energizing terminal 72U. The shielding wall 78a extends from a position that does not overlap the vertical tip (that is, the upper end) of the energizing terminal 72U on the opposite side of the core 60, that is, upward. As shown in FIG. 6, the shielding wall 78a is located on the outer peripheral side of the rotor 54 with respect to the energizing terminal 72U. In the direction perpendicular to the axial direction of the rotor 54, the shielding wall 78a is curved and surrounds the outer peripheral side of the rotor 54 of the energizing terminal 72U. Further, the shielding wall 78a extends downward beyond the tip of the energizing terminal 72U at the right end of FIG. 11 and is connected to the connecting portion 79.

Similar to the shielding wall 78a for the energizing terminal 72U, the shielding wall 78c is arranged with respect to the energizing terminal 72W. As shown in FIGS. 10 and 11, the shielding wall 78b is separated into two in the left-right direction of FIG. It extends from the vicinity of the tip of the energizing terminal 72V in the vertical direction to the opposite side of the core 60, that is, upward. The shielding wall 78b surrounds the outer peripheral side of the rotor 54 of the energizing terminal 72V.

As shown in FIG. 6, the terminal group 70 is attached to the core 90 by connecting the fixing portion 73 to the core 90.

As shown in FIG. 1, the resin layer 66 covers the upper end portion, the lower end portion, and the inner peripheral portion of the core 90. The resin layer 66 is arranged in the core 90 by so-called insert molding, in which the combination of the core 90 and the terminal group 70 in the state shown in FIG. 8 is arranged in a molding mold to execute resin molding.

The resin layer 66 includes an outer wall 80, a partition wall 82, a connector 84, and a discharge port 11. The outer wall 80, the partition wall 82, the connector 84, and the discharge port 11 are integrally molded. "Integrally molded" means that the outer wall 80, the partition wall 82, the connector 84, and the discharge port 11 are molded by one resin molding, and no joint appears in any of the portions. The outer wall 80 covers the upper end portion, the lower end portion, and the inner peripheral portion of the core 90. The energizing terminals 72U, 72V, 72W and the grounding terminal 76 project upward from the upper end of the outer wall 80. A partition wall 82, a connector 84, and a discharge port 11 are arranged at the upper end of the outer wall 80. The discharge port 11 has a cylindrical shape. The discharge port 11 communicates with the pump portion 30 via the inside of the core 90.

The partition wall 82 is arranged between the shielding portion 78 and the energizing terminals 72U, 72V, 72W. As shown in FIG. 5, the partition wall 82 is arranged on the surface of the shielding walls 78a, 78b, 78c facing the energizing terminals 72U, 72V, 72W. The partition wall 82 is arranged on the surface of the shielding walls 78a, 78b, and 78c facing the energizing terminals 72U, 72V, and 72W, and covers the entire partition wall 82. Further, as shown in FIGS. 3 to 5, the partition wall 82 covers each of the upper end, the lower end, and the side end of the shielding walls 78a, 78b, and 78c.

The connector 84 is arranged around the ground terminal 76. The connector 84 and the partition wall 82 are formed in a shape that follows the shape of the connector 100 of the external terminal for supplying electric power to the motor unit 50. Thereby, by moving the connector 100 along the connector 84 and the partition wall 82, the external terminal can be connected to the energizing terminals 72U, 72V, 72W and the ground terminal 76. Therefore, when connecting the external terminal to the energizing terminals 72U, 72V, 72W and the grounding terminal 76, the load on the energizing terminals 72U, 72V, 72W and the grounding terminal 76 can be reduced.

When the external terminal and the energizing terminals 72U, 72V, 72W and the ground terminal 76 are connected, the external terminal and the energizing terminals 72U, 72V, 72W are connected to the switching circuit via the external terminal. Further, the ground terminal 76 is grounded via an external terminal. In a situation where the fuel pump 10 is driven, electric power is supplied from the external terminal to the energizing terminals 72U, 72V, and 72W. At this time, electromagnetic noise generated in the switching circuit is radiated at the connection portion between the external terminal and the energizing terminals 72U, 72V, and 72W. In particular, the electromagnetic noise is radiated perpendicular to the direction in which the current flows, that is, the stretching direction of the energizing terminals 72U, 72V, and 72W.

Since the shielding walls 78a, 78b, 78c grounded via the grounding terminal 76 are arranged on the outer peripheral side of the stator 60 of the energizing terminals 72U, 72V, 72W, the shielding walls 78a, 78b, 78c are electromagnetic noise. To absorb. As a result, it is possible to prevent electromagnetic noise from being transmitted beyond the shielding walls 78a, 78b, and 78c.

