JPH04131181U - Stator structure of outer rotor stepping motor - Google Patents

Abstract

(57) [Summary] [Purpose] This invention relates to a stator structure for an outer rotor type stepping motor, which includes an inner yoke having a plurality of flanges on the outer periphery of a central cylindrical portion, an intermittent slit type integral cylindrical outer yoke, and a coil. Reduce the manufacturing cost of each part and the assembly cost of each part. [Structure] A plurality of parts 50, 51, and 52 are coaxially combined and integrated to form an inner yoke. The flanged component 50 has only one flange 50b. Two flanged parts 50 are combined to form two flanges 5.
A coil 8 is placed between 0b.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to permanent magnet stepping motors, and is particularly applicable to the outer periphery of the stator. The outer rotor type stepping motor has a ring-shaped rotor magnet. Regarding improvement of data structure.

0002

[Conventional technology]

A stepping motor with a permanent magnet type claw pole structure has magnetic pole teeth due to its sheet metal structure. It constitutes a magnetic circuit surrounding the column and the excitation coil. This is a common inner rotor Not limited to the type of motor, for example, the outer The same applies to rotor type motors.

0003 In a conventional general claw pole stator, the magnetic pole tooth row for one phase is made of two sheets of metal. To attach a large number of claws to the plate, and to combine the claws of two sheet metal parts so that they face each other correctly. It is composed of And a coil wound on a bobbin between the two sheet metal parts It is sandwiched between. In this structure, each stator part (sheet metal part) is assembled together. The air gap in the magnetic pole tooth row may not be uniform due to positioning errors when Therefore, there was a problem in that the static angle accuracy of the motor varied greatly.

0004 As a means to solve this problem, for example, Japanese Patent Laid-Open No. 61-135356 discloses As shown, slits are formed in one sheet metal part in the form of dashed lines. A technique is known in which magnetic pole tooth rows for two phases are formed on one sheet metal part by this method. According to this technique, the position and shape accuracy of the magnetic pole tooth row is extremely improved.

[0005] Adopting technology to form a magnetic pole tooth row using broken line slits in one sheet metal part, The present inventors previously proposed an outer rotor-type stepping motor with the structure shown in FIGS. 1 and 2. Developed a motor.

[0006] First, we will explain the previously proposed outer rotor type stepping motor based on Figures 1 and 2. This will be explained in detail below.

[0007] 5 is an inner yoke, which integrally has three flanges 5a on the outer periphery of the central cylindrical portion. It is a magnetic bulk part. The outer periphery of the inner yoke 5 is provided with two flanges 5a. A half-split bobbin 7 made of insulating material is set in each groove. The coil 8 is wound on top of the coil 8.

[0008] Reference numeral 6 denotes an outer yoke made of a ring-shaped magnetic material. A magnetic pole tooth row is formed by the slits 6a. The inner diameter of the outer yoke 6 is a flange. 5a, and as shown in the figure, there is a ring-shaped The outer yoke 6 is fitted in a tight fit.

[0009] 9 is a bearing fixed to the center hole of the inner yoke 5, and 3 is inserted through the bearing 9 and rotates. The rotor shaft is rotatably supported, and 15 is a retaining ring that stops the rotor shaft 3 from moving in the axial direction. , 1 is a cup-shaped case fixed to the upper end of the rotor shaft 3, 2 is a cup-shaped case This is a rotor magnet consisting of a ring-shaped permanent magnet fixed to the inner peripheral surface of the rotor magnet.

0010 The inner diameter of the rotor magnet 2 is slightly larger than the outer diameter of the outer yoke 6. The magnetic pole face faces the magnetic pole tooth row of the outer yoke 6 with a slight gap therebetween. In addition The magnetization pattern of the rotor magnet 2 and the pattern of the magnetic pole tooth row on the stator side are usually Since it may be the same as the permanent magnet type stepping motor, it will not be described in detail here.

[0011] Further, 10 is a base plate fixed to one end surface of the inner yoke 5 with a screw 11. A terminal portion 14 for external connection is integrally formed on a part of the outer periphery. Be The base plate 10 is made of a metal plate, and the terminal part 14, which is thinner than other parts, is After forming an insulating layer on the surface, a wiring pattern 13 is formed by printed wiring on it. Ru. Then, the coil 8 The terminal end 12 is pulled out and soldered to the wiring pattern of the terminal portion 14.

