JPH1175353A - Motor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor structure which makes it possible to reduce the weight and increase the slots of a cylindrical motor with a radial gap without degrading characteristics of the motor. SOLUTION: The motor structure comprising a yoke 21 for the adjustment of magnetic flux density of magnetically soft material which is shaped into a cylinder and has upper salient poles 18 in a number half the number of all the salient poles, protruded inward from the inside upper edge at equal inner angles, and further lower salient poles 18 in the number half the number of all the salient poles, protruded inward from the inside lower edge at the equal inner angles in such a manner that the upper salient poles and the lower salient poles do not overlap each other in the vertical direction; and driving coils wound around the upper salient poles and the lower salient poles, respectively. The yoke for the adjustment of magnetic flux density may be formed in two stages or of a laminate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radial gap type motor structure, and more particularly, to a radial gap type motor structure which is reduced in size, weight and cost.

[0002]

2. Description of the Related Art In recent years, there has been remarkable progress in improving the performance of various types of OA equipment, particularly in increasing the speed, and accordingly, various types of OA equipment use a plurality of dedicated motors according to their functions. . In particular, in the case of a small DC motor, there is a demand for a motor with high magnetic efficiency, low cogging torque, and low electromagnetic noise and good controllability according to the application. As a countermeasure, increasing the number of core slots (the number of salient poles) and the number of magnetic poles of the magnet will shorten the length of each magnetic circuit and reduce the magnetic resistance, thereby increasing the magnetic efficiency. The coil is concentrated winding to increase the winding efficiency.

FIG. 11 shows a configuration of a conventionally used laminated inner rotor type brushless DC motor, and FIG. 12 shows a cross section thereof. In the drawing, 1 indicates a lead wire, and 2 indicates a coil formed by inserting a bobbin 9 from above and below into a salient pole 13 of a stator 8 formed by laminating soft magnetic steel sheets, and winding a magnet wire thereon. . Reference numeral 3 denotes a rotor magnet, and reference numeral 4 denotes a sleeve that connects the rotor magnet and a shaft 5 that is a rotation center of the rotor.
Reference numeral 7 denotes a flange, in which a bearing 6 for supporting the rotor shaft 5 is disposed at the center, and the stator 8 is sandwiched from both sides.
Here, the tip of the salient pole 10 is wider than the winding portion in order to increase the flux linkage with the rotor magnet and to hold the bobbin (coil). Further, the stack of the stators 8 has substantially the same length as the rotor magnet 3 for the same reason as described above.

[0004]

However, in the case of the multi-slot configuration, the space between the slots is narrowed because the interval between the slots is narrowed, so that a required amount of windings cannot be accommodated unless the motor size is increased. In addition, if the dimensions are the same, a necessary amount of winding cannot be formed, so that the cost is increased, but a permanent magnet having high magnetic characteristics is adopted for the rotor to obtain desired motor characteristics. In addition, in the configuration of the conventional laminated stator, in order to secure the opposing area between the salient poles and the rotor magnet, the stator thickness must be substantially the same as the length of the rotor magnet. The wire length becomes longer and the efficiency of the winding becomes worse. Further, the surface of the salient pole facing the rotor magnet is widened for both securing the facing area and holding the coil, so that the workability of the winding is also poor. This tendency is particularly noticeable in the inner rotor type.
At the same time, there are more stators than necessary, making them heavy and unwieldy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a motor structure capable of reducing the weight and increasing the number of slots in a radial gap cylindrical motor without impairing the motor characteristics. It is intended to provide.

[0006]

