JPH11308839A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultra miniaturized motor having new constitution. SOLUTION: In the constitution of a motor, a magnet 1 formed in a cylindrical type, in which at least outer peripheral surface is divided into (n) in the circumference direction and alternately magnetized on different poles is installed. A first coil 2 and a second coil 3 are arranged in the shaft direction of the magnet 1. First outside magnetic poles and first inside magnetic poles which are excited with the first coil 2 are faced toward the outer peripheral surface and the inner peripheral surface of one end side of the magnet 1, and second outside magnetic poles and a second inside magnetic poles which are excited with the second coil 3 face towards the outer peripheral surface and the inner peripheral surface of the other end side of the magnet 1. A holding member, in which the tips of the first outside poles and the tips of the second outside poles are faced with each other, and the first outside poles and the second outside poles are held, is installed. First trenches engaging the first and the second outside magnetic poles are formed on both end surfaces of the holding member. Notches 20g, 20h, 20i, 20j and second trenches 20k, 20p containing the notches are formed on the end surfaces of the first trenches, and peripheries of the second trenches containing the notches and the first and the second outside magnetic poles are bonded with an adhesive agent 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical motor having a very small size.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional small cylindrical step motor. A stator coil 105 is concentrically wound around the bobbin 101, and the bobbin 101
The stator teeth 106a and 106b are alternately arranged on the stator yoke 106 in the circumferential direction of the inner diameter surface of the bobbin 101. The case 103 has the stator teeth 106a or 106a. The stator 102 is configured by fixing the stator yoke 106 integral with the stator 106b.

One of two cases 103 has a flange 1
15 and the bearing 108 are fixed, and another bearing 108 is fixed to the other case 103. The rotor 109 includes a rotor magnet 111 fixed to a rotor shaft 110, and the rotor magnet 111 forms a radial gap with the stator yoke 106a of the stator 102. And
The rotor shaft 110 is rotatably supported between the two bearings 108.

[0004]

However, in the above-mentioned conventional small stepping motor, the magnetic flux generated when the stator coil 105 is energized mainly has the end faces 106a1 of the stator teeth 106 and the end faces of the stator teeth 106b as shown in FIG. There is a disadvantage that the output of the motor does not increase because it does not effectively act on the rotor magnet 111 for passing through the rotor 106b1.

Accordingly, an object of the present invention is to provide a micro motor having a novel configuration.

[0006]

In order to achieve the above-mentioned object, the present invention relates to a magnet formed in a cylindrical shape and having at least its outer peripheral surface divided by n in the circumferential direction and alternately magnetized to different poles. A first coil and a second coil are arranged in the axial direction of the magnet, and a first outer magnetic pole and a first inner magnetic pole that are excited by the first coil are disposed on the outer periphery of one end of the magnet. And a second outer magnetic pole and a second inner magnetic pole excited by the second coil are opposed to the outer peripheral surface and the inner peripheral surface on the other end side of the magnet. A holding member that holds the first outer magnetic pole and the second outer magnetic pole with the tip of the first outer magnetic pole and the tip of the second outer magnetic pole facing each other; First and second outer A first groove for fitting the pole is formed, a notch and a second groove including the notch are formed on an end face of the first groove, and the periphery of the second groove including the notch and the first groove are formed. And a motor wherein the second outer magnetic pole is bonded with an adhesive.

In the above construction, (1) the diameter of the motor is determined by the first and second outer magnetic poles facing the outer peripheral surface of the magnet, and the axial length of the motor is determined by the first coil, the magnet and the second coil. The coils can be made smaller by arranging them in order. Also, the magnetic flux generated by the first coil crosses the magnet between the first outer magnetic pole and the first inner magnetic pole, so that it works effectively,
The magnetic flux generated by the second coil crosses the magnet between the first outer magnetic pole and the first inner magnetic pole and acts effectively, thereby increasing the output of the motor. (2) The notch of the holding member serves as a mark for a position where the adhesive is applied and a guide for an instrument for applying the adhesive, and the second groove serves as a reservoir for the adhesive. To the outer magnetic pole. Therefore, the adhesive does not stick out on the outer diameter side of the holding member, and stable adhesive strength can be achieved.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing a step motor of the present invention, in which FIG. 1a is an exploded perspective view of the step motor, and FIG. 1b is a view in the direction of arrow D in FIG. 1a after the step motor is assembled. 1c is a view in the direction of arrow E in FIG. 1a after the step motor is assembled, and FIG. 1d is a view in the direction of arrow F in FIG. 1b. FIG. 2 is an axial sectional view after the step motor is assembled. FIG. 3 is a sectional view taken along the line AA of FIG. 2 and a sectional view taken along the line BB of FIG.

In FIGS. 1 to 3, reference numeral 1 denotes a cylindrical magnet constituting a rotor. The magnet 1, which is a rotor, has its outer peripheral surface divided into n parts in the circumferential direction (in this embodiment, divided into four parts). T) S-poles and N-poles are alternately magnetized to be magnetized portions 1a, 1b, 1c, and 1d.
c is magnetized to the S pole, and the magnetized portions 1b and 1d are magnetized to the N pole. Reference numeral 7 denotes an output shaft serving as a rotor shaft.
Are fixed to a magnet 1 which is a rotor. The output shaft 7 and the magnet 1 constitute a rotor.
Reference numerals 2 and 3 denote cylindrical coils, and the coils 2 and 3 are concentric with the magnet 1 and are disposed at positions sandwiching the magnet 1 in the axial direction, and the outer diameters of the coils 2 and 3 are outside the magnet 1. It is almost the same size as the diameter.

