WO2024237053A1 - Motor - Google Patents

Abstract

A motor (100, 200, 300) comprises: a stator (150, 250, 350) having an energization phase and a phase energized weaklier than the energization phase or a non-energization phase at a predetermined electrical angle; and a magnetic sensor (180, 280, 380). The magnetic sensor (180, 280, 380) is disposed at the weakly energized phase or the non-energization phase.

Description

Motor

The present invention relates to a motor.

It is known that a magnetic sensor is used in a motor to detect the magnetic pole position of the rotor (for example, see Patent Document 1). A typical magnetic sensor detects, for example, that the magnetic flux density exceeds (or falls below) a predetermined operating point and switches the output signal. However, since a stator equipped with a coil is present near the magnetic sensor, for example, when the load is high (when the current is high), an error may occur in the angle detected by the magnetic sensor due to the influence of the magnetic field generated by the stator.

Japanese Utility Model Application Publication No. 62-149271

The present invention aims to provide a motor that can reduce detection angle errors under high load.

The motor of the present invention comprises a stator having a current-carrying phase and a phase that is weakly current-carrying or a non-current-carrying phase at a specified electrical angle, and a magnetic sensor, the magnetic sensor being disposed opposite the weakly current-carrying phase or the non-current-carrying phase.

1 is a perspective view of a motor according to an embodiment that is an example of the present invention; 1 is a cross-sectional view taken along a rotation shaft of a motor according to an embodiment that is an example of the present invention. 1 is a cross-sectional view taken along a radial direction of a motor according to an embodiment that is an example of the present invention. FIG. 2 is a schematic diagram showing an example of a wiring configuration of a motor according to an embodiment of the present invention. FIG. 11 is a perspective view of a motor according to another embodiment which is an example of the present invention. FIG. 11 is a perspective view of a motor according to still another embodiment which is an example of the present invention.

In explaining the embodiments of the present invention, for convenience of explanation, the direction along the rotation axis X of the rotor (rotation axis direction) is simply referred to as the axial direction. In the axial direction, the direction of arrow a in Figures 1, 2, 5, and 6 is referred to as one side, and the opposite direction, the direction of arrow b, is referred to as the other side. In a plane perpendicular to the rotation axis X, the direction approaching or moving away from the rotation axis X is referred to as the radial direction. In the radial direction, the direction of arrow c away from the rotation axis X is referred to as the outer side or one side, and the direction of arrow d approaching the rotation axis X is referred to as the inner side or other side. The direction rotating around the rotation axis X is referred to as the circumferential direction.

Below, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view of a motor 100 according to this embodiment. Fig. 2 is a cross-sectional view taken along the rotation axis X of the motor 100. However, in Fig. 2, the shaft 130 is not shown in cross section. Fig. 3 is a cross-sectional view taken along the radial direction of the motor 100, and is a view of the A-A cross section in Fig. 2 (viewed from one side (arrow a direction) to the other side (arrow b direction) in the axial direction). Fig. 4 is a schematic diagram showing the wiring arrangement in the motor 100.

As shown in FIG. 1, the motor 100 includes a housing 110, a cover 120, and a shaft 130, and has an approximately cylindrical shape overall. The housing 110 includes a housing body 111 having an approximately cylindrical shape, a flange portion 112 extending from an end on one side in the axial direction (arrow a direction) to one side in the radial direction (arrow c direction), and a bottom portion 113 (see FIG. 2) that closes the other side in the axial direction (arrow b direction) of the housing body 111. The cover 120 includes a plate portion 121 having an approximately disk shape, and the plate portion 121 has an outer shape that corresponds to the outer shape (shape of the outer edge portion in the radial direction) of the flange portion 112 of the housing 110. The edge portion of the plate portion 121 of the cover 120 is connected to the flange portion 112 of the housing 110 by a plurality of bolts B (six in FIG. 1) that are inserted in the axial direction.

In the radial direction, a circular hole 120h is formed in the center of the cover 120 coaxially with the housing body 111. The hole 120h penetrates the plate portion 121 of the cover 120 in the axial direction. As shown in FIG. 2, on one side in the radial direction (the direction of the arrow c) of the hole 120h of the cover 120, a cylindrical protrusion 122 that protrudes to the other side in the axial direction (the direction of the arrow b) is provided coaxially with the circular hole 120h. The protrusion 122 holds a first bearing 141, which will be described later.

