DE102010020850A1 - Rotor for brushless motor, has rotor core with magnetic flux dividing portions each dividing magnetic flux in vicinity of backside of corresponding magnet to both sides in circumferential direction - Google Patents

Abstract

The rotor (10B) has salient poles (14) integrally formed with a rotor core (12). Each salient pole is located between a circumferentially adjacent pair of magnets (13), and functioning as a second magnetic pole. Magnets are provided along the circumferential direction of the rotor core and function as first magnetic pole. The rotor core has magnetic flux dividing portion at each position that faces one of the magnets. Each magnetic flux dividing portion divides magnetic flux in the vicinity of the backside of the corresponding magnet to both sides in the circumferential direction.

Description

The present invention relates to a rotor having a follower pole structure and a motor having such a rotor.

Background of the invention

For example, in the Japanese Laid-Open Publication No. 9-327139 discloses a rotor having a follower pole rotor for a motor. The rotor of the above publication has a rotor core, a plurality of magnets arranged along the circumferential direction of the rotor core, and a plurality of salient poles integrally formed with the rotor core. Each protruding pole is disposed between a circumferentially adjacent pair of magnets. The magnets act as either north or south poles and the protruding poles act as magnetic poles different from those of the magnets.

In a known rotor in which all the magnetic poles are formed by magnets, the magnetic flux flows through a part of the rotor core near the back side of each magnet and is equally divided at the center in the circumferential direction of the magnet on both sides in the circumferential direction. Thus, the rotor has a stable magnetic balance. In contrast, in a rotor having a follower pole structure according to the above publication, no magnetic flux is induced by the salient poles. Due to the ever-changing local relationships between the salient poles and the teeth of the stator, which are opposite the salient poles, the magnetic flux flows through a part of the rotor core near the back of each magnet and does not become uniform on both sides in the circumferential direction divided by a peripheral center of the magnet. Rather, the magnetic flux flows to a greater extent through one of the salient poles at the ends in the circumferential direction of the magnet, which protruding pole has a lower magnetic resistance. Thus, since the directional property and the amount of magnetic flux at each salient pole change depending on the local relationship between the salient pole and the tooth, the rotor becomes magnetically unstable. This reduces the rotational power of the engine. In particular, it may happen that the torque is reduced or the vibration increases.

Summary of the invention

Accordingly, it is an object of the present invention to provide a rotor that provides improved magnetic balance and rotational performance and a motor having such a rotor.

In order to achieve the above-mentioned objects and in connection with a first aspect of the present invention, a rotor has a rotor core, magnets and salient poles. The magnets are arranged along the circumferential direction of the rotor core. Each magnet acts as the first magnetic pole. Each magnet has a backside that faces the rotor core. The salient poles are integrally formed with the rotor core so that each salient pole is disposed between circumferentially adjacent pairs of magnets. Each protruding pole acts as a second magnetic pole different from the first magnetic pole. The rotor core has a division area for magnetic River, which is provided in any place that lies opposite one of the magnets. Each magnetic flux dividing section actively splits the magnetic flux near the back of the corresponding magnet circumferentially on both sides.

In the context of a second aspect of the present invention, the rotor has a rotor core, magnets, and salient poles. The magnets are arranged along the circumferential direction of the rotor core. Each magnet acts as the first magnetic pole. Each magnet has a surface that is oriented toward the outside. The salient poles are integrally formed with the rotor core such that each salient pole is disposed between circumferentially adjacent pairs of magnets. Each protruding pole acts as a second magnetic pole different from the first magnetic pole. A gap is formed between circumferentially adjacent pairs of magnets and corresponding protruding poles. A slot is formed either in the distal surface of each salient pole or in the interior of each salient pole. In the context of a third aspect of the present invention, a motor has a stator and a rotor. The rotor has a rotor core, magnets and salient poles. The magnets are arranged along the circumferential direction of the rotor core. Each magnet acts as a first magnetic pole. Each magnet has a backside that faces the rotor core. The salient poles are integrally formed with the rotor core so that each salient pole is disposed between a circumferentially adjacent pair of magnets. Each protruding pole acts as a second magnetic pole different from the first magnetic pole. The rotor core has a magnetic flux dividing area located at each location opposite one of the magnets. Each magnetic flux division section actively splits the magnetic flux near the back of the corresponding magnet on both sides in the circumferential direction.

In the context of a fourth aspect of the present invention, a motor is provided with a stator and a rotor. The rotor has a rotor core, magnets and salient poles. The magnets are arranged along the circumferential direction of the rotor core. Each magnet acts as a first magnetic pole. Each magnet has a surface that is directed towards the outside. The salient poles are integrally formed with the rotor core so that each salient pole is disposed between circumferentially adjacent pairs of magnets. Each protruding pole acts as a second magnetic pole different from the first magnetic pole. A gap is disposed between a circumferentially arranged pair of magnets and corresponding protruding poles. A slot is formed either in the distal surface of each salient pole or in the interior of each salient pole.

Description of the drawings

1 Fig. 10 is a plan view showing a motor according to a first embodiment of the present invention;

2 is an enlarged partial view showing the engine according to 1 shows;

3 is a graph showing the relationship between the ratio Ws / Wm and the torque of the motor according to FIG 1 represents;

4 FIG. 12 is a graph showing the relationship between the ratio Ws / Wm and the radial force of the motor according to FIG 1 represents;

5 Fig. 10 is a plan view illustrating a motor according to a second embodiment of the present invention;

6 is an enlarged partial view of the engine according to 5 ;

7 FIG. 12 is a graph showing the relationship between the ratio Ws / Wn and the torque of the motor according to FIG 5 represents;

8th is a graph showing the relationship between the ratio Wt / Wn and the radial force of the motor according to 5 represents;

9 Fig. 10 is a plan view illustrating a motor according to a third embodiment of the present invention;

10 Fig. 15 is a diagram illustrating the flow of the magnetic flux when the inner surface of each magnet is formed to have a triangular cross section;

10 Fig. 12 is a diagram explaining the flow of magnetic flux when the inner surface of each magnet is formed to have a linear cross section;

11 FIG. 12 is a graph showing the relationship between an electrical angle and the surface of the magnetic flux density in a motor according to FIG 9 represents;

12 Fig. 10 is a plan view illustrating a rotor according to a modification of the third embodiment;

13 FIG. 10 is a plan view illustrating a rotor according to a modification of the third embodiment; FIG.

14 FIG. 10 is a plan view illustrating a motor according to a fourth embodiment; FIG.

15 is an enlarged partial view showing the engine according to 14 represents;

16 is a diagram showing the flow of magnetic flux in a motor according to 14 explains;

17 FIG. 13 is a graph showing the relationship between the ratio G / T and the radial pulsation of a motor according to FIG 14 represents;

18 FIG. 12 is a graph showing the relationship between the ratio G / T and the displacement force of the rotor for an engine according to FIG 14 represents;

19 FIG. 12 is a graph showing the relationship between the ratio G / T and the torque fluctuation according to an engine according to FIG 14 represents;

20 FIG. 12 is a graph showing the relationship between the ratio G / C and the maximum torque of a motor according to FIG 14 represents;

21 FIG. 12 is a graph showing the relationship between (Wa / Wm) / (Wb × (ρb / ρr)) and the rotor deflection force for a rotor according to FIG 14 represents;

22 FIG. 15 is a graph showing the relationship between (Wa / Wm) / (Wb × (ρb / ρr)) and the maximum torque of a motor according to FIG 14 represents;

23 Fig. 10 is an enlarged partial view illustrating a motor of a modified embodiment of the fourth embodiment;

24 Fig. 10 is a plan view illustrating a motor according to a fifth embodiment of the present invention;

25 is an enlarged partial view of an engine according to 24 ;

26a is a diagram showing the flow of magnetic flux in a motor according to 24 explains;

26b Fig. 10 is a diagram explaining the flow of magnetic flux in a motor in which no slot is formed in the salient poles;

27 is a graph showing the relationship between the ratio Wa1 / Wb1 and the torque of the motor according to FIG 24 represents;

28 FIG. 12 is a graph showing the relationship between the ratio Ws1 / AG and the torque fluctuation of a motor according to FIG 24 represents;

29 Fig. 10 is an enlarged partial view illustrating a motor according to a modification with the fifth embodiment;

30 Fig. 15 is a partial enlarged view illustrating a motor of a modification of the fifth embodiment;

31 FIG. 10 is a plan view illustrating a motor according to the sixth embodiment; FIG.

32 is an enlarged partial view showing a motor according to 31 represents;

33 FIG. 12 is a graph showing the relationship between an electrical angle and the offset torque of an engine according to FIG 33 represents;

34 FIG. 12 is a graph showing the relationship between the ratio W1 / W2 and the offset torque of a motor according to FIG 33 represents;

35 FIG. 15 is a graph showing the relationship between the ratio D1 / W2 and the offset torque of a motor according to FIG 33 represents;

36 FIG. 10 is an enlarged partial view illustrating a motor according to a modification of the sixth embodiment; FIG.

37 Fig. 10 is a plan view showing a motor according to a seventh embodiment of the present invention;

38 is an enlarged partial view showing a motor according to 37 shows;

39 is a diagram showing the flow of magnetic flux in a motor according to 37 explains;

39b Fig. 12 is a diagram explaining the flow of magnetic flux in a motor in which no crimping means is provided in the salient poles;

40 is a graph showing the relationship between the ratio Ty / Tm and the torque of the motor according to FIG 37 represents;

41 FIG. 12 is a graph showing the relationship between the ratio Ty / Tm and the torque fluctuation in an engine according to FIG 37 represents;

42 Fig. 10 is a plan view illustrating a motor according to an eighth embodiment of the present invention;

43 Figure 11 is a further developed partial view of a rotor explaining angled slots in an engine of a modification of the eighth embodiment;

44 FIG. 15 is a graph showing the relationship between the ratio a ° / (360 ° / N) and the offset torque of a motor according to FIG 42 represents;

45 Fig. 11 is a further developed partial view of a rotor illustrating the angled slots in an engine of a modification of the eighth embodiment;

46 Figure 11 is a further developed partial view of a rotor illustrating the angled slots in a motor according to a modification of the eighth embodiment;

47 Figure 11 is a further developed partial view of a rotor illustrating the angled slots in a motor according to a modification of the eighth embodiment;

48a FIG. 10 is an enlarged partial view illustrating a motor according to a modification of the first and second embodiments; FIG.

