JP2024021436A - Motors and power tools - Google Patents

Abstract

An object of the present invention is to provide a motor and a power tool that can prevent a detection element from erroneously detecting the rotation angle of a rotor. A motor 1 includes a stator 2, a rotor 3, and a detection board 4. The stator 2 has a stator core 20 and stator wiring 21. A detection element 41 for detecting the rotation angle of the rotor 3 is mounted on the detection board 4 . Teeth core 5 of stator core 20 includes a cylindrical inner cylinder portion 51 and a plurality of teeth 52 including a body portion 521. The stator wiring 21 includes a coil wire 22 and a crossover wiring 23. The crossover wiring 23 electrically connects the plurality of coil wires 22 wound around the plurality of body parts 521. The motor 1 further includes a shield member 81 that blocks magnetic flux generated in the crossover wiring 23. The shield member 81 has a higher magnetic permeability than air, the detection substrate 4, and the insulator 7, and is arranged between the detection element 41 and the crossover wiring 23. [Selection diagram] Figure 1

Description

TECHNICAL FIELD This disclosure generally relates to motors and power tools. More specifically, the present disclosure relates to a motor including a stator core and a rotor, and a power tool.

Patent Document 1 discloses a disk drive motor in which both end edges of an annular yoke are caulked and fixed so as to be in a sealed state over the entire circumference.

Japanese Patent Application Publication No. 11-32463

By the way, in general, in a motor, a rotor rotates with respect to the stator core by magnetic flux generated when current flows through a plurality of coil wires wound around the stator core. The motor also includes a detection element that detects the rotation angle of the rotor, and controls the rotation of the rotor by controlling the current flowing through each of the plurality of coil wires based on the detection result of the detection element. However, when a current flows through the crossover wiring that electrically connects the plurality of coil wires, the detection element may be affected by the magnetic flux generated from the crossover wiring. That is, there is a problem in that the detection element incorrectly detects the rotation angle of the rotor.

An object of the present disclosure is to provide a motor and a power tool that can prevent a detection element from erroneously detecting the rotation angle of a rotor.

A motor according to one aspect of the present disclosure includes a stator, a rotor, and a detection board. The stator has a stator core and stator wiring. The rotor has magnets and rotates relative to the stator core. A detection element for detecting a rotation angle of the rotor is mounted on the detection board. The stator core includes a tee core, a yoke core, and an insulator. The teeth core includes a cylindrical inner cylinder part in which the rotor is disposed, and a plurality of teeth including a body part protruding outward from the inner cylinder part in a radial direction of the inner cylinder part. do. The yoke core is attached to the plurality of teeth and has a cylindrical shape surrounding the plurality of teeth. The insulator covers at least a portion of the tee core. The stator wiring includes a coil wire and a crossover wiring. The coil wiring is wound around the body through the insulator. The crossover wiring electrically connects the plurality of coil wires wound around the plurality of body parts. The motor further includes a shield member that blocks magnetic flux generated in the crossover wiring. The shield member has higher magnetic permeability than air, the detection board, and the insulator, and is disposed between the detection element and the crossover wiring.

A motor according to one aspect of the present disclosure includes a stator, a rotor, and a detection board. The stator has a stator core and stator wiring. The rotor has magnets and rotates relative to the stator core. A detection element for detecting a rotation angle of the rotor is mounted on the detection board. The stator core includes a tee core, a yoke core, and an insulator. The teeth core includes a cylindrical inner cylinder part in which the rotor is disposed, and a plurality of teeth including a body part protruding outward from the inner cylinder part in a radial direction of the inner cylinder part. do. The yoke core is attached to the plurality of teeth and has a cylindrical shape surrounding the plurality of teeth. The insulator covers at least a portion of the tee core. The stator wiring includes a coil wire and a crossover wiring. The coil wiring is wound around the body through the insulator. The crossover wiring electrically connects the plurality of coil wires wound around the plurality of body parts. The detection element and the crossover wiring are arranged along the axial direction of the rotation axis of the rotor when viewed from a direction perpendicular to the rotation axis of the rotor. The motor further includes a guide member that guides magnetic flux generated in the crossover wiring. The guiding member has higher magnetic permeability than air, the detection substrate, and the insulator. The guiding member is arranged in the axial direction on the opposite side of the detection element with respect to the crossover wiring, or is arranged in parallel with the crossover wiring along the radial direction of the rotating shaft. There is.

A power tool according to one aspect of the present disclosure includes the above motor and a drive shaft. The drive shaft is rotated by the motor.

According to the present disclosure, there is an advantage that it is possible to suppress the detection element from erroneously detecting the rotation angle of the rotor.

FIG. 1 is a sectional view of a motor according to a first embodiment. FIG. 2 is an exploded view of the stator core included in the above motor. FIG. 3 is a schematic diagram of a power tool including the same motor as above. FIG. 4 is an exploded view of the same motor (excluding the base). FIG. 5 is a rear view of the motor (excluding the current control board and base) seen from one end side. FIG. 6 is an enlarged sectional view of the main parts of the same motor. FIG. 7 is a sectional view of the motor according to the second embodiment. FIG. 8 is a sectional view of a motor according to a modification of the second embodiment.

(Embodiment 1)
(1-1) Overview Hereinafter, an overview of the motor 1 according to the first embodiment will be described with reference to FIGS. 1 and 2.

The motor 1 according to the first embodiment includes a stator 2, a rotor 3, and a detection board 4, as shown in FIG.

The stator 2 has a stator core 20 and stator wiring 21. The rotor 3 has magnets 31 and rotates with respect to the stator core 20. A detection element 41 for detecting the rotation angle of the rotor 3 is mounted on the detection board 4 .

As shown in FIG. 1, stator core 20 includes a tee core 5, a yoke core 6, and an insulator 7. As shown in FIG. 2, the tee core 5 includes a cylindrical inner cylinder part 51 in which the rotor 3 is disposed, and a body part 521 that projects outward from the inner cylinder part 51 in the radial direction of the inner cylinder part 51. A plurality of teeth 52 including. The yoke core 6 is attached to the plurality of teeth 52 and has a cylindrical shape surrounding the plurality of teeth 52. The insulator 7 covers at least a portion of the tee core 5, as shown in FIG.