As shown in FIG. 2, the shaft 130 is a generally cylindrical member that extends in the axial direction from near the bottom 113 of the housing 110 to one side of the cover 120 (in the direction of the arrow a). The shaft 130 passes through a hole 120h in the cover 120 and protrudes to one side in the axial direction (in the direction of the arrow a).

Shaft 130 has one end 131 on one side in the axial direction (arrow a direction), and the other end 134 on the other side (arrow b direction). A helical gear is formed on the outer circumferential surface (surface on one radial side (arrow c direction)) of one end 131 of shaft 130, allowing power to be extracted. However, one end 131 of shaft 130 does not necessarily have to have a gear formed. The other end 134 of shaft 130 has an outer diameter (dimension on one radial side (arrow c direction)) slightly smaller than the other parts.

Shaft 130 also has an annular portion 132 on one side (arrow a direction) slightly from the center in the axial direction, which has a larger outer diameter (dimension on one side in the radial direction (arrow c direction)) than the other portions. In the axial direction, an annular portion (second annular portion) 133 having an even larger outer diameter than annular portion 132 is connected to the other side (arrow b direction) of annular portion (first annular portion) 132 of shaft 130.

The first bearing 141 is disposed on one side (arrow c direction) of the annular portion 132 of the shaft 130 in the radial direction. The first bearing 141 is a ball bearing including an inner ring 141i, an outer ring 141o, and rolling elements. Note that the first bearing 141 is not limited to a ball bearing, and may be various other bearings such as a sleeve bearing. The first bearing 141 may also be another type of ball bearing having an outer ring and rolling elements fitted into recesses in the outer peripheral surface of the shaft (the surface on the outer side in the radial direction (arrow c direction)).

The inner ring 141i of the first bearing 141 is bonded or pressed into the outer peripheral surface (surface on one side in the radial direction (direction of arrow c)) of the annular portion 132 of the shaft 130. As a result, the inner ring 141i of the first bearing 141 is fixed to the shaft 130 and rotates integrally with the shaft 130 around the rotation axis X. Also, in the axial direction, the inner ring 141i of the first bearing 141 contacts the surface on one side (direction of arrow a) of the annular portion 133 of the shaft 130 from one side (direction of arrow a). As a result, the shaft 130 is positioned in the axial direction. The outer ring 141o of the first bearing 141 is bonded or pressed into the inner peripheral surface (surface on the other side in the radial direction (direction of arrow d)) of the protruding portion 122 of the cover 120. As a result, the outer ring 141o of the first bearing 141 is held by the protruding portion 122 of the cover 120. With the above configuration, the first bearing 141 rotatably supports the shaft 130 relative to the cover 120.

A second bearing 142 is disposed on one radial side (arrow c direction) of the other end 134 of the shaft 130. The second bearing 142 is a ball bearing including an inner ring 142i, an outer ring 142o, and rolling elements. Note that the second bearing 142 is not limited to a ball bearing, and may be various other bearings such as a sleeve bearing. The second bearing 142 may also be another type of ball bearing having an outer ring and rolling elements fitted into recesses in the outer peripheral surface of the shaft (the surface on the radially outer side (arrow c direction)).

The inner ring 142i of the second bearing 142 is bonded or pressed into the outer peripheral surface (surface on one side in the radial direction (arrow c direction)) of the other end 134 of the shaft 130. As a result, the inner ring 142i of the second bearing 142 is fixed to the shaft 130 and rotates around the rotation axis X together with the shaft 130. A cylindrical retaining portion 113a protruding to one side in the axial direction (arrow a direction) is provided at the center of the bottom 113 of the housing 110. The outer ring 142o of the second bearing 142 is bonded or pressed into the inner peripheral surface (surface on the other side in the radial direction (arrow d direction)) of the retaining portion 113a of the housing 110. As a result, the outer ring 142o of the second bearing 142 is held by the retaining portion 113a of the housing 110. With the above configuration, the second bearing 142 supports the shaft 130 rotatably relative to the housing 110.

As shown in FIG. 2, the rotor 160 is disposed between the annular portion 132 and the other end 134 of the shaft 130 in the axial direction. The inner circumferential surface (surface on the other radial side (arrow d direction)) of the annular portion 163a of the rotor 160, which will be described later, is fixed to the outer circumferential surface (surface on one radial side (arrow c direction)) of the shaft 130. Therefore, the shaft 130 can rotate integrally with the rotor 160.

