JP2007274802A - Switched reluctance motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly perform suction and separation by switching without braking rotation. <P>SOLUTION: An air gap when magnetic suction is generated and a rotor and a stator begin to overlap each other is made smaller than an air gap when the rotor and the stator are separated. A ratio of magnetic flux density at a magnetizing force 5,000 A/m of a core material for use in the rotor, and magnetic flux density at a magnetizing force 5,000 A/m of an iron core material for use in the stator, is 0.90 to 1.10 times a ratio of the rotational directional width of a salient pole of the rotor and the rotational directional width of a comb tooth of the stator. More concretely, for example, the radial length of the front side end of the rotational directional width is maximized, and the radial length of the rear side end of the rotational directional width is minimized. As a result, the air gap is the smallest at the beginning of the overlapping of the salient pole and the comb tooth that requires a suction force, so that they strongly attract each other, and a residual magnetic field after they face each other wherein power supply is cut is abruptly attenuated due to the fact that the air gap is expanded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a switched reluctance motor produced by laminating electromagnetic steel sheets.

  The switched reluctance motor has a simple and robust structure because the rotor and the stator are made by laminating electromagnetic steel plates and no magnet is used. For this reason, attention has recently been focused on motors for driving automobiles. In this switched reluctance motor, the comb teeth of the stator are magnetized one after another by selectively energizing each exciting coil formed by winding the stator with a switching current, and the comb teeth of the stator When the salient pole portion of the rotor is attracted by magnetic attraction (hereinafter referred to as attraction force), the rotor rotates to generate a rotational torque. In this case, after the comb tooth portion of the stator is magnetized by energization and the salient pole portion of the rotor is attracted, the current of the switch is cut off at the time when the salient pole portion and the comb tooth portion face each other. It will be switched to the tooth.

  That is, a strong suction force is required when the salient pole portion approaches the comb tooth portion, but it is necessary to quickly leave when the salient pole portion faces each other. If the attraction force remains when the salient pole part and the comb tooth part are opposed to each other, the brake is applied to the rotation and the rotation does not smoothly occur.

  In contrast to the above, conventionally, only the propulsive force is generated without applying a brake, and the current switching timing is optimized, whereby the suction and the separation are smoothly performed and rotated. However, this technique requires complex control. Furthermore, since the residual magnetic field exists after the current is cut off, the rotation is braked at the time of facing or after. In order to avoid this, the current is switched at an early stage.

On the other hand, in order to perform suction and separation smoothly, techniques for devising the shapes of the rotor and the stator are also disclosed (for example, Patent Documents 1 to 5). However, even if it has patent documents 1-5, it is still inadequate in order to perform suction and isolation | separation smoothly.
JP 2004-236369 A JP 2003-32979 A Japanese Patent Laid-Open No. 2002-136073 Japanese Patent Laid-Open No. 2001-268868 Japanese Patent Laid-Open No. 2001-186693

  In view of such circumstances, an object of the present invention is to propose a switched reluctance motor having a rotor and a stator having an advantageous shape for generating only propulsive force without applying a brake in the switched reluctance motor. To do.

In order to solve the above-mentioned problems, the inventors paid attention to the gap between the rotor salient pole part and the stator comb tooth part, and investigated and examined in detail. As a result, the following knowledge was obtained and the present invention was completed.
1) In a conventional switched reluctance motor, when the rotor salient pole part and the stator comb tooth part are separated from each other, the brakes are applied to the rotor salient pole part and stator comb tooth part. This is due to the fact that the air gap between them is constant from the beginning to the end of the overlap.
2) In order to smoothly perform magnetic attraction and separation of the rotor salient pole part and the stator comb tooth part, the air gap at the beginning of the overlap where the attraction force is required is kept constant without separating the air gap. It is important to make it smaller than the voids in.
3) Furthermore, by devising the shape of the salient pole part of the rotor and the comb tooth part of the stator, an appropriate gap can be obtained at the time of suction and separation.
4) Further, the relationship between the magnetic flux density of the iron core material used for the rotor and the stator and the rotation direction width of the rotor salient pole part and the stator comb tooth is found, and the rotation of the rotor salient pole part and the stator comb tooth is found. By selecting the rotor core material and the stator core material independently according to the ratio of the direction width, it is possible to alleviate the concentration of magnetic flux and the occurrence of iron loss at the local area of the rotor salient pole or stator comb teeth. I found out.

