JP7820737B2 - electric motor - Google Patents

Description

The present invention relates to an electric motor.

A known electric motor includes a cylindrical case with both axial ends closed, a rotating shaft journaled in the case, an annular core attached to the inner surface of the case and having multiple teeth protruding toward the center at equiangular intervals around the rotating shaft, a coil wound around each tooth of the core, and multiple permanent magnets attached to the rotating shaft at equiangular intervals around the rotating shaft so as to face each tooth (see, for example, Patent Document 1).

However, in conventional electric motors such as those described in Patent Document 1, coils are formed by winding coated wire, such as enameled wire, around each of the multiple teeth that protrude toward the center of an annular core. This makes forming these coils time-consuming and makes it difficult to prevent costs from increasing.

Japanese Patent Application Laid-Open No. 2022-116563

In light of the above situation, the present invention aims to provide an electric motor that can suppress cost increases.

In order to solve the above problems, the electric motor according to the present invention comprises:
"A hollow casing,
a rotating shaft rotatably supported by the casing;
a stator unit formed in an annular shape coaxial with the axis of the rotary shaft and attached within the casing;
a rotor unit attached to the rotary shaft within the casing with a gap between the rotor unit and the stator unit;
Equipped with
The stator unit is
an annular coil unit including an annular core, a full-circumference coil wound toroidally around the entire circumference of the core, and a plurality of partial coils that are partially toroidally wound at a plurality of locations on the full-circumference coil and are arranged at equal angular intervals around the axis;
a plurality of stator magnets arranged at equal angular intervals around the axis on one end face side of the coil unit in the axial direction, with their respective magnetic poles facing the axial direction and the orientation of the magnetic poles facing the end face of the coil unit being alternately reversed in the circumferential direction;
The rotor unit comprises:
a plurality of first rotor magnets, which are arranged on the opposite side of the coil unit from the plurality of stator magnets at equal angular intervals around the axis, with their respective magnetic poles facing the axial direction and with the orientation of the magnetic poles facing the end face of the coil unit alternately reversed in the circumferential direction;
a plurality of second rotor magnets arranged within the ring of the coil unit at the same equal angular intervals as the plurality of first rotor magnets around the axis, with their respective magnetic poles facing in a radial direction around the axis, and with the orientation of their magnetic poles facing the inner circumferential surface of the coil unit being alternately reversed in the circumferential direction ;
The first rotor magnet and the second rotor magnet are provided at the same angular position around the axis,
The second rotor magnet has a magnetic pole that faces the inner surface of the coil unit that is the same as the magnetic pole that faces the end face of the coil unit in the first rotor magnet, which is arranged at the same angular position centered on the axis .

In an electric motor with this configuration, the coil unit has a full-circumference coil or partial coil wound toroidally around a circular core. This makes it easier to form the coil compared to conventional electric motors, where coils are formed by winding coated wire around each of multiple teeth that protrude toward the center, and reduces the cost of the electric motor.

In addition to the above configuration, the electric motor according to the present invention has:
"A plurality of base units each consisting of one stator unit and one rotor unit are provided,
The base units of each set are:
Each stator unit is arranged relative to one of the rotating shafts, and each stator unit has an outer circumferential coil wound cylindrically so as to surround the outer circumferential surface of the coil unit.

With this configuration, multiple sets of base units, each equipped with a stator unit and a rotor unit, are provided for one rotating shaft, resulting in a higher rotational torque for the rotating shaft compared to when there is only one base unit.

Furthermore, since each set of base units is equipped with a cylindrical outer coil, if two sets of base units are provided (an even number of sets is preferable when more than two sets are used), for example, two outer coils of the same radius are lined up coaxially. By making the distance between the two outer coils the same as the radius of the outer coil, it is possible to form a Helmholtz coil using two outer coils, i.e., a pair of outer coils. As a result, when a Helmholtz coil is formed using a pair of outer coils, passing current through the pair of outer coils to generate a magnetic field in the same direction can produce a uniform magnetic field on the axis of the pair of outer coils. This magnetic field can cancel out magnetic fields generated by coil units and other components located within the rings of the pair of outer coils, making it possible to provide an electric motor with little magnetic leakage to the outside.