As shown in FIG. 3, the rotor 160 has a plurality of first magnets 161, a plurality of second magnets 162, and a rotor core (magnetic body) 163. The rotor core 163 has an annular portion 163a and a plurality of (14 in FIG. 3) magnetic pole pieces 163b extending radially from the annular portion 163a via a pair of connecting portions 163c, 163d. A plurality of magnets are arranged inside the rotor core 163. Specifically, a first magnet 161 is arranged in each of the approximately rectangular spaces between the magnetic pole pieces 163b adjacent to each other in the circumferential direction, and a second magnet 162 is arranged in each of the approximately trapezoidal spaces between the pair of connecting portions 163c, 163d. In the circumferential direction, the first magnet 161 contacts both side surfaces of the two adjacent pole pieces 163b, and in the radial direction, the second magnet 162 contacts the outer circumferential surface of the annular portion 163a and the inner circumferential surface of the pole piece 163b.

Focusing on one pole piece 163b, of the two circumferential side surfaces of the pole piece 163b, the magnetic pole of one first magnet 161 on one side surface, the magnetic pole of the other first magnet 161 on the other side surface, and the magnetic pole of the second magnet 162 on the inner peripheral surface of the pole piece 163b all have the same magnetic pole. A magnetic force of a north pole or south pole is applied to each pole piece 163b, which becomes a single magnetic flux and is emitted radially outward (in the direction of arrow c). The magnetic poles of the pole piece 163b are configured so that north poles and south poles are alternately repeated in the circumferential direction.

The stator 150 is supported on the other radial side (arrow d direction) of the housing body 111 of the housing 110 so as to face the rotor 160 in the radial direction. The stator 150 is disposed on one radial side (arrow c direction) of the rotor 160, and surrounds the rotor 160 from one radial side (arrow c direction).

As shown in FIG. 3, the stator 150 has a stator core (magnetic body) 151 and coils 152. The stator core 151 is a laminated body in which silicon steel plates or the like are stacked in the axial direction, and has an annular portion 154 arranged coaxially with the shaft 130, and a plurality of teeth (magnetic pole portions) 153 (12 in FIG. 3) formed to extend from the annular portion 154 toward the shaft 130. The teeth 153 face the rotor 160. The coils 152 are wound around each of the plurality of teeth 153. The stator core 151 and the coils 152 are insulated by insulators 155 formed of an insulating material.

For the sake of convenience, in the following, an arbitrary tooth among the multiple teeth 153 of the stator 150 will be referred to as the first tooth, and the tooth adjacent to the first tooth in the first circumferential direction P (clockwise direction in FIG. 3) will be referred to as the second tooth, with the tooth numbers increasing toward the first direction P. Among the multiple teeth 153 of the stator 150, the first tooth will be referred to as U1, the second tooth as U2, the third tooth as W3, the fourth tooth as W4, the fifth tooth as V1, the sixth tooth as V2, the seventh tooth as U3, the eighth tooth as U4, the ninth tooth as W1, the tenth tooth as W2, the eleventh tooth as V3, and the twelfth tooth as V4. In the stator 150, the tooth adjacent to V4 in the first direction P is U1.

Figure 4 is a schematic diagram of stator 150 expanded onto a plane as viewed from the other radial side (inside, in the direction of arrow d). The first coil group 10 forming the first phase (U phase) is wound around U1, U2, U3, and U4 of the multiple teeth 153 of stator 150. The coils wound around U1, U2, U3, and U4 are referred to as coil 11, coil 12, coil 13, and coil 14, respectively. The second coil group 20 forming the second phase (V phase) is wound around V1, V2, V3, and V4 of the multiple teeth 153 of stator 150. The coils wound around V1, V2, V3, and V4 are referred to as coil 21, coil 22, coil 23, and coil 24, respectively. The third coil group 30 that forms the third phase (W phase) is wound around W1, W2, W3, and W4 of the multiple teeth 153 of the stator 150. The coils wound around W1, W2, W3, and W4 are referred to as coil 31, coil 32, coil 33, and coil 34, respectively.

The first coil group 10 is formed as follows. First, winding is started from the winding start part U _start near U1, and the electric wire is wound counterclockwise (CCW) around U1 to form the coil 11. In this specification, "clockwise (CW)" and "counterclockwise (CCW)" refer to the winding direction as seen from the other radial side (inner side, arrow d direction). Next, the electric wire is wound clockwise (CW) around U2 to form the coil 12. Next, while forming a jumper, the electric wire is wound clockwise (CW) around U3 to form the coil 13. Finally, the electric wire is wound counterclockwise (CCW) around U4 to form the coil 14, and reaches the winding end part U _finish .