As shown in FIG. 1, the stator wiring 21 includes a coil wire 22 and a crossover wiring 23. The coil wire 22 is wound around the body 521 via the insulator 7. The crossover wiring 23 electrically connects the coil wires 22 wound around the plurality of body parts 521.

The motor 1 further includes a shield member 81 that blocks magnetic flux generated in the crossover wiring 23. The shield member 81 has a higher magnetic permeability than air, the detection substrate 4, and the insulator 7, and is arranged between the detection element 41 and the crossover wiring 23. "Magnetic permeability" as used in the present disclosure is a value indicating the ease with which magnetic flux passes, that is, a value indicating how much magnetic flux is absorbed. In short, a member with high magnetic permeability is a member that allows magnetic flux to pass through easily and easily absorbs magnetic flux. On the other hand, a member with low magnetic permeability is a member that is difficult for magnetic flux to pass through and is difficult to absorb magnetic flux.

That is, by disposing the shield member 81 having a higher magnetic permeability than air, the detection board 4, and the insulator 7 between the detection element 41 and the crossover wiring 23, the magnetic flux generated in the crossover wiring 23 is transferred to the shield member 81. The shield member 81 becomes difficult to pass through. As a result, the detection element 41 is less susceptible to the influence of the magnetic flux generated in the crossover wiring 23. In short, the motor 1 according to the first embodiment has the advantage that it is possible to prevent the detection element 41 from erroneously detecting the rotation angle of the rotor 3.

(1-2) Detailed configuration (1-2-1) Power tool The detailed configuration of the power tool 10 of the first embodiment will be described below with reference to FIG. 2.

The power tool 10 includes a motor 1, as shown in FIG. In addition to the motor 1, the power tool 10 further includes a drive transmission section 101, a drive shaft 102, a chuck 103, a trigger volume 104, and a control circuit 105. The power tool 10 is a tool that drives the tip tool B1 with the driving force of the motor 1.

The motor 1 is a drive source that rotates the drive shaft 102. The motor 1 is, for example, a brushless motor. More specifically, the motor 1 is driven by electric power supplied from the power supply section C1 to perform rotational operation. As an example, the power supply unit C1 is a rechargeable battery pack that is detachably attached to the power tool 10. The power supply unit C1 is not a component of the power tool 10. However, the power tool 10 may include the power supply section C1 as a component.

The drive transmission unit 101 adjusts the output of the motor 1 and outputs it to the drive shaft 102 . The drive shaft 102 is rotated by the motor 1. More specifically, the drive shaft 102 is rotated by the output of the motor 1 via the drive transmission section 101. The chuck 103 is provided at the tip of the drive shaft 102, and is a portion to which the tip tool B1 is detachably attached. The tip tool B1 is, for example, a driver bit, a socket bit, a drill bit, or the like. Among the various types of tip tools B1, the tip tool B1 depending on the application is attached to the chuck 103 and used. Note that only the specific tip tool B1 may be attachable to the chuck 103, or the chuck 103 and the specific tip tool B1 may be integrally formed. In the first embodiment, the tip tool B1 is not included in the configuration of the power tool 10. However, the tip tool B1 may be included in the configuration of the power tool 10.

The trigger volume 104 is an operation unit that receives operations for controlling the rotation of the motor 1. By pulling the trigger volume 104, the motor 1 can be turned on and off. Further, the rotational speed of the drive shaft 102, that is, the rotational speed of the motor 1, can be adjusted by the amount of operation of pulling the trigger volume 104. The control circuit 105 rotates or stops the motor 1 according to an operation input to the trigger volume 104, and also controls the rotation speed of the motor 1. In this power tool 10, the tip tool B1 is attached to the chuck 103. Then, by controlling the rotational speed of the motor 1 by operating the trigger volume 104, the rotational speed of the tip tool B1 is controlled.

(1-2-2) Motor Next, the detailed configuration of the motor 1 of the first embodiment will be described with reference to FIGS. 1 to 6.

As shown in FIGS. 1 and 4, the motor 1 includes a stator 2, a rotor 3, a detection board 4, a shield member 81, a current supply board 91, a first bearing 92, a second bearing 93, A base 95 is provided.

(stator)
The stator 2 has a stator core 20 and stator wiring 21, as shown in FIG. Stator core 20 includes a tee core 5, a yoke core 6, and an insulator 7.

First, the details of the configuration of the tee score 5 will be explained.

Tee core 5 includes a plurality of steel plates 50, as shown in FIGS. 1 and 4. The tee core 5 is formed by laminating a plurality of steel plates 50 in the thickness direction. Each steel plate 50 is made of a magnetic material. Each steel plate 50 is, for example, a silicon steel plate.

As shown in FIG. 2, the teeth core 5 includes a cylindrical inner tube portion 51 and a plurality of (nine in FIG. 2) teeth 52.

The shape of the inner cylinder portion 51 is cylindrical. The rotor 3 is arranged inside the inner cylinder part 51. The center axis of the inner cylinder portion 51 coincides with the center axis 320 of the output shaft 32 of the rotor 3, which will be described later. As shown in FIG. 1, the thickness direction of the plurality of steel plates 50 coincides with the central axis 320 direction. The inner cylinder portion 51 is continuous in the circumferential direction. In other words, the inner cylinder portion 51 is continuous in the circumferential direction.

Each of the plurality of teeth 52 includes a body portion 521 and a tip plate portion 522, as shown in FIG. The shape of the body portion 521 is a rectangular parallelepiped. The body portion 521 projects outward from the inner tube portion 51 in the radial direction of the inner tube portion 51 . The body parts 521 are provided at equal intervals in the circumferential direction of the inner cylinder part 51. In other words, a plurality of (nine in FIG. 2) body portions 521 are formed in the inner cylinder portion 51 at intervals in the circumferential direction.

The tip plate portion 522 is a plate member that is curved along the circumferential direction of the inner cylinder portion 51. When viewed from the direction of the central axis 320, the shape of the tip plate portion 522 is an arcuate shape along a circle concentric with the inner cylinder portion 51. The thickness direction of the tip plate portion 522 is along the radial direction of the inner cylinder portion 51. The tip plate portion 522 of each tooth 52 is provided on the tip side of the body portion 521 of the tooth 52. The tip plate portion 522 has two tip pieces 523 that protrude in the circumferential direction of the inner tube portion 51 from respective side surfaces of the body portion 521 that face each other along the circumferential direction of the inner tube portion 51 .