In order to achieve the object of the present invention as described above, the invention according to claim 1 of the present invention comprises a rotor having a field magnet and rotatably held, and a rotor having a field magnet. In a motor structure composed of a field magnet and fixed magnetic poles having salient poles facing each other, half of the total number of salient poles project from the inner upper edge to the inner upper edge at an equal inner angle. Also, a magnetic flux density adjustment made of a soft magnetic material with half of the total number of salient poles projecting from the inner lower edge at the same inner angle in the inward direction so as not to overlap the upper salient poles vertically A motor structure comprising: a yoke; and a driving coil wound around the upper salient pole and the lower salient pole. In the invention according to claim 2 of the present invention, in addition to the invention according to claim 1, the magnetic flux density adjusting yoke is vertically divided into two in the shaft direction, and each magnetic flux density adjusting yoke is half of the total number of salient poles. And the upper and lower magnetic flux density adjusting yokes are formed at positions where the salient poles electrically generate a phase difference of 180 degrees. Provide a motor structure. According to a third aspect of the present invention, in addition to the second aspect, the motor structure is characterized in that the magnetic flux density adjusting yoke is formed by laminating soft magnetic electromagnetic steel sheets in a shaft direction. provide. In the invention according to claim 4 of the present invention, in addition to the invention according to claim 1, the salient poles projecting radially inward are formed by laminating electromagnetic steel sheets in a weekly direction, and winding the driving coil. The motor structure is characterized in that the parts are arranged such that they do not overlap in the weekly direction. In the invention according to claim 5 of the present invention, in a motor structure including a rotor having a field magnet and rotatably held, and a fixed magnetic pole having salient poles facing the field magnet of the rotor, the motor has a cylindrical shape. The upper salient poles that are half of the total number of salient poles are formed at the inner upper edge and protrude inward at an equal inner angle, and the lower salient poles that are half of the total number of salient poles are evenly inwardly oriented at the inner lower edge. A magnetic flux density adjusting yoke made of a soft magnetic material protruding so as not to overlap the upper salient pole with the upper salient pole at an inner angle of, and a cup-shaped bottom protruding inward at the bottom and overlapping the upper salient pole An upper stator yoke having an upper protruding portion and made of a soft magnetic material overlapping the upper side of the magnetic flux density adjusting yoke, and a lower protruding portion formed in a cup shape and projecting inward at the bottom portion and overlapping the lower salient pole. Holding it under the magnetic flux density adjusting yoke. A lower stator yoke made of a soft magnetic material, and a driving coil wound around an overlapping portion of the upper salient pole and the upper salient, and a lower salient pole and an overlapping portion of the lower salient. A motor structure is provided. In the invention according to claim 6 of the present invention, in addition to the invention according to claim 5, the magnetic flux density adjusting yoke is vertically divided into two in the shaft direction, and each magnetic flux density adjusting yoke has a half of the total number of salient poles. A motor having radially inwardly projecting salient poles, wherein the upper and lower magnetic flux density adjusting yokes are stacked so that the salient poles are electrically shifted to generate a phase difference of 180 degrees. Provide structure. In the invention according to claim 7 of the present invention, claim 6
In addition, the present invention provides a motor structure wherein the magnetic flux density adjusting yoke is formed by laminating electromagnetic steel sheets in a shaft direction. In the invention according to claim 8 of the present invention, in addition to the invention according to claim 5, the salient pole projecting radially inward is formed by laminating electromagnetic steel sheets in a week direction, and the winding portion of the driving coil is formed. Provide a motor structure characterized by being arranged so as not to overlap in the week direction. In the invention according to claim 9 of the present invention, claim 1 or 5
In addition, the present invention provides a motor structure characterized in that the magnetic flux density adjusting yoke is made of a polymer material containing soft magnetic powder. In the invention according to claim 10 of the present invention,
In addition to the invention according to claim 1 or 5, there is provided a motor structure wherein the magnetic flux density adjusting yoke is made of a sintered metal. In the invention according to claim 11 of the present invention,
In addition to the invention according to claim 5, there is provided a motor structure wherein the stator yoke is made of a polymer material containing soft magnetic powder. According to a twelfth aspect of the present invention, there is provided a motor structure in which the stator yoke is made of a sintered metal in addition to the fifth aspect. In the invention according to claim 13 of the present invention, claim 6
In addition to the present invention, there is provided a motor structure characterized by integrating the stator yoke, the coil and the pole teeth plate by molding. According to a fourteenth aspect of the present invention, in addition to the fifth aspect, a motor structure is provided in which the flange is integrated with a stator by insert molding using a polymer material on one side of the flange.

[0007]

An embodiment of the present invention will be described below in detail with reference to the drawings. 1 and 2 show an embodiment of the present invention. FIG. 1 is a side view showing a part of the embodiment, and FIG. 2 is a top view showing a part of the embodiment. FIG. In the figure, reference numeral 11 denotes a lead line,
Denotes a driving coil formed by winding a magnet wire around a bobbin 19. The terminal of the drive coil 12 is connected to the relay board 22, and the relay board 22 performs necessary connection such as delta connection of each drive coil 12. 13 denotes a rotor magnet, 14 denotes a rotor magnet
2 shows a sleeve for connecting a shaft 15 which is a center of rotation of.