The present invention has been made based on the above findings, and the gist thereof is as follows.
[1] In a switched reluctance motor having a rotor having four or more poles and a stator, the rotor and the stator are formed by laminating electromagnetic steel plates and used for the rotor. The ratio of the magnetic flux density at a magnetizing force of 5000 A / m of the iron core material to the magnetic flux density at the magnetizing force of 5000 A / m of the iron core material used for the stator is the rotation width of the rotor salient pole and the rotation of the stator comb teeth. It is 0.90 to 1.10 times the ratio of the direction width, and the gap between the salient pole part of the rotor and the comb tooth part of the stator is at the beginning of the overlap of the rotor and the stator. A switched reluctance motor, wherein a gap is smaller than a gap at the time of separation between the rotor and the stator.
[2] The switched reluctance motor according to [1], wherein the gap at the beginning of the overlap is 5/6 or less of the gap at the time of separation.
[3] In the above [1] or [2], the gap when the front side 1/6 portion of the rotor salient pole portion overlaps the stator comb tooth portion is the width of the rotor salient pole portion in the rotational direction. A switched reluctance motor characterized in that the rear 1/6 portion is 5/6 or less of the gap when it overlaps the stator comb teeth.
[4] The switched reluctance motor according to any one of [1] to [3], wherein the radial length of the rotor salient pole portion is not constant throughout the width in the rotational direction.
[5] The switched reluctance motor according to any one of [1] to [3], wherein the radial length of the comb teeth of the stator is not constant throughout the width in the rotational direction.

  According to the present invention, when the rotor salient pole part and the stator comb tooth part face each other, suction and separation by switching can be performed smoothly and smoothly without braking. As a result, high motor efficiency can be obtained.

  Hereinafter, the present invention will be described in detail.

  First, the switched reluctance motor targeted in the present invention is a switched reluctance motor having a rotor and a stator having four or more poles. And a rotor and a stator shall be produced by laminating | stacking an electromagnetic steel plate. The ratio of the magnetic flux density at a magnetizing force of 5000 A / m of the iron core material used for the rotor to the magnetic flux density at the magnetizing force of 5000 A / m of the iron core material used for the stator is the rotation direction width of the rotor salient pole part and the fixed value. The ratio is 0.90 to 1.10 times the ratio of the width of the child comb teeth in the rotational direction. This is the most important requirement of the present invention and is a feature of the present invention. Furthermore, with respect to the gap between the salient pole part of the rotor and the comb tooth part of the stator, the gap at the time when magnetic attraction occurs and the rotor and the stator start to overlap each other is separated from the rotor and the stator. It is also a feature of the present invention that it is smaller than the gap in Hereinafter, the background to the completion of the present invention will be described.