The second coil group 20 is formed as follows. First, winding is started from a winding start portion V _start near V1, and the electric wire is wound counterclockwise (CCW) around V1 to form coil 21. Next, the electric wire is wound clockwise (CW) around V2 to form coil 22. Next, while forming a jumper, the electric wire is wound clockwise (CW) around V3 to form coil 23. Finally, the electric wire is wound counterclockwise (CCW) around V4 to form coil 24, and then the electric wire reaches a winding end portion V _finish .

The third coil group 30 is formed as follows. First, winding is started from a winding start portion W _start near W1, and the electric wire is wound counterclockwise (CCW) around W1 to form coil 31. Next, the electric wire is wound clockwise (CW) around W2 to form coil 32. Next, while forming a jumper, the electric wire is wound clockwise (CW) around W3 to form coil 33. Finally, the electric wire is wound counterclockwise (CCW) around W4 to form coil 44, and reaches the winding end portion W _finish .

When forming each of the coils in the first coil group 10 to the third coil group 30 as described above, the coils are formed by winding electric wire in a spiral shape around each tooth 153 from the other radial side (inner side, direction of arrow d) to one side (outer side, direction of arrow c) or in the opposite direction. The number of turns in the coil is arbitrary.

Depending on the number of turns, for example, a first layer of coil may be formed so that it is directed from the other side (inner side, arrow d direction) in the radial direction to one side (outer side, arrow c direction), and then a second layer of coil may be formed so that it is directed from one side (outer side, arrow c direction) in the radial direction to the other side (inner side, arrow d direction). The number of layers is arbitrary. When the coil is formed in multiple layers, the layer closer to the teeth 153 (inner layer) is the winding start side, and the layer farther from the teeth 153 (outer layer) is the winding end side, so that in two coils connected by a jumper wire, it can be determined that the coil with the jumper wire connected to the outer layer is the coil with the winding start side, and the coil with the jumper wire connected to the inner layer is the coil with the winding end side.

Also, if a coil is formed by winding from the other side (inner side, direction of arrow d) in the radial direction to one side (outer side, direction of arrow c), the next coil formed may be formed by winding from one side (outer side, direction of arrow c) in the radial direction to the other side (inner side, direction of arrow d). In that case, multiple jumper wires formed in sequence in the circumferential direction may be arranged alternately on the other side (inner side, direction of arrow d) and one side (outer side, direction of arrow c) in the radial direction, or may be arranged so that the winding start side is always either the other side (inner side, direction of arrow d) or one side (outer side, direction of arrow c) in the radial direction.

The electrical connections between the first coil group 10 to the third coil group 30 may be made by connecting conductors together, or may be made via the substrate 170 described below. The electrical connections between coils belonging to the same phase (same coil group) may be made by jumper wires as described above, or may be made via the substrate 170 described below. If one or both of the electrical connections between the first coil group 10 to the third coil group 30 and the electrical connections between coils belonging to the same phase (same coil group) are made via the substrate 170, the jumper wires can be omitted, and the motor 100 can be made smaller.

As shown in FIG. 2, a circular circuit board 170 is disposed on the other side of the stator 150 in the axial direction (the direction of the arrow b). The circuit board 170 is a flat insulating member. A printed wiring circuit (not shown) is formed on the circuit board 170. The circuit board 170 is fixed to, for example, the insulator 155 of the stator 150 directly or via an adapter (not shown).

In the axial direction, on one side (in the direction of the arrow a) of the substrate 170 (the surface closer to the rotor 160), multiple (in this embodiment, three) magnetic sensors 180 (magnetic sensors 181, 182, 183) are arranged to detect the magnetic pole position (rotation angle) of the rotor 160. In the axial direction, the magnetic sensors 180 face the rotor 160. In this embodiment, the magnetic sensor 180 is a Hall IC, which is surface-mounted on the substrate 170 and electrically connected to the circuit of the substrate 170. In this embodiment, the magnetic sensor 180 is a Hall IC of a zero-cross detection type that detects a change in the magnetic pole of the rotor 160 (switching from the S pole to the N pole, or from the N pole to the S pole) and switches the output signal. However, the magnetic sensor 180 may be a Hall IC of another type, or may be a magnetic sensor other than a Hall IC.

