JP2003284280A - Motor and stepping motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To limit the fixing height of a motor by forming a flange part without lengthening the overall length of the motor. <P>SOLUTION: The motor comprises a cylindrical magnet being bonded to the rotor shaft 10, a yoke disposed oppositely to the outer circumference of the magnet, a coil being wound on the outer circumferential side of the yoke, and a casing member 3 forming the outer circumference of the motor wherein flange parts 11 and 12 for fixing the motor to the apparatus body are formed on the outer circumferential part of the casing member 3 by resin molding. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a motor and a stepping motor which can be attached to small equipment by a flange portion.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional PM (Permanent Magnet).
It is sectional drawing which shows a t) type stepping motor.

As shown in the drawing, the coil 5 is attached to the coil bobbin 1.
Are concentrically wound, and the coil bobbin 1 is fixed by two stator yokes 6 so as to be sandwiched in the axial direction (the left-right direction in FIG. 9). In addition, each stator yoke 6
In the circumferential direction of the inner peripheral surface of the coil bobbin 1, magnetic pole teeth 6a and 6b are arranged alternately so as to face the outer circumference of a magnet, which will be described later. The yoke unit 2 is fixed by being fixed with respect to 3. Further, the rotor shaft 10 is fixed to a cylindrical magnet 9 whose outer peripheral surface is divided in the circumferential direction and is alternately magnetized to different poles.
Is rotatably supported by.

A stepping motor is constituted by the two sets of the yoke unit 2 and the magnet 9, and a flange 7 and a bearing 8 are fixed to one casing member 3,
Another bearing 8 is fixed to the other casing member 3.

The PM type stepping motor having such a structure is used as a driving source for small AV equipment, for example, an auto focus mechanism of a digital camera or a video camera or a light quantity adjusting device.

[0006]

In the devices using the above stepping motor, there is an increasing demand for reduction in size and weight, and as a result, it is necessary to reduce the size of the stepping motor as well.

However, in the above-mentioned conventional stepping motor having a flange structure, as shown in FIG. 9, the total length of the unit serving as a drive source is the sum of the total length of the stepping motor body and the thickness of the flange, and the determined length is set. In order to accommodate this, it is necessary to shorten the length of the stepping motor main body, and as a result, there is a problem that the motor characteristics, for example, the output torque becomes low.

(Object of the Invention) A first object of the present invention is to provide a motor and a stepping motor in which a flange portion is formed without increasing the total length of the motor and the mounting height of the motor can be suppressed to a low level. It is what

A second object of the present invention is to provide a stepping motor capable of improving the coupling strength between the stepping motor body and the flange portion and preventing the casing member and the flange portion from being separated from each other by vibration or impact. It is a thing.

A third object of the present invention is to provide a stepping motor which can reduce the size of the flange portion and can mount the stepping motor in a small space.

[0011]

In order to achieve the first object, a cylindrical magnet fixed to a rotor shaft according to claim 1 and a yoke arranged to face the outer circumference of the magnet. And a coil wound around the outer circumference of the yoke, and a casing member forming the outer circumference of the motor, a flange portion for mounting the motor to the device body is formed by resin molding on the outer circumference of the casing member. The motor is characterized in that it is formed in the portion.

In order to achieve the above-mentioned object, the invention according to claims 2 to 9 is a cylindrical magnet in which the outer peripheral surface is divided around the rotor shaft in the circumferential direction and magnetized to different poles alternately. And a coil for exciting a plurality of magnetic pole teeth arranged to face the outer circumference of the magnet, and a casing member forming the outer circumference of the stepping motor. The portion is a stepping motor formed on the outer peripheral portion of the casing member by resin molding.

In order to achieve the second object,
The invention according to claim 3 is the stepping motor according to claim 2, wherein a part of the casing member is bent and bent toward the outer peripheral side so as to be protruded and embedded in the flange portion formed by resin molding. .

Also in order to achieve the above second object,
The invention according to claim 4 is the stepping motor according to claim 2, wherein a convex portion is formed on a part of the casing member, and the convex portion projects into a flange portion formed by resin molding. Is.

Also in order to achieve the above second object,
According to a fifth aspect of the present invention, a recess or a hole is formed in a part of the casing member, and the recess or the hole is filled with resin at the same time when the flange portion formed by resin molding is formed. The stepping motor according to item 2 is used.

Also in order to achieve the above second object,
The invention according to claim 6 is the stepping according to claim 2, wherein the surface of the casing member is subjected to a satin finish, and the flange portion made of resin molding is formed on the surface of the casing member subjected to the satin finish. It is a motor.

Further, in order to achieve the third object,
The invention according to claim 7 is the stepping motor according to any one of claims 2 to 6, wherein the width of the flange portion made of resin molding is equal to or smaller than the outer diameter of the stepping motor. is there.