FIG. 1 is a front view showing a conventional switched reluctance motor. In FIG. 1, the salient pole part 2 a of the rotor 1 and the comb tooth part 4 a of the stator 3 both have a constant radial length with respect to the rotational direction width. Therefore, the gap 5a between the salient pole part 2a and the comb tooth part 4a is always constant. Here, when the rotor 1 is rotated by the suction force of the comb tooth portion 4a of the stator 3, the suction force can be used as the thrust of the motor because the approaching force before the salient pole portion 2a and the comb tooth portion 4a face each other. Is at that point. On the contrary, if the attractive force is applied when the salient pole part 2a and the comb tooth part 4a are completely opposed to each other, a force to stay in place will act, and the salient pole part 2a and the comb tooth part 4a are separated. If a suction force is applied at a certain point, a force is generated in the opposite direction to the rotation, and the rotation is braked. Considering this point, if it is considered that the suction force affects the size of the air gap, in the conventional switched reluctance motor shown in FIG. This is presumably because there is no change in the gap 5a between the salient pole part 2a and the comb tooth part 4a of the stator 3.
Therefore, in the present invention, without making the gap between the salient pole part and the comb tooth part constant, when the salient pole part and the comb tooth part are approaching each other, and at the opposite time point Research focused on changing the gap of And the gap at the time when the salient pole part and the comb tooth part are approaching each other, that is, when the magnetic attraction occurs and the rotor and the stator start to overlap, It has been found that by reducing the size, the suction and separation in switching can be performed smoothly. Furthermore, it was considered that the most reliable and simple method for giving the feature to the gap in this way is to devise the shape and structure of the salient pole part of the rotor and the comb tooth part of the stator. Furthermore, the magnetic characteristics of the electromagnetic steel sheet (iron core material) used for the salient pole part of the rotor and the comb tooth part of the stator were also focused. The rotor rotates due to the attractive force generated when the magnetic flux crosses the space between the stator comb teeth and the rotor salient poles. At that time, the magnetic flux is locally generated between the rotor salient pole portions and the stator comb teeth. Concentrate and cause iron loss at that point. Since the occurrence of iron loss causes a reduction in motor efficiency, it is preferable to reduce the local concentration of magnetic flux in order to minimize the occurrence of iron loss. In a switched reluctance motor, the rotor salient poles and the stator comb teeth generally have different rotational widths. If the rotor and stator are made of exactly the same steel type as before, the concentration of magnetic flux in the direction where the rotor salient pole part and the stator comb teeth are narrower in the rotation direction is biased, and a large iron loss occurs at that point. Resulting in. Therefore, in order to alleviate the magnetic flux bias between the rotor salient poles and the stator comb teeth, the rotor core material and the stator core material are selected independently, and the magnetic flux at the magnetizing force of 5000 A / m of the iron core material used for the rotor is selected. The ratio of the magnetic flux density at a magnetic force of 5000 A / m of the core material used for the stator and the stator was 0.90 to 1.10 times the ratio of the rotor salient pole portion to the rotation width of the stator comb teeth. As a result, it has been found that there is no magnetic flux bias to either the rotor salient pole portion or the stator comb teeth, which contributes to reduction of iron loss and improvement of efficiency.

FIG. 2 and FIG. 3 are views showing an embodiment of the present invention, and are enlarged views of a main part of a salient pole part of a rotor and a comb tooth part of a stator. In practice, the salient pole portions of the rotor and the comb teeth portions of the stator face each other, and each end surface is a cylindrical curved surface. However, in order to simplify the description, FIGS. In FIG. 5, each of the end faces is represented as a plane. 2 and 3, the rotor rotates in the direction of arrow A in the figure. As the rotor rotates, the salient pole portion 2b of the rotor and the comb tooth portion 4b of the stator approach and overlap each other from the initial state (a) to the state in which the rotor 2b and the comb tooth portion 4b of the stator face each other (b). Then, the salient pole part 2b of the rotor and the comb tooth part 4b of the stator begin to separate and move to the state (c) at the time of separation. Here, the salient pole part 2b of the rotor changes in the radial direction length from the center defined in FIG. 4 to the end face of the salient pole part as (a) → (b) → (c), The radial length of the front end in the rotational direction width in (a) is the longest, and the radial length of the rear end in the rotational direction width in (c) is the shortest. Therefore, the gap 5b at the beginning of overlapping of the salient pole part 2b and the comb tooth part 4b is smaller than the gap 5c at the time of separation. In FIG. 2, the gap 5 b is the smallest at the beginning of overlapping, the gap is then widened, and the gap 5 c is widened most away. In FIG. 3, the gap 5b is constant from the beginning of the overlap to a certain stage, and at a certain stage, the gap starts to widen, and the gap 5c spreads most away. Further, in the rotational direction widths w (r) and w (s) of the rotor salient pole part 2b and the stator comb tooth part 4b, the magnetizing force 5000 A / m of the electromagnetic steel sheet used as the core material of each of the rotor and the stator. When the magnetic flux density (hereinafter referred to as B50) is B50 (r) and B50 (s), respectively,
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 An electrical steel sheet was used as the core material of each of the rotor and the stator.

