JP2007221911A - Rotor and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor capable of attaining high torque. <P>SOLUTION: The rotor 1 is Halvat-arranged with four types of downward magnets 4 to 7 polarized in a direction inclined to a diametrical direction. The polarizing direction in each downward magnets 4 to 7 is set so that an inclination angle to a diametrical direction satisfies θ≤2×ä18×ln(t)-10}, where a diametrical width in the downward magnets 4 to 7 is t. Furthermore, the inclination angle θ is set so as to satisfy θ=ä18×ln(t)-10}±10%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotor and a motor in which magnets are arranged in a Halbach array.

Conventionally, there is a motor in which a magnet included in a rotor has a Halbach array (see, for example, Patent Document 1). In such a rotor, the magnetization direction of the magnet is set not only in the radial direction but also in other directions, so that the distribution of the magnetic flux density can be made ideal. High torque can be achieved.
JP 2002-354721 A

  By the way, as a rotor as mentioned above, what consists only of four types of inclination direction magnets magnetized in the direction inclined with respect to radial direction can be considered (refer FIG. 1). However, for such a rotor, a sufficient effect is obtained unless the radial width (thickness) t of the tilt magnet and the magnetization direction (tilt angle θ with respect to the radial direction) of the tilt magnet are set to appropriate values. There was a risk that the torque could not be obtained and the torque would decrease.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a rotor and a motor capable of achieving high torque.

  The invention according to claim 1 is a rotor arranged in a Halbach array by four kinds of inclined magnets magnetized in a direction inclined with respect to the radial direction, wherein the radial width of the inclined magnet is t. In this case, the magnetization direction in each of the inclined direction magnets was set such that the inclination angle θ with respect to the radial direction satisfies θ ≦ 2 × {18 × ln (t) −10}.

  According to this configuration, the torque of the motor having this rotor is made substantially higher than when the tilt magnet is simply magnetized in the radial direction (the tilt angle is the same as 0 °). (See FIGS. 2 and 3). In other words, based on the tilt angle, it is possible to suppress the torque from being lowered as compared with a case where the tilt magnet is simply magnetized in the radial direction (the tilt angle is the same as 0 °).

  The invention according to claim 2 is a rotor arranged in a Halbach array by four kinds of inclined magnets magnetized in a direction inclined with respect to the radial direction, wherein the radial width of the inclined magnet is t. In this case, the magnetization direction in each of the inclined direction magnets was set so that the inclination angle θ with respect to the radial direction satisfies θ = {18 × ln (t) −10} ± 20%.

According to this configuration, the torque of the motor including this rotor can be set to a high range including the maximum value (see FIGS. 2 and 3).
The invention according to claim 3 is a rotor arranged in a Halbach array by four kinds of inclined magnets magnetized in a direction inclined with respect to the radial direction, wherein the radial width of the inclined magnet is t. In this case, the magnetization direction in each of the inclined direction magnets was set so that the inclination angle θ with respect to the radial direction satisfies θ = {18 × ln (t) −10} ± 10%.

According to this configuration, the torque of the motor including this rotor can be set to a substantially maximum value (see FIGS. 2 and 3).
According to a fourth aspect of the present invention, in the rotor according to any one of the first to third aspects, each of the four types of the inclined direction magnets is provided.

  According to the same configuration, since each of the four types of tilt direction magnets is provided in six pieces, the rotor is the same as in the experiment (see FIG. 2 and FIG. 3), and high reliability is achieved in any one of claims 1 to 3. The effects of the described invention can be obtained.

According to a fifth aspect of the present invention, there is provided a motor including the rotor according to any one of the first to fourth aspects and a stator having a winding.
According to this configuration, the effect of the invention described in any one of claims 1 to 4 can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the rotor and motor which can achieve high torque can be provided.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
The motor includes a stator (not shown) and a rotor 1 shown in FIG. The stator is formed in a substantially cylindrical shape, and includes a plurality of teeth extending radially inward and windings wound around the teeth. The stator is configured to generate a rotating magnetic field for rotating the rotor 1 when power is supplied to the winding from the power supply device.

  The rotor 1 is rotatably supported inside the stator. The rotor 1 includes a rotating shaft 2, a substantially cylindrical rotor core 3 in which the rotating shaft 2 is fitted, and a plurality of inclined direction magnets 4 to 7 fixed to the outer periphery of the rotor core 3 so as to form a Halbach array. .