Further, a partition wall 82 is arranged between the shielding walls 78a, 78b, 78c and the energizing terminals 72U, 72V, 72W. Therefore, the electrical path between the shielding walls 78a, 78b, 78c and the energizing terminals 72U, 72V, 72W can be lengthened. As a result, even when the stator 60 is used as fuel in the fuel tank, it is possible to prevent the energizing terminals 72U, 72V, and 72W from being electrolytically corroded.

Further, although the shielding wall is not arranged on the inner peripheral side of the stator 60 of the energizing terminals 72U, 72V, and 72W, the grounding terminal 76 is arranged. As a result, it is possible to suppress the transmission of electromagnetic noise of the energizing terminals 72U, 72V, and 72W by the ground terminal 76.

Further, since the connecting portion 79 of the ground terminal portion 74 is arranged at the upper end of the coil 96, it is possible to suppress the radiation of electromagnetic noise generated in the coil 96.

Although the embodiments of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

(1) As shown in FIG. 12, a case 200 accommodating the fuel pump 10 may be arranged in order to suppress electromagnetic noise generated from the fuel pump 10. In this case, the case 200 may be grounded via a ground terminal 201 arranged between the outer wall of the housing 2 and the case 200.

(2) In the above embodiment, the shielding walls 78a, 78b, and 78c are electrically connected to the ground terminal 76 and are grounded via the ground terminal 76. However, the shielding walls 78a, 78b, 78c do not have to be electrically connected to the ground terminal 76. In this case, the shielding walls 78a, 78b, and 78c may be installed via a portion different from the ground terminal 76, such as the housing 2. Further, in this case, the shielding walls 78a, 78b, and 78c do not have to be integrally formed with the ground terminal 76.

(3) As shown in FIG. 13, the housing 2 may extend upward along the outer wall 80. According to this configuration, the housing 2 can also suppress the transmission of electromagnetic noise from the energizing terminals 72U, 72V, and 72W.

(4) As shown in FIG. 14, the shielding walls 78a and 78c may also be arranged on the inner peripheral side of the stator 60 of the energizing terminals 72U and 72W. The shielding wall arranged on the inner peripheral side of the stator 60 of the energizing terminals 72U and 72W does not have to be continuously provided with the shielding walls 78a and 78c, and is arranged apart from the shielding walls 78a and 78c. You may be.

(5) The shielding walls 78a, 78b, 78c may extend downward beyond the tips of the energizing terminals 72U, 72V, 72W.

(6) In the above embodiment, the motor unit 50 is used for the fuel pump 10. However, the motor unit 50 may be used in addition to the fuel pump 10 such as a water pump.

In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in this specification or drawings achieve a plurality of objectives at the same time, and achieving one of the objectives itself has technical usefulness.

2: Housing 10: Fuel pump 30: Pump part 50: Motor part 52: Shaft 54: Rotor 60: Stator 66: Resin layer 70: Terminal group 72: Energizing terminal part 72U, 72V, 72W: Energizing terminal 72a: Connecting part 74 : Ground terminal 76: Ground terminal 77: Common terminal 78: Shielding part 78a, 78b, 78c: Shielding wall 79: Connecting part 80: Outer wall 82: Partition 84: Connector 90: Core 96: Coil 97: Lead wire

Claims (6)

A stator used for brushless motors
With the core
The energizing terminal protruding from the core and
A conductive shielding wall arranged on the peripheral side of the stator with respect to the energizing terminal, at least on the side opposite to the core from the tip of the energizing terminal, and near the tip of the energizing terminal.
A resin partition wall arranged between the energizing terminal and the shielding wall is provided .
The septum of the shielding wall, that covers the surfaces other than the surface on the opposite side to the conductive terminal surface facing the stator. Further provided with a resin outer wall located at the end of the core
The stator according to claim 1 , wherein the partition wall is integrally formed with the outer wall. The stator according to claim 1 or 2 , wherein the partition wall has a shape along a connector of an external terminal to be connected to the current-carrying terminal. With a grounding terminal
The stator according to any one of claims 1 to 3 , wherein the shielding wall is integrally manufactured with the ground terminal. The stator according to claim 4 , wherein the ground terminal is arranged on the opposite side of the energizing terminal to the shielding wall. The stator according to any one of claims 1 to 5,
A brushless motor comprising a rotor housed in the stator and rotatably arranged with respect to the stator.

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