Also in order to achieve the above third object,
The invention according to claim 9 is the stepping motor according to claim 8, wherein the plurality of flange portions are formed by forming cuts on the outer periphery of the stepping motor.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail based on the illustrated embodiments.

(First Embodiment) FIG. 1 is a perspective view showing a stepping motor according to a first embodiment of the present invention. The same parts as those in FIG. 9 are designated by the same reference numerals, and their description will be omitted. Omit it.

As shown in FIG. 1, flange portions 11 and 12 are formed by resin molding on a casing member 3 which is the outer peripheral portion of the stepping motor (needless to say, means the direction orthogonal to the rotor axis). . The resin molding is to install the casing member 3 in a mold for resin formation and then inject a resin, that is, a molding material into the mold to form a flange shape. The flange portions 11 and 12 are provided with screw mounting holes 11a and 12a.
Are formed.

FIG. 2 is a sectional view showing the internal structure of the stepping motor of FIG.

A part 3a of the casing member 3 is bent and bent toward the outer peripheral side of the stepping motor so as to be projected and embedded in the flange portions 11 and 12. The casing member 3, that is, the stepping motor main body and the flange portion 1 are formed.
The bond strengths of 1 and 12 are improved. By this,
The casing member 3 and the flange 11, due to vibration and impact,
Sufficient bonding strength is enabled so that 12 does not peel off.

Needless to say, the position where the casing member 3 is bent and bent toward the flange portions 11 and 12 may be anywhere within the range of the flange thickness.

According to the first embodiment described above, the outer peripheral surface is divided around the rotor shaft 10 in the circumferential direction and the cylindrical magnets 9 are alternately magnetized to different poles. Magnetic pole teeth 6 arranged to face the outer circumference of the
In a stepping motor having a structure having a coil 5 for exciting a _and 6b, flanges 11 and 12 for attaching the stepping motor to a device body (not shown) are formed on the outer peripheral portion of the casing member 3 by resin molding. .

As described above, by forming the flange portions 11 and 12 on the outer peripheral surface of the stepping motor, as a result, the total length of the unit as the drive source is not increased, and
It is possible to form a flange portion that is a mounting member to the device body (not shown), and it is possible to keep the mounting height of the stepping motor low.

In other words, the total length of the stepping motor can be adjusted to the allowable mounting space (length), and when the stepping motor is lengthened by that amount (the thickness of the flange 7 in comparison with FIG. 9). Can improve the output characteristics of the stepping motor.

Further, a portion 3a of the casing member 3 forming the outer periphery of the stepping motor as described above is bent and bent toward the outer peripheral side of the stepping motor (it may be a convex portion), and the flange portions 11 and 12 made of resin molding are formed. Since the protrusion is embedded, the coupling strength between the stepping motor body and the flange portions 11 and 12 is improved, and the casing member 3 and the flange portions 11 and 12 can be prevented from peeling off due to vibration or impact.

(Second Embodiment) FIG. 3 is a sectional view showing a stepping motor according to a second embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. To do.

As shown in FIG. 3, flanges 14 and 15 are formed by resin molding on the casing member 13 which is the outer peripheral portion of the stepping motor. The flange portions 14 and 15 are provided with screw mounting holes 14a and 1
5a is formed.

In the second embodiment, the flange portion 1
When forming the holes 4 and 15, the holes (or recesses) 13a and 13b provided in the casing member 13 are simultaneously filled with resin, and the stepping motor main body and the flange 14 are formed.
The bonding strength of 15 is improved. Other effects are similar to those of the first embodiment described above.

(Third Embodiment) FIGS. 4 and 5 are views showing a stepping motor according to a third embodiment of the present invention. FIG. 4 is a perspective view of the stepping motor before forming a flange portion. 5 and 5 are cross-sectional views of the stepping motor after the flange portion is formed. The same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted.

A satin-finished portion 17 is formed on a part of the outer peripheral surface of the casing member 16, and flange portions 18 and 19 are formed by resin molding on the outer periphery in contact with the surface, as shown in FIG. . Then, the flange portions 18 and 19
Are formed with mounting holes 18a and 19a by screws.

The above-mentioned satin treatment is to chemically or mechanically form unevenness on the surface of the casing member 16, and the size of the unevenness should be such that the required peel strength of the flange portion can be achieved. The satin finish does not have to be the entire surface in contact with the flange, and a part of the casing member in contact with the flange may be subjected to the satin finish as long as the required peel strength can be achieved. Needless to say.

(Fourth Embodiment) FIG. 6 is a view showing a shape of a flange portion when a stepping motor according to a fourth embodiment of the present invention is viewed from the front, and is the same as FIG. 1 and the like. Are denoted by the same reference numerals, and description thereof will be omitted.

Flange portion 20 or 2 formed by resin molding
By making the width W of 1 equal to (or smaller than) the outer diameter D of the stepping motor, the stepping motor can be mounted in a narrow width, and the stepping motor can be downsized. The installation space can be reduced.