A flange 16 is mounted on an end surface of the lower stator yoke 20 and a bearing 16 for rotatably supporting a shaft 15 of the rotor is fixed. At the tip of the salient pole 23, a pole plate 24 for obtaining a large amount of flux linkage with the rotor magnet 13 is arranged, and is fitted with the salient pole 23. Here, the stator yoke 20 is formed by squeezing a soft magnetic steel plate in a cup shape as shown in FIG. A magnetic flux adjusting yoke 21 between the upper and lower stator yokes 20 is formed by molding soft magnetic powder and has a cylindrical shape as shown in FIG. The same number of salient poles 18 as the salient poles 23 of the yoke 20 are provided radially. When this is viewed from the axial direction, the number of salient poles required for the motor is obtained. When the magnetic flux adjusting yoke 21 is opened, the salient poles 18 are arranged in a staggered manner.

FIG. 5 shows a bobbin 19 around which the driving coil 12 is wound and a pole plate 24 fixed to an end of the bobbin 19.
FIG. As can be seen from FIG. 5, the pole plate 24 has a hole into which the salient pole 18 and the salient pole 23 fit. The hole communicates with the salient pole of the bobbin 19 and the hole through which the salient pole is inserted. FIG. 5 shows a state where the salient poles 18 and 23 are inserted through the holes. The length L1 of the pole plate 24 in the longitudinal direction is equal to the length of the rotor magnet 13 constituting the rotor.
Is substantially equal to the length in the longitudinal direction.

The assembly of the motor according to the present invention will be briefly described. As shown in FIG. 1, the upper and lower stator yokes 20 are arranged above and below a magnetic flux adjusting yoke 21 as a center.
Layer. At this time, the salient poles 18 of the magnetic flux adjusting yoke 21 and the salient poles 23 of the upper and lower stator yokes 20 are overlapped. After that, the pole plate 24 fixed to the end of the bobbin 19 around which the coil 12 is wound is alternately inserted and fixed to the portion where the salient poles 18 and 23 overlap as shown in FIG. FIG. 6 is an expanded view of the stator. FIG. 13 shows a conventional example in which the same six magnetic poles as those shown in FIG. 6 are arranged at the same interval, and salient poles are arranged on the same surface. As shown in FIG. 6, in the present invention, the magnetic flux adjusting yoke 21 is
By arranging the salient poles 18 provided inside the magnetic flux adjusting yoke 21 in a staggered manner, the salient poles can be alternately arranged in the vertical direction. As shown in FIG. 13, in the conventional one in which the salient poles are provided in a horizontal row, the width W2 of the bobbin 19 must be equal to the pitch between the salient poles, while the embodiment of the present invention shown in FIG. In the embodiment, the width W1 of the bobbin 19 is set to be equal to the interval between the salient poles 23 of each stator 20, that is, an interval twice as large as the interval W2 shown in FIG.
× W2).

In the conventional motor structure shown in FIG. 13, the winding space of the coil is determined by the width of the interval 2 and the longitudinal length W3 of the bobbin is determined. In the case of W1 = W4, it can be enlarged to the same size as the vertical interval W4 between the salient poles. For this reason, more windings can be applied to the bobbin than conventional ones. By adjusting the vertical length of each stator yoke 20 and the vertical length of the magnetic flux adjusting yoke 21, the vertical and horizontal widths of the bobbin can be made the same, that is, square. In contrast, an ideal coil can be wound.

The embodiment shown in FIGS. 7 and 8 differs from the previous embodiments in that no stator yokes are provided above and below the magnetic flux adjusting yoke 25. In this embodiment, the entire magnetic flux density adjusting yoke 25 is integrally formed of a sintered metal or a polymer material containing soft magnetic powder. The yoke 25 for adjusting the magnetic flux density will be described. The yoke 25 has a cylindrical yoke portion 26. Grooves 27 and 28 are formed inside the upper and lower ends of the yoke portion 25 so that flanges for holding a bearing for supporting a shaft are fitted. The salient poles 29, 30, 31 extending inward near the center C of the inner side of the cylindrical yoke part 26 and near the middle of the upper edge groove 27 are half of the total number of salient poles (six poles). Only books are provided at an equal inner angle. 7, only the salient poles 29 are visible. In addition, salient poles 32, 33, and 34 extending inward near the center C of the inner side of the cylindrical yoke portion 26 and near the middle of the lower edge groove 28 have a total salient pole number (6 poles). ) Are provided at equal inner angles. In the sectional view shown in FIG. 7, two salient poles 32 and 34 are visible. In this embodiment, a rotor magnet is provided in the same manner as in the above embodiment, but the details are omitted because they are duplicated. In this embodiment, since the stator is integrally formed above and below the magnetic flux density adjusting yoke 25, the structure is simplified.