0012 In Fig. 1, 16 is a flat washer and 17 is a spring washer, which connects the rotor and stator. This is to ensure smooth rotation of the rotor while eliminating looseness.

[0013]

[Problem that the idea aims to solve]

The previously proposed outer rotor stepping motor shown in Figures 1 and 2 has multiple Rather than meshing protrusions on yoke parts to form a magnetic pole tooth row, Since the magnetic pole tooth row is formed on the yoke 6, the accuracy of the pattern of the magnetic pole tooth row depends on each part. It no longer depends on the assembly accuracy of the cylindrical part, and the plurality of flanges 5a can be aligned around the outer periphery of the central cylindrical part. The stator is constructed by combining the inner yoke 5 provided on the body and the outer yoke 6. Its basic features include a simplified structure and easy assembly. deer However, the illustrated structure has the following problems that should be improved.

[0014] First, a bulk part of a magnetic material that integrally has a plurality of flanges 5a on the outer periphery of a central cylindrical part. In order to manufacture the inner yoke 5 made of metal, even if it is made of ferrite molded product, metal Even in the case of machining, there is a problem in that the production cost is extremely high.

[0015] In addition, in the structure of FIGS. 1 and 2, inside the circumferential groove between each flange 5a on the outer periphery of the inner yoke 5, A halved bobbin 7 is set on the holder, and a coil 8 is wound on it. Here, one The work efficiency when setting the two half-split bobbins 7 in the groove and winding the coil is very high. There was a problem that it was bad. In other words, the fitting force between the half bobbin 7 and the groove of the inner yoke 5 is Because it is weak, the half bobbin 7 may fall off when winding starts, or the half bobbin 7 may slip during winding. It was idling, and the workability was poor. In particular, two half-split bobbins are formed in the radial direction of the inner yoke 5. It is very difficult to automate the assembly work of setting the cylinder 7 from both sides. Note that the halved bobbin 7 should be fixed to the inner yoke 5 with adhesive before winding the coil. Although this improves the winding workability, the half-split bobbin 7 is glued to the inner yoke 5. Since the number of steps increases, the overall workability does not improve much. In addition, one code Since two half-split bobbins 7 are used for the installation groove, the number of parts is large and the cost is high. .

[0016] This idea was made in view of the problems of the conventional methods mentioned above, and its purpose is as shown in Figure 1. An outer rotor type stem using an integral cylindrical outer yoke with intermittent slits as shown. Regarding the stepping motor, especially the structure of the inner yoke combined with this outer yoke, The objective is to improve assembly and ease of assembly.

[0017]

[Means to solve the problem]

Therefore, in this invention, a magnetic material is used that has multiple flanges on the outer periphery of the central cylindrical part. The inner yoke is constructed by combining multiple parts coaxially and integrating them. A structure in which each component constituting this is provided with at most only one flange. It was completed.

[0018]

[Effect]

The coils constituting the stator are wound in the groove-shaped part between the two flanges of the inner yoke. However, in the structure of this invention, the two flanges are provided on two parts, respectively. Since the coils are combined into one flanged part and another The assembly procedure involves combining flanged parts.

[0019]

【Example】

3 and 4 show the structure of an embodiment of this invention. In this example The part corresponding to the inner yoke 5 made of magnetic bulk parts in the configuration of FIG. integrates the four flanged parts 50 and these flanged parts 50. A cylindrical holder 51 for the It is composed of donut disc-shaped spacers 52 arranged at the same positions. with flange The component 50 is a press-molded product made of a magnetic plate, and as shown in FIG. One flange 50b is integrally formed at one end of the flange. In addition, flange 5 A notch 50c for pulling out the end 12 of the coil 8 is formed at a predetermined position of 0b. ing.

[0020] Also, unlike the configuration shown in FIG. It's wrapped. A coil 8 wound around this bobbin 70 and two flanged parts 5 0 as shown in Figure 4. In other words, two flanged parts 50 are facing each other. The end faces of the central cylinder portions 50a are brought together and abutted against each other. At that time, the center of both The cylindrical portion 50a is fitted into the center hole of the coil bobbin 70.