According to FIGS. 2 and 3, due to the change in the gap, the salient pole portion 2b and the comb tooth portion 4b, which require attraction force, begin to overlap (a). 2b and the comb-tooth portion 4b are attracted most strongly, and the residual magnetic field in (a) and (c) after the facing when the current is cut off is abruptly attenuated due to the expansion of the gap. As a result, even if the current switching timing is delayed a little from the conventional timing, the rotation is not braked, and the suction force can be obtained more effectively and smoothly and separated. Further, B50 of the electromagnetic steel sheet used as the iron core material of each of the rotor and the stator is respectively set to B50 (B50) in the rotational direction widths w (r) and w (s) of the rotor salient pole part 2b and the stator comb tooth part 4b. r), B50 (s),
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 Because the magnetic steel sheet used as the core material of each of the rotor and the stator is used, the magnetic flux deviation and it The generation of iron loss due to easing has been alleviated and the efficiency has been improved.

FIG. 5 is a view showing another embodiment of the present invention, and is an enlarged view of a main part of a salient pole part of a rotor and a comb tooth part of a stator. In FIG. 5, the rotor rotates in the direction of arrow A in the figure. 2 and 3, as the rotor rotates, the rotor salient pole portion 2c and the stator comb tooth portion 4c approach each other and overlap with the rotor salient pole portion 2c from the initial state (a). The child comb teeth 4c face each other (a), and the rotor salient poles 2c and the stator comb teeth 4c begin to move away and move to the separated state (c). Here, the comb tooth portion 4c of the stator has a diameter from the outer periphery to the end surface of the comb tooth portion when the outer periphery is a perfect circle as defined in FIG. 6 as (a) → (b) → (c). The directional length is changed, the radial length of (a) at the beginning of the overlap is the longest, and the radial length at (c) at the time of separation is the shortest. Therefore, the gap 5d at the beginning of the overlap between the salient pole part 2c and the comb tooth part 4c is smaller than the gap 5e at the time of separation. In FIG. 5, the gap 5d is the smallest at the beginning of the overlap, the gap is then widened, and the gap 5e is widened the far away. In addition, in the rotational direction widths w (r) and w (s) of the rotor salient pole part 2c and the stator comb tooth part 4c, B50 of the electromagnetic steel sheet used as the iron core material of each of the rotor and the stator is B50 ( r), B50 (s),
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 An electrical steel sheet was used as the core material of each of the rotor and the stator.

According to FIG. 5, as in FIGS. 2 and 3, due to the change in the gap, the gap 5 d is the smallest at the point where the salient pole portion and the comb tooth portion requiring suction force start to overlap (a). Therefore, the salient pole part 2c and the comb tooth part 4c are attracted most strongly, and the residual magnetic field in (a) and (c) after the opposing time when the current is cut is rapidly attenuated by the expansion of the gap. As a result, even if the current switching timing is delayed a little from the conventional timing, the rotation is not braked, and the suction force can be obtained more effectively and smoothly and separated. Further, B50 of the electromagnetic steel sheet used as the iron core material of each of the rotor and the stator is respectively set to B50 (B50 ( r), B50 (s),
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 Because the magnetic steel sheet used as the core material of each of the rotor and the stator is used, the magnetic flux deviation and it The generation of iron loss due to easing has been alleviated and the efficiency has been improved.