As described above, the present invention provides an electric motor that can suppress cost increases.

1 is a perspective view of an electric motor according to an embodiment of the present invention; FIG. FIG. 2 is an exploded perspective view showing the electric motor disassembled into its main components. FIG. 2A is a perspective view of a stator unit in an electric motor, and FIG. 2B is a perspective view showing the stator unit in FIG. 2A from the opposite side. 1A is an exploded perspective view showing a stator unit in an exploded state, and FIG. 1B is an exploded perspective view showing the stator unit in FIG. 1A from the opposite side. (a) is a front view of the core of the coil unit in the stator unit, (b) is a front view showing the state in which a full-circumference coil is wound around the core, and (c) is a front view showing the state in which a partial coil is wound around (b) to form a coil unit. FIG. 2 is an explanatory diagram showing the arrangement of stator magnets in a stator unit. FIG. 2A is a perspective view of a rotor unit in an electric motor, and FIG. 2B is a perspective view showing the rotor unit in FIG. 2A from the opposite side. FIG. 2 is an explanatory diagram showing the arrangement of a first rotor magnet and a second rotor magnet in a rotor unit.

An electric motor 1, which is one embodiment of the present invention, will be described in detail below with reference to the drawings. The electric motor 1 comprises a hollow casing 10, a rotating shaft 20 rotatably supported by the casing 10, a stator unit 30 formed in an annular shape coaxial with the axis of the rotating shaft 20 and attached to the casing 10, and a rotor unit 50 attached to the rotating shaft 20 within the casing 10 with a gap between the stator unit 30 and the rotor unit 50.

The electric motor 1 of this embodiment has two sets of one stator unit 30 and one rotor unit 50. This set of stator unit 30 and rotor unit 50 corresponds to the base unit of the present invention. Below, the direction in which the rotating shaft 20 extends will be referred to as the axial direction, the central axis of the rotating shaft 20 will be referred to as the axis, and the direction along the circumference of a circle centered on that axis will be referred to as the circumferential direction.

First, as shown in Figures 1 to 3, the casing 10 comprises a pair of end plates 11 spaced apart in the axial direction, an intermediate plate 12 located between the pair of end plates 11, two upper cases 13 connecting the upper edges of each end plate 11 and intermediate plate 12, two lower cases 14 connecting the lower edges of each end plate 11 and intermediate plate 12, and a total of four side cases 15 connecting the side edges of each end plate 11 and intermediate plate 12.

In other words, in this embodiment, an intermediate plate 12 is provided between a pair of end plates 11, and therefore two sets of one upper case 13, one lower case 14, and two side cases 15 are provided.

When assembled, this casing 10 can form spaces on both sides in the axial direction with the intermediate plate 12 in between, and each space can accommodate a pair of stator units 30 and rotor units 50.

The casing 10 also includes, on the end plate 11, a shaft bearing 16 for rotatably supporting the rotating shaft 20 and a rotor bearing 17 for rotatably supporting the rotor unit 50.

Specifically, the pair of end plates 11 are flat plates parallel to a plane perpendicular to the axial direction and have a square outer shape. The end plates 11 have a through-hole 11a that penetrates the axial direction at the center and through which the rotating shaft 20 is inserted, and multiple vent holes 11b that are arranged at equal angular intervals around the center and penetrate the axial direction. The multiple vent holes 11b are used to release heat from the coil unit 31 to the outside. A shaft bearing 16 and a rotor bearing 17 are attached to each end plate 11.

The intermediate plate 12 is flat and parallel to a plane perpendicular to the axial direction, and has the same square outer shape as the end plates 11. The intermediate plate 12 has a through-hole 12a that penetrates the axial direction at its center and through which the rotating shaft 20 is inserted, and multiple vent holes 12b that penetrate the axial direction and are spaced equiangularly around the center. The multiple vent holes 12b are intended to improve ventilation within the casing 10. The axial thickness of the intermediate plate 12 is set so that the distance between the outer coils 41 (described below) provided on each stator unit 30 is the same as the radius of the outer coils 41, with respect to the stator units 30 arranged on both sides of the intermediate plate 12.