Here, the details of the configuration of the stator wiring 21 will be explained.

As shown in FIGS. 1 and 5, the stator wiring 21 includes a coil wire 22 wound around a body portion 521 and a crossover wire 23 that electrically connects the coil wires 22 wound around a plurality of body portions 521. have The coil wires 22 are provided in correspondence to the number of teeth 52. In the first embodiment, as shown in FIG. 2, nine coil wires 22 are provided corresponding to the nine teeth 52. The electric wires constituting each coil wire 22 and the crossover wiring 23 are enameled wires, for example. This winding has a linear conductor and an insulating coating that covers the conductor. The stator wiring 21 is composed of one electric wire. As shown in FIG. 5, the crossover wiring 23 is arranged inside the plurality of coil wires 22 in the radial direction of the inner cylinder portion 51 (see FIG. 2). Further, the crossover wiring 23 is arranged inside the plurality of body parts 521 in the radial direction of the inner cylinder part 51.

The two tip pieces 523 are provided as a retainer to prevent the coil wire 22 from falling off the body 521. That is, when the coil wire 22 tries to move toward the tip side of the body portion 521, the coil wire 22 is caught by the two tip pieces 523, so that the coil wire 22 can be prevented from falling off.

Next, details of the configuration of the insulator 7 will be explained.

The insulator 7 partially covers the tee core 5. More specifically, the insulator 7 covers a portion of each of the teeth 52 of the teeth core 5 . The insulator 7 has electrical insulation properties. As shown in FIG. 1, the coil wire 22 is wound around the body 521 of the teeth 52 via the insulator 7, so the insulator 7 insulates the coil wire 22 and the teeth 52. The insulator 7 is made of, for example, synthetic resin.

As shown in FIGS. 1 and 4, the insulator 7 is composed of two members, a first insulator 71 and a second insulator 72. The first insulator 71 and the second insulator 72 are aligned in the central axis 320 direction. The first insulator 71 and the second insulator 72 are formed in a shape into which a plurality of teeth 52 can be fitted from the direction of the central axis 320. That is, the first insulator 71 covers the plurality of teeth 52 from one end side in the direction of the central axis 320 (the left side in FIG. 1, hereinafter simply referred to as the left side) in a state where the first insulator 71 is fitted and attached to the tooth core 5. On the other hand, when the second insulator 72 is fitted and attached to the tooth core 5, it covers the plurality of teeth 52 from the other end side in the direction of the central axis 320 (the right side in FIG. 1, hereinafter simply referred to as the right side). ing.

As shown in FIG. 1, the first insulator 71 includes a cylindrical body 73a that overlaps the inner cylindrical portion 51 when viewed from the axial direction D1, and a plurality of tooth covering portions 74a that cover a portion of the plurality of teeth 52. ing. Similarly, the second insulator 72 includes a cylindrical body 73b that overlaps the inner cylinder portion 51 when viewed from the axial direction D1, and a plurality of teeth covering portions 74b that cover a portion of the plurality of teeth 52. Each of the cylindrical body 73a and the cylindrical body 73b is formed into a cylindrical shape concentric with the inner cylinder portion 51, and the central axis thereof coincides with the central axis 320 of the output shaft 32. Each tooth covering portion 74a projects outward from the cylindrical body 73a in the radial direction of the cylindrical body 73a. Similarly, each tooth covering portion 74b projects outward from the cylindrical body 73b in the radial direction of the cylindrical body 73b.

As shown in FIG. 1, the second insulator 72 further includes a plate portion 76. The plate part 76 is a disk concentric with the inner cylinder part 51, and covers an opening at one end of the cylinder body 73b. The "opening at one end of the cylindrical body 73b" here refers to the opening on the opposite side to the first insulator 71 side, of the two openings that the cylindrical body 73b of the second insulator 72 has. A detection board 4 is arranged between the rotor 3 and the plate portion 76 of the second insulator 72. The thickness direction of the plate portion 76 is along the axial direction D1 (see FIG. 1) of the rotation shaft of the rotor 3, which will be described later. A hole 760 is formed in the center of the plate portion 76, into which an outer ring of a second bearing 93 (see FIG. 1), which will be described later, is fitted. As shown in FIG. 1, the plate portion 76 of the second insulator 72 has a first surface 761 on the detection substrate 4 side and a second surface 762 opposite to the first surface 761. The first surface 761 of the first embodiment is in close contact with the detection substrate 4.

A recess 77 is provided on the first surface 761 of the plate portion 76 of the second insulator 72, as shown in FIG. The recess 77 covers a detection element 41 of the detection substrate 4, which will be described later. In short, the second insulator 72 is arranged between the detection element 41 and the crossover wiring 23 so as to cover the detection element 41. The recess 77 is a substantially rectangular depression. The cross section of the recess 77 is approximately rectangular, as shown in FIG. That is, the recessed portion 77 of the first embodiment has a side surface 771 that extends in the thickness direction of the plate portion 76 and a bottom surface 772 that is substantially orthogonal to the side surface.

In a state where the first insulator 71 and the second insulator 72 are attached to the tee core 5 , the outer surface of the tip plate portion 522 in the radial direction of the inner cylinder portion 51 is not covered by the insulator 7 and is covered with the yoke core 6 . are in contact with each other.

As shown in FIG. 1, the tooth covering portion 74a of the first insulator 71 extends from the cylinder body 73a to the right side. Further, the tooth covering portion 74b of the second insulator 72 extends to the left side from the cylindrical body 73b, but does not reach the tooth covering portion 74a of the first insulator 71. That is, the tooth covering portion 74a of the first insulator 71 and the tooth covering portion 74b of the second insulator 72 are not in contact with each other, and a gap 75 is formed between them, and each tooth 52 is not exposed in this portion. are doing. In short, each tooth 52 is not covered with the insulator 7 in the portion where the gap 75 is formed.

In addition, the tooth covering part 74a of the 1st insulator 71 and the teeth covering part 74b of the 2nd insulator 72 may contact, and may be comprised so that a gap may not be formed between them. For example, the gap may not be formed because the thickness of the tooth core 5 becomes thin, or the gap may not be formed because the dimensions of the teeth covering portions 74a and 74b in the axial direction D1 become large. good.