48b Fig. 10 is an enlarged partial view illustrating a motor according to a modification of the first embodiment;

49a Fig. 10 is an enlarged partial view illustrating a motor according to a modification of the third embodiment; and

49b FIG. 15 is a partial enlarged view illustrating a motor according to a modification of the third embodiment. FIG.

Description of the Preferred Embodiments

A first embodiment of the present invention will now be explained with reference to the drawings.

1 and 2 show a brushless motor M with an internal rotor. A rotor 10A is used in the motor M of the present embodiment. The rotor 10A has a substantially circular rotor core 12 , seven magnets 13 and seven protruding poles 14 on. The rotor core 12 is made of magnetic metal and attached to the outer peripheral surface of a rotary shaft 11 glued. The magnets 13 are on the outer peripheral surface of the rotor core 12 arranged along the circumferential direction. Each protruding pole is between a circumferentially adjacent pair of magnets 13 arranged. The magnets 13 act as north poles. The protruding poles 14 are integral with the rotor core 12 formed and act as south poles. The rotor 10A is a follower pole rotor with fourteen magnetic poles. A stator 20 has a stator core 21 with twelve teeth 21a , A coil 22 is around each of the teeth 21a wrapped in a predetermined manner. In this way, the stator has 20 twelve magnetic poles. The spools 22 are due to a concentrated winding around the teeth 21a wound. The winding 22 of the stator 20 is formed by a U-phase, a V-phase and a W-phase. Forward windings and reverse windings are arranged side by side for each phase, as indicated below: U-phase (forward winding), one U Phase (reverse winding), one V Phase, a V phase, a W phase, a W Phase, one U Phase, a U-phase, a V-phase, a V Phase, one W Phase and a W phase in a clockwise direction. The magnets 13 and the protruding poles 14 are alternately on the outer circumference of the rotor 10A arranged in the circumferential direction at equal angular intervals.

The dimension of the magnets 13 in the circumferential direction is slightly larger than that of the protruding poles 14 , Every magnet 13 is essentially formed as a rectangular plate and has a flat inner surface 13a and a curved outer surface 13b , The inner surface 13a from every magnet 13 is on an adhesive surface (contact surface) 12a of the rotor core 12 glued between a circumferentially adjacent pair of protruding poles 14 is trained. Each adhesive surface 12a is a flat surface perpendicular to the radial direction of the rotor core 12 , The outer surface 13b from every magnet 13 opens to the radially outer side of the rotor core 12 so they are directly opposite the stator 20 (the teeth 21a ) lies. Therefore, the brushless motor M is an SPN motor.

The rotor core 12 has right-angled slots 12b extending radially inward from a peripheral center of the adhesive surfaces 12a extend. Every slot 12b reaches the vicinity of the radially inner edge of the rotor core 12 so that the longitudinal direction of the slot 12b coincides with the radial direction, in a view in the axial direction. In addition, each slot extends 12b through the rotor core 12 in the axial direction. The slots 12b are designed such that they act as magnetic resistors. Magnetic flux passing through a part of the rotor core 12 near the inner surface (back, south pole) 13a of every magnet 13 flows is equally divided at the circumferential center on both sides in the circumferential direction. The slots 12b therefore act as splitting areas for magnetic flux.

Every protruding pole 14 has a shape that protrudes radially outward. Both end sides in the circumferential direction of each protruding pole 14 are flat surfaces along the radial direction of the rotor core 12 , Both end faces in the circumferential direction of each magnet 13 are flat surfaces parallel to a straight line in the radial direction passing through the perimeter center of the magnet 13 and the axis of the rotary shaft 11 runs. This is between every protruding pole 14 and the circumferentially adjacent magnet 13 formed a free space, which has a triangular cross section, so that they do not touch each other in the circumferential direction. The outer surface 14a from each protruding pole 14 is curved and arranged on the same circumference as the outer surface 13b the magnet 13 , A clearance exists between the outer surfaces 13b . 14a the magnet 13 and the protruding poles 14 and the inner ends in the radial direction of the teeth 21a of the stator 20 ,

When the ratio Ws / Wm of the width (circumferential dimension) Ws of the slots 12b and the width (circumferential dimension) Wm of the magnets 13 is changed, the torque of the motor M and the radial force, which is the cause of vibration, also changes. The torque and the radial force were therefore measured in relation to the ratio Ws / Wm.

3 shows the torque of the motor M when the ratio Ws / Wm has been changed. The torque was zero when the ratio Ws / Wm was zero, so if no slots 12b were intended and was set here to 100%. In this case, the torque increases stepwise as the ratio Ws / Wm increases from zero. The torque had a maximum value or about 102.3% when the ratio Ws / Wm was 1.0. As the ratio Ws / Wm continues to increase, the torque gradually decreases. When the ratio Ws / Wm was 0.2, the torque was about 101.8%. When the ratio Ws / Wm was 0.3, the torque was about 100.5%. Regarding 3 has been achieved a sufficient torque of over 100% in a range in which 0 <Ws / Wm ≤ 0.3. It is therefore preferable that the ratio Ws / Wm is set in this range. The range in which 0.05 ≦ Ws / Wm ≦ 0.2 is particularly preferable since the torque in this range was extremely large.

4 shows the radial force of the motor M when the ratio Ws / Wm has been changed. The radial force was set to 100% for the case when the ratio Ws / Wm was zero, so if no slots 12b were provided. When the ratio Ws / Wm increased from 0, the radial force gradually decreased. When the ratio Ws / Wm was 0.05, the radial force was about 80%. When the ratio Ws / Wm was 0.1, the radial force was about 74%. When the ratio Ws / Wm was 0.2, the radial force was about 67%. When the ratio Ws / Wm was 0.3, the radial force was about 64%. Regarding 4 For example, the radial force was sufficiently reduced (to about 80%) in a range where 0.05 ≦ Ws / Wm. It is therefore preferable that the ratio Ws / Wm is set in this range.

In consideration of the above results, the ratio Ws / Wm is the width Ws of the slots 12b to the width Wm of the magnets 13 in a range where 0 <Ws / Wm≤0.3. This will be a slot 12b in every part of the rotor core 12 formed, facing the inner surface 13a of the corresponding magnet 13 lies. This improves the flow of magnetic flux in the part of the rotor core 12 near the inner surface 13a and thus improves the flow of magnetic flux in the entire magnetic circuit of the rotor 10A while the shape and size of the slots 12b is optimized. Thus, torque is improved and vibration is reduced due to reduced radial forces. This improves the rotational performance of the motor M.

The present embodiment has the present advantages.

In the rotor 10A according to the present embodiment is a slot 12b in every part of the rotor core 12 near the inner surface (back side) 13a of the corresponding magnet 13 educated. The slot 12a acts as a magnetic flux dividing area, which distributes the magnetic flux evenly and actively on both sides in the circumferential direction. This prevents the slots 12b Reliable magnetic imbalance due to the presence of protruding poles 14 which do not induce magnetic flux. This improves the magnetic balance of the rotor 10A and thus improves the rotational performance. In particular, the torque is improved and vibration is reduced. In addition, the shape and size of the slots 12b optimized in the present embodiment, so that the rotational performance is reliably improved.

Because the slots 12b in the rotor core 12 are formed and act as magnetic flux dividing portions in the present embodiment, the magnetic flux dividing portions are easily formed and no additional components are necessary.

Because the slots 12b each in a part of the rotor core 12 near the inner surface (back side) 13a of the corresponding magnet 13 are formed in the present embodiment, the magnetic flux passing through a part of the rotor core 12 near the inner surface (back side) 13a flows, evenly distributed in a reliable manner.

A second embodiment of the present invention will now be described with reference to FIGS 5 to 8th explained.

As in the 5 and 6 is shown, a rotor core 12 in a rotor 108 used in the present embodiment, the one slot 12c in every protruding pole 14 in addition to the slots 12b of the first embodiment. The slots 12c are in the center in the circumferential direction in the corresponding protruding poles 14 arranged and have a rectangular shape, which extends along the radial direction of the rotor core. Like the slots 12b , the radially inner end of each slot extends 12c to the vicinity of the radially inner edges of the rotor core 12 when viewed in the axial direction. The radially outer end of each slot 12c is at the center in the radial direction in a corresponding protruding pole 14 arranged. This extends each slot 12c from the vicinity of an inner edge of the rotor core 12 to a Position, which is radially outside the proximal end of the corresponding protruding pole 14 lies. In addition, each slot extends 12c through the rotor core 12 in the axial direction. The slots 12c act as magnetic resistors and therefore act as magnetic flux compensation regions which control the magnetic flux through the salient pole 14 in the radial direction.

When the ratio Wt / Wm of the width (circumferential dimension) Wt of the slots 12c and the width (circumferential dimension) Wn of the salient poles 14 is changed, also change the torque of the motor M and the radial force, which is the cause of vibration. The torque and the radial force were measured in relation to the ratio Wt / Wn.