The set of upper case 13, lower case 14, and two side cases 15 all have the same axial length, and the surfaces (inner surfaces) facing the rotating shaft 20 are curved in an arc shape centered on the axis. The upper case 13, lower case 14, and two side cases 15 each have a flange portion 18 that protrudes from their inner surfaces toward the rotating shaft 20 and extends circumferentially along the inner surfaces. The flange portion 18 is located on each of the upper case 13, lower case 14, and two side cases 15, offset to one side from the axial center.

The upper case 13, lower case 14, and two side cases 15 each have at least one positioning protrusion 18a protruding axially from the flange portion 18. The positioning protrusion 18a protrudes axially toward the center on the upper case 13, lower case 14, and two side cases 15. When assembled to the casing 10, these positioning protrusions 18a are spaced at equal angular intervals (60 degrees in this case) around the axis. By inserting the positioning protrusion 18a into the positioning notch 37e of the second cover portion 37 of the stator unit 30 (described later), the rotational angle of the casing 10 and stator unit 30 around the axis can be determined.

The upper case 13, lower case 14, and two side cases 15 also have multiple ventilation slits 19 that penetrate from their respective inner surfaces in the thickness direction. The multiple ventilation slits 19 are intended to allow heat from the coil unit 31 to escape to the outside. The upper case 13, lower case 14, and two side cases 15 are arranged to surround the outer periphery of the stator unit 30.

As shown in Figure 3, the rotating shaft 20 has cylindrical portions 21 at both axial ends and rectangular portions 22 sandwiched between the cylindrical portions 21 at both ends. The cylindrical portions 21 are supported by being inserted into the shaft bearings 16 of the casing 10. Meanwhile, the rectangular portions 22 can be inserted into the rectangular hole portions 51b of the base portion 51 of the rotor unit 50 (described later), allowing the rotor unit 50 to rotate integrally.

As shown in Figures 4 and 5, the stator unit 30 comprises an annular coil unit 31, a coil cover 35 covering the coil unit 31, a plurality of stator magnets 40 attached to the coil cover 35, an outer coil 41 wound around the outer periphery of the coil cover 35, and a rotor bearing 42 attached to the coil cover 35 for rotatably supporting the rotor unit 50.

The coil unit 31 comprises a circular core 32, a full-circumference coil 33 wound toroidally around the entire circumference of the core 32, and multiple partial coils 34 wound toroidally at multiple locations on the full-circumference coil 33 (see Figure 6). The inner diameter of the circular coil unit 31 is larger than the outer diameter of the base 51 (described below) of the rotor unit 50.

The core 32 has an annular core body 32a and annular guide portions 32b provided on both the inner and outer peripheries of the core body 32a. The core body 32a is made of laminated electromagnetic steel sheets. The guide portions 32b are made of synthetic resin. Both axial edges of the circumferential surface of the guide portion 32b opposite the surface that contacts the core body 32a are rounded along the entire circumference, preventing the insulated wire from bending at right angles when the insulated wire is toroidally wound to form the full-circumference coil 33. Unlike cores of conventional electric motors, the core 32 of this embodiment does not have any tooth-like protrusions that protrude toward the axis (center).

The full-circumference coil 33 is toroidally wound around the core 32 without any gaps. In this embodiment, the full-circumference coil 33 is triple-wound. Multiple partial coils 34 are toroidally wound around the full-circumference coil 33 and are arranged at equal angular intervals around the axis. There is a gap between adjacent partial coils 34 in the circumferential direction. While the number is not limited, in this embodiment, six partial coils 34 are provided, each of which is triple-wound.

The coil cover 35 is divided into two axially, consisting of a first cover part 36 and a second cover part 37.

The first cover portion 36 comprises an annular base portion 36a, an outer flange portion 36b and an inner flange portion 36c extending radially from one axial end of the outer and inner peripheral surfaces of the base portion 36a, respectively, and a cylindrical bobbin portion 36d extending from the outer flange portion 36b coaxially with the shaft core toward the opposite side of the base portion 36a in the axial direction. The bobbin portion 36d has an inner diameter larger than the outer diameter of the base portion 36a.