In a state where the first insulator 71 and the second insulator 72 are attached to the tooth core 5 and partially cover the plurality of teeth 52, the coil wire 22 is inserted into the insulator 7 constituted by the first insulator 71 and the second insulator 72. It is wound around the body portion 521 of each tooth 52 via. Here, the coil wire 22 is wound around the body 521 so as to pass through a slot (cavity) between the body 521 and each of the two body parts 521 adjacent to the body 521 . Furthermore, as shown in FIG. 5, the transition wiring 23 is arranged on the second surface 762 of the second insulator 72.

Next, details of the configuration of the yoke core 6 will be explained.

The yoke core 6 includes a plurality of steel plates 60, as shown in FIGS. 1 and 4. The yoke core 6 is formed by laminating a plurality of steel plates 60 in the thickness direction. Each steel plate 60 is made of a magnetic material. Each steel plate 60 is, for example, a silicon steel plate.

As shown in FIG. 2, the shape of the yoke core 6 is cylindrical, and its central axis coincides with the central axis 320 of the output shaft 32. The yoke core 6 is attached to the outer periphery of the tee core 5 and covers the outer periphery of the tee core 5. In other words, the tee core 5 is arranged inside the yoke core 6.

The yoke core 6 has a plurality (nine) of fitting parts 61. That is, the yoke core 6 has the same number of fitting parts 61 as the teeth 52. Each of the plurality of fitting parts 61 is a recess provided in the inner peripheral surface of the yoke core 6. The plurality of fitting portions 61 correspond to the plurality of teeth 52 on a one-to-one basis. Each of the plurality of fitting portions 61 and the tooth 52 corresponding to the fitting portion 61 among the plurality of teeth 52 fit into each other. Thereby, the yoke core 6 is attached to the outer periphery of the tee core 5.

The tip plate portion 522 of the corresponding tooth 52 is fitted into each fitting portion 61 . Therefore, the length of each fitting portion 61 in the circumferential direction of the yoke core 6 is equal to the length of the tip plate portion 522 of each tooth 52 in the circumferential direction of the inner cylinder portion 51. Note that in the present disclosure, "equal" is not limited to the case where the plurality of values completely match each other, but also includes the case where the values are different within an allowable error range. For example, this includes cases where there is an error within 3%, within 5%, or within 10%.

With the insulator 7 attached to the tee core 5 and the coil wire 22 wound, the yoke core 6 is attached to the outer periphery of the tee core 5 by shrink fitting, for example. That is, the tee core 5 is placed inside the yoke core 6 while the yoke core 6 is heated and expanded in the radial direction. Thereby, the inner surface of the yoke core 6 faces the tips of the plurality of teeth 52 in the radial direction of the inner cylinder portion 51 with a slight gap between the inner surface and the plurality of teeth 52 . Thereafter, when the temperature of the yoke core 6 decreases and the yoke core 6 contracts, the inner surface of the yoke core 6 comes into contact with the tips of the plurality of teeth 52. That is, as the yoke core 6 contracts, the plurality of fitting parts 61 move inward in the radial direction of the yoke core 6, so that the plurality of fitting parts 61 and the plurality of teeth 52 fit together. The yoke core 6 applies radially inward contact pressure to the plurality of teeth 52.

(rotor)
As shown in FIGS. 1 and 2, the rotor 3 includes a cylindrical rotor core 30, a plurality of (six in FIG. 2) magnets 31, and an output shaft 32. The rotor 3 rotates around the central axis 320 of the output shaft 32 with respect to the stator 2 . In other words, the rotation axis X1 of the rotor 3 coincides with the central axis 320 of the output shaft 32. The "rotational axis X1 of the rotor 3" here is an axis that is the center of rotational movement of the rotor 3. The axial direction D1 shown in FIG. 1 is the axial direction of the rotation axis X1 of the rotor 3.

Magnetic flux generated from a plurality of (nine in FIG. 2) coil wires 22 wound around the stator core 20 of the stator 2 generates electromagnetic force that rotates the rotor 3. The motor 1 transmits the rotational force (driving force) of the rotor 3 from the output shaft 32 to the drive transmission section 101 (see FIG. 3).

As shown in FIG. 1, the rotor core 30 of the rotor 3 includes a plurality of steel plates 301. The rotor core 30 is formed by laminating a plurality of steel plates 301 in the thickness direction. Each steel plate 301 is made of a magnetic material. Each steel plate 301 is, for example, a silicon steel plate.

The rotor core 30 is formed into a cylindrical shape concentric with the inner cylinder portion 51 of the stator core 20 , and its center axis coincides with the center axis 320 of the output shaft 32 . In the direction of the central axis 320, the positions of both ends of the rotor core 30 are substantially aligned with the positions of both ends of the stator core 20. Note that the positions of both ends of the rotor core 30 and the positions of both ends of the stator core 20 do not need to exactly overlap, and may deviate within an allowable error range. For example, there may be a deviation within 3%, within 5%, or within 10% of the thickness of the rotor core 30.

The output shaft 32 is held inside the rotor core 30. The rotor core 30 includes a plurality of (six in FIG. 2) magnet housing portions 302. The plurality of magnet accommodating parts 302 accommodate the plurality of magnets 31. Each of the plurality of magnet accommodating parts 302 is a through hole that penetrates the rotor core 30 in the direction of the central axis 320. Each of the plurality of magnets 31 is held in the magnet housing part 302 by being inserted into the magnet housing part 302 with an adhesive attached thereto. Note that each of the plurality of magnets 31 may be held in the magnet accommodating portion 302 by magnetic attraction between the magnets 31 and the rotor core 30 without using an adhesive. The magnet 31 of the first embodiment is a permanent magnet. For example, magnet 31 is a neodymium magnet.

The plurality of magnet housing portions 302 are provided at equal intervals in the circumferential direction of the rotor core 30. Thereby, the plurality of magnets 31 are arranged at equal intervals in the circumferential direction of the rotor core 30. In the first embodiment, the magnets 31 are arranged in a polygonal shape (hexagonal shape). Further, the longitudinal direction of each of the plurality of magnets 31 is along the circumferential direction of the rotor core 30.

(Detection board)
A detection element 41 for detecting the rotation angle of the rotor 3 is mounted on the detection board 4 . The detection substrate 4 is made of, for example, synthetic resin.