7 shows the torque of the motor M when the ratio Wt / Wn has been changed. The torque was set to 100% if the ratio Wt / Wn was zero, so if no slots 12c were provided. In this case, the torque gradually increased as the ratio Wt / Wn increased from zero. The torque had a maximum value or about 101.2% when the ratio Wt / Wn was 0.3. The torque gradually decreased as the ratio Wt / Wn continued to increase. The torque was about 100.1% when the ratio Wt / Wn was 0.55. Regarding 7 For example, sufficient torque over 100% was achieved in a range where 0 <Wt / Wn ≤ 0.55. It is therefore preferable that the ratio Wt / Wn is set in this range. It is particularly preferable that the ratio Wt / Wn is about 0.3, since the torque was partially increased in this range.

8th shows the radial force of the motor M when the ratio Wt / Wn has been changed. The radial force was set to 100% when the ratio Wt / Wn was zero, that is, when no slots 12c were provided. As soon as the ratio Wt / Wn increased from zero, the radial force gradually decreased. When the ratio Wt / Wn was 0.1, the radial force was about 98%. When the ratio Wt / Wn was 0.3, the radial force was about 75%. When the ratio Wt / Wn was 0.55, the radial force was about 60%. Regarding 8th The radial force was reduced in a range where 0.1 ≦ Wt / wn. It is therefore preferable that the ratio Wt / Wn is set in this range.

In consideration of the above results, the ratio Wt / Wn is the width Wt of the slots 12c and the width Wn of the salient poles 14 is set in a range in which 0.1 ≦ Wt / Wn ≦ 0.55. This will in addition to the slots 12b which are in a part of the rotor core 12 are shaped, the inner surface 13a of the corresponding magnet 13 lie opposite, a slot 12c in every protruding pole 14 educated. This improves the flow of magnetic flux in the salient poles 14 while the flow of magnetic flux in a part of the rotor core 12 near the inner surface 13a is improved and thus the flow of magnetic flux in the entire magnetic circuit of the rotor 10B is improved. In addition, by optimizing the shape and size of the slots 12c , which improves torque and reduces vibration due to the reduced radial force. This improves the rotational performance of the motor M.

The present embodiment has the following advantages.

The rotor 10B according to the present embodiment has the same advantages as the advantages ( 1 ) to ( 3 ) of the first embodiment.

In the present embodiment, each protruding pole 14 a slot formed therein 12c , where the slots 12c act as compensation areas for magnetic flux, which actively the direction of magnetic flux through the interior of the salient pole 14 change. This improves the flow of magnetic flux in each salient pole 14 , whereby the magnetic balance and the rotational power of the rotor 10B be improved. Moreover, in the present embodiment, the shape and the size of the slot 12c optimized so that the rotational performance is improved in a reliable manner.

A third embodiment of the present invention will now be described with reference to FIGS 9 to 13 explained.

In a rotor 10C According to the present embodiment, each adhesive surface is 12a of the rotor core 12 , on which a magnet 13 is glued, V-shaped, so that its peripheral center is set back radially inward. This shows every adhesive surface 12a a pair of angled surfaces 12a1 . 12a2 which extend from each other in the circumferential direction from the peripheral center of the adhesive surfaces 12a extend away. In connection with the angled surfaces 12a1 and 12a2 is the inner surface 13a every magnet 13 is formed so that it is triangular, so that its peripheral center projects radially inwardly. Every inner surface 13a is through a pair of angled surfaces 13a1 and 13a2 formed extending away from each other in the circumferential direction from the peripheral center of the inner surface 13a , The angled surfaces 13a1 and 13a2 of every magnet 13 are in surface contact with the corresponding angled surfaces 12a1 and 12a2 of the rotor core 12 brought and glued with these. At this time, the position of the magnet 13 be easily determined.

As in 1 Shown divides each pair of angled surfaces 12a1 and 12a2 even the magnetic flux flowing through a part of the rotor core 12 near the inner surface (the back of the South Pole) 13a of the corresponding magnet 13 flows from the peripheral center of the magnet 13 to both directions in the circumferential direction, on. Therefore, the pairs of angled surfaces act 12a1 and 12a2 as magnetic flux dividing areas, so that the flow of the magnetic flux through the entire magnetic circuit is improved. For comparison shows 5 a case in which the adhesive surfaces 12a of the rotor core 12 have a linear cross-section. In this case, the magnetic flux flows through part of the rotor core 12 near the inner surface (back side) 13a of the magnet 13 and is not equally divided at the circumferential center on both sides in the circumferential direction. This could increase the torque pulsation and give a reason for vibration.

The thickness of each end in the circumferential direction of each magnet 13 in the present embodiment, which is formed that the inner surface 13a extends radially inward, is smaller than in the direction of the circumferential center. This prevents, as in 11 shown that the magnetic flux density at each circumferential end of the outer surface 13b every magnet 13 is changed abruptly. In 11 shows a solid line changes in the magnetic flux density on the surface of each magnet 13 of the rotor 10C who in 10a is shown, and a broken line shows changes in the magnetic flux density on the surface of the magnet 13 of the rotor 10C who in 10b is shown. The changes in the magnetic flux density on the surface of each magnet 13 run approximately in the form of a sinusoid. This reduces the torque pulsation.

In the foregoing embodiment, the outer surface is 13b every magnet 13 formed with a curved surface on the same circumference, as the outer surfaces 14a the protruding poles 14 , As in 12 shown, the outer surface 13b every magnet 13 however, also be flat and radially inward from the outer surfaces 14a the protruding poles 14 be arranged. This configuration reduces the material for making the magnets and simplifies the shape of the magnets 13 , Accordingly, the cost of the magnets 13 reduced.

The rotor 10C according to the present embodiment has an SPM structure in which the outer surfaces 13b every magnet 13 are open radially outward. However, an IPM structure may also be provided in which a plurality of insertion holes 12X in the rotor core 12 are formed, which are arranged along the circumferential direction and the magnets 13 in each of these insert openings 12X , as in 13 shown, are used. The number of magnets 13 is four in this case, and the number of salient poles which are follower poles is also four. The rotor 10D therefore has eight magnetic poles.

It is also possible that the radially innermost part of the inner surface 13a every magnet 13 (the tip of the triangular shape), as in 13 shown is raised to the sizes of the angled surfaces 13a3 and 13a4 adapt. This allows the flow of the magnetic flux of the magnetic circuit in the rotor 10D to optimize.

The present embodiment has the following advantages.

In the rotors 10C and 10D In the present embodiment, angled surfaces form 12a1 and 12a2 each adhesive surfaces 12a of the rotor core 12 , which act as division areas for magnetic flux. This changes the direction of the magnetic flux at each of the angled surfaces 12a1 and 12a2 so that the magnetic flux in each part of the rotor core 12 , facing the inner surface (back) 13a of the corresponding magnet 13 is divided in the desired manner.

In the present embodiment, the inner surface (back) 13a every magnet 13 formed so that it projects radially inward. This simplifies the shape of the inner surfaces 13a every magnet 13 and allows in this way the production of the magnets 13 ,

A fourth embodiment of the present invention will now be described with reference to FIGS 14 to 23 explained.

The 14 and 15 show a brushless motor in the internal rotor. As in 14 shown is a rotor 10E used in a motor M of the present embodiment. The rotor 10E has a circular non-magnetic area 32 , a substantially circular rotor core 33 , seven magnets 34 and seven protruding poles 35 on. The non-magnetic area 32 is made of non-magnetic Material (for example, aluminum) is made and is on the outer peripheral surface of the rotary shaft 31 fixed. The rotor core 33 is made of magnetic metal and on the outer peripheral surface of the non-magnetic region 32 bonded. The magnets 34 are circumferentially along the outer circumference of the rotor core 33 arranged. Each protruding pole block 35 is between a circumferentially adjacent pair of magnets 34 arranged. The magnets 34 act as south poles. The protruding poles 35 are integral with the rotor core 33 educated. Each protruding pole block 35 has a protruding pole 41 which extends radially outward and further have a base 42 radially inward from the salient pole 41 lies. Every protruding pole 41 has a sectional section, which is considered in the axial direction. The protruding poles 41 act as north poles. These are the magnets 34 and the protruding poles 41 alternately on the outer circumference of the rotor 10A arranged in the circumferential direction and at regular angular intervals. In the present embodiment, each protruding pole is 41 arranged in a place by one of the magnets 34 is spaced by 180 °. The rotor 10A is a follower pole rotor with 14 magnetic poles. A stator 37 has twelve teeth 37a , A winding 38 is around each of the teeth 37a wrapped in a predetermined manner. This has the stator 36 twelve magnetic poles.

The dimension in the circumferential direction of the magnets 34 is slightly larger than the protruding poles 41 , Every magnet 34 is essentially shaped as a square prism and has a flat inner surface 34 and a curved outer surface 34b , The inner surface 34a every magnet 34 is an adhesive surface (contact surface) 33a of the rotor core 33 between a circumferentially adjacent pair of salient poles 41 is arranged, glued. Each adhesive surface 33a is a flat surface perpendicular to a radial direction of the rotor core 33 extends. Between every protruding pole 41 and the circumferentially adjacent magnet 34 a free space is formed so that they do not touch each other in the circumferential direction. The outer surfaces 34b the magnet 34 are arranged on the same circumference.

The protruding poles 35 of the rotor core 33 are arranged in the circumferential direction at equal angular intervals. Every protruding pole 35 is formed such that the protruding pole 41 radially from the peripheral center of the base 42 protrudes outwards. This is the circumferential dimension of the base 42 larger than the protruding poles 41 , Each protruding pole block 35 is symmetrical with respect to a line passing through the peripheral center of the protruding pole block 35 extends and extends along the radial direction. The ends in the circumferential direction of each base 42 extend to positions opposite to the radially inner side of a circumferentially adjacent pair of magnets 34 lie and the inner surfaces 34a the magnet 34 touch.