When forming two or more flange portions, it is possible to similarly reduce the mounting space by providing one or more cuts 22, and the description will be given in the first to third embodiments. Even if the casing member and the structure for improving the peeling strength of the flange portion are combined, the mounting can be performed while maintaining sufficient strength.

FIG. 7 is a perspective view showing an example where there is one flange portion (only 21 in FIG. 6). As described above, the width W of the flange portion is made smaller than the outer diameter of the stepping motor. Moreover, the installation space can be further reduced by installing it in one place.

(Fifth Embodiment) FIG. 8 is a perspective view showing a stepping motor according to a fifth embodiment of the present invention. The same parts as those in FIG. Omit it.

This fifth embodiment shows an example in which one flange portion 23 is provided at an intermediate position of the casing member 24, and the same method as in the first to third embodiments described above is adopted. By forming the stepping motor as described above, a high-strength flange portion can be formed at an arbitrary position, which increases the degree of freedom in the method of attaching the stepping motor, and enables more effective use of the attachment space.

In each of the above-mentioned embodiments, the stepping motor is taken as an example, but other small motors can be similarly applied.

[0042]

As described above, according to the present invention,
The flange is formed without increasing the total length of the motor,
It is possible to provide a motor or a stepping motor that can keep the mounting height of the motor low.

Further, according to the invention described in any one of claims 3 to 6, the coupling strength between the stepping motor body and the flange portion is improved, and the casing member and the flange portion are prevented from being separated from each other by vibration or impact. It is possible to provide a stepping motor capable of performing the above.

Further, according to the invention described in claim 7 or 9, it is possible to provide a stepping motor in which the size of the flange portion is reduced and the stepping motor can be mounted in a small space.

[Brief description of drawings]

FIG. 1 is a perspective view showing a stepping motor according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the stepping motor of FIG.

FIG. 3 is a sectional view showing a stepping motor according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a stepping motor according to a third embodiment of the present invention.

5 is a cross-sectional view showing the stepping motor of FIG.

FIG. 6 is a diagram showing a shape of a flange portion when a stepping motor according to a third embodiment of the present invention is viewed from the front.

FIG. 7 is a perspective view showing a stepping motor when the flange portion shown in FIG. 6 is bet at one place.

FIG. 8 is a perspective view showing a stepping motor according to a fifth embodiment of the present invention.

FIG. 9 is a perspective view showing a conventional stepping motor.

[Explanation of symbols]

1 bobbin 2 York unit 3 Casing member 5 coils 6 Stator yoke 6a, 6b magnetic pole teeth 8 bearings 9 magnets 10 rotor shaft 11,12 Flange made of resin molding 11a, 12a mounting holes 14,15 Flange made of resin molding 14a, 15a mounting holes 17 satin processing section 18, 19 Flange part made of resin molding 18a, 19a mounting holes 20,21 Flange made of resin molding 20a, 21a mounting holes 23 Flange made of resin molding 24 mounting holes

Claims (9)

[Claims] 1. A cylindrical magnet fixed to a rotor shaft, a yoke arranged to face the outer circumference of the magnet, a coil wound around the outer circumference of the yoke, and an outer circumference of the motor. A motor having a casing member for forming a motor, wherein a flange portion for attaching the motor to the device body is formed on the outer peripheral portion of the casing member by resin molding. 2. A cylindrical magnet whose outer peripheral surface is divided in the circumferential direction about the rotor axis and is alternately magnetized to different poles, and a plurality of magnetic pole teeth arranged to face the outer periphery of the magnet. In a stepping motor having an exciting coil and a casing member forming an outer periphery of the stepping motor, a flange portion for attaching the stepping motor to a device body is formed on the outer peripheral portion of the casing member by resin molding. And stepping motor. 3. A structure in which a part of the casing member is bent and bent toward the outer peripheral side so as to be projected and embedded in the flange portion formed by resin molding.
The stepping motor described in 1. 4. The stepping motor according to claim 2, wherein a convex portion is formed on a part of the casing member, and the convex portion is projected in a flange portion formed by resin molding. 5. A structure in which a concave portion or a hole portion is formed in a part of the casing member and the concave portion or the hole portion is filled with resin at the same time when the flange portion made of resin molding is formed. The stepping motor according to claim 2. 6. The surface of the casing member is subjected to a satin finish, and the flange portion made of resin molding is formed on the surface of the casing member subjected to the satin finish. Stepping motor. 7. The stepping motor according to claim 2, wherein the width of the flange portion made of resin molding is equal to or smaller than the outer diameter of the stepping motor. 8. The stepping motor according to claim 2, wherein the flange portion is provided in plural. 9. The stepping motor according to claim 8, wherein the plurality of flanges are formed by forming a cut on the outer periphery of the stepping motor.