  The inclined direction magnets 4 to 7 are magnetized in a direction inclined with respect to the radial direction (at an angle larger than 0 ° and smaller than 90 °). Further, there are four types of tilt direction magnets 4 to 7, and more specifically, the first tilt direction magnet 4 in which the magnetization direction is diagonally outward in the radial direction and the vector component in the circumferential direction is clockwise, the magnetization direction Is a second inclined magnet 5 in which the radial vector component is diagonally outward and the circumferential vector component is counterclockwise, and the magnetization direction is diagonally inward in the radial direction and the circumferential vector component is counterclockwise third. There are four types: a tilt direction magnet 6 and a fourth tilt direction magnet 7 in which the magnetization direction is diagonally inward in the radial direction and the vector component in the circumferential direction is clockwise. In addition, the magnetization direction in each inclination direction magnet 4-7 is set to the same inclination angle (theta) (an angle larger than 0 degree and smaller than 90 degree) with respect to a radial direction. In the present embodiment, the first and second tilt direction magnets 4 and 5 constitute an N pole, and the third and fourth tilt direction magnets 6 and 7 constitute an S pole. In FIG. 1, the tilt direction magnets 4 to 7 having the same polarity (that is, the set of the first and second tilt direction magnets 4, 5 and the third and fourth tilt direction magnets 6, 7). Each boundary line of the (set) is shown with a broken line. Also, each of the (first to fourth) inclined direction magnets 4 to 7 of the present embodiment is provided in six pieces.

  The circumferential widths of the (first to fourth) tilt direction magnets 4 to 7 are set to be the same (constant). That is, the circumferential width of each of the (first to fourth) tilt direction magnets 4 to 7 is set to a width corresponding to 15 ° (360 ° / 24 pieces) around the rotation axis 2. Further, the radial widths (thicknesses) t in the inclined direction magnets 4 to 7 are the same (constant). And each inclination direction magnet 4-7 repeats the order of the 1st inclination direction magnet 4, the 2nd inclination direction magnet 5, the 3rd inclination direction magnet 6, and the 4th inclination direction magnet 7 6 times. It is fixed to the outer periphery of the rotor core 3 (that is, so as to constitute 12 poles as a whole).

  Here, the torque of the motor configured as described above will be described with reference to FIG. FIG. 2 is an inclination angle-torque characteristic diagram for each radial width t of the inclination direction magnets 4 to 7, which is obtained from an experiment. As shown in FIG. 2, when the radial width t is 10 mm, the torque becomes maximum when the inclination angle θ is 32.5 ° (indicated by white circles in the figure). In addition, when the radial width t is 10 mm, the inclination direction magnets 4 to 7 are simply magnetized in the radial direction in a state where the inclination angle θ is smaller than 64.5 ° (indicated by x in the figure) ( Compared to the case where the inclination angle θ is the same as 0 °, the torque becomes higher. When the radial width t is 7.5 mm, the torque becomes maximum when the inclination angle θ is 27.5 ° (illustrated by white circles in the figure). In addition, when the radial width t is 7.5 mm, the inclination direction magnets 4 to 7 are simply magnetized in the radial direction in a state where the inclination angle θ is smaller than 54 ° (indicated by x in the figure) ( Compared to the case where the inclination angle θ is the same as 0 °, the torque becomes higher. Further, when the radial width t is 5 mm, the torque becomes maximum when the inclination angle θ is 20 ° (illustrated by white circles in the figure). In addition, when the radial width t is 5 mm, the inclination direction magnets 4 to 7 are simply magnetized in the radial direction with the inclination angle θ smaller than 39 ° (illustrated by x in the figure) Compared with the case where the angle θ is the same as 0 °, the torque becomes higher. When the radial width t is 4 mm, the torque becomes maximum when the inclination angle θ is 15 ° (illustrated by white circles in the figure). In addition, when the radial width t is 4 mm, the inclination direction magnets 4 to 7 are simply magnetized in the radial direction in a state where the inclination angle θ is smaller than 30 ° (illustrated by x in the figure) Compared with the case where the angle θ is the same as 0 °, the torque becomes higher. When the radial width t is 3 mm, the torque becomes maximum when the inclination angle θ is 10.5 ° (illustrated by white circles in the figure). In addition, when the radial width t is 3 mm, the inclination direction magnets 4 to 7 are simply magnetized in the radial direction with the inclination angle θ smaller than 21 ° (illustrated by x in the figure) Compared with the case where the angle θ is the same as 0 °, the torque becomes higher.

Then, the torque becomes higher or lower than the case where the tilt direction magnets 4 to 7 are simply magnetized in the radial direction (the tilt angle θ is the same as 0 °). When the upper limit point at which this is suppressed is drawn on the radial width-inclination angle characteristic diagram shown in FIG.
θ = 2 × {18 × ln (t) −10}
It becomes.

Therefore, in the present embodiment, when the radial width of the tilt direction magnets 4 to 7 is t [mm], the magnetization direction of each of the tilt direction magnets 4 to 7 has the tilt angle θ with respect to the radial direction,
θ ≦ 2 × {18 × ln (t) −10}
It is set to satisfy.