As described above, in the present invention, with respect to the gap between the salient pole part of the rotor and the comb tooth part of the stator, the gap at the beginning of the overlap between the rotor and the stator is the gap when the rotor and the stator are separated. Let it be smaller. In order to make the gap at the beginning of overlap smaller than the gap at the time of separation, the radial length of the salient pole part of the rotor is preferably not constant throughout the width in the rotation direction, more preferably the front end in the rotation direction width It is preferable that the structure has the longest radial direction length and the shortest radial end length of the rear end. Alternatively, the radial length of the comb teeth of the stator is preferably not constant throughout the width in the rotational direction, more preferably the longest radial length at the beginning of overlap and the shortest radial length at the time of separation. It is preferable to have a structure as follows.
In addition to the above, in the rotational direction widths w (r) and w (s) of the rotor salient pole part and the stator comb tooth part, respectively, B50 of the electromagnetic steel sheet used as the iron core material of each of the rotor and the stator When B50 (r) and B50 (s),
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 0.90 to 1.10 An electromagnetic steel sheet is used as the core material of each of the rotor and the stator. As a result, there is no magnetic flux bias to either the rotor salient pole portion or the stator comb teeth, the iron loss is reduced, and the efficiency is improved.
However, {B50 (r) / B50 (s)} / {w (r) / w (s)} <0.90
Then, the magnetic flux is biased to the stator comb teeth, resulting in an increase in iron loss and a decrease in efficiency.
Also, {B50 (r) / B50 (s)} / {w (r) / w (s)}> 1.10
As a result, the magnetic flux is biased to the rotor salient poles, resulting in an increase in iron loss and a decrease in efficiency.
Therefore, an electromagnetic steel sheet that satisfies {B50 (r) / B50 (s)} / {w (r) / w (s)} = 0.90 to 1.10 is used as the iron core material of each of the rotor and the stator. Preferably, the above formula is in the range of 0.95 to 1.05, more preferably 0.97 to 1.03.

  Furthermore, in order to obtain better motor efficiency, we investigated a structure that can perform suction and separation by switching more smoothly and smoothly. As a result, if the gap at the beginning of overlap is a and the gap at the time of separation is b, when a ≦ (5/6) b, suction and separation by switching are performed smoothly, and higher motor efficiency is exhibited. all right. Therefore, in the present invention, the gap at the beginning of the overlap is preferably 5/6 or less of the gap at the time of separation. Details will be described later in Examples.