The detection element 41 of the first embodiment detects the magnetic field generated by the magnet 31 of the rotor 3, and detects the rotation angle of the rotor 3. More specifically, the detection element 41 of the first embodiment detects the magnetic field generated by the magnet 31 of the rotor 3, and detects the rotation angle of the rotor 3 based on the timing at which the polarity of the detected magnetic field switches. As an example, the detection element 41 is a Hall element that detects the magnetic field generated by the magnet 31 of the rotor 3 using the Hall effect.

The detection board 4 of Embodiment 1 is arranged between the rotor 3 and the second insulator 72, as shown in FIG. More specifically, the detection substrate 4 of the first embodiment is arranged between the rotor core 30 of the rotor 3 and the plate portion 76 of the second insulator 72. The detection element 41 of the first embodiment is mounted on the surface of the detection substrate 4 on the second insulator 72 side. The thickness direction of the detection substrate 4 is along the axial direction D1 of the rotation axis X1.

In the first embodiment, the detection element 41 and the crossover wiring 23 are arranged side by side in the axial direction D1 of the rotation axis X1 of the rotor 3 when viewed from a direction perpendicular to the rotation axis X1. The “direction perpendicular to the rotational axis X1 of the rotor 3” herein refers to the surface direction of the detection board 4 and the radial direction of the inner cylinder portion 51 of the rotor 3.

(shield member)
The shield member 81 prevents the magnetic flux generated by the crossover wiring 23 from reaching the detection element 41 . The shield member 81 has a higher magnetic permeability than air, the detection substrate 4, and the second insulator 72, and is arranged between the detection element 41 and the crossover wiring 23. As an example, the shield member 81 is made of iron, ferrite, nickel, iron-cobalt alloy, or the like.

The shield member 81 is fixed to the second insulator 72. More specifically, the shield member 81 is fixed to the second insulator 72 so as to be disposed between the detection element 41 and the crossover wiring 23. According to this configuration, there is an effect that there is no need to provide a fixing part for fixing (arranging) the shield member 81 on the detection board 4. That is, there is an advantage that the circuit pattern on the detection board 4 can be designed regardless of where the shield member 81 is fixed (arranged). In other words, there is an advantage that the degree of freedom in designing the circuit pattern on the detection board 4 is improved. The "circuit pattern on the detection board 4" herein includes not only the routing of the wiring formed on the detection board 4, but also the position on the detection board 4 where the detection element 41 is mounted.

In the first embodiment, the shield member 81 is a foil member, and is provided on at least a portion of the first surface 761 of the second insulator 72 on the detection element 41 side. More specifically, the shield member 81 of the first embodiment is provided on the side surface 771 and the bottom surface 772 of the recess 77 of the second insulator 72, as shown in FIG. That is, the shield member 81 of the first embodiment is provided on the entire surface of the recess 77 of the second insulator 72. Specifically, the shield member 81 is formed by providing a film made of a material having a higher magnetic permeability than air, the detection substrate 4, and the second insulator 72 in the recess 77 of the second insulator 72. This configuration has the advantage that the shield member 81 can be placed between the detection element 41 and the crossover wiring 23 without increasing the dimensions of the motor 1.

(Current supply board)
Current supply board 91 supplies current to stator wiring 21 . More specifically, current supply board 91 supplies current to stator wiring 21 based on the detection result of detection element 41.

The current supply board 91 includes an electrical component to be mounted and a motor terminal 911 that is electrically connected to the electrical component and to which the crossover wiring 23 is electrically connected. That is, the current supply board 91 supplies current to the stator wiring 21 via the motor terminal 911 and the crossover wiring 23. As shown in FIG. 1, the motor terminal 911 is provided so as to protrude toward the second surface 762 of the second insulator 72 where the crossover wiring 23 is arranged. As shown in FIG. 5, three motor terminals 911 are provided, and each motor terminal 911 corresponds to the U phase, V phase, and W phase of the three-phase alternating current, respectively. The current supply board 91 switches the power supplied to each motor terminal 911 based on the detection result of the detection element 41.

(bearing)
As shown in FIG. 1, the motor 1 further includes a first bearing 92 and a second bearing 93. The first bearing 92 is arranged on the left side of the rotor core 30, and its inner ring is attached to the left side portion of the output shaft 32. The second bearing 93 is arranged on the right side of the rotor core 30. The inner ring of the second bearing 93 is attached to the right side portion of the output shaft 32 and rotates together with the output shaft 32, and the outer ring of the second bearing 93 is attached to the second insulator 72.

(base)
The base 95 is attached to the rotor core 30 and rotates integrally with the rotor core 30, the output shaft 32, and the inner ring of the first bearing 92.

(1-3) Advantages The motor 1 further includes a shield member 81 that blocks the magnetic flux generated in the crossover wiring 23. The shield member 81 has a higher magnetic permeability than air, the detection substrate 4, and the insulator 7, and is arranged between the detection element 41 and the crossover wiring 23.

According to this configuration, the magnetic flux generated in the crossover wiring 23 passes through the inside of the shield member 81 and becomes difficult to pass through the shield member 81. As a result, the detection element 41 is less susceptible to the influence of the magnetic flux generated in the crossover wiring 23. In short, the motor 1 according to the first embodiment has the advantage that it is possible to prevent the detection element 41 from erroneously detecting the rotation angle of the rotor 3.

Generally, in order to make the detection element 41 less susceptible to the influence of magnetic flux generated in the crossover wiring 23, the transition wiring 23 is moved away from the detection element 41, that is, the distance between the crossover wiring 23 and the detection element 41 is decreased. Possible countermeasures include making the design larger. However, if the above measures are taken and the distance between the crossover wiring 23 and the detection element 41 is designed to be large, there is a problem in that the dimensions of the motor 1 become large. On the other hand, according to the configuration of the first embodiment, there is no need to design a large distance between the crossover wiring 23 and the detection element 41, and it is possible to suppress the detection element 41 from erroneously detecting the rotation angle of the rotor 3. Therefore, there is an advantage that the detection element 41 can be prevented from erroneously detecting the rotation angle of the rotor 3 without increasing the dimensions of the motor 1.

(1-4) Modification of Embodiment 1 Embodiment 1 described above is only one of various embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved.