A gap S is in a part of the rotor core 33 formed, facing the inner surface 34a every magnet 34 lies. The gap S is between the bases 42 circumferentially adjacent pairs of protruding poles 35 arranged and acts as a division area for magnetic flux. Each end in the circumferential direction of each base 42 is at a predetermined distance from the base 42 the circumferentially adjacent protruding pole block 35 spaced. The gaps S are in the inner circumferential surface of the rotor core 33 formed and extend through the rotor core 33 in the axial direction.

Each gap S is formed such that a radial line passing through its peripheral center coincides with a radial line passing through the peripheral center of the corresponding magnet 34 runs. Each clearance S is configured such that its width Wa is constant in the circumferential direction along the radial direction. In the present embodiment, the gap S is empty. The protruding poles 35 each circumferentially adjacent pair are interconnected via a coupling region 43 connected between the corresponding gap S and the corresponding adhesive surface 33a of the rotor core 33 is arranged.

The coupling areas 43 are integral with the protruding poles 35 educated. Each coupling area 43 is formed such that it the radially outer ends of the base portions 42 from a circumferentially adjacent pair of protruding blocks 35 coupled with each other. The outer surface of each coupling area 43 and the outer surface of the adjacent base portions 42 form a flat adhesive surface 33a at which the magnet 34 is glued on. This is a rotor core 33 as he is in the 14 and 15 is shown arranged such that the outer surface of each coupling region 43 the inner surface 34a of the magnet 34 touched. Not only the outer surface, but also the inner surface of each coupling area 43 is flat, so that the thickness (the radial extent) of the coupling area 43 is constant.

The outer surface 41a from each protruding pole 41 is curved. In particular, the outer surface 41a from each protruding pole 41 is formed so as to have a curved shape such that its peripheral center portion extends radially outward relative to the ends in the circumferential direction. In other words, every protruding pole 41 curved so as to extend radially inwardly toward the ends in the circumferential direction away from the circumferential center. Every outer surface 41a has a constant curvature and is symmetrical with respect to a radial line passing through the circumferential center. In addition, the outer surface 41a every protruding pole 41 from the outer surface 34b every magnet 34 arranged radially inward.

In such a motor M is the magnetic flux passing through a part of the rotor core 33 flows, facing the inner surface 34a from every magnet 34 is evenly through the gap S on both sides in the circumferential direction at the peripheral center of the magnet 34 divided up. The coupling area 43 The present embodiment contacts the inner surface 34a of the magnet 34 so that this magnetic flux near the inner surface 34a is magnetically saturated. In a case where each coupling area 43 is formed in a place that has something of the inner surface 34a of the magnet 34 radially offset inwardly away is the coupling region 43 with magnetic flux near the inner surface 34a of the magnet 34 magnetically saturated. However, if the coupling area 43 is not formed at a position sufficiently far away from the inner surfaces of the corresponding magnets in the radially inward direction (for example, when each coupling portion 43 at the radially inner ends of the base 42 is arranged), is the coupling area 43 not magnetically saturated. In a status in which the coupling areas 43 are not magnetically saturated, flows a portion of the magnetic flux passing through one of the circumferentially adjacent pairs of the protruding pole blocks 35 should flow to another protruding pole block 35 through the coupling area 43 , depending on the local relationship between the magnets 34 and the teeth 37a , In contrast, in the present embodiment, each coupling area is affected 43 the inner surface 34a of the corresponding magnet 34 so that the coupling area 43 is magnetically saturated. This turns the magnetic flux passing through the coupling region 43 flows evenly divided between both sides in the circumferential direction at the peripheral center. In contrast to the case described above, in this way magnetic flux is prevented only by a protruding pole block 35 an adjacent pair of protruding poles 35 flows. Thus, the magnetic flux near the inner surface 34 every magnet 34 be evenly distributed between both sides in the circumferential direction at the circumferential center, regardless of the local relationship between the teeth 37a and the magnet 34 , This improves the magnetic balance of the rotor 10A and increases the rotational performance. In particular, the torque is improved and the vibration is reduced.

The distance between the inner surface 34a every magnet 34 and the outer surface of the corresponding coupling region 43 is expressed by a gap length G (see 23 ). When the ratio G / T of the gap length G and the radial thickness T of the magnet 34 is changed, the radial pulsation ratio of the motor M, as in 17 it is shown how the rotor unbalance force ratio changes, as in FIG 18 and how the torque fluctuation ratio changes, as in FIG 19 shown, as well as the change of the maximum torque ratio, as in 20 shown. The radial pulsation, the rotor unbalance force and the torque fluctuation are reasons for amplification of vibration when the rotor 10E rotates. In the examples given in the 14 to 16 are shown, the gap length G is equal to zero.

17 shows the radial pulsation ratio in the case where the ratio G / T is changed. The radial pulsation is set to 100% at a time when the ratio G / T is increased, that is, when the coupling range 43 sufficiently far away from the inner surface 34a of the magnet 34 lies. In the range in which the ratio G / T is greater than 0.4, the radial pulsation is only slightly reduced by about 100%, while the ratio of G / T is reduced, that is, while the gap G at the same thickness T of the magnet 34 is shortened. In the range in which the ratio G / T ≦ 0.4, the radial pulsation significantly reduces as the ratio G / T further decreases. Thus, it is expected that the radial pulsation, when the ratio G / T ≤ 0.4, is reduced. When the ratio G / T = 0 (the status in which the coupling range 43 the inner surface 34a of the magnet 34 the radial pulsation is about 90%, so that the reduction of the radial pulsation is maximized.

18 shows the rotor unbalance force ratio when the ratio G / T is changed. In the case described above, the rotor unbalance force is set to 100% in the time in which the ratio G / T is sufficiently large. In the range in which the ratio G / T is larger than 0.4, the rotor unbalance force is slightly from about 100%. reduced as the ratio G / T decreases. In a range in which the ratio G / T ≦ 0.4, the rotor unbalance force is significantly reduced while the ratio G / T decreases. Thus, it is expected that when the ratio G / T ≦ 0.4, the rotor unbalance force is reduced. When the ratio G / T is 0, the rotor unbalance force becomes about 40%, so that the reduction of the rotor unbalance force is maximized.

19 shows the torque fluctuation ratio when the ratio G / T is changed. As described in the case above, the torque fluctuation at the time when the ratio G / T is sufficiently large is set to 100%. In a range in which the ratio G / T> 0.4, the torque fluctuation of about 100% is slightly reduced as the ratio G / T decreases. In a range in which the ratio G / T ≦ 0.4, the torque fluctuation is significantly reduced as the ratio G / T decreases. Thus, it is expected that when the ratio G / T ≦ 0.4, the torque fluctuation is reduced. When the ratio G / T = 0, the torque fluctuation becomes about 65%, so that the reduction of the torque fluctuation is maximized.

20 shows the maximum torque ratio when the ratio G / T is changed. As described in the case above, the maximum torque is set to 100% when the ratio G / T is sufficiently large. In a range in which the ratio G / T> 0.4, the maximum torque is gradually increased as the ratio G / T decreases. In a range in which the ratio G / T ≦ 0.4, the maximum torque is significantly increasing as the ratio G / T decreases. Thus, it is expected that when the ratio G / T ≦ 0.4, the maximum torque increases. When the ratio G / T is 0, the maximum torque is maximized to about 106%.

With reference to the rotor 10E In the present embodiment, the ratio G / T is the gap length G between the magnets 34 and the coupling area 43 and the radial extent of the magnet 34 is set in a range ≦ 0.4, in which the radial pulsation and the rotor unbalance force and the torque fluctuation can be reduced and the torque can increase. In particular, the ratio G / T is set to zero, so that the effects are maximized. Accordingly, the radial pulsation ( 17 ), which causes vibration when the rotor 10 rotates, the rotor unbalance force ( 18 ) and the torque fluctuation ( 19 ) as the torque increases. It follows that the reasons for vibration when the rotor 10E rotates, are reduced and the rotational power of the rotor 10E is improved.

The 21 and 22 The torque unbalance force ratio and the maximum torque ratio are changed when (Wa / Wm) / (Wb × (ρb / ρr)) in which the width (circumferential dimension) of the gaps S is expressed by Wa, the width (circumferential dimension) of the magnets 34 is expressed by Wm, the radial thickness of the coupling regions 43 is expressed by Wb, the space factor of the rotor core 33 is expressed by ρr, and the space factor of the coupling area is expressed by ρb. The space factor ρr of the rotor core 23 refers to the amount of magnetic flux flowing per unit area in parts that are not part of the coupling region 43 of the rotor core 33 belong, in the radial viewing direction (or in the circumferential direction). The space factor ρr of the coupling area 43 refers to the amount of magnetic flux flowing per unit area in the coupling region 43 in a view in the radial direction (or in the circumferential direction).

21 shows the rotor unbalance force ratio when (Wa / Wm) / (Wb × (ρb / ρr)) is changed. The rotor unbalance force is set to 100% when (Wa / Wm) / (Wb × (ρb / ρr)) is equal to zero. In a range where (Wa / Wm) / (Wb × (ρb / ρr)) <0.25, the rotor unbalance force only slightly decreases when the ratio (Wa / Wm) / (Wb × (ρb / ρr) ) increases from zero. In a range where 0.25 ≦ (Wa / Wm) / (Wb × (ρb / ρr)), the rotor unbalance force is significantly reduced as (Wa / Wm) / (Wb × (ρb / ρr)) increases. Thus, it is expected that the rotor unbalance force decreases when 0.25 ≦ (Wa / Wm) / (Wb × (ρb / ρr)).