Further, a 1/6 portion of the rotor salient pole front side in the rotational direction width overlaps with the stator comb tooth portion a ₁ , and a rotor salient pole rear side width of 1/6 portion of the rotor salient pole portion is the stator. When the gap when overlapped with the comb teeth is b ₁ , a ₁ ≦ (5/6) b ₁ , and it was confirmed that higher motor efficiency is exhibited. Therefore, preferably the gap when the front side 1/6 portion of the rotor salient pole portion overlaps the stator comb teeth portion is the gap, and the rotor side pole 1/6 portion of the rotor salient pole portion on the rear side in the rotational direction width is the stator. It should be 5/6 or less of the gap when it overlaps with the comb teeth. An embodiment of the present invention in this case is shown in FIGS.
FIG. 7 shows that the radial length of the front end in the rotational direction of the salient pole part 2b of the rotor is the longest, the radial length of the rear end in the rotational direction is the shortest, and the gap is the smallest at the beginning of overlapping, After that, the gap is widened, and the gap is widened most away. Then, the gap 5f in the case where the front side 1/6 portion of the rotor salient pole portion 2b overlaps with the stator comb tooth portion 4b (D) is the rear side width 1 / of the rotor salient pole portion 2b. This is a case where the 6 portion is 5/6 or less of the gap 5g when the portion 6 overlaps with the stator comb tooth portion 4b. In addition, in the rotational direction widths w (r) and w (s) of the rotor salient pole part 2b and the stator comb tooth part 4b, B50 of the electromagnetic steel sheet used as the iron core material of each of the rotor and the stator is B50 ( r), B50 (s),
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 An electrical steel sheet was used as the core material of each of the rotor and the stator.
FIG. 8 shows that the radial length of the front end in the rotation direction of the salient pole portion 2b of the rotor is the longest and the radial length of the rear end in the rotation direction is the shortest, and the salient pole portions of the rotor overlap. The gap is constant from the beginning to a certain stage, and at a certain stage, the gap starts to widen, and the gap is widened most away. Then, the gap 5f in the case where the front side 1/6 portion of the rotor salient pole portion 2b overlaps with the stator comb tooth portion 4b (D) is the rear side width 1 / of the rotor salient pole portion 2b. This is a case where the 6 portion is 5/6 or less of the gap 5g when the portion 6 overlaps with the stator comb tooth portion 4b. In addition, in the rotational direction widths w (r) and w (s) of the rotor salient pole part 2b and the stator comb tooth part 4b, B50 of the electromagnetic steel sheet used as the iron core material of each of the rotor and the stator is B50 ( r), B50 (s),
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 An electrical steel sheet was used as the core material of each of the rotor and the stator.
In FIG. 9, the radial length of the stator is the longest at the beginning of the overlap of the salient pole portion 2c of the rotor and the comb tooth portion 4c of the stator, and the radial length of the stator is the shortest when separated. The gap 5h is the smallest at the beginning of the overlap, then the gap is widened, and the gap 5i is widened the farthest away. Then, when the 1/6 portion of the rotor salient pole part 2c on the front side in the rotational direction width overlaps the stator comb tooth part 4c (D), the gap 5h is the rear side 1 / of the rotor salient pole part 2c in the rotational direction width. This is a case where the six portions overlap with the stator comb teeth portion 4c (5) or less of the gap 5i. In addition, in the rotational direction widths w (r) and w (s) of the rotor salient pole part 2c and the stator comb tooth part 4c, B50 of the electromagnetic steel sheet used as the iron core material of each of the rotor and the stator is B50 ( r), B50 (s),
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 An electrical steel sheet was used as the core material of each of the rotor and the stator.

Using the switched reluctance motor shown in FIGS. 2, 3, 5, 7, 8 and 9, which is one of the embodiments of the present invention described above, the gap 5 b in FIGS. 2, 3, 5, 7, 8 and 9, The values of 5d, 5f, and 5h and the gaps 5c, 5e, 5g, and 5i were changed, and the motor efficiency in each case was measured. The switched reluctance motor used in the experiment is an inner rotor type in which the rotor is located inside the stator, the average distance from the center of the rotor to the tip of the salient pole is 20 mm, and the outer diameter of the stator is 80 mm. The average gap between the rotor salient poles and the stator comb teeth was 0.20 mm. Both the rotor and stator were made by punching and laminating non-oriented electrical steel sheets with a thickness of 0.5 mm, and the axial length was 50 mm. Here, an electromagnetic steel sheet satisfying {B50 (r) / B50 (s)} / {w (r) / w (s)} = 1.00 was used as the iron core material of each of the rotor and the stator. The motor efficiency was measured by applying a load with a load motor directly connected to the switched reluctance motor while rotating it. The rotational speed and torque were measured to determine the output value, and the motor efficiency was determined from the ratio of this to the input power measured with the power meter. In this example, the efficiency was measured at a rotational speed of 3000 rpm and a torque of 0.5 Nm. The values of the gaps 5b, 5d, 5f, and 5h are a, the values of the gaps 5c, 5e, 5g, and 5i are b, and the motor efficiency is arranged as a ratio with the motor efficiency at a = b. The obtained result is shown in FIG.
FIG. 10 shows that in the case of a <b, the motor efficiency is increased, and the suction and separation are performed smoothly. Furthermore, this tendency is remarkable when a ≦ (5/6) b. On the other hand, when b <a, the efficiency is worse than that of a normal switched reluctance motor having a constant gap.