The first cover portion 36 is recessed at one of the axial end faces of the base portion 36a, the end face closest to the bobbin portion 36d. The recesses 36e are spaced at equal angles around the axis, and the base portion 36a has multiple through-holes 36f axially penetrating the base portion 36a between adjacent recesses 36e. Each recess 36e accommodates a stator magnet 40. The distance from the axis of the recesses 36e is approximately the same as the distance from the axis of the core 32 of the coil unit 31, and the depth from the end face of the base portion 36a is the same as the length of the stator magnet 40 in the magnetic pole direction (the direction in which the two magnetic poles are separated). The through-holes 36f are used to release heat from the coil unit 31 to the outside. While the number of recesses 36e is not limited, in this embodiment, six recesses 36e and six through-holes 36f are provided. Furthermore, the circumferential length of each accommodating recess 36e is set within an angular range of 30 degrees centered on the axis.

The second cover portion 37 comprises a flat, annular base portion 37a, a cylindrical bobbin portion 37b extending axially from the outer peripheral edge of the base portion 37a, an outer flange portion 37c extending radially outward from the axial base end of the outer peripheral surface of the bobbin portion 37b, and an inner tube portion 37d extending axially from the inner peripheral edge of the base portion 37a in the same direction as the bobbin portion 37b. The bobbin portion 37b of the second cover portion 37 has the same outer and inner diameters as the bobbin portion 36d of the first cover portion 36. The length of the inner tube portion 37d is set so that when the tip of the bobbin portion 37b is butted against the tip of the bobbin portion 36d of the first cover portion 36, the tip of the inner tube portion 37d abuts against the inner flange portion 36c of the first cover portion 36. The inner diameter of the inner cylinder 37d near the end on the base 37a side in the axial direction is larger than the inner diameter near the opposite end, and the rotor bearing 42 is attached to the part with the larger inner diameter.

The second cover portion 37 is also cut out from the outer periphery of the outer flange portion 37c toward the axis, and is provided with multiple positioning notches 37e spaced at equal angular intervals (here, 30 degrees) around the axis. Positioning protrusions 18a provided on the upper case 13, lower case 14, and two side cases 15 are inserted into the positioning notches 37e, allowing the rotational angle positions of the casing 10 and stator unit 30 around the axis to be determined.

Furthermore, the second cover portion 37 has a plurality of through holes 37f that penetrate the base portion 37a in the axial direction and are provided at equal angular intervals around the axis, and a plurality of slits 37g that penetrate the base portion 37a in the axial direction between adjacent through holes 37f. The plurality of slits 37g extend in an arc shape centered on the axis, and are arranged in a row in the radial direction around the axis. The plurality of through holes 37f and the plurality of slits 37g are intended to release heat from the coil unit 31 to the outside.

This coil cover 35 can be assembled by butting together the first cover portion 36 and the second cover portion 37 at the tips of the respective bobbin portions 36d, 37b. When assembled to the coil cover 35, an annular space is formed surrounded by the two base portions 36a, 37a, the two outer flange portions 36b, 37c, and the inner cylinder portion 37d, and the coil unit 31 is housed within this space. Furthermore, when the coil cover 35 is assembled, the outer peripheral surfaces of the bobbin portions 36d, 37b form a continuous, flush surface, and the outer coil 41 is wound around this outer peripheral surface.

The multiple stator magnets 40 are housed one by one in each of the housing recesses 36e of the first cover portion 36 of the coil cover 35 with their magnetic poles facing in the axial direction, and the orientation of each magnetic pole is oriented so that it alternates in the circumferential direction (see Figure 7). When the stator magnets 40 are housed and attached in the housing recesses 36e, their axial end faces are located flush with the axial end face of the base portion 37a. By attaching the multiple stator magnets 40 to the coil cover 35, they are arranged at equal angular intervals around the axis. Furthermore, when assembled into the stator unit 30, the end face on the opening side of the housing recess 36e of each of the multiple stator magnets 40 faces and abuts one of the axial end faces of the coil unit 31 (see Figure 2).