22 shows the maximum torque ratio when (Wa / Wm) / (Wb × (ρb / ρr)) is changed. The maximum torque is set to 100% when (Wa / Wm) / (Wb × (ρb / ρr)) is equal to zero. In a range where (Wa / Wm) / (Wb × (ρb / ρr)) ≦ 0.6, the maximum torque decreases only slightly when the ratio (Wa / Wm) / (Wb × (ρb / ρr)) increases from zero. In a range where 0.6 <(Wa / Wm) / (Wb × (ρb / ρr)), the maximum torque is significantly reduced as (Wa / Wm) / (Wb × (ρb / ρr)) increases , Thus, it is expected that the abrupt decrease of maximum torque will be prevented when (Wa / Wm) / (Wb × (ρb / ρr)) ≦ 0.6.

The present embodiment has the following advantages.

With a rotor 10E In the present embodiment, there is a gap S which actively conducts magnetic flux to both sides Circumferential divides, on a part of the rotor core 33 provided, facing the inner surface 34a every magnet 34 and between circumferentially adjacent corresponding projecting blocks 35 is arranged. Thus, the gap S reliably prevents the generation of magnetic imbalance by the presence of the salient poles 41 which do not induce magnetic flux. This improves the magnetic balance of the rotor 10E and increases the rotational performance. In particular, the torque is improved and the vibration is reduced. In addition, the coupling area 43 in the present embodiment, between each gap S and the corresponding magnet 34 arranged and connects a circumferentially adjacent pair of protruding Polblöcken 35 together. The coupling area 43 is designed to be magnetic flux near the inner surface 34a of the magnet 34 is saturated. Thus, the amount of magnetic flux to be split between the two sides in the circumferential direction can be reliably further tuned.

In the present embodiment, the ratio G / T is the gap length D between the magnet 34 and the coupling area 43 and the radial dimension T of the magnet 34 set to be less than or equal to 0.4. This reduces the radial pulsation, the rotor unbalance force and the torque fluctuation, which are the reasons for the vibration when the rotor 10E rotates (see 17 and 19 ), whereby the rotational performance of the rotor is improved.

In the present embodiment, each coupling area touches 43 the inner surface of the corresponding magnet 34 (whereby the ratio G / T = 0). This is the coupling area 43 in a simple way near the inner surface 34a saturated with magnetic flux. Thus, the proportion of magnetic flux split between the two sides in the circumferential direction can be further reliably tuned.

A fifth embodiment of the present invention will now be described with reference to FIGS 24 to 30 explained.

The 24 and 25 show a brushless motor M with an inner rotor. As in 24 shown, becomes a rotor 10F used in a motor M of the present embodiment. The rotor 10F has a substantially annular rotor core 52 , seven magnets 53 and seven protruding poles 54 on. The rotor core 52 is made of magnetic metal and to the outer peripheral surface of a rotary shaft 41 glued. The magnets 53 are on the outer peripheral portion of the rotor core 52 arranged along the circumferential direction. Every protruding pole 54 is between a circumferentially adjacent pair of magnets 53 arranged. The magnets 53 act as north poles. The protruding poles 54 are integral with the rotor core 52 trained and act as south poles. This is the rotor 10F a follower pole rotor with fourteen magnetic poles. A stator 60 has a stator core 61 with twelve teeth 61a , A winding 62 is about every tooth 61 wrapped in a predetermined manner. This has the stator 60 twelve magnetic poles. The magnets 53 and the protruding poles 54 are on the outer circumference of the rotor 10F arranged alternately in the circumferential direction at equal angular intervals.

The circumferential dimension of the magnets 53 is slightly larger than the protruding poles 54 , Every magnet 53 is essentially formed as a rectangular plate and has a flat inner surface 53a and a curved outer surface (distal surface) 53b , The inner surface 53a every magnet 53 is on an adhesive surface (contact surface) 52a of the rotor core 52 glued between a neighboring pair of protruding poles 54 is trained. Each adhesive surface 52a has a flat surface perpendicular to the radial direction of the rotor core 52 runs. The outer surface 53a every magnet 53 opens to the radially outer side of the rotor core 52 so they are directly opposite the stator 60 (the teeth 61a ) lies. Thus, the brushless motor M is an SPM motor.

Every protruding pole 54 has a shape that protrudes radially outward. Both end sides in the circumferential direction of the protruding pole 54 are flat surfaces along the radial direction of the rotor core 52 , At the end side in the circumferential direction of each magnet 53 are flat surfaces parallel to a straight line passing through the perimeter center of the magnet 53 and the axis of the rotary shaft 11 runs. This will be between each protruding pole 24 and the circumferentially adjacent magnet 53 formed a space with a triangular cross-section so that they do not touch each other in the circumferential direction. The outer surface 54a every protruding pole 54 is curved and on the same circumference as the outer surface 53b the magnet 53 arranged. A clearance (air gap with the length AG) exists between the outer surfaces 53a and 54a the magnet 53 and the protruding poles 54 on the one hand and the radially inner ends of the teeth 61a of the stator 60 ,

Every protruding pole 54 has three slots 54b , which by a linear section of the protruding poles 54 starting from the outer surface 54a in the direction of the radial inner end (towards the center of the rotor core 52 ) are formed. The three slots 54b are spaced from each other at equal angular intervals between the end sides in the circumferential direction of the salient poles 54 , The slots 54b they all have the same shape. The slots 54b extend from the outer surface 54a the protruding poles 54 to the proximal portion of the protruding poles 54 , This is the radial dimension of the slots 54b equal to the protruding length of the protruding poles 54 , The width (circumferential dimension) of each slot 54b is defined as Ws1. Accordingly, a slot extends 54b through the rotor 10F (the rotor core 52 ) in the axial direction. The flow of the magnetic flux is improved in a protruding pole 54 due to the slots 54b ,

As in 26A shown and due to the fact that the slots in each protruding pole 54 are formed, the flow of magnetic flux in each salient pole 54 between two sides in the circumferential direction through each slot 54b divided up. This will increase the number of teeth virtually. The flow of the magnetic flux becomes circumferentially in each salient pole 54 and in every tooth 61a finely distributed, and the flow of magnetic flux in each protruding pole 54 approaches the flow of magnetic flux in each magnet 53 at. This equalizes the magnetic flux density in each salient pole 54 and in every tooth 61a to magnetic saturation in the protruding pole 54 and the teeth 61a to avoid. In contrast, if no slots 54b in the protruding poles 54 are trained, as in 26B As shown, the flow of magnetic flux in each salient pole 54 and in every tooth 61a divided into two large passages on both sides in the circumferential direction, so that the magnetic flux is locally concentrated. This increases the difference between the high magnetic flux density and the low magnetic flux density in each salient pole 54 and every tooth 61a and thus leads to local magnetic saturation. These are the slots 54b in a protruding pole 54 of the present invention.

The sum of the widths Ws1 of the slots 54b in a single protruding pole 54 is expressed by the total slot width whale. When the ratio Wa1 / Wb1 between the total width Wa and the total width (circumferential dimension) Wb1 from a single salient pole 54 is changed, so that the engine torque is changed. Therefore, the torque ratio was measured relative to the ratio Wa / Wb1.

27 shows the torque ratio of the motor M when the ratio Wa1 / Wb1 has been changed. The motor torque was set to 100% when the ratio Wa1 / Wb1 was zero, that is, when there were no slots 54b were provided. The torque ratio was over 100% until the ratio Wa1 / Wb1 increased above 0.2 (about 0.23). As the ratio Wa1 / Wb1 further increased, the torque ratio decreased by 100%. Regarding 27 For example, when the ratio Wa1 / Wb1 was in a range where 0 <Wa1 <Wb1 ≦ 0.4, sufficient torque was obtained. Therefore, it is preferable that the ratio Wb1 is set in this range. The range in which 0 <Wa1 / Wb1 ≦ 0.23 is particularly preferable since the torque in this range was larger than 100%.

When the ratio Ws1 / AG of the width Ws1 of each slot 54b and the air gap length AG, which is the distance between the rotor 10F and the stator 60 is changed, the torque fluctuation also changes. Therefore, the torque fluctuation ratio was measured in relation to the ratio Ws1 / AG.

28 shows the torque fluctuation ratio when the ratio Ws1 / AG has been changed. The torque fluctuation was set to 100% when the ratio Ws1 / AG was zero, that is, when there were no slots 54b were provided. In this case, the torque fluctuation gradually decreased as the ratio Ws1 / AG increased. The torque fluctuation had a minimum value or about 48% when the ratio Ws1 / AG was about 1.4. As soon as the ratio Ws1 / AG continued to increase, the torque fluctuation also increased gradually. When the ratio Ws1 / AG was about 2.2, the torque fluctuation reached about 88%. With reference to the 28 was the torque fluctuation in a range in which 0.5 ≤ Ws1 / AG ≤ 2.2 effectively reduced. The ratio Ws1 / AG is therefore preferably set in this range. In particular, when the ratio WS1 / AG is set to preferably about 1.4, the torque fluctuation is sufficiently reduced.

Considering the above results, the ratio Wa1 / Wb of the entire width of the slots is Wal 54b in a single protruding pole 54 and the circumferential width Wb1 of the salient pole 54 is set in a range in which 0 <Wa1 / Wb1 ≦ 0.4. The ratio Ws1 / AG of the width Ws1 of each slot 54b and the air gap length AG is set in a range in which 0.5 ≦ Ws1 / AG ≦ 2.2. This is through the formation of slots 54b in every protruding pole 54 of the rotor 10F and by optimizing the shape and size of the slots 54b Vibration of the engine M reduces while sufficient torque is generated.