Further, from the above experimental results, the point where the torque becomes the maximum value is drawn on the radial width-tilt angle characteristic diagram shown in FIG. 3 (in white circles in FIG. 3), and the equation of the approximate curve Z2 is calculated.
θ = 18 × ln (t) −10
It becomes.

Therefore, the inclination angle θ in the present embodiment is such that the torque is approximately the maximum value.
θ = {18 × ln (t) −10} ± 10%
It is set to satisfy. In FIG. 3, a range Z3 satisfying θ = {18 × ln (t) −10} ± 10% is illustrated by a pair of two-dot chain lines.

Next, characteristic effects of the above embodiment will be described below.
(1) When the radial width of the tilt direction magnets 4 to 7 is t, the tilt direction θ of the tilt direction magnets 4 to 7 with respect to the radial direction is θ ≦ 2 × {18 × ln (t) −. 10} is set. Therefore, the torque of the motor including the rotor 1 is substantially higher than that in the case where the tilt direction magnets 4 to 7 are simply magnetized in the radial direction (the tilt angle θ is the same as 0 °). (See FIGS. 2 and 3). In other words, on the basis of the inclination angle θ, the torque is lower than when the inclination direction magnets 4 to 7 are simply magnetized in the radial direction (the inclination angle θ is the same as 0 °). Is suppressed.

  (2) When the radial width of the tilt direction magnets 4 to 7 is t, the magnetization direction of each of the tilt direction magnets 4 to 7 is the tilt angle θ with respect to the radial direction, θ = {18 × ln (t) −10}. It is set to satisfy ± 10%. Therefore, the torque of the motor including the rotor 1 can be set to a substantially maximum value (see FIGS. 2 and 3).

  (3) Since each of the four types (first to fourth) of the tilt direction magnets 4 to 7 is provided, the rotor 1 is the same as that of the experiment (see FIGS. 2 and 3), and the above-described effect (with high reliability) 1) (2) can be obtained.

The above embodiment may be modified as follows.
In the above embodiment, the inclination angle θ is set to satisfy θ = {18 × ln (t) −10} ± 10%. However, the present invention is not limited to this. For example, the inclination angle θ is θ It may be set so that ≦ 2 × {18 × ln (t) −10} is satisfied and θ = {18 × ln (t) −10} ± 10% is not satisfied. Even if it does in this way, the effect similar to the effect (1) of the said embodiment can be acquired.

  Further, for example, the inclination angle θ may be set so as to satisfy θ = {18 × ln (t) −10} ± 20%. Even in this case, the torque of the motor including this rotor can be set to a high range including the maximum value (see FIGS. 2 and 3). In FIG. 3, a range Z4 that satisfies θ = {18 × ln (t) −10} ± 20% is illustrated by a pair of broken lines.

  In the above embodiment, the four types (first to fourth) of the tilt direction magnets 4 to 7 are each provided in six pieces, but each other number (that is, four types of multiples, other than six times). You may change so that it may be provided. Of course, in this case, it is necessary to change the circumferential width of the inclined magnets 4 to 7.

The top view of the rotor in this Embodiment. Inclination angle vs. torque characteristics Radial width-tilt angle characteristic diagram.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 4-7 ... Inclination direction magnet, (theta) ... Inclination angle, t ... Radial width.

Claims (5)

A rotor arranged in a Halbach array by four kinds of inclined magnets magnetized in a direction inclined with respect to a radial direction,
When the radial width in the tilt direction magnet is t, the magnetization direction in each tilt direction magnet is the tilt angle θ with respect to the radial direction,
θ ≦ 2 × {18 × ln (t) −10}
Rotor characterized by being set to satisfy. A rotor arranged in a Halbach array by four kinds of inclined magnets magnetized in a direction inclined with respect to a radial direction,
When the radial width in the tilt direction magnet is t, the magnetization direction in each tilt direction magnet is the tilt angle θ with respect to the radial direction,
θ = {18 × ln (t) −10} ± 20%
Rotor characterized by being set to satisfy. A rotor arranged in a Halbach array by four kinds of inclined magnets magnetized in a direction inclined with respect to a radial direction,
When the radial width in the tilt direction magnet is t, the magnetization direction in each tilt direction magnet is the tilt angle θ with respect to the radial direction,
θ = {18 × ln (t) −10} ± 10%
Rotor characterized by being set to satisfy. The rotor according to any one of claims 1 to 3,
A rotor comprising six kinds of the four kinds of inclined direction magnets. The rotor according to any one of claims 1 to 4,
A motor comprising a stator having windings.

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