In the 14-pole, 12-slot motor 100, teeth 153 are arranged at 30° intervals in the circumferential direction. In a given current phase (electrical angle), the first coil group 10 to the third coil group 30 of the stator 150 are divided into a phase that is energized and excited (energized phase or excited phase), and a phase that is energized weaker than the energized phase and weakly excited (weakly energized phase or weakly excited phase), or a phase that is not energized and not excited (non-energized phase or non-excited phase). Hereinafter, in a given current phase, the coil wound around the teeth 153 of the energized phase is also referred to as the first coil, and the coil wound around the weakly energized phase or non-energized phase is also referred to as the second coil. In the radial direction, a given magnetic pole of the rotor 160 faces the teeth 153 of the energized phase. As the energized phase, weakly energized phase, and non-energized phase are switched in sequence, the rotor 160 rotates due to the electromagnetic interaction between the stator 150 and the rotor 160.

The "weakly energized phase" may be, for example, a phase through which a current of 50% or less of the maximum amplitude is passed, a phase through which a current of 40% or less of the maximum amplitude is passed, a phase through which a current of 30% or less of the maximum amplitude is passed, a phase through which a current of 20% or less of the maximum amplitude is passed, or a phase through which a current of 10% or less of the maximum amplitude is passed.

The magnetic sensor 180 is disposed facing a weakly energized or non-energized phase in a predetermined current phase. Here, the magnetic sensor 180 is "disposed facing a weakly energized or non-energized phase" means that the magnetic sensor 180 is disposed in a position (angle) in the circumferential direction that corresponds to the teeth 153 that are weakly energized or non-energized phase. When the teeth 153 that are weakly energized or non-energized phase are continuous in the circumferential direction, the magnetic sensor 180 may be disposed in any position (angle) between adjacent teeth 153. In other words, in the circumferential direction, the magnetic sensor 180 is disposed in a position (angle) that overlaps with the second coil or a position (angle) between two adjacent second coils among the multiple second coils.

In the circumferential direction, the magnetic sensor 180 may be positioned within a range of -15° to 15°, within a range of -10° to 10°, within a range of -5° to 5°, or at a position (angle) of 0° relative to the position (angle) of the teeth 153 that constitute the weakly energized or non-energized phase (or, in the case where the teeth 153 that constitute the weakly energized or non-energized phase are continuous, relative to the center position (angle) between adjacent teeth 153).

In the motor 100 of this embodiment, control is performed so that the back electromotive force and the current are in phase (so-called "Id = 0 control"), and if the phase (electrical angle) of the current at the zero crossing point of the back electromotive force of the U phase is 0°, then the U phase becomes a non-energized phase when the current phase is 0° and 180°, the V phase becomes a non-energized phase when the current phase is 120° and 300°, and the W phase becomes a non-energized phase when the current phase is 240° and 60°. Therefore, when the current phase is 0° and 180°, the coils belonging to the V phase and W phase (coils 21, 22, 23, 24, 31, 32, 33, 34) become the first coils, and the coils belonging to the U phase (coils 11, 12, 13, 14) become the second coils. When the current phase is 120° and 300°, the coils belonging to the U and W phases (coils 11, 12, 13, 14, 31, 32, 33, 34) are the first coils, and the coils belonging to the V phase (coils 21, 22, 23, 24) are the second coils. When the current phase is 240° and 60°, the coils belonging to the U and V phases (coils 11, 12, 13, 14, 21, 22, 23, 24) are the first coils, and the coils belonging to the W phase (coils 31, 32, 33, 34) are the second coils.

When multiple magnetic sensors 180 are present, each magnetic sensor 180 is disposed facing a weakly energized phase or a non-energized phase in a different current phase. In the motor 100 according to the present embodiment, among the multiple magnetic sensors 180, the magnetic sensor 181 is disposed at a position (angle) of 15° mechanical angle from U1 in the first direction P (position (angle) between U1 and U2) (FIG. 3). That is, the magnetic sensor 181 corresponding to the U phase is disposed between adjacent coils 11 and 12 among the second coils when the current phase is 0° and 180°. Among the multiple magnetic sensors 180, the magnetic sensor 182 is disposed at a position (angle) of 15° mechanical angle from V1 in the first direction P (position (angle) between V1 and V2). That is, the magnetic sensor 182 corresponding to the V phase is disposed between adjacent coils 21 and 22 among the second coils when the current phase is 120° and 300°. Of the multiple magnetic sensors 180, magnetic sensor 183 is disposed at a position (angle) of 15° mechanical angle from W1 in the first direction P (a position (angle) between W1 and W2). That is, magnetic sensor 183 corresponding to the W phase is disposed between adjacent coils 31 and 32 of the second coils when the current phase is 240° and 60°. However, magnetic sensor 181 may be disposed between U3 and U4, magnetic sensor 182 may be disposed between V3 and V4, and magnetic sensor 183 may be disposed between W3 and W4.