The outer coil 41 is wound around the outer surface of the bobbin portions 36d and 37b between the outer flange portion 36b of the first cover portion 36 and the outer flange portion 37c of the second cover portion 37 of the coil cover 35. This outer coil 41 is used to form a Helmholtz coil.

As shown in Figure 8, the rotor unit 50 comprises a base 51 having an attachment hole 51a through which the rotating shaft 20 is inserted, a disk-shaped support plate 52 extending outward from the base 51 in a direction perpendicular to the axis, a plurality of first rotor magnets 53 attached to the support plate 52, and a plurality of second rotor magnets 54 attached to the base 51.

The base 51 has a mounting hole 51a that is composed of two sections: a square hole section 51b and a round hole section 51c. More specifically, the square hole section 51b is located halfway from one axial end of the mounting hole 51a to the opposite axial end, and has an inner circumferential shape that matches the outer circumferential shape of the prismatic section 22 of the rotating shaft 20. The round hole section 51c is located in the remaining section of the mounting hole 51a excluding the square hole section 51b, and has an inner circumferential shape with a larger diameter than the outer periphery of the prismatic section 22. By inserting the prismatic section 22 of the rotating shaft 20 into the square hole section 51b of the mounting hole 51a, the base 51 can rotate integrally with the rotating shaft 20.

The base 51 also has a first bearing portion 51d provided on the outer peripheral surface near the end on the round hole portion 51c side in the axial direction, a second bearing portion 51e provided on the outer peripheral surface near the center in the axial direction, and multiple storage recesses 51f recessed from the outer peripheral surface on the end side on the square hole portion 51b side, on the opposite side of the first bearing portion 51d in the axial direction, with the second bearing portion 51e in between.

The first bearing 51d is supported by the rotor bearing 17 of the casing 10. The second bearing 51e is supported by the rotor bearing 42 of the stator unit 30. The multiple accommodating recesses 51f are provided at equal angular intervals around the axis, and each accommodates a second rotor magnet 54. The depth of the multiple accommodating recesses 51f from the outer peripheral surface of the base 51 is slightly deeper than the length of the second rotor magnet 54 in the magnetic pole direction. Each of the multiple accommodating recesses 51f is open to one axial side of the base 51. In this embodiment, six accommodating recesses 51f are provided, the same number as the number of mounting recesses 52a described below.

The support plate 52 is located in the base 51 between the first and second support shafts 51d and 51e, and has an outer diameter that is approximately the same as the outer diameter of the coil unit 31. The support plate 52 is recessed at the end face on the axial side where the multiple storage recesses 51f are located in the base 51, and is equipped with multiple mounting recesses 52a spaced at equal angular intervals around the axis, and multiple through holes 52b that penetrate in the axial direction between adjacent mounting recesses 52a.

A first rotor magnet 53 is attached to each of the multiple mounting recesses 52a. The distance from the axis of the multiple mounting recesses 52a is approximately the same as the distance from the axis of the core 32 in the coil unit 31, and the depth from the end face of the support plate portion 52 is shallower than the length of the first rotor magnet 53 in the magnetic pole direction. The number of multiple mounting recesses 52a is the same as the number of accommodating recesses 51f in the base portion 51 (six in this case), and they are located at the same angular positions as the accommodating recesses 51f around the axis. The multiple through holes 52b are intended to allow heat from the coil unit 31 to escape to the outside.

The multiple first rotor magnets 53 are mounted one by one in each mounting recess 52a of the support plate 52 with their magnetic poles facing axially, and are oriented so that the orientation of their magnetic poles alternates in the circumferential direction (see Figure 9). By mounting the multiple first rotor magnets 53 on the support plate 52, they are arranged at equal angular intervals around the axis. The multiple second rotor magnets 54 are housed one by one in each housing recess 51f of the base 51 with their magnetic poles facing radially around the axis, and are oriented so that the orientation of their magnetic poles alternates in the circumferential direction (see Figure 9).

