JPH0715340Y2 - Flat type step motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Field of Industrial Application] The present invention relates to a flat step motor.

[Prior Art] As shown in FIG. 4, a flat type step motor of this type is integrally formed by joining a pair of housings a and b forming independent magnetic circuits at their outer peripheral portions. The housings a and b are joined to each other by forming a rectangular joint portion c formed by thinly extending from a part of an outer peripheral end of one housing a and thinly forming a rectangular joint portion c on a side surface of the other housing b corresponding to the joint portion c. This is done by spot welding on the formed recess d.

Housing a, stator e and housing b, stator f
Originally form independent magnetic circuits, but a magnetic path is formed by welding the abutting portions of the housings a and b formed of the joint portion c and the concave portion d, and the independent magnetic circuit is formed. Will interfere with each other. In order to suppress this interference as much as possible, conventionally, the width of the joint portion c is formed as narrow as possible.

[Problems to be solved by the invention] However, further improvements have been demanded in the following points.

The rectangular joint portion c extending and formed on the outer peripheral end of the housing a is formed to be thinner than the entire thickness of the housings a and b. Therefore, the volume of the joint c is small compared to the volume in the vicinity of the recess d where the joint c is superposed, and a large gap is created between the heat capacity of the joint c and the heat capacity of the vicinity of the recess d. As a result, when performing spot welding by superimposing the joint c on the recess d, even if the welding location, welding time, applied voltage, etc. are adjusted, the heat balance deviation cannot be eliminated, and the welding locations are unevenly distributed. We could not perform reliable welding.

For this reason, there are cases in which the housing cannot be joined unless the spot welding is performed twice or three times, or when a plurality of spot weldings are performed, the joint c is finely deformed and the strength is reduced.

In addition, there is a problem that the quality of the welded portion varies and the yield decreases.

The present invention has been made for the purpose of solving the above problems and simply and reliably welding a pair of housings.

Configuration of the Invention The configuration of the invention that achieves the above object will be described below.

[Means for Solving the Problems] A flat type stepping motor of the present invention includes a flat type rotor, a pair of housings for housing a coil wound in a ring shape, and a ring shaped pole tooth. And a pair of yokes that are respectively provided at the opening end portions of the respective housings and that form an independent magnetic circuit together with the respective housings. In a flat step motor that is joined so as to sandwich the rotor, a plurality of welded portions projecting from the side surface of each housing are formed at the outer peripheral edge of each yoke, and at the outer peripheral end of each housing, A joint portion that abuts on the welded portion of the yoke provided on the other housing is formed in a protruding manner, and each of the housings is connected to the outer peripheral end of the one housing and the housing. It is joined by welding and the joint of the welded portion and the other of the housing of the yoke provided on Managing together, is characterized in.

[Operation] In the flat stepping motor of the present invention having the above-described structure, the outer peripheral edge of the yoke, which is provided at the opening end of each housing and constitutes an independent magnetic circuit together with each housing, has A plurality of welds are formed to project from the side surface of the housing. On the other hand, on the outer peripheral end of each housing, a joint portion that abuts on a welded portion of a yoke provided on the other opposing housing is formed in a protruding manner.

The flat step motor according to the present invention is constructed such that the outer peripheral end of one housing, the welded portion of the yoke provided in the housing, and the jointed portion of the other housing are welded together, so that the housings are separated from each other. Are integrally joined.

At the time of this welding, the portion of the welded portion formed on the yoke that protrudes from the side surface of the housing serves as a welding rod for forming a swell after welding.

The thickness of the joint formed on each housing may be the same as or thinner than the thickness of the housing. Further, depending on the case, it may be formed thick. Further, if the pair of housings have the same shape, the housings can be shared and the number of manufacturing parts can be reduced.

On the other hand, the shape of the welded portion formed on each yoke may be any shape such as an arc shape or a rectangular shape. Further, in the case of forming the arc shape, it becomes easy to mold the mold used for molding the yoke.

[Embodiment] A preferred embodiment of the flat type stepping motor of the present invention will be described below.

FIG. 1 is a sectional view of the flat step motor of this embodiment, and FIG. 2 is a front view of the flat step motor.

As shown, the flat type step motor 1 of this embodiment
Is a rotor wheel 8 to which a ring-shaped permanent magnet 5 is attached.
A rotor 15 having a rotating shaft 13 at the center thereof, a pair of stators 20 and 25 arranged on both sides of the permanent magnet 5 at positions facing each other with a gap, and a pair of stators 20 and 25, respectively. And a pair of housings 30 and 3 that together form an independent magnetic circuit
5 is a substantially columnar structure.

Support members 41 and 43 are fitted in the openings formed in the centers of the housings 30 and 35, and the thrust bearing 4 is fitted inside the support members 41 and 43.
5,47 are provided. These thrust bearings 45, 47 are for the rotor 15
Rotatably supports the rotor wheel 8 of. Rotor 15 rotation axis
A gear 17 is attached to the tip of 13 and meshes with a drive device (not shown).