In the configuration of motor 100 according to this embodiment, the zero-cross point (point where the sign changes) of the U-phase back electromotive force is shifted by 15° electrical angle from the magnetic pole angle of rotor 160. Taking this into consideration, if the magnetic pole angle of rotor 160 is 0° when U1 and the N pole of rotor 160 face each other, then when the current phase is 0°, the zero cross (magnetic pole change) of the magnetic pole of rotor 160 can be obtained at a position of 105° electrical angle from U1 or U3 (a position of 15° mechanical angle in the first direction P). In motor 100, magnetic sensor 181, which is a Hall IC using a zero-cross detection method, is positioned at a position (angle) of 15° mechanical angle in the first direction P from U1. Therefore, when the magnetic sensor 181 detects a change in the magnetic pole of the rotor 160, the phase present nearby (for example, the phase closest to the magnetic sensor 181, the U phase in this embodiment) is a non-conductive phase, so that the magnetic sensor 181 is less susceptible to the influence (disturbance) of the magnetic field generated by the stator 150. The same is true for the V phase and W phase. When the magnetic sensor 182 detects a change in the magnetic pole of the rotor 160, the phase present nearby (for example, the phase closest to the magnetic sensor 182, the V phase in this embodiment) is a non-conductive phase, and when the magnetic sensor 183 detects a change in the magnetic pole of the rotor 160, the phase present nearby (for example, the phase closest to the magnetic sensor 183, the W phase in this embodiment) is a non-conductive phase, so that the magnetic sensors 182 and 183 are less susceptible to the influence (disturbance) of the magnetic field generated by the stator 150. As described above, the motor 100 according to this embodiment reduces the detection angle error even under high load (high current).

In the motor 100, if the board 170 is fixed to the housing 110, positioning between the housing 110 and the stator 150 and positioning between the board 170 and the housing 110 are required to arrange the magnetic sensor 180 as described above. If the board 170 is fixed to the cover 120, positioning between the housing 110 and the stator 150, positioning between the housing 110 and the cover 120, and positioning between the cover 120 and the board 170 are required. In the motor 100 according to this embodiment, the board 170 on which the magnetic sensor 180 is arranged is fixed to the stator 150, so that arrangement of the magnetic sensor 180 as described above requires only positioning between the stator 150 and the board 170. Therefore, the motor 100 according to this embodiment is advantageous in terms of manufacturing costs.

In the motor 100 according to this embodiment, one or both of the mutual electrical connections of the first coil group 10 to the third coil group 30 and the electrical connections between the coils belonging to the same phase (same coil group) can be made via wiring and circuits formed on the substrate 170. Therefore, with the motor 100 according to this embodiment, the space required for wiring can be reduced, making it possible to make the motor smaller (thinner).

The motor of the present invention has been described above with reference to preferred embodiments, but the motor of the present invention is not limited to the configuration of the above embodiments. The motor of the present invention may be an inner rotor type motor or an outer rotor type motor. The motor of the present invention may be a three-phase AC motor or other AC motor, or may be a DC motor.

In the motor 100 according to the above embodiment, the rotor 160 has 14 magnetic poles and the stator 150 has 12 teeth 153, giving a so-called 14-pole, 12-slot configuration, but in the motor of the present invention, the number of magnetic poles in the rotor and the number of slots in the stator may each be any number. Also, in the motor 100 according to the above embodiment, magnets are arranged inside the rotor core 163, but in the motor of the present invention, the rotor configuration is not limited to this, and for example, some or all of the magnets may be arranged outside the rotor core.

In the motor 100 according to the above embodiment, the magnetic sensor 180 is disposed radially inward relative to the inner circumference of the stator 150 and axially facing the rotor 160 (axial arrangement), but in the motor of the present invention, the magnetic sensor may be disposed radially on the stator 150 side relative to the outer circumference of the rotor 160 and axially facing the stator 150 (radial arrangement). In the motor of the present invention, the magnetic sensor is less susceptible to the effects of the magnetic field generated by the stator, so the magnetic sensor can be disposed radially on the stator side relative to the outer circumference of the rotor and axially facing the stator.

In the motor 100 according to the above embodiment, the substrate 170 is fixed to the stator 150, but in the motor of the present invention, the substrate and the stator may be integrally formed. Below, an embodiment in which the substrate and the stator are integrally formed will be described.

