JPH08172737A - Winding for stator and slotless motor using the winding - Google Patents

Abstract

PURPOSE: To reduce a cogging torque which is undesired as a motor characteristic by a method wherein the thickness in the winding direction of a coil can be made thin by winding a part of a flat cylindrical coil so as to be piled up continuously and a magnetic flux passing a winding row is changed smoothly. CONSTITUTION: A shaft 4 to which a permanent magnet 3 has been attached is supported by a bearing 6 and a bearing 7 which are fixed to a frame 5, and it takes charge of the function of a rotor as a whole. When the rotor is turned, a flat cylindrical coil 1 is fixed to a cylindrical core 2 around a cylindrical track formed by the permanent magnet in a state that both are insulated. In addition, the cylindrical core 2 is fixed and bonded to the frame 5 so as to function as a stator as a whole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator winding and a slotless motor using this winding.

[0002]

2. Description of the Related Art A conventional motor will be described with reference to the drawings. FIG. 4 shows a generally known motor with teeth, which is cut in a ring shape and has a substantially sectional shape. As shown in FIG. 4, the winding 101 is provided in the space provided between the teeth 100. In addition to the motor with teeth, for example, a slotless motor is known. FIG. 5 is a sectional view in which the slotless motor is sliced. In this slotless motor, the winding 102 as shown in FIG. 6 is formed as a coil,
It has a shape arranged around the rotor 103. Figure 7
FIG. 11 is a cross-sectional view of another example of the slotless motor, which is sliced like the one shown in FIG. 5. This is also winding 10 as shown in FIG.
2 is arranged around the rotor 103. Figure 5
7 is that the coils shown in FIG. 7 are partially overlapped with each other.

[0003]

As described above, as shown in FIG.
In the motor with teeth as described above, the magnetic flux from the permanent magnet 103A on the rotor 103 is passed to the stator 104 side via the teeth 100 protruding to the rotor 103 side. Since there are a plurality of teeth 100, each of which has a certain interval, the density of the magnetic flux can be uneven, which adversely affects the motor characteristics as cogging, and the winding density is low due to the presence of the teeth 100. There is a drawback that the size must be increased and the size becomes large for the above-mentioned reason. The slotless motors of FIGS. 5 and 7 are improved in comparison with the slotted motor in terms of cogging and winding density, but the dimension in the thickness direction of the winding as shown in FIG. 6 is the minimum required. In particular, in the lap winding type as shown in FIG. 7, due to an increase in the dimension in the thickness direction at the portion where the coils overlap each other,
As a result, there is a drawback that the size of the motor is increased.

[0004]

That is, according to the first aspect of the present invention, there is provided a stator winding which is slotlessly provided around a rotor to which a permanent magnet is attached, wherein the stator winding has parallel four sides. As in the case of the opposite sides of the shape, the windings are wound in parallel and with the facing winding surfaces shifted in parallel.

Further, according to the invention of claim 2, a coil for each stator, which is formed into a flat cylindrical shape by crushing a substantially cylindrical winding in an oblique direction with respect to a winding direction, is provided in a circumferential direction for each phase. It has a stator that is formed in a substantially cylindrical shape by being partially overlapped with each other in a densely wound state and continuously arranged in the circumferential direction.

According to the third aspect of the present invention, the coils for the respective stators, which are formed into a flat cylindrical shape by crushing the substantially cylindrical winding in an oblique direction with respect to the winding direction, are provided in the circumferential direction for each phase. And has a stator formed in a substantially cylindrical shape, which is continuously arranged next to each other.

[0007]

According to the present invention, since the stator coil is a thin and thick coil in the winding direction, it is possible to reduce the leakage of magnetic flux when these coils are arranged side by side, so that the characteristics of the motor are greatly improved. To do. Further, in this stator coil, since the area of the overlapping portion can be made large, the contact between the coils for each phase is good, and the workability at the time of forming into a tubular shape is also good. Further, electrically, the rows of the coils are arranged to be inclined with respect to the magnetic flux, so that the cogging torque can be smoothed and reduced by gradually increasing and gradually decreasing the magnetic flux across the coil.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing the structure of the slotless motor of the present invention. The slotless motor of this embodiment includes a flat tubular coil 1 forming a stator and a tubular coil made of a magnetic material. 1 is provided with a core 2 provided outside, a permanent magnet 3, and a rotary shaft 4 to which the permanent magnet 3 is attached.