[0021] In this way, the two flanged parts 50 and the coil 8 wound around the bobbin 70 are connected. are combined in the axial direction and integrated, and the assembled product is fitted onto the outer periphery of the holder 51, A positioning flange 51a and a flange 50 provided at one end of the holder 51 b. Next, add a donut disc-shaped spacer 52. It is fitted into the holder 51 and brought into contact with the flange 50b. In addition, 2 flans Another assembly consisting of the threaded part 50 and the coil 8 wound on the bobbin 70 is hoisted. the spacer 52 and sandwich it between the two flanges 50b. . Then, four flanged parts 50, one holder 51, and one spacer 52 and two coils 8 wound around a bobbin 70 are integrated. This completes the configuration of Figure 1. By combining four half-split bobbins 7 with an inner yoke 5 made of bulk parts, An assembly corresponding to a stator wound with the phase coils 8 is completed.

[0022] Note that it is preferable to use a magnetic material as the holder 51, so that the stator magnetic saturation is less likely to occur at the butt part of the two flanged parts 50. A good magnetic circuit can be constructed to compensate for the magnetic resistance. Also, the spacer 52 If non-magnetic parts are used as a part, it is effective to separate the two-phase magnetic circuit, but the It is not necessary to use the spacer 52 in favor of the strike.

[0023] Using the stator configured as above, the other configuration is the same as in Figure 1, and the outer - A rotor-type stepping motor can be realized. In other words, in Figure 3, Cup-shaped case 1, rotor magnet 2, rotor shaft 3, bearing 9, holder 51 and screw 1 A wiring pattern to which the base plate 10 fixed at 1 and the end 12 of the coil 8 are connected. The spring 13, terminal portion 14, flat washer 16, spring washer 17, etc. are the same as those in FIG. Ru.

[0024] In the embodiment shown in FIG. 4, the coil 8 is wound around the bobbin 70 in advance, and this The flange-equipped part 50 is combined in the axial direction, but this invention but not limited to. For example, as shown in FIG. 5, the holder 51 has four flanges. The part 50 and one spacer 52 are fitted and integrated to form two flanged parts. An insulator coating 71 is formed on the inner surface of the coil winding groove formed by the product 50, and The coil 8 may be wound directly on the insulating film 71 without using a bobbin.

[0025]

[Effect of the idea]

As explained in detail above, the outer rotor type stepping motor based on this invention In the stator structure of the It is composed of multiple parts that are combined and integrated into one, and each part has many parts. Since only one flange is provided, each part that makes up the inner yoke is made of magnetic material. It can be easily manufactured by press working. Also one flanged part The coil is combined with the first flanged part, and then another flanged part is combined. The assembly procedure can be adopted, and the ease of assembling the stator is greatly improved. Coilbo It is no longer necessary to use a half-split bobbin like in the past, but instead a complete ring. Since it is possible to use shaped bobbins, it not only improves work efficiency but also reduces costs. . It also becomes easier to automate the assembly of the stator.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an outer rotor type stepping motor, which is the premise of the present invention, which was previously proposed by the present inventors.

FIG. 2 is a partially cutaway perspective view of a conventional stator assembly in the same motor.

FIG. 3 is a half-sectional view of an outer rotor type stepping motor employing a stator structure according to a first embodiment of the present invention.

FIG. 4 is an exploded perspective view showing an assembled structure of two flanged parts and a coil in the embodiment of FIG. 3;

FIG. 5 is a half-sectional view of an outer rotor type stepping motor employing a stator structure according to a second embodiment of the invention.

[Explanation of symbols]

1 Rotor magnet 3 Rotor shaft 5 Inner yoke (conventional) 5a Flange (conventional) 6 Outer yoke 7 Half bobbin (conventional) 8 coil 50 Flange parts 50a Center cylinder part 50b flange 51 Holder 52 Spacer 70 bobbin 71 Insulator coating

Claims (1)

[Scope of utility model registration request] Claim 1: An inner yoke made of a magnetic material having a plurality of flanges on the outer periphery of a central cylindrical portion, a coil wound in a groove-shaped portion between the flanges of this inner yoke, and a magnetic pole formed by slits arranged intermittently in the shape of broken lines. A cylindrical outer yoke is made of a magnetic sheet metal part with tooth rows formed on the outer periphery of the flange of the inner yoke, and the inner yoke has a plurality of parts arranged coaxially. A stator structure for an outer rotor type stepping motor, characterized in that the stator structure is combined and integrated, and each part has at most one flange.