The first rotor magnet 53 and second rotor magnet 54 are positioned at the same angular position around the axis, and are attached so that the magnetic pole of the first rotor magnet 53 on the side farther from the support plate portion 52 and the magnetic pole of the second rotor magnet 54 facing radially outward around the axis are the same pole.

Next, the assembly of the electric motor 1 of this embodiment will be described mainly with reference to Figures 1 to 3. First, the upper case 13, lower case 14, and two side cases 15 are assembled into a frame, and then the stator unit 30 is inserted into the frame on the side where the positioning protrusion 18a protrudes from the flange portion 18. Note that in Figure 2, the differences in the magnetic poles of each magnet are indicated by different shades of shading.

At this time, the stator unit 30 is inserted into the frame from the second cover portion 37 side, the positioning protrusions 18a are inserted into the positioning notches 37e of the second cover portion 37, and the second cover portion 37 is abutted against the flange portion 18. This forms a first temporary assembly in which the outer periphery of the stator unit 30 is surrounded by the upper case 13, the lower case 14, and the two side cases 15. In this embodiment, two first temporary assemblies are prepared. Note that the two first temporary assemblies are assembled so that the magnetic poles of the stator magnets 40, which are positioned at the same specific angle around the axis, have different orientations. Specifically, for example, at the same specific angle around the axis, the magnetic poles of the stator magnets 40 facing the coil unit 31 are aligned so that the north pole in one first temporary assembly and the south pole in the other first temporary assembly.

Then, a first temporary assembly is attached to each axial side of the intermediate plate 11 to form a second temporary assembly. At this time, each first temporary assembly is attached so that the first cover portion 36 of the stator unit 30 faces the intermediate plate 11.

Next, the bases 51 of the rotor units 50 are inserted into the rings of the respective stator units 30 from both axial outsides of the second temporary assembly, with the support plate portions 52 facing outward in the axial direction, and the second bearing portions 51e of the rotor units 50 are supported by the rotor bearings 42 of the stator units 30.

After attaching the rotor units 50 to both axial sides of the second temporary assembly, the rotating shaft 20 is passed through the mounting holes 51a of the two rotor units 50 from one axial side, penetrating the second temporary assembly. When attaching the two rotor units 50 to this rotating shaft 20, the two first rotor magnets 53, which are positioned at the same predetermined angle around the axis, are attached so that the magnetic poles of each are oriented in the same direction.

Then, the end plates 11 are attached to the upper case 13 and lower case 14 of the second temporary assembly from both axially outer sides. At this time, the cylindrical portion 21 of the rotating shaft 20 and the first bearing portion 51d of the rotor unit 50 are supported by the shaft bearing 16 and rotor bearing 17 attached to the end plates 11, respectively. In this way, the electric motor 1 can be assembled.

In the electric motor 1 assembled as described above, the rotating shaft 20 is rotatably supported by two end plates 11 in the casing 10, and two rotor units 50 are attached to this rotating shaft 20 so that they rotate as a unit. This electric motor 1 also has two sets, each consisting of one stator unit 30 and one rotor unit 50, and these two sets are arranged symmetrically with the intermediate plate 12 in between. In other words, in each set, the ends on the axial sides where multiple stator magnets 40 are provided are arranged to face each other.

As shown in FIG. 2, in this electric motor 1, the multiple first rotor magnets 53 attached to the support plate portion 52 of the rotor unit 50 are located on the opposite side of the coil unit 31 from the multiple stator magnets 40 provided in the stator unit 30. The magnetic poles of the multiple stator magnets 40 and the multiple first rotor magnets 53 are oriented in the axial direction. Furthermore, the multiple stator magnets 40 provided on each side of the axial direction with the intermediate plate 12 in between are aligned parallel to the axis, with the magnetic poles of each of the two stator magnets 40 aligned parallel to the axis facing the same direction. Furthermore, the multiple first rotor magnets 53 provided on each side of the axial direction with the intermediate plate 12 in between are aligned parallel to the axis, with the magnetic poles of each of the two first rotor magnets 53 aligned parallel to the axis facing the same direction.