The shield member 81 of the first embodiment described above is provided on the entire surface of the recess 77 of the second insulator 72, but is located at least between the detection element 41 and the crossover wiring 23 in the recess 77 of the second insulator 72. It suffices if it is provided in the part where the Specifically, the shield member 81 may be provided only on the bottom surface of the recess 77 located between the detection element 41 and the crossover wiring 23 in the axial direction D1.

Moreover, although the shield member 81 of the above-mentioned Embodiment 1 is a foil member, it may be a plate member. More specifically, by arranging a plate member made of a material having higher magnetic permeability than air, the detection substrate 4, and the second insulator 72 between the detection element 41 and the crossover wiring 23, the plate member may be used as the shield member 81. More specifically, air, the detection substrate 4, and a plate member made of a material having higher magnetic permeability than the second insulator 72 are placed between the detection element 41 and the plate member in a space surrounded by the recess 77 and the detection substrate 4. The plate member may be used as the shield member 81 by disposing it between the crossover wiring 23 and the crossover wiring 23 . The shield member 81 may be a plate member bent along the shape of the recess 77, or may be a flat member. Note that a gap may exist between the shield member 81 and the second insulator 72.

The shield member 81 may be fixed to the second insulator 72 by screwing, double-sided tape, caulking, or the like. Further, the shield member 81 may be fixed to the second insulator 72 by being sandwiched between the detection board 4 and the second insulator 72. That is, the method of fixing the shield member 81 to the second insulator 72 is not limited.

Although the recess 77 in the above-described first embodiment is a substantially rectangular recess, it may also be a cylindrical, prismatic, or hemispherical recess.

In the first embodiment described above, the detection element 41 and the crossover wiring 23 are arranged along the axial direction D1 of the rotation axis X1 of the rotor 3 when viewed from a direction perpendicular to the rotation axis X1. However, the detection element 41 and the crossover wiring 23 may be arranged so as to overlap each other when viewed from a direction perpendicular to the rotation axis X1 of the rotor 3. In this case, the shield member 81 is arranged between the detection element 41 and the crossover wiring 23 in a direction perpendicular to the rotation axis X1 of the rotor 3.

In the first embodiment described above, the plurality of magnets 31 are arranged in a polygonal shape. However, the plurality of magnets 31 are not limited to being arranged in a polygonal shape, but may be arranged in a spoke shape. That is, the configuration of the rotor 3 can be changed arbitrarily.

In the first embodiment described above, the number of magnets 31 is six. However, the number of magnets 31 is not limited to six, and may be two or more. Further, in the first embodiment described above, the magnets 31 of the rotor 3 are permanent magnets, but may be electromagnets.

The shape of the rotor core 30 viewed from the direction of the central axis 320 of the rotor core 30 is not limited to a perfect circle, but may be, for example, a circle or an ellipse with protrusions and depressions provided on the circumference. Good too.

Although the insulator 7 of the first embodiment described above covers a part of the tee core 5, it may cover the entire tee score 5. That is, the insulator 7 only needs to cover at least a portion of the tee core 5.

The motor 1 is not limited to being included in the power tool 10. The motor 1 may be included in, for example, an electric bicycle or an electric assist bicycle.

The stator wiring 21 may be composed of a plurality of electric wires instead of one electric wire.

(Embodiment 2)
(2-1) Overview The motor 1a according to the second embodiment will be described below using FIG. 7. Components similar to those in Embodiment 1 are designated by the same reference numerals and description thereof will be omitted.

The motor 1a of the second embodiment is provided in the power tool 10 similarly to the motor 1 of the first embodiment.

The motor 1a of the second embodiment differs from the first embodiment in that the motor 1a of the second embodiment includes a guide member 82 that guides the magnetic flux generated in the crossover wiring 23 instead of the shield member 81.

The guiding member 82 has higher magnetic permeability than air, the detection substrate 4, and the second insulator 72. For example, the guide member 82 is made of iron, ferrite, nickel, iron-cobalt alloy, or the like. The guide member 82 is arranged on the opposite side of the detection element 41 with respect to the crossover wire 23 in the axial direction D1 (on the right side of the crossover wire 23 in FIG. 7).

With the above configuration, the guiding member 82 absorbs the magnetic flux generated in the crossover wiring 23, and guides the magnetic flux to the side opposite to the detection element 41 with reference to the crossover wiring 23 in the axial direction D1. It is possible to prevent the light from reaching the detection element 41. As a result, the detection element 41 is less susceptible to the influence of the magnetic flux generated in the crossover wiring 23. In short, the motor 1 of the second embodiment has the advantage that it is possible to prevent the detection element 41 from erroneously detecting the rotation angle of the rotor 3.

(2-2) Details As shown in FIG. 7, the motor 1a of the second embodiment includes a stator 2, a rotor 3, a detection board 4, an induction member 82, a current supply board 91, and a first bearing 92. , a second bearing 93.

The guiding member 82 is a plate member. The guiding member 82 of the second embodiment is a disc-shaped member. More specifically, the guiding member 82 of the second embodiment is a flat member made of a material having higher magnetic permeability than air, the detection substrate 4, and the second insulator 72.

The guide member 82 is fixed to the second insulator 72. The guide member 82 of the second embodiment is fixed to the second insulator 72 so as to be disposed on the opposite side of the detection element 41 with respect to the crossover wiring 23 in the axial direction D1. More specifically, the guiding member 82 is fixed to the second insulator 72 by the fixing portion 78 provided on the second insulator 72 so as to be disposed on the opposite side of the detection element 41 with respect to the crossover wiring 23 in the axial direction D1. It is fixed at 72. The fixing portion 78 protrudes from the second surface 762 of the second insulator 72 toward the current supply board 91 (protrudes to the right in FIG. 7). The fixing portion 78 of the second embodiment has a columnar shape. The fixing portion 78 of the second embodiment is made of synthetic resin and is integrally formed with the second insulator 72. In the second insulator 72 of the second embodiment, at least two fixing parts 78 are provided. As an example, the guide member 82 is attached to the fixed part 78 by screwing or the like. Note that the guiding member 82 may be attached to the fixing portion 78 by inserting and fitting the fixing portion 78 into a through hole provided in the guiding member 82. According to the above configuration, there is an advantage that the guiding member 82 can be fixed at a position close to the crossover wiring 23 without complicating the internal structure of the motor 1b.