The rotating shaft 4 is supported by bearings 6 and 7 fixed to a frame 8 and has a rotor function as a whole. A cylindrical coil 1 is provided around the permanent magnet 3 with a slight gap. Further, on the outside of the cylindrical coil 1, a core 2 made of a magnetic material is provided.
, The tubular coil 1 and an insulating material (not shown) are sandwiched between them.

2A and 2B show a flat cylindrical coil 1
Front view of each coil element forming a part of FIG.
It is sectional drawing. As shown in FIG. 2A, in the case of a coil element wound in a polygonal tubular shape (hexagonal tubular shape in this embodiment) at a right angle, the shape of the wire material forming the coil element and the number of turns (windings). , In particular, in this embodiment, seven wires are the thickness of the coil element in the winding direction. In the case of this embodiment, when the crushed angle is θ, of course, for the width (W) of the seven coil wire rods, W · cos θ becomes the thickness (D) of each coil element. By doing so, it can be seen that the thickness in the coil winding direction can be reduced. When winding,
This is possible by using a simple jig. Further, in this embodiment shown in FIG. 1, each coil element is wound in one row, but it may be wound in plural rows.

FIG. 3A shows a perspective view of a case where the stator coil is formed in a flat tubular shape. In this stator coil, the coil elements (U, V, W) of FIG. 2 (A) are arranged side by side so as to overlap each other, and are arranged up to a predetermined length (L), and are rounded into a flat tubular coil ( Radius is L / 2π)
3A is formed, and FIG. 3A shows a state in which a part thereof is cut off and expanded. FIG. 3B is a diagram of FIG.
A sectional view when (A) is cut along BB 'is shown. As is apparent from FIG. 3 (B), the coil elements (U, V, W) are crushed to reduce the thickness thereof so that the coil elements may partially overlap each other. However, it can be seen that the structure can be made thin in the thickness direction, and that the spatial waste caused by overlapping is greatly reduced.

A core having a cylindrical diameter (diameter) in which coil elements arranged as shown in FIG. 3 (A) are formed for a required length and a gap is added to the rotary shaft 4 on which the magnet 3 is attached (see FIG. (Omitted) (This core is prepared in advance) is wrapped around. After that, a molding material is filled from above these coil elements to fix the coil in a flat cylindrical shape, and then the core is pulled out. The coil 1 thus formed has a flat tubular shape in the thickness direction of FIG.

[0013]

As described above, according to the present invention,
By using the flat cylindrical winding for the winding of the stator, it is possible to make it thinner in the thickness direction as compared with a coil having the same number of turns, and it is possible to make the size smaller, especially the motor diameter smaller. Further, according to the present invention, since the windings of each coil are crushed and inclined, the coil elements are in good contact with each other, and it is possible to reduce the amount of molding material used for cylindrical fixing. Further, according to the present invention, since the coil row is inclined, the amount of change in the magnetic flux across the coil is gradually increased or gradually decreased, which is disliked as a motor characteristically. It is possible to reduce the cogging torque.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention.

FIG. 2A is a plan view showing one element of a flat tubular coil that constitutes a part of the stator of the present invention. (B) A-A line sectional view.

FIG. 3 (A) is a schematic perspective view showing a state in which the stator coil of the present invention is wound in layers. (B) BB sectional drawing.

FIG. 4 is a cross-sectional view showing a conventional slotted motor.

FIG. 5 is a sectional view showing a conventional slotless motor.

FIG. 6 is a perspective view showing a laminated state of coils used in a conventional slotless motor.

FIG. 7 is a sectional view showing another embodiment of a conventional slotless motor.

[Explanation of symbols]

 1 flat cylindrical coil 2 core 3 permanent magnet 4 rotating shaft 5 frame 6,7 bearing

Claims (3)

[Claims] 1. A stator winding, which is slotlessly provided around a rotor having a permanent magnet, wherein the stator windings are parallel to each other, such as opposite sides of a parallelogram, and A stator winding characterized in that the windings are arranged such that the winding surfaces facing each other are shifted in parallel. 2. A closely wound state in which a coil for a stator formed by crushing a substantially cylindrical winding in an oblique direction with respect to a winding direction to form a flat tubular shape is partially displaced in the circumferential direction for each phase. A slotless motor having a substantially cylindrical stator that is superposed on and aligned in the circumferential direction. 3. A coil for each stator, which is formed into a flat cylindrical shape by crushing a substantially cylindrical winding in an oblique direction with respect to a winding direction, is continuously arranged side by side in the circumferential direction for each phase. A slotless motor having a stator formed in a substantially cylindrical shape.