In the foregoing explanation, the slots open 54 radially outward. However, as in 29 shown the rotor core 52 bridge areas 54C each of which is between a slot 54b and the outer surface 54a of the protruding pole 54 in the radially outer end of the salient pole 54 are arranged. Such a structure improves the rigidity of the salient poles 54 and thus improves the rigidity of the rotor 10F , Accordingly, the vibration volume of the motor M is reduced. Next, every tooth can 61a like this in 32 is shown, slots 61b in a part near the radially inner end. The number and angular steps of the slots 61b a tooth 61a are identical to those of the slots 54b the protruding poles 54 , The slots 61b in every tooth 61a improve the flow of magnetic flux into the tooth 61a , In 30 are the slots 61b not open in the direction of the radially inner side. However, the slots can 61b be open in the direction of the radially inner side. The number and angular steps of the slots 61b the teeth 61a are not strictly limited to those described above.

The foregoing embodiment has the following advantages.

With a rotor 10F In the present embodiment, the slots are 54b either in the outer surface 54a every protruding pole 54 , as in 25 shown, formed or in each protruding pole 54 as in the 29 and 30 shown. These are the slots 54b that in every protruding pole 54 are formed, suitable for the flow of magnetic flux in the protruding pole 54 to improve, so that the flow rate is the flow of magnetic flux in the magnet 53 approaches. This improves the magnetic balance of the rotor 10F and thus reduces the engine vibration.

In the present embodiment, the radial dimension of the slots is 54b equal to the protruding length of the protruding poles 54 , This allows the magnetic flux in the protruding poles 54 flows along the radial direction, so that the flow is more reliable to the flow of magnetic flux in the magnet 53 adapts. This more reliably improves the magnetic balance of the rotor 10F and thus reduces the engine vibration. Also, the optimization of the shape and size of the slots 54b can be used to adjust the engine settings. In particular, the engine vibration is reduced and the engine torque is improved. Because the radial dimension of the slots 54b substantially equal to the protruding length of the salient poles 54a is, reduce the slots 54b continue the weight of the rotor core 52 and thus lead to a reduction of the weight of the rotor 10F , As a result, the inertia of the rotor 10F reduced.

A sixth embodiment of the present invention will now be described with reference to FIGS 31 to 36 described.

As in the fifth embodiment, a rotor 10G used in a motor M of the present invention, the three slots 54d which are spaced at regular angular intervals from each other and in each protruding pole 54 are provided, as in the 31 and 32 will be shown. In every protruding pole 54 are the slots 54d in the outer surface 54a (distal surface) and extend through the protruding pole 54 in the axial direction. The width (circumferential dimension) W1 and the depth (radial dimension) D1 of each slot 54d are each set to a predetermined value so that the depth D1 is smaller than the protruding length (radial dimension) of the salient pole 54 is.

33 shows the change of the offset torque in a range in which the electrical angle is between 0 and 30 °, in a case where the slits 54d in every protruding pole 54 are shaped, as well as in a case in which no slots 54d are formed. The offset moment and the associated rotation of the rotor 10G repeats this change in the range of 30 ° of the electrical angle. As in the fifth embodiment, the flow of magnetic flux is in the salient poles 54 and the teeth 61a improved in the circumferential direction in the present embodiment, as in 35 shown, finely distributed. This virtually increases the number of teeth. This is compared to a rotor without slots 54d reduces the offset torque to a lower level.

When the ratio W1 / W2 of the width W1 of the slots 54d and the distance between the radially inner ends of each circumferentially adjacent pair of teeth 61a or the inner tooth width W2 is changed accordingly changes the offset torque. Therefore, the offset torque ratio was measured with respect to the ratio W1 / W2.

34 shows the offset torque ratio when the ratio W1 / W2 has been changed. The offset moment was set to 100% when the ratio W1 / W2 was zero, that is, when there were no slots 54d in the protruding pole 54 were provided. In this case, the offset moment increased gradually as the ratio W1 / W2 increased. The offset moment was a minimum or about 35% when the ratio W1 / W2 was about 0.5 (about 0.48). As the ratio W1 / W2 further increased, the offset torque also gradually increased. When the ratio W1 / W2 was 1.2, the offset torque reached about 90%. Regarding 34 For example, the offset torque was reduced in a range in which 0.2 ≦ W1 / W2 ≦ 0.4. It is therefore preferable that the ratio W1 / W2 is set in this range. The range in which 0.4 ≤ W1 / W2 ≤ 0.6 is particularly preferable because the offset torque was sufficiently reduced in this range.

When the ratio D1 / W2 of the depth D1 and the width W1 of the slots 54d every protruding pole 54 is changed, the offset torque changes accordingly. Therefore, the offset torque ratio was measured in relation to the ratio W1 / W2.

35 shows the offset torque ratio when the ratio D1 / W1 has been changed. The offset torque ratio was set to 100% when the ratio D1 / W1 was zero, that is, when there were no slots 54d in the protruding poles 54 were provided. In this case, the offset torque gradually decreased as the ratio D1 / W1 increased. The offset moment dropped to about 43% as soon as the ratio D1 / W1 was about 0.25. When the ratio D1 / W1 increased to about 0.5, the offset torque dropped to about 38%. After that, the offset torque remained constant, although the ratio D1 / W2 continued to increase. Regarding 37 For example, the offset moment has been reduced in a range where 0.25 ≦ D1 / W1. It is therefore preferable that the ratio D1 / W1 is set in this range. A range in which 0.25 ≦ D1 / W1 ≦ 0.5 is particularly preferred since the offset torque was further reduced in this range.

In the present embodiment, the ratio W1 / W2 is the width W1 and the circumferential dimension W2 of the teeth 61a is set in a range where 0.2 ≦ W1 / W2 ≦ 0.9, and the ratio D1 / W1 of the depth D1 and the width W1 of the slots 54d the protruding poles 54 is set in a range where 0.25 ≦ D1 / W1. This is done by forming slots 54d in every protruding pole 54 of the rotor 10G and optimizing the shape and size of the slots 54d reduces the vibration of the motor M.

As in 36 represented, every tooth can 61a slots 61c have, which open radially inward. The slots 61c are arranged in pairs along the circumferential direction. In this case, the flow of magnetic flux is in the protruding poles 54 and the teeth 61a as improved in the fifth embodiment. Next, the number and the angular increment of the slots 61d the teeth 61a the same as the slits 54d the protruding poles 54 ,

The present embodiment has the following advantages.

In a rotor 10G In the present embodiment, there are three slots 54d along the circumferential direction of the outer surface 54a every protruding pole 54 trained, like this in 32 is shown. This will improve the slots 54d in every protruding pole 54 the flow of magnetic flux in the protruding poles 54 and the teeth 61a , so that the flow of magnetic flux in the protruding poles 54 and the teeth 61a the flow of magnetic flux into the magnet 53 approaches. This improves the magnetic balance of the rotor 10G and reduces engine vibration in this way.

In the present embodiment, the radial dimension of the slots is 54d smaller than the protruding length of the protruding poles 54 , In other words, the amount of the cutout for the formation of the slots 54d small, so the stiffness of the protruding pole 54 is maintained. This further reduces engine vibration. As the proportion of the section for the formation of the slots 54d small, can the slots 54d in the protruding pole 54 generated after installation. By optimizing the shape and size of the slots 54d also the engine characteristics can be tuned. In particular, engine vibration is reduced and engine torque is improved.

A seventh embodiment of the present invention will now be described with reference to FIGS 37 to 43 explained.

As in the 37 and 38 shown, has a rotor 10H a motor M according to the present embodiment Verpressbereiche 55 each at predetermined positions of each protruding pole 54 on. In particular, it is the rotor core 52 that in the rotor 10H of the present embodiment, a laminated core formed by laminating a plurality of steel sheets in the axial direction. In each steel sheet are rectangular slots 55a in predetermined areas of the salient poles 54 educated. The steel sheets are laminated with each other, leaving the slots 55a are aligned with each other in the axial direction. A grout 55b is in any continuous axial set of slots 55a used. By pressing the grout 55b The laminated steel sheets are connected axially with each other.

The grouting areas 55 each of which has the slot 55a and the grout 55b are in each protruding pole 54 of the rotor core 52 intended. The injection area 55 is in the center of the protruding pole 54 arranged on the circumferential direction and at a location which is slightly radially inward from the outer surface 54a of the protruding pole 54 is located. The injection area 55 (Slot 55a ) has a rectangular cross-section with respect to a view in the axial direction, so that the longer sides extend along the axial direction.

Because of the injection area 55 formed in each protruding pole, as in 39A shown, the magnetic flux on both sides in the circumferential direction of the pressing area 55 in every protruding pole 54 split and flows along the longer sides of the grout area 55 , Thus, in every protruding pole 54 and in every tooth 61a improves the flow of magnetic flux by being finely distributed in the circumferential direction. Thus, the distribution of magnetic flux in each salient pole approaches 54 and in every tooth 61 the distribution of the magnetic flux in each magnet 53 at. In contrast, when the protruding pole 54 no injection area 55 has, as in 39B is shown, the flow of magnetic flux in each salient pole concentrates on one side in the circumferential direction. Thus, the magnetic flux is locally concentrated. As a result, in the present embodiment, the press portion improves 54 that in every protruding pole 54 is provided, the flow of magnetic flux in each protruding pole 54 and in each of the teeth 61a so that vibration of the motor M is reduced.