(2-3) Modification Embodiment 2 described above is only one of various embodiments of the present disclosure. The embodiments described above can be modified in various ways depending on the design, etc., as long as the objective of the present disclosure can be achieved.

Although the guiding member 82 of the second embodiment described above is a disc-shaped member, it may be a rectangular plate-shaped member. That is, the shape of the guiding member 82 is not limited.

Although the fixing portion 78 in the second embodiment described above has a columnar shape, it may also have a plate shape. That is, the shape of the fixing part 78 is not limited.

Further, the fixing part 78 may be formed of a material having higher magnetic permeability than air, the detection substrate 4, and the second insulator 72. For example, the fixing portion 78 may be made of iron, ferrite, nickel, iron-cobalt alloy, or the like. That is, since the fixed part 78 is arranged so as to overlap the crossover wiring 23 when viewed from the direction perpendicular to the axial direction D1, the fixed part 78 may be included in the guiding member 82. According to this configuration, the detection element 41 is less susceptible to the influence of the magnetic flux generated by the crossover wiring 23. In short, the motor 1 of the second embodiment has the advantage that it is possible to further suppress the detection element 41 from erroneously detecting the rotation angle of the rotor 3.

Although the guiding member 82 of the second embodiment described above is fixed to the second insulator 72, it may be fixed to the current supply board 91. That is, the guide member 82 is not limited to a configuration in which it is fixed to the second insulator 72.

Furthermore, the guiding member 82 of the second embodiment described above is arranged on the opposite side of the detection element 41 with respect to the crossover wiring 23 in the axial direction D1. However, as shown in FIG. 8, the guide member 82a of the motor 1b may be arranged along the radial direction of the rotating shaft of the rotor 3, in line with the crossover wiring 23. According to this configuration, the guiding member 82a absorbs the magnetic flux generated in the crossover wiring 23 and guides the magnetic flux in the radial direction of the rotating shaft of the rotor 3, thereby suppressing the magnetic flux from reaching the detection element 41. Is possible.

The guide member 82a may be formed integrally with the second insulator 72 when it is arranged along the radial direction of the rotation axis of the rotor 3 and in line with the crossover wiring 23. More specifically, the guiding member 82a is a plate member, and is formed integrally with the second insulator 72 so as to protrude toward the current supply board 91 from the surface of the second insulator 72 facing the transition wiring 23. You can. According to this configuration, the motor 1 of the second embodiment has the advantage that it is possible to prevent the detection element 41 from erroneously detecting the rotation angle of the rotor 3 without complicating the internal structure of the motor 1b.

From the above, the guiding member 82 is disposed on the opposite side of the detection element 41 with respect to the crossover wire 23 in the axial direction D1, or is arranged in line with the crossover wire 23 along the radial direction of the rotation axis of the rotor 3. It is sufficient if it is placed.

Further, the guide member 82 may be arranged to surround the crossover wiring 23. More specifically, the guide member 82 may be a plate member formed of a material having higher magnetic permeability than air, the detection substrate 4, and the second insulator 72, and curved so as to surround the crossover wiring 23. According to this configuration, the detection element 41 can more efficiently guide the magnetic flux generated in the crossover wiring 23. In short, the motor 1 of the first embodiment has the advantage that it is possible to more efficiently prevent the detection element 41 from erroneously detecting the rotation angle of the rotor 3.

(summary)
The motor (1) of the first aspect according to the embodiment includes a stator (2), a rotor (3), and a detection board (4). The stator (2) has a stator core (20) and stator wiring (21). The rotor (3) has magnets (31) and rotates relative to the stator core (20). A detection element (41) for detecting the rotation angle of the rotor (3) is mounted on the detection board (4). The stator core (20) includes a tee core (5), a yoke core (6), and an insulator (7). The tee core (5) includes a cylindrical inner cylinder part (51) in which the rotor (3) is disposed, and a cylindrical inner cylinder part (51) that protrudes outward in the radial direction of the inner cylinder part (51). A plurality of teeth (52) including a body (521). The yoke core (6) is attached to the plurality of teeth (52) and has a cylindrical shape surrounding the plurality of teeth (52). The insulator (7) covers at least a portion of the tee core (5). The stator wiring (21) includes a coil wire (22) and a crossover wiring (23). The coil wiring is wound around the body (521) via the insulator (7). The crossover wiring (23) electrically connects the plurality of coil wires (22) wound around the plurality of body parts (521). The motor (1) further includes a shield member (81) that blocks magnetic flux generated in the crossover wiring (23). The shield member (81) has higher magnetic permeability than air, the detection board (4), and the insulator (7), and is arranged between the detection element (41) and the crossover wiring (23).

According to this aspect, there is an advantage that it is possible to suppress the detection element (41) from erroneously detecting the rotation angle of the rotor (3).

The motor (1a, 1b) of the second aspect according to the embodiment includes a stator (2), a rotor (3), and a detection board (4). The stator (2) has a stator core (20) and stator wiring (21). The rotor (3) has magnets (31) and rotates relative to the stator core (20). A detection element (41) for detecting the rotation angle of the rotor (3) is mounted on the detection board (4). The stator core (20) includes a tee core (5), a yoke core (6), and an insulator (7). The tee core (5) includes a cylindrical inner cylinder part (51) in which the rotor (3) is disposed, and a cylindrical inner cylinder part (51) that protrudes outward in the radial direction of the inner cylinder part (51). A plurality of teeth (52) including a body (521). The yoke core (6) is attached to the plurality of teeth (52) and has a cylindrical shape surrounding the plurality of teeth (52). The insulator (7) covers at least a portion of the tee core (5). The stator wiring (21) includes a coil wire (22) and a crossover wiring (23). The coil wiring is wound around the body (521) via the insulator (7). The crossover wiring (23) electrically connects the plurality of coil wires (22) wound around the plurality of body parts (521). The detection element (41) and the crossover wiring (23) are arranged along the axial direction (D1) of the rotation axis (X1) when viewed from a direction perpendicular to the rotation axis (X1) of the rotor (3). . The motors (1a, 1b) further include guide members (82, 82a) that guide magnetic flux generated in the crossover wiring (23). The guiding member (82, 82a) has higher magnetic permeability than air, the detection substrate (4), and the insulator (7). The guiding member (82, 82a) is arranged on the opposite side of the detection element (41) with respect to the crossover wiring (23) in the axial direction (D1), or in the radial direction of the rotating shaft (X1). Along the line, the wiring line (23) is arranged along the line.