FIG. 9 shows a drive coil 12 wound around a bobbin 19, a stator 20 including a pole plate 24, and a magnetic flux density adjusting yoke 21 integrally formed by insert molding. Therefore, as is apparent from FIG. 9, the inserted resin 29, 30, 31 is inserted into the formed space.
Is satisfied. Note that, in this embodiment, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 10 shows a driving coil 12 wound around a bobbin 19 and a stator 20 including a pole plate 24 as described above.
This shows an embodiment in which not only the magnetic flux density adjusting yoke 21 and the yoke 21 are integrally molded, but also the flange 32 holding the lower bearing 16 is made of resin. Note that, in this embodiment, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Next, in the embodiment shown in FIG. 14, the magnetic flux density adjusting yoke 25 shown in FIG.
And a lower yoke 25-2. The respective heights l1 and l2 are respectively equal. The salient poles 251 projecting inward from the upper yoke 25-1 and the salient poles 252 projecting inward from the lower yoke 25-2 are shifted to positions where a phase difference of 180 degrees in electrical angle with respect to the shaft direction occurs. It is provided. The upper yoke 25-1 and the lower yoke 25-2 are formed by laminating soft magnetic steel plates in the shaft direction. By separating the magnetic flux density adjusting yoke 25 into upper and lower portions in this manner, the motor can be easily assembled.

Further, in the embodiment shown in FIG. 15, the salient poles 253 projecting radially inward of the magnetic flux density adjusting yoke 25 are formed by laminating magnetic steel sheets in a week direction.
The winding portions of the driving coil wound around the coil are arranged so as not to overlap in the week direction.

Although the present invention has been described with reference to the above embodiment, various modifications and applications are possible within the scope of the present invention, and these modifications and applications are excluded from the scope of the present invention. is not.

[0018]

As described above in detail, the present invention provides a rotor having a field magnet and rotatably held therein,
In a motor structure comprising a rotor field magnet and fixed magnetic poles having salient poles facing each other, the upper salient poles formed in a cylindrical shape and having a half of the total number of salient poles on the inner upper edge are formed at an equal inner angle in the inward direction. A magnetic flux density made of a soft magnetic material that protrudes and has half of the total number of salient poles on the inner lower edge projecting so that the lower salient poles at an equal inner angle in the inward direction and do not overlap the upper salient poles in the vertical direction A motor structure comprising: an adjusting yoke; and a drive coil wound around the upper salient pole and the lower salient pole. In addition, a bottom portion formed in a cup shape is provided. Has a salient pole protruding inwardly, an upper stator yoke made of a soft magnetic material overlapping the salient pole on the upper side of the magnetic flux density adjusting yoke, and a salient pole formed in a cup shape and projecting inward on the bottom. Pole, and a salient pole below the magnetic flux density adjustment yoke. A lower stator yoke made of a soft magnetic material that overlaps and a driving coil wound around the overlapping portion of the upper salient pole and the overlapping portion of the lower salient pole, respectively. Also provide motor structure,
Further, the magnetic flux adjusting yoke stator yoke can be made of a polymer material containing soft magnetic powder or a sintered metal. Then, by providing a motor structure in which the stator portion can be resin-molded integrally including the yoke and the drive coil, and in some cases, the flange holding the bearing can also be formed by this molding.
The volume of salient poles can be reduced to the required minimum, and even if multiple slots (multiple poles) are used, a large coil space can be taken.
A motor structure that can secure the coil space even if the motor size is reduced, so that the characteristics of the motor constituent materials such as the rotor magnets can be brought out to the limit while reducing the weight of the motor.
A highly efficient motor can be configured at low cost.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention.

FIG. 2 is a partially broken plan view showing an embodiment of the present invention.

FIG. 3 is a partially cutaway perspective view of a magnetic flux density adjusting yoke.

FIG. 4 is a perspective view of a stator.

FIG. 5 is a perspective view of a bobbin on which a coil is wound and a pole plate is attached.

FIG. 6 is a developed view of the stator of the present invention.

FIG. 7 is a sectional view of a magnetic flux density adjusting yoke according to another embodiment of the present invention.

FIG. 8 is a plan view of the yoke for adjusting magnetic flux density shown in FIG. 7;

FIG. 9 is a cross-sectional view of a motor formed by molding in another embodiment of the present invention.

FIG. 10 is a cross-sectional view showing another embodiment configured by molding.

FIG. 11 is a partially cutaway side view of a conventional example.

FIG. 12 is a partially cutaway front view of a conventional example.

FIG. 13 is a development view of a conventional stator.

FIG. 14 is a partial cross-sectional perspective view of a magnetic flux density adjusting yoke according to another embodiment of the present invention.