The stators 20 and 25 are composed of yokes 51 and 53, which together with the housings 30 and 35, form a ring-shaped duct, and coils 55 and 57 wound inside the duct. A pair of yokes 51,
As shown in FIG. 3, 53 has a ring shape with an outer diameter of 42 [mm], and the outer peripheral edge thereof has a width of 2.5 [mm] and a height of 1 [m.
m] arc-shaped welds 61 and 63 are formed at a position of 180 degrees. The arc-shaped welded portions 61, 63 are portions protruding from the side surfaces of the housings 30, 35 (see the portion indicated by arrow A in FIG. 1). Welds 61, 63 on the yoke 53 and welds 64 on the yoke 51
(Only one shown in the figure) and 90
It is placed in the degree position. In addition, on the inner surfaces of the yokes 51 and 53, "Π" -shaped and "V" -shaped openings 54 are provided every 30 degrees.
12 places are formed. This opening 54 forms a pole tooth,
A magnetic pole is generated at the pole tooth.

Further, on the side surfaces of the housings 30, 35, rectangular joint portions 67, 68, 69 extending from the outer peripheral ends of the housings 30, 35 are formed in correspondence with the weld portions 61, 63, 64. The thickness of the joint portions 67, 68, 69 is the same as the thickness of the housings 30, 35. The joint portions 67, 68, 69 of one of the housings 30, 35 together with the outer peripheral end surface of the other housing form a butt portion sandwiching the weld portions 61, 63, 64 of the yokes 51, 53.

On the other hand, spacers 65 and 66 are interposed between the stators 20 and 25, and the thickness of the spacers 65 and 66 determines the air gap which is the distance between the permanent magnet 5 and the yokes 51 and 53.

Also, the housings 30 and 35 are centered on the welded portions 61, 63 and 64,
The welded portions 61, 63, 64 and the butt portion are joined together by plasma arc welding. A portion indicated by an arrow A in FIG. 1 shows a state before welding, and a portion indicated by an arrow B in FIGS. 1 and 2 shows a state after welding. After welding, an extra heap 70 is formed at the abutting portion.

Further, on the side surfaces of the housings 30 and 35, a holder 7 for taking out the harness of the coils 55 and 57 of the stators 20 and 25 to the outside.
1 is installed.

In the flat type step motor 1 configured as described above,
A butt portion formed of the joint portions 67, 68, 69 of the one housing 30, 35 and the outer peripheral end surface of the other housing 30, 35 is welded portions 61, 63 of the yokes 51, 53 inserted between the butt portions. Can be welded with a uniform heat balance around 64. Therefore,
Welding can be done easily and surely without having to perform welding twice or thrice and without fine adjustment of heat balance. As a result, the quality of the welded portion does not vary, and the yield can be improved.

Further, since the welded portions 61, 63, 64 of the yokes 51, 53 serve as a welding rod and the extra bulge 70 can be formed after welding, extremely strong welding can be performed.

Further, the structure of the outer peripheral end of the housing can be simplified, and the cost can be reduced.

Effect of the Invention As described in detail above, in the flat type step motor of the present invention, the welded portions protruding from the side surface of each housing are provided at a plurality of locations on the outer peripheral edge of the yoke that constitutes an independent magnetic circuit together with each housing. Formed, and also
At the outer peripheral end of each housing, a joining portion is formed so as to project into contact with a welded portion of a yoke provided on the other housing that faces the housing.

Then, the outer peripheral end of one housing, the welded portion of the yoke provided in the housing, and the joint portion of the other housing are welded together, so that the housings are joined together. . Further, at this time, the portion of the welded portion formed on the yoke, which protrudes from the side surface of the housing, serves as a welding rod for forming a swell after welding.

Therefore, according to the flat type step motor of the present invention, unlike the conventional flat type step motor described above, it is easy and extremely strong without welding twice or three times or finely adjusting the heat balance. The housings can be joined together.

As a result, the joint portion of the housing can be made thinner or thinner, and interference between the magnetic circuits can be suppressed. Further, the quality of the welded portion does not vary, and the yield can be improved.

Here, in the flat type step motor of this type, if the relative positions of the yokes are displaced, the relative positions of the pole teeth formed on the respective yokes are displaced, so that the rotation control of the rotor cannot be performed. Therefore, in the conventional flat type stepping motor as described above, it is necessary to position and fix each yoke in the housing in advance, and further to align and join the housings.

On the other hand, according to the flat step motor of the present invention, fixing of the housing and the yoke, alignment of the yokes, and joining of the housings can be performed at the same time, which is simpler. It becomes possible to manufacture flat type stepping motors.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a flat type step motor of the embodiment, FIG. 2 is a front view showing the outer shape of the flat type step motor, FIG. 3 is a plan view showing the shape of a yoke, and FIG. It is a partially broken sectional view showing the structure of the conventional flat type step motor. 1 Flat type step motor 15 Rotor 20,25 Stator 51,53 ...... Yoke 61,63,64 ...... Welded part 67,68,69 ...... Joined part

Claims (1)

[Scope of utility model registration request] 1. A flat rotor, a pair of housings for accommodating coils wound in a ring shape, and ring-shaped and having pole teeth, each of which is provided at an open end of each housing. And a pair of yokes each of which forms an independent magnetic circuit together with each of the housings, and the flat step formed by joining the housings so that the yokes sandwich the rotor with a predetermined gap. In the motor, welded portions projecting from the side surface of each housing are formed at a plurality of locations on the outer peripheral edge of each yoke, and at the outer peripheral end of each housing, the welded portion of the yoke provided on the other housing is formed. Each of the housings is formed by projecting a contacting portion that abuts on the other housing. The outer peripheral end of the one housing, the welding portion of the yoke provided in the housing, and the other housing Flat type stepping motor, characterized in that, formed by joining by welding and said joint ring together.