According to this aspect, there is an advantage that it is possible to suppress the detection element (41) from erroneously detecting the rotation angle of the rotor (3).

In the motor (1) of the third aspect according to the embodiment, the shield member (81) is fixed to the insulator (7) in the first aspect.

According to this aspect, there is an advantage that the degree of freedom of the circuit pattern on the detection board (4) is improved.

In the motor (1) of the fourth aspect according to the embodiment, in the third aspect, the insulator (7) covers the detection element (41) between the detection element (41) and the crossover wiring (23). It is arranged like this. The shield member (81) is a foil member, and is provided on at least a portion of the surface of the insulator (7) on the detection element (41) side.

According to this aspect, there is an advantage that the shield member (81) can be placed between the detection element (41) and the crossover wiring (23) without increasing the dimensions of the motor (1).

In the motor (1a, 1b) of the fifth aspect according to the embodiment, in the second aspect, the guiding member (82, 82a) is fixed to the insulator (7).

According to this aspect, the guide member (82, 82a) can be fixed at a position close to the crossover wire (23), and the guide member (82, 82a) can absorb the magnetic flux emitted from the crossover wire (23). It has the advantage of being easier to guide.

In the motor (1a) of the sixth aspect according to the embodiment, in the fifth aspect, the guiding member (82) detects the transition wire (23) in the axial direction (D1) of the rotating shaft (X1). When placed on the opposite side to the element (41), it is fixed to the insulator (7) by a fixing part (78) provided on the insulator (7).

According to this aspect, there is an advantage that the motor (1b) can be fixed at a position close to the crossover wiring (23) without complicating its internal structure.

In the motor (1a) of the seventh aspect according to the embodiment, in the sixth aspect, the fixing portion (78) is included in the guiding member (82).

According to this aspect, there is an advantage that it is possible to further suppress the detection element (41) from erroneously detecting the rotation angle of the rotor (3).

In the motor (1b) of the eighth aspect according to the embodiment, in the fifth aspect, the guiding member (82a) is arranged in line with the crossover wiring (23) along the radial direction of the rotating shaft (X1). If so, it is formed integrally with the insulator (7).

According to this aspect, there is an advantage that it is possible to suppress the detection element (41) from erroneously detecting the rotation angle of the rotor (3) without complicating the internal structure of the motor (1b).

The power tool of the ninth aspect according to the embodiment includes the motor (1, 1a, 1b) of the first or second aspect and a drive shaft (102). The drive shaft is rotated by a motor (1, 1a, 1b).

According to this aspect, there is an advantage that it is possible to provide a power tool that can suppress the detection element (41) from erroneously detecting the rotation angle of the rotor (3).

1, 1a, 1b motor 2 stator 20 stator core 21 stator wiring 22 coil wire 23 crossover wiring 3 rotor 30 rotor core 31 magnet 32 output shaft 4 detection board 41 detection element 5 tee core 50 steel plate 51 inner cylinder 52 teeth 6 yoke core 60 steel plate 61 Fitting part 7 Insulator 78 Fixed part 81 Shield member 82, 82a Guide member 10 Power tool 102 Drive shaft D1 Axial direction X1 Rotating shaft

Claims (9)

a stator having a stator core and stator wiring;
a rotor having a magnet and rotating with respect to the stator core;
a detection board on which a detection element for detecting the rotation angle of the rotor is mounted;
The stator core is
A teeth core including a cylindrical inner cylinder part in which the rotor is disposed, and a plurality of teeth including a body part protruding outward from the inner cylinder part in a radial direction of the inner cylinder part;
a cylindrical yoke core attached to the plurality of teeth and surrounding the plurality of teeth;
an insulator that covers at least a portion of the tee core,
The stator wiring is
a coil wire wound around the body through the insulator;
a crossover wiring that electrically connects the plurality of coil wires wound around the plurality of body parts,
Further comprising a shield member that blocks magnetic flux generated in the crossover wiring,
The shield member is
has higher magnetic permeability than air, the detection board, and the insulator;
arranged between the detection element and the crossover wiring,
A motor characterized by: a stator having a stator core and stator wiring;
a rotor having a magnet and rotating with respect to the stator core;
a detection board on which a detection element for detecting the rotation angle of the rotor is mounted;
The stator core is
A teeth core including a cylindrical inner cylinder part in which the rotor is disposed, and a plurality of teeth including a body part protruding outward from the inner cylinder part in a radial direction of the inner cylinder part;
a cylindrical yoke core attached to the plurality of teeth and surrounding the plurality of teeth;
an insulator that covers at least a portion of the tee core,
The stator wiring is
a coil wire wound around the body through the insulator;
a crossover wiring that electrically connects the plurality of coil wires wound around the plurality of body parts,
The detection element and the crossover wiring are arranged along the axial direction of the rotation axis of the rotor when viewed from a direction perpendicular to the rotation axis of the rotor,
Further comprising a guide member that guides the magnetic flux generated in the crossover wiring,
The guiding member is
has higher magnetic permeability than air, the detection board, and the insulator;
In the axial direction, it is arranged on the opposite side from the detection element with respect to the crossover wiring, or it is arranged in parallel with the crossover wiring along the radial direction of the rotating shaft.
A motor characterized by: the shield member is fixed to the insulator;
The motor according to claim 1, characterized in that: The insulator is disposed between the detection element and the crossover wiring so as to cover the detection element,
The shield member is
A foil member,
provided on at least a part of the surface of the insulator on the detection element side;
The motor according to claim 3, characterized in that: The guide member is fixed to the insulator.
The motor according to claim 2, characterized in that: When the guiding member is disposed on the opposite side of the detection element with respect to the crossover wiring in the axial direction of the rotating shaft, the guiding member is fixed to the insulator by a fixing part provided on the insulator. ,
The motor according to claim 5, characterized in that: The fixing part is included in the guiding member,
The motor according to claim 6, characterized in that: When the guiding member is arranged along the radial direction of the rotating shaft and alongside the crossover wiring, the guiding member is formed integrally with the insulator.
The motor according to claim 5, characterized in that: The motor according to claim 1 or claim 2,
a drive shaft rotated by the motor;
A power tool characterized by:

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