FIG. 15 is a partial sectional perspective view of a magnetic flux density adjusting yoke according to another embodiment of the present invention.

[Explanation of symbols]

 1 ... Lead wire 2 ... Coil 3 ... Rotor magnet 4 ... Sleeve 5 ... Shaft 6 ... Bearing 7 ... Flange 8 ... Stator 9 ... Bobbin 10 ... Salient pole 11 ... Lead wire 12 ... Coil 13 ... Rotor magnet 14 ... ··· Sleeve 15 ····· Shaft 16 ··· Bearing 17 ··· Flange 18 ··· Salient pole 19 ··· Bobbin 20 ··· Stator 21 ··· ..Yoke for adjusting magnetic flux density 22 .......................... 27 Groove 28 Groove 29 Resin 30 Resin 31 Resin 32 Upper yoke 25-1 and lower yoke 25-2 flange 25-1 ... upper yoke 25-2 ... lower yoke 251 ... salient pole 252 ... salient pole 253 ... salient pole

Claims (14)

[Claims] 1. A motor structure comprising: a rotor having a field magnet and rotatably held; and a fixed magnetic pole having salient poles facing the field magnet of the rotor. Half of the total number of salient poles protrudes inward at an equal inner angle and half of the total salient poles lower salient poles at the inner lower edge at an equal inner angle and upper side. A magnetic flux density adjusting yoke made of a soft magnetic material protruding so as not to overlap the salient poles in the vertical direction; and a driving coil wound around the upper salient pole and the lower salient pole,
A motor structure comprising: 2. The magnetic flux density adjusting yoke is vertically divided into two parts in the shaft direction. Each magnetic flux density adjusting yoke has half of the total number of salient poles and radially inwardly projecting salient poles. 2. The motor structure according to claim 1, wherein the magnetic flux density adjusting yoke is formed such that the salient poles are electrically shifted to positions where a phase difference of 180 degrees is generated. 3. The motor structure according to claim 2, wherein the magnetic flux density adjusting yoke is formed by laminating soft magnetic electromagnetic steel sheets in a shaft direction. 4. A salient pole protruding radially inward is formed by laminating electromagnetic steel sheets in a week direction, and a winding portion of a driving coil is arranged so as not to overlap in a week direction. The motor structure according to claim 1, wherein 5. A motor structure comprising: a rotor having a field magnet and rotatably held; and a fixed magnetic pole having salient poles facing the field magnet of the rotor. Half of the total number of salient poles protrudes inward at an equal inner angle and half of the total salient poles lower salient poles at the inner lower edge at an equal inner angle and upper side. A magnetic flux density adjusting yoke made of a soft magnetic material protruding so as not to overlap the salient poles in the vertical direction; and An upper stator yoke made of a soft magnetic material overlapping the upper side of the magnetic flux density adjusting yoke, and a lower protrusion formed in a cup shape and projecting inward at a bottom portion and overlapping the lower salient pole; Made of soft magnetic material that overlaps the lower side of the yoke A lower stator yoke, and a driving coil wound around the overlapping portion of the upper salient pole and the upper salient, and the lower salient pole and the overlapping portion of the lower salient. Motor structure. 6. The magnetic flux density adjusting yoke is vertically divided into two parts in the shaft direction, and each magnetic flux density adjusting yoke has half of the total number of salient poles and radially inwardly projecting salient poles. 6. The motor structure according to claim 5, wherein the magnetic flux density adjusting yokes are stacked so that their salient poles are electrically shifted to a position where a phase difference of 180 degrees is generated. 7. The motor structure according to claim 6, wherein the magnetic flux density adjusting yoke is formed by laminating electromagnetic steel sheets in a shaft direction. 8. A salient pole radially projecting inward is formed by laminating electromagnetic steel sheets in a week direction, and a winding portion of a driving coil is arranged so as not to overlap in a week direction. The motor structure according to claim 5, wherein 9. The motor structure according to claim 1, wherein the magnetic flux density adjusting yoke is made of a polymer material containing soft magnetic powder. 10. The motor structure according to claim 1, wherein the magnetic flux density adjusting yoke is made of a sintered metal. 11. The motor structure according to claim 5, wherein said stator yoke is made of a polymer material containing soft magnetic powder. 12. The motor structure according to claim 5, wherein said stator yoke is made of sintered metal. 13. The motor structure according to claim 6, wherein the stator yoke, the coil and the pole tooth plate are integrated by molding. 14. The motor structure according to claim 5, wherein one side of the flange is integrated with the stator by insert molding using a polymer material.