In a rotor 10H , which is such injection areas 55 varies as the ratio Ty / Tm between the thickness (radial dimension) of the magnets 53 in the present embodiment, the thickness Tm at the center in the circumferential direction and the thickness Ty in a region of the rotor core 52 that faces the inner surface 53a the magnet 53 (rear bracket thickness) is changed, the torque accordingly. Thus, the torque ratio was measured with respect to the ratio Ty / Tm.

40 shows the torque ratio of the motor M when the ratio Ty / Tm has been changed. The torque was at 100% when the ratio Ty / Tm was 1, that is, when the thickness of the magnet and the back ironing thickness were identical. When the ratio Ty / Tm> 1, the torque was constant at about 100% even when the ratio Ty / Tm increased. When the ratio Ty / Tm <1, the torque increased above 100% until the ratio Ty / Tm reached about 0.4 (about 0.36). When the ratio Ty / Tm was about 0.5, the torque had a maximum value of 105%. When the Ty / Tm ratio of about 0.4 (about 0.36) was reduced, the torque gradually decreased from 100%. When the ratio Ty / Tm was about 0.2, the torque was about 85%. When the ratio Ty / Tm was about 0.1, the torque was about 70%.

The torque fluctuation ratio with respect to the ratio Ty / Tm of the back strap thickness Ty and the magnet thickness Tm was also measured.

41 shows the torque fluctuation ratio when the ratio Ty / Tm has been changed. The torque fluctuation was set to 100% when the ratio Ty / Tm was 1. When the ratio Ty / Tm> 1, the torque fluctuation increased to about 105% when the ratio Ty / Tm was 1.2. Subsequently, the torque fluctuation was substantially constant. When the ratio Ty / Tm <1, the torque fluctuation had a maximum value of 95% when the ratio Ty / Tm was about 0.5. When the ratio Ty / Tm of about 0.5 was further reduced, the torque fluctuation gradually increased. When the ratio Ty / Tm was about 0.2, the torque fluctuation was about 120%. When the ratio Ty / Tm was about 0.1, the torque fluctuation was about 145%.

In consideration of the above results, the ratio Ty / Tm of the back temple thickness Ty and the magnet thickness Tm is set in a range where 0.4 ≦ Ty / Tm ≦ 1.5. So that's the injection areas 55 in the protruding poles 54 are formed so as to improve the flow of the magnetic flux, whereby the vibration of the motor M is reduced.

Moreover, the ratio Ty / Tm of the rear temple thickness Ty and the magnet thickness Tm is optimized, thereby improving the engine torque and the torque fluctuation. In particular, when the ratio Ty / Tm is in a range in which 0.4 ≦ Ty / Tm ≦ 1, the torque increases and the torque fluctuation is reduced. This range is therefore preferred.

With reference to the foregoing, a plurality of steel sheets for forming the rotor core are connected to each other by the fitting of grout 55b in the slots 55a , However, other coupling agents can be used. For example, steel sheets be coupled with each other in the axial direction, are formed in the fitting projections and fitting recesses in the steel sheets. Even in this case, the coupling portions of the projections and the recesses (crimping) act in the same manner as the slits 55a , so that the flow of magnetic flux in the protruding poles 54 is improved.

The present embodiment has the following advantages.

In the rotor 10H In the present embodiment, slots are 55a (Verpressbereiche 55 ) in the protruding poles 54 trained, like this in 38 is shown. These are the slots 55a in every protruding pole 54 formed and improve the flow of magnetic flux in the protruding pole 54 and the tooth 61a in the present embodiment, so that the flow rate is the flow of magnetic flux in the magnet 53 approaches. This improves the magnetic balance of the rotor 10H and thus reduces engine vibration.

In the present embodiment, the rotor core is 52 a lamination core formed by laminating a plurality of steel sheets in the axial direction. Every protruding pole 54 has slots 55a , The grout 55b is in every slot 55a used so that it connects the steel sheets with each other. So that's the grout 55b in the slots 55a used to measure the flow of magnetic flux in the protruding poles 54 improve, and the steel sheets in the laminated core are through the means in the slots 55a connected with each other. Accordingly, no coupling means for the coupling of the steel sheets with each other must be provided at other locations otherwise. This reduces the weight of the rotor 10H ,

In the present embodiment, the back ironing thickness Ty of the rotor core 52 optimized to the size of the rotor core 52 to prevent it from becoming unnecessarily large. This reduces the weight of the rotor core 52 or reduces the weight of the rotor 10H , The inertia of the rotor 10H is also reduced.

An eighth embodiment of the present invention will now be described with reference to FIGS 42 to 49 explained.

In a rotor 10I used in a motor M of the present embodiment is a single slot 54e in the outer surface 54a from each protruding pole 54 trained, as in the 42 and 43 is shown. Every slot 54e extends along a direction relative to the axes L1 of the rotor 10I extends angled from the radial outer side in a viewing direction. The slot 54e in the outer surface 54a from each protruding pole 54 improves the flow of magnetic flux in the salient pole 54 in that the flow is distributed in peripheral vision, as is the case in the sixth embodiment. In addition, the flow of magnetic flux in each salient pole becomes 54 gently changed to smooth the entire waveform of the offset torque. In other words, the "gradient effect" is generated. Accordingly, the vibration of the motor M is reduced.

If the inclination angle is A ° of each slot 54e relative to the axis L1, with respect to a viewing direction from the radially outer side, is changed, the offset torque changes accordingly. Thus, the offset torque ratio was measured with respect to the inclination angle A °. In this case, the offset moment was measured while the inclination angle A ° of each slot 54e and the ratio A ° / (360 ° / N), the least common multiple of the number of teeth 61a of the stator 60 (the number of slots) and the number of magnetic poles of the rotor 10E (the sum of the number of magnets and the number of protruding poles 54 ).

44 shows that the offset moment, when the ratio A ° 1360 ° / N was changed. The offset moment was set to 100% if the ratio A ° / 360 / N was zero, so if the slots 54e were not inclined. The offset moment decreased until the ratio A ° reached 1360 ° / N about 0.5 and had a minimum value of about 90% when the ratio was about 0.5. Further, when the ratio A ° / 360 ° / N increased, the offset torque also gradually increased. When the ratio A ° / 360 ° / N was about 1.0, the offset torque was about 92%. Subsequently, the rate of increase increased slightly. When the ratio A ° / 360 ° / N was about 1.9, the offset torque was about 98%, and when the ratio A ° 1360 ° / N was about 2.0, the offset torque was about 100%. With reference to the 54 For example, if the offset moment was reduced in a range where 0 <A ° 1360 ° / N ≦ 2, it is preferable to define the ratio A ° / 360 ° / N in this range. In particular, a ratio of A ° / 360 ° / N is more preferably about 0.5 because the offset torque is sufficiently reduced here. In the present embodiment, the number of teeth 61 12 and the number of magnetic poles in a rotor 10I 14 (the least common multiple N = 84). This is a tilt angle for the slot 54e which produces a ratio A ° / 360 ° / N of 0.5, about 2.1 °. This angle of inclination minimizes the offset moment.

In the foregoing description, the inclination angle is A ° of the slots 54e that are in the outer surfaces 54a the protruding poles 54 are trained, the same everywhere. However, as in 45 shown, the angle of inclination of the slots of protruding Pol 54 to protruding pole 54 be different. For example, slots can 54e and 54f be arranged alternately with different inclination angles. This configuration smooths the waveform of the offset momentum that exists in each salient pole 54 is generated and further reduces the offset torque.

Alternatively to providing slots 54e and 54f which are relative to the axis 11 Slits can also be slanted in the same direction 54g and 54h be provided, which are inclined in different directions and in the protruding poles 54 are trained, as in 56 is shown. The slots 54g and 54h which are inclined in different directions smooth the waveform of the offset moment passing through each salient pole 54 is generated, while further reducing the offset torque. In addition, the direction of inclination of each slit can be changed at a point of the axial direction.

Alternatively, slots can 54g and 54a be formed, which does not extend to the axial ends of the rotor core 52 extend. These are the slots 54g and 54h shorter than the rotor core 52 in the axial direction.

Unlike the slots 54e . 54f . 54g and 54h , which in each protruding pole 54 are formed, can also have two inclined slots 541 in every protruding pole 54 be trained as in 47 is shown. Further, three or more slots in each protruding pole may also be used 54 be educated.

The above embodiment has the following advantages.

In the rotor 10I The present embodiment is the slot 54e in the outer surface 54a from each protruding pole 54 trained, like this in 42 shown (the slots 54f to 54h in the respective modifications). This is the slot 55E in every protruding pole 54 designed to detect the flow of magnetic flux in the protruding pole 54 and the tooth 61a Improve the present embodiment, so that the flow is the flow of magnetic flux in the magnet 53 approaches. This improves the magnetic balance of the rotor 10I and thus reduces the engine vibration.

According to the present embodiment, the slot 54e continuously in the outer surface 54a from each protruding pole 54 designed to be relative to the axis L1 of the rotor 10I to tilt. This improves the slot 54e the flow of magnetic flux in the protruding poles 54 and achieves a "feathering effect" in which the magnetic flux of the salient poles 54 is smoothed so that the waveform of the offset moment is rounded off. Accordingly, the engine vibration is further reduced.

The above-described embodiments may be modified as follows.

In the first to third embodiments, the ranges of the ratio Ws / Wm may be the width Ws of the slots 12b and the width Wn of the magnets 13 , as well as the ratio Wt / Wn of the width Wt of the slots 12c and the width Wn of the salient poles are changed as occasion demands.