The motor 200 according to the embodiment shown in FIG. 5 includes a stator 250, a rotor 260 shown in phantom lines, a substrate 270, and a magnetic sensor 280. In FIG. 5, components of the motor 200 other than the stator 250, the rotor 260, the substrate 270, and the magnetic sensor 280 are omitted. The configuration of the omitted parts may be the same as or different from that of the motor 100.

In the radial direction, rotor 260 is arranged coaxially on the inside (the other side, in the direction of arrow d) of stator 250 so as to face stator 250. Stator 250 and rotor 260 have the same general configuration as stator 150 and rotor 160 of motor 100, except for the number of poles and the number of slots.

In motor 200, stator 250 and substrate 270 are integrally formed. Specifically, the insulator of stator 250 and substrate 270 are integrally formed. Substrate 270 is an annular portion that protrudes from the end of stator 250 on the other axial side (arrow b direction) to the other radial side (arrow d direction). Substrate 270 is a flat insulating portion. Wiring and circuits (not shown) are formed on substrate 270. In motor 200, electrical connections between coil groups constituting each phase and electrical connections between coils belonging to the same phase are all made via wiring and circuits formed on substrate 270.

In the axial direction, a plurality of (three in this embodiment) magnetic sensors 280 for detecting the magnetic pole position (rotation angle) of the rotor 260 are arranged on one side (direction of arrow a) of the substrate 270 (the surface closer to the rotor 260). In the axial direction, the magnetic sensors 280 face the rotor 260 (axial arrangement). In this embodiment, the magnetic sensors 280 are Hall ICs and are surface-mounted on the printed wiring circuit of the substrate 270. In this embodiment, the magnetic sensors 280 are Hall ICs of a zero-cross detection type that detect a change in the magnetic pole of the rotor 260 (switching from S pole to N pole, or N pole to S pole) and switch the output signal. However, the magnetic sensors 280 may be Hall ICs of other types, or may be magnetic sensors other than Hall ICs.

The motor 200 has a 20-pole, 18-slot configuration. That is, the stator 250 has 18 teeth, and the rotor 260 has 20 magnetic poles. In the motor 200, each magnetic sensor 280 is disposed facing a phase that is a weakly energized phase or a non-energized phase at a different predetermined electrical angle. That is, when each magnetic sensor 280 detects a change in the magnetic poles of the rotor 260, the nearby phase (e.g., the phase closest to the magnetic sensor 280 that detects the change in the magnetic poles) is a non-energized phase, and the magnetic sensor 280 is configured to be less susceptible to the influence (disturbance) of the magnetic field generated by the stator 250.

The motor 200 according to this embodiment has the same characteristics as the motor 100 described above. Furthermore, in the motor 200 according to this embodiment, the substrate 270 and the stator 250 are integrally formed. Therefore, positioning between the substrate 270 and the stator 250 is not required, and the magnetic sensor 280 can be easily arranged. Therefore, with the motor 200, the control accuracy and motor efficiency are improved, and the number of parts is reduced. Furthermore, in the motor 200, the electrical connections between all the coils are made on the substrate 270, so there is no need to reserve space for jumper wires, and the motor can be made thinner.

The motor 300 according to the embodiment shown in FIG. 6 includes a stator 350, a rotor 360 shown in phantom lines, a substrate 370, and a magnetic sensor 380. In FIG. 6, components of the motor 300 other than the stator 350, the rotor 360, the substrate 370, and the magnetic sensor 380 are omitted. The configuration of the omitted parts may be the same as or different from that of the motor 100 or the motor 200.

In the radial direction, rotor 360 is arranged coaxially on the inside (the other side, in the direction of arrow d) of stator 350 so as to face stator 350. Stator 350 and rotor 360 have the same general configuration as stator 150 and rotor 160 of motor 100, except for the number of poles and the number of slots.

In the motor 300, the stator 350 and the substrate 370 are integrally formed. Specifically, the insulator of the stator 350 and the substrate 370 are integrally formed. In the axial direction, the substrate 370 is an annular portion located near the end of the stator 350 on the other side (the direction of the arrow b). The inner diameter of the substrate 370 is the same or approximately the same as the inner diameter of the stator 350. The substrate 370 is a flat insulating portion. Wiring or circuits (not shown) are formed on the substrate 370. In the motor 300, the electrical connections between the coil groups constituting each phase and the electrical connections between the coils belonging to the same phase are all made via the wiring or circuits formed on the substrate 370.