The multiple second rotor magnets 54 attached to the base 51 of the rotor unit 50 are positioned within the ring of the coil unit 31 in the stator unit 30 with their magnetic poles facing radially around the axis. The magnetic poles of the multiple second rotor magnets 54 facing the inner circumferential surface of the coil unit 31 are the same as the magnetic poles facing the coil unit 31 of the first rotor magnet 53, which is located at the same angular position around the axis.

Therefore, the two sets of stator units 30 and rotor units 50 are arranged symmetrically with the intermediate plate 12 in between, and the magnetic poles of the stator magnets 40, first rotor magnets 53, and second rotor magnets 54 are oriented in opposite directions with the intermediate plate 12 in between.

The electric motor 1 also has two outer coils 41 that surround the outer periphery of each of the two coil units 31. The two outer coils 41 are spaced apart in the axial direction by a distance equal to their radii. Therefore, the two (pair) outer coils 41 form a Helmholtz coil.

When the rotating shaft 20 (rotor unit 50) is free to rotate, the magnetism of the stator magnet 40 provided in the stator unit 30 causes the rotor unit 50 to stop at a rotational position where the magnetic pole orientation of the first rotor magnet 53 of the rotor unit 50 provided on the opposite side of the coil unit 31 corresponds to the magnetic pole orientation of the stator magnet 40 spaced apart in the axial direction.

Next, we will explain how to use the electric motor 1 of this embodiment. The electric motor 1 of this embodiment can rotate the rotating shaft 20 via the rotor unit 50 by passing a pulse current through at least one of the full-circumference coil 33 and the multiple partial coils 34 in the coil unit 31. It is believed that this electric motor 1 rotates based on the following principle. The coil unit 31 of this embodiment forms the full-circumference coil 33 and the multiple partial coils 34 by toroidally winding a coated electric wire around a circular core. Therefore, when current is passed through the full-circumference coil 33, etc., magnetic flux circulates circumferentially along the ring and is rarely released to the outside.

When a current (voltage) greater than a predetermined level is applied to the coil unit 31, magnetic saturation occurs, causing magnetic flux (magnetism) to be emitted to the outside. Here, a pulse current is applied, causing magnetic flux to be emitted from the coil unit 31 for a short period corresponding to the pulse width. Because multiple stator magnets 40 are located on the opposite side of the coil unit 31 from the multiple first rotor magnets 53, magnetic flux is emitted from the coil unit 31 to the outside, influenced by the magnetic flux from the multiple stator magnets 40. The first rotor magnet 53 and second rotor magnet 54 of the rotor unit 50 then react (attract and repel) to the magnetic flux emitted from the coil unit 31, and this cycle is repeated, causing the rotor unit 50 (rotating shaft 20) to rotate. Note that the two stator units 30 and rotor units 50, located on both sides of the axial direction with the intermediate plate 12 in between, have the magnetic poles of the stator magnets 40, first rotor magnet 53, and second rotor magnet 54 facing in opposite directions across the intermediate plate 12, so rotational forces do not cancel each other out. Incidentally, the inventors of the present application have confirmed that applying a pulse current to the electric motor 1 of this embodiment causes the rotating shaft 20 to rotate.

In addition, in this electric motor 1, current is applied to two (a pair of) outer coils 41 in accordance with the timing of applying pulse current to the coil unit 31. As a result, when current is passed through the pair of outer coils 41 and magnetic fields in the same direction are generated, a uniform magnetic field can be obtained on the axis of the pair of outer coils 41. This magnetic field can cancel out magnetic fields generated by the coil units 31 and other components located within the rings of the pair of outer coils 41, reducing magnetic leakage to the outside.

As such, according to this embodiment, in the coil unit 31, the full-circumference coil 33 and partial coil 34 are toroidally wound around the annular core 32. This makes it easier to form the coils than in conventional electric motors, where coils are formed by winding coated wire around each of multiple teeth that protrude toward the center, and reduces the cost of the electric motor 1.