The slots 12b of the first embodiment can through slots 12b of the 48A and 48B be replaced. The slots 12b and 12c of the second embodiment can through slots 12b and 12c according to the 48A be replaced. In the slots 12b , in the 48A are inner surfaces 12D which are opposed in the circumferential direction, formed as flat surfaces, so that the distance between them increases in the direction of the radially inner end. This decreases the width of each slot 12b (Circumferential dimension) in the direction of the radially inner end. In the first and second embodiments, the inner surfaces are 12D every slot 12b parallel to each other. If the width of each slot 12b along the radial direction increases, as in 48A is shown, magnetic flux becomes in the salient poles as compared with the first and second embodiments 54 more easily approved.

As in 48A shown, each slot has 12c the same shape as the slot 12b , This will be in every slot 12c inner surfaces 12E formed facing each other in the circumferential direction and which are formed as flat surfaces, so that the distance between the same in the direction of the radially inner end increases. If the width of each slot 12c is large, magnetic flux is directed towards the protruding poles 14 more easily allowed compared to the first and second embodiments. 48A shows an example in which the slots 12b having the above-explained shape and slots 12b and 12c the second embodiment are applied. However, the slots can 12b on the first embodiment are applied, which the slots 12c does not have.

As in 48B represented, each slot can 12b be formed fork-shaped in the direction of the radial inner end, as in 48B is shown while being curved in the direction of the two sides in the circumferential direction. This shape of the slots 12b allows the magnetic flux near the adhesive surfaces 12a to flow in a desired course, namely in the direction of the protruding poles 14 on both sides in the circumferential direction. 48 shows an example in which the slot 12b of the first embodiment has been changed to a fork-shaped slot. However, the slots can 12b of the second embodiment also have the shape as shown in FIG 48B is shown.

In the third embodiment, the shape of the inner surface 13a of the magnet 13 and the shape of the adhesive surfaces 12a of the rotor core 12 not particularly limited. For example, as in 49A shown, the cross section perpendicular to the axial direction of the rotary shaft 11 on the inner surface 13a from every magnet 13 have a trapezoidal shape so that the center in the circumferential direction of the inner surface 13 extends radially inward. Every inner surface 13a is through a shallow area 13a5 formed in the center in the circumferential direction and has inclined portions 13a6 and 13a7 on which on both sides of the flat area 13a5 are formed in the circumferential direction. This configuration increases the radial extent (thickness) of each magnet 13 in a peripheral center area compared to the third embodiment, in which the inner surface 13a from every magnet 13 is triangular shaped. As a result, the motor generates strong magnetic flux.

Next, as in 49B shown, the inner surface can be 13a every magnet 13 be arcuate, so that the center extends in the circumferential direction radially inwardly. This configuration increases the radial dimension (thickness) of each magnet 13 in the end regions in the circumferential direction in comparison to the magnets 13 as they are in 49B are shown. As a result, the rotor generates a large amount of magnetic flux.

In the fourth embodiment, each coupling area touches 43 the inner surface 34 the corresponding magnet 34 (the ratio G / T is 0). However, this configuration is not limiting but may be modified as shown in FIG 23 is shown. So it does not have to be every coupling area 53 the inner surface 34a of the corresponding magnet 43 touch (0 <G / T ≤ 0.4). Even this configuration allows the coupling area 43 Magnetically saturated with magnetic flux is from the inner surface 34a of the corresponding magnet 34 , This will prevent magnetic flux from entering the protruding pole block 35 flows through which magnetic flux should not happen. Thus, magnetic flux becomes uniform in each coupling area 43 from a perimeter center to both sides in the circumferential direction, regardless of the local relationship to the teeth 37a , Also, a welding area between the laminated steel sheets of the rotor core 33 be provided, which between each coupling area 43 and the inner surface 34a of the corresponding magnet 34 is located. This increases the stiffness of the rotor core 33 while reducing the influence on the rotational performance. As in 23 shown, the inner surface can be 34a from every magnet 34 be formed to extend radially inwardly. Part of the inner surface 34a attached to the outer surface (the adhesive surface 33a ) the base 42 is fixed as an inclined area 34C educated. The outer surface of the base 42 is inclined so that it is with the inclined area 34C Corresponds and it allows the position of the magnet 34 opposite the inner surface 34a permit. This allows the magnet 34 is accurately fixed. Because the inclined area 34C from every magnet 34 the magnetic flux conducts, so that the magnetic flux is divided from the circumferential center to both sides in the circumferential direction, the magnetic flux from the inner surface 34a of the magnet 34 divided easily and evenly between both sides in the circumferential direction away from the peripheral center.

In the fourth embodiment, the coupling area is 43 integral with the protruding pole block 35 educated. However, the coupling area can 43 also separate from the protruding pole block 35 be educated.

In the fourth embodiment, the magnetic resistance of each coupling region 43 be increased, for example, by generating a mechanical stress in each coupling region 43 to deform it, so that the magnetic property by changing the material of the coupling area 43 decreases or the magnetic property of the coupling region 43 is changed by laser irradiation.

In the fourth embodiment, the gap S is empty. However, the gap S may have a non-magnetic region 32 filled out.

In the fourth embodiment, the range of the ratio G / T of the gap length G and the radial dimension T of the magnet 34 and the Range of the ratio (Wa / Wm) / (WbX (ρb / ρr)) can be changed as necessary. In the fourth embodiment, the shape of the magnets 34 and the shape of the rotor core 33 which are the protruding blocks 35 and the coupling areas 43 included, changed as needed.

In the fourth embodiment, the magnets 34 as south poles and the protruding poles 41 used as north poles. However, the magnets can 34 be used as north poles and the protruding poles 41 be used as south poles.

The configurations of the fifth to eighth embodiments may be added to those of the first to fourth embodiments.

The ranges and the values in the fifth to eighth embodiments may be adjusted as necessary depending on the respective conditions.

In the embodiments explained above, the present invention is directed to the rotors 10A to 10I applied, which are formed in a motor M with internal rotor. However, the present invention can also be applied to a motor having an external rotor.

The number of magnetic poles of the rotors 10A to 10I and the stator 20 are not limited to what has been described in the first to eighth embodiments, but may be changed as necessary.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 9-327139 [0002]

Claims (16)

A rotor comprising: a rotor core; a plurality of magnets along a circumferential direction of the rotor core, each magnet acting as a first magnetic pole and having a back side opposed to the rotor core; and a plurality of salient poles integrally formed with the rotor core, each salient pole being disposed between circumferentially adjacent pairs of poles and acting as second magnetic poles different from the first poles, the rotor being characterized in that the rotor core has a magnetic flux dividing area at each position opposite to one of the magnets, each magnetic flux dividing area near the back of the corresponding magnet actively dividing the magnetic flux circumferentially on both sides. The rotor according to claim 1, characterized in that the magnetic flux dividing regions are slots. The rotor according to one of claims 1 or 2, characterized in that the magnetic flux dividing regions are respectively provided in a part of the rotor core which contacts the back side of the corresponding magnet. The rotor of claim 1, characterized in that the rotor core has contact surfaces, each of which contacts the backside of one of the magnets, each contact surface having a pair of inclined surfaces extending circumferentially away from each other from the circumferential center of the contact surface, each one Pair of the inclined surfaces acts as the magnetic flux dividing areas. The rotor according to claim 4, characterized in that the back of each magnet is formed to project radially inwardly. The rotor according to any one of claims 1 to 5, characterized in that each magnetic flux dividing portion is formed so as to split magnetic flux in the vicinity of the back of the corresponding magnets in the circumferential direction of a center of the circumferential direction to both sides. The rotor according to claim 1, characterized in that each of the salient poles has therein a magnetic flux alignment section which forcibly changes the direction of magnetic flux passing through the salient pole. The rotor of claim 1, characterized in that the rotor core comprises a plurality of projecting pole blocks having the salient poles, each salient pole block being disposed between a pair of circumferentially adjacent magnets; a plurality of spaces respectively provided at a position opposite to the rear side of one of the magnets, each space being circumferentially disposed between an adjacent pair of the projecting pole blocks, and the spaces serve as magnetic flux dividing portions; and a plurality of coupling portions, each coupling portion coupling a circumferentially adjacent pair of protruding pole blocks with each other; wherein each coupling portion is formed to be magnetically saturated near the back of the corresponding magnetic flux magnet. The rotor according to claim 8, characterized in that when a gap length between each magnet and the corresponding coupling region is defined and the radial dimension of the magnets is expressed by G and T, the ratio G / T is less than or equal to 0.4. The rotor according to claim 9, characterized in that each coupling portion is formed so as to contact the back side of the corresponding magnet. A rotor, comprising: a rotor core; a plurality of magnets along a circumferential direction of the rotor core, each magnet acting as a first magnetic pole and having a surface facing outward; and a plurality of salient poles integrally formed with the rotor core, each salient pole being disposed between a circumferentially adjacent pair of magnets and acting as second magnetic poles different from the first magnetic poles, wherein a gap is formed between a circumferentially adjacent pair of the magnets and the corresponding protruding poles; wherein the rotor is characterized in that a slot is formed either in a distal surface of each salient pole or within each salient pole. The rotor according to claim 11, characterized in that the slots respectively in the distal surface of the corresponding protruding pole is formed, and wherein the radial dimension of each slot is smaller than the protruding length of each salient pole. The rotor of claim 1, characterized in that the slots are respectively formed in the distal surface of the corresponding protruding poles, and wherein the radial dimension of each slot is equal to the protruding length of each salient pole. The rotor according to claim 1, characterized in that the rotor core is formed by laminating a plurality of steel sheets, each slot being formed inside the corresponding protruding pole, and wherein the laminated steel sheets are coupled to each other by means of crimping means disposed respectively in one of Slots are introduced so that the rotor core is formed. The rotor of claim 11, characterized in that the slots are formed in the distal surface of the corresponding protruding pole, and wherein each slot extends to slant relative to the axis of the rotor. A motor comprising a rotor according to any one of claims 1 to 15.

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