In the axial direction, on the other side (arrow b direction) surface (surface away from rotor 260) of substrate 370, multiple (three in this embodiment) magnetic sensors 380 are arranged to detect the magnetic pole position (rotation angle) of rotor 360. Magnetic sensor 380 faces stator 350 in the axial direction and is arranged on one side in the radial direction (arrow c direction) of rotor 360 (radial arrangement). In this embodiment, magnetic sensor 380 is a Hall IC and is surface mounted on the printed wiring circuit of substrate 370. In this embodiment, magnetic sensor 380 is a Hall IC of a zero-cross detection type that detects a change in the magnetic pole of rotor 360 (switching from S pole to N pole, or N pole to S pole) and switches the output signal. However, magnetic sensor 380 may be a Hall IC of another type or a magnetic sensor other than a Hall IC. The magnetic sensor 380 may be disposed inside the structure of the stator 350 and the substrate 370 which are integrally formed, for example, the magnetic sensor 380 may be disposed inside the resin that covers the stator 350 and the substrate 370.

The motor 300 has a 20-pole, 18-slot configuration. That is, the stator 350 has 18 teeth, and the rotor 360 has 20 magnetic poles. In the motor 300, each magnetic sensor 380 is also arranged in a phase that is a weakly energized phase or a non-energized phase at a different predetermined electrical angle. That is, when each magnetic sensor 380 detects a change in the magnetic poles of the rotor 360, the nearby phase (e.g., the phase closest to the magnetic sensor 380 that detects the change in the magnetic poles) is a non-energized phase, and the magnetic sensor 380 is configured to be less susceptible to the influence (disturbance) of the magnetic field generated by the stator 350.

The motor 300 according to this embodiment has the same characteristics as those of the motors 100 and 200 described above. In addition, in the motor 300, the magnetic sensor 380 is disposed radially on the stator 350 side with respect to the outer periphery of the rotor 260, and is disposed facing the stator 350 in the axial direction. In the motor 300, the magnetic sensor 380 is not easily affected by the magnetic field generated by the stator 350, so that even with the radial arrangement, the control accuracy and motor efficiency are excellent. In addition, since the substrate 370 does not protrude radially to the inside of the stator 350 (the other side, in the direction of the arrow d), when assembling the motor 300, the insertion direction of the rotor 360 is not limited to one direction, improving the degree of freedom during manufacturing.

The motors 100, 200, and 300 according to the above embodiments are so-called radial type motors (radial gap motors), and are equipped with a rotor having a magnet, and the energized phase includes a magnetic body having a magnetic pole portion facing the rotor and a first coil wound around the magnetic body, and a specific magnetic pole of the rotor faces the magnetic pole portion of the energized phase in the radial direction. However, the motor of the present invention is not limited to this, and may be a so-called axial type motor (axial gap motor). In other words, the motor of the present invention may be configured such that a specific magnetic pole of the rotor faces the magnetic pole portion of the energized phase in the axial direction.

In addition, those skilled in the art can modify the motor of the present invention as appropriate, and change the shape, dimensions, and combination of the various components, in accordance with previously known knowledge. As long as the configuration of the present invention is still achieved even after such modifications, it is of course included in the scope of the present invention.

100, 200, 300...motor, 150, 250, 350...stator, 152...coil, 153...teeth (magnetic poles), 160, 260, 360...rotor, 161, 162...magnet, 163...rotor core (magnetic material), 180, 280, 380...magnetic sensor.

Claims (5)

a stator having, at a predetermined electrical angle, a conducting phase and a phase that is conducted weaker than the conducting phase or a non-conducting phase;
A magnetic sensor,
The motor, wherein the magnetic sensor is disposed opposite the weakly energized phase or the non-energized phase. A rotor having a magnet is provided,
the current-carrying phase includes a magnetic body having a magnetic pole portion facing the rotor, and a first coil wound around the magnetic body,
The motor according to claim 1 , wherein a predetermined magnetic pole of the rotor faces the magnetic pole portion of the current-carrying phase. the weakly energized phase or the non-energized phase includes one or more second coils;
The motor according to claim 1 , wherein the magnetic sensor is located at a position overlapping with the second coil or between two adjacent second coils of the plurality of second coils in a circumferential direction. A rotor having a magnetic body and a plurality of magnets inside the magnetic body,
The motor according to claim 1 , wherein the magnetic sensor detects a change in magnetic pole of the rotor. The motor of claim 4, wherein the magnetic sensor faces the rotor in the direction of the rotation axis.

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