Furthermore, according to this embodiment, the core 32 in the coil unit 31 has a simple annular shape without any protrusions, which reduces the cost of manufacturing the core compared to conventional electric motor cores that have multiple protrusions (teeth).

Furthermore, according to this embodiment, two sets of stator units 30 and rotor units 50 are provided for one rotating shaft 20, which increases the rotational torque of the rotating shaft 20 compared to when only one set is provided.

Furthermore, according to this embodiment, the rotor unit 50 is equipped with a plurality of first rotor magnets 53 arranged on one axial end face side of the coil unit 31, and a plurality of second rotor magnets 54 arranged within the ring of the coil unit 31, making it possible to utilize as much of the magnetic force emitted from the coil unit 31 to the outside as possible.

The present invention has been described above using preferred embodiments, but the present invention is not limited to the above embodiments, and as described below, various improvements and design modifications are possible without departing from the spirit of the present invention.

For example, in the above embodiment, the electric motor 1 is shown to have two pairs of stator units 30 and rotor units 50, but this is not limited to this, and it may have one pair of stator units 30 and rotor units 50, or three or more pairs.

In addition, in the above embodiment, the number of partial coils 34 is the same as the number of stator magnets 40, first rotor magnets 53, and second rotor magnets 54, but this is not limited to this, and the number of partial coils 34 and the number of magnets may be different.

In addition, in the above embodiment, the stator unit 30 is shown equipped with an outer coil 41, but this is not limited to this, and the stator unit 30 may not be equipped with an outer coil 41.

Furthermore, in the above embodiment, an air-cooled device is shown that uses multiple ventilation holes 11b, 12b and multiple ventilation slits 19 to discharge heat to the outside, but this is not limited to this, and water-cooled devices (for example, a water-circulating water jacket or cooling gel) may also be used.

REFERENCE SIGNS LIST 1 Electric motor 10 Casing 20 Rotating shaft 30 Stator unit 31 Coil unit 32 Core 33 Full-circumference coil 34 Partial coil 40 Stator magnet 41 Peripheral coil 50 Rotor unit 53 First rotor magnet 54 Second rotor magnet

Claims (2)

a hollow casing;
a rotating shaft rotatably supported by the casing;
a stator unit formed in an annular shape coaxial with the axis of the rotary shaft and attached within the casing;
a rotor unit attached to the rotary shaft within the casing with a gap between the rotor unit and the stator unit;
Equipped with
The stator unit is
an annular coil unit including an annular core, a full-circumference coil wound toroidally around the entire circumference of the core, and a plurality of partial coils that are partially toroidally wound at a plurality of locations on the full-circumference coil and are arranged at equal angular intervals around the axis;
a plurality of stator magnets arranged at equal angular intervals around the axis on one end face side of the coil unit in the axial direction, with their respective magnetic poles facing the axial direction and the orientation of the magnetic poles facing the end face of the coil unit being alternately reversed in the circumferential direction;
The rotor unit comprises:
a plurality of first rotor magnets, which are arranged on the opposite side of the coil unit from the plurality of stator magnets at equal angular intervals around the axis, with their respective magnetic poles facing the axial direction and with the orientation of the magnetic poles facing the end face of the coil unit alternately reversed in the circumferential direction;
a plurality of second rotor magnets arranged within the ring of the coil unit at the same equal angular intervals as the plurality of first rotor magnets around the axis, with their respective magnetic poles facing in a radial direction around the axis, and with the orientation of their magnetic poles facing the inner circumferential surface of the coil unit being alternately reversed in the circumferential direction ;
The first rotor magnet and the second rotor magnet are provided at the same angular position around the axis,
The magnetic pole of the second rotor magnet that faces the inner circumferential surface of the coil unit is the same as the magnetic pole of the first rotor magnet that faces the end face of the coil unit and is provided at the same angular position around the axis.
An electric motor characterized by: a plurality of base units each including one stator unit and one rotor unit;
The base units of each set are:
2. The electric motor according to claim 1, wherein each of the stator units is arranged for one of the rotating shafts, and each of the stator units has an outer coil wound cylindrically so as to surround the outer circumferential surface of the coil unit.