Using the switched reluctance motor shown in FIG. 2 which is one of the embodiments of the present invention described above, the ratio w (r) / w (s) of the rotation direction width of the rotor salient pole portion 2b and the stator comb tooth portion 4b. = 1.2, where B50 (r) and B50 (s) are B50 (r) and B50 (s), respectively, of the magnetic steel sheets used as the cores of the rotor and stator, B50 (r) / B50 (s) = 9.6 to 1.44
That is, using a magnetic steel sheet such that {B50 (r) / B50 (s)} / {w (r) / w (s)} = 0.8 to 1.2 as the iron core material of each of the rotor and the stator, motor efficiency Was measured. In this case, the gap 5b is 4/6 of the gap 5c. Experimental conditions and motor efficiency measurement were the same as in Example 1.
The obtained results are shown in FIG. The motor efficiency becomes the maximum when B50 (r) / B50 (s) = 1.2, that is, {B50 (r) / B50 (s)} / {w (r) / w (s)} = 1. It is expressed as a ratio to efficiency.
As is apparent from FIG. 11, the motor efficiency is maximized when {B50 (r) / B50 (s)} / {w (r) / w (s)} = 1, whereas the rotor is And the same iron core material for the stator, that is, {B50 (r) / B50 (s)} / {w (r) / w (s)}
= 1 / 1.2 = 0.83 The efficiency decreased by about 10%.
{B50 (r) / B50 (s)} / {w (r) / w (s)} = 0.90 to 1.10, the efficiency is 95% or more of the maximum, and 0.90 to 1.10 is 98% of the maximum In addition, in 0.97 to 1.03, it was 99% or more of the maximum.

  Since the switched reluctance motor of the present invention rotates and generates torque without being braked, it has high energy efficiency and is expected to be used in a wide range of applications such as compressors and automobile drive motors.

It is a front view which shows the conventional switched reluctance motor. It is a figure which shows one Embodiment of this invention, and is the principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. It is a figure which shows one Embodiment of this invention, and is the principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. It is a figure which shows the radial direction length in a rotor. It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. It is a figure which shows the radial direction length in a stator. It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. It is a figure which shows other one Embodiment of this invention, and is a principal part enlarged view of the salient pole part of a rotor, and the comb-tooth part of a stator. It is a figure which shows the relationship between a porosity (a / b) and motor efficiency. Example 1 {(B50 of the rotor core material) / (B50 of the stator core material)} / {(Rotational width w of the rotor salient poles) / (Rotational width w of the stator comb teeth)} and motor efficiency It is a figure which shows the relationship. (Example 2)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor 2a, 2b, 2c Salient pole part 3 Stator 4a, 4b, 4c Comb tooth part 5a, 5b, 5c, 5d, 5e Air gap A Rotation direction

Claims (5)

In a switched reluctance motor having a rotor and a stator having four or more poles, the rotor and the stator are made by laminating electromagnetic steel plates,
The ratio of the magnetic flux density at the magnetizing force 5000 A / m of the iron core material used for the rotor to the magnetic flux density at the magnetizing force 5000 A / m of the iron core material used for the stator is the width in the rotation direction of the rotor salient pole part. 0.90 to 1.10 times the ratio of the rotational width of the stator comb teeth,
Furthermore, with respect to the gap between the salient pole part of the rotor and the comb tooth part of the stator, the gap at the beginning of overlapping of the rotor and the stator is at the time of separation of the rotor and the stator. A switched reluctance motor characterized by being smaller than the gap.   2. The switched reluctance motor according to claim 1, wherein a gap at the beginning of the overlap is 5/6 or less of the gap at the time of separation.   When the 1/6 part of the rotor salient pole front side of the rotation direction width overlaps the stator comb teeth, the gap of the rotor salient pole part of the rotor salient pole rear side width of 1/6 overlaps the stator comb teeth. The switched reluctance motor according to claim 1 or 2, wherein the gap is 5/6 or less.   The switched reluctance motor according to any one of claims 1 to 3, wherein the radial length of the rotor salient pole portion is not constant throughout the width in the rotational direction. The switched reluctance motor according to any one of claims 1 to 3, wherein the radial length of the comb teeth of the stator is not constant throughout the width in the rotational direction.

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