Reference numerals 18 and 19 denote first members made of a soft magnetic material.
The phase of the stator 18 and the stator 19 is 180 / n
The first stator 18 and the second stator 19 are composed of an outer cylinder and an inner cylinder. The coil 2 is provided between the outer cylinder and the inner cylinder between the first stators 18, and when the coil 2 is energized, the first stator 18 is excited. The outer cylinder and the inner cylinder of the first stator 18 have outer magnetic poles 18a, 18b and inner magnetic poles 18c, 18d formed at the tips, and the phases of the inner magnetic pole 18c and the inner magnetic pole 18d are the same. The outer magnetic pole 18c is formed so as to be shifted from the inner magnetic pole 18c by 360 / (n / 2) degrees, that is, 180 degrees.
The outer magnetic pole 18b is opposed to d.

Outer magnetic poles 18a, 1 of the first stator 18
The magnet 8b and the inner magnetic poles 18c and 18d are provided so as to sandwich the one end of the magnet 1 in opposition to the outer peripheral surface and the inner peripheral surface at one end of the magnet 1. One end of the rotating shaft 7 is rotatably fitted into the hole 18e of the first stator 18.

The coil 3 is provided between the outer cylinder and the inner cylinder between the second stators 19, and when the coil 3 is energized, the second stator 19 is excited. The outer cylinder and the inner cylinder of the second stator 19 have outer poles 1 at their distal ends.
9a, 19b and inner magnetic poles 19c, 19d are formed, and the phases of the inner magnetic pole 19c and the inner magnetic pole 19d are 360 / (n / 2) degrees, that is, the same as each other.
The outer magnetic pole 19c is formed so as to be shifted by 180 degrees, and the outer magnetic pole 19c is arranged to face the inner magnetic pole 19c, and the outer magnetic pole 19b is arranged to face the inner magnetic pole 19d.

Outer magnetic poles 19a, 1 of the second stator 19
The magnet 9b and the inner magnetic poles 19c and 19d are provided so as to face the outer peripheral surface and the inner peripheral surface on the other end side of the magnet 1 and sandwich the other end side of the magnet 1. The other end of the rotating shaft 7 is rotatably fitted in the hole 19e of the second stator 19.

Accordingly, the magnetic flux generated by the coil 2 traverses the magnet 1 which is the rotor between the outer magnetic poles 18a and 18b and the inner magnetic poles 18c and 18d. Is generated by the outer magnetic poles 19 a and 19 b and the inner magnetic pole 19.
Acts on the magnet 1 which is a rotor between c and 19d to increase the output of the motor.

Further, the relative rotational positions of the first stator 18 and the second stator 19 are made exactly the same, and the magnet 1 sandwiched between the outer magnetic pole and the inner magnetic pole of the first stator.
And the magnetized phase of the magnet 1 sandwiched between the outer and inner magnetic poles of the second stator may be shifted by 180 / n degrees, that is, 45 degrees.

Reference numeral 20 denotes a holding member as a cylindrical member made of a non-magnetic material. First holding grooves 20a and 20b are provided on one end surface inside the holding member 20, and grooves 20a and 20b are provided on the other end side. First grooves 20c and 20d having a phase shifted by 45 degrees with respect to 20b are provided.

The outer magnetic poles 18a, 18b of the first stator 18 are fitted into the first grooves 20a, 20b.
Outer magnetic poles 19a, 1d of the second stator 19
9b is fitted. The first stator 18 and the second stator 19 have the outer magnetic poles 18a, 18b and the inner magnetic poles 18c, 18d and the outer magnetic poles 19a, 19b and the inner magnetic poles 19c, 19d facing each other.
Are fixed at a certain distance from each other by protrusions 20e and 20f (FIG. 2) on the inner surface side.

Notches 20g, 20h, 20i, 20j and second grooves 20k, 20m, 20n, 20p for storing the adhesive are provided in the grooves 20a, 20b, 20c, 20d (in the direction of arrow D in FIG. 1). (See figure and arrow view in the direction of arrow E.)

The adhesive 21 has notches 20 g, 20 h,
A device for applying the adhesive to the portions Q, R, S, and T on the back side of 20i and 20j, for example, the tip of a dispenser is pressed and applied. As a result, the adhesive is applied to the second grooves 20k, 2k
It flows into 0m, 20n, and 20p. And
The adhesive 21 is located as shown by hatching in FIGS. 1b, 1c and 1d. Then, if the adhesive is cured, the holding member 20
The first stator 18 and the second stator 19 are firmly fixed.

In other words, the notch in the holding member serves as a guide for the position of the adhesive and a device for applying the adhesive, for example, a tip of an injector, and the second groove is used as a reservoir for the adhesive. Thus, stable adhesive strength and preventing the adhesive from sticking to the outer diameter of the holding member are prevented. The width of the notch may be greater than the width of the tip of the device for applying the adhesive, for example, the injector, and the length is approximately equal to the width in the present embodiment. The size of the second groove is larger than the notch, and the depth is preferably about 0.02 to 0.2 mm in consideration of the inflow and hardening of the adhesive.

The shape, number and position of the notches and recesses can be appropriately selected depending on the shape of the motor and the ease of adhesion. As the adhesive, an epoxy resin having a high adhesive strength may be used, but since the curing requires heating, the handling is troublesome. In this respect, an ultraviolet curable resin provided with anaerobic properties is suitable. Since the holding member of the motor of the present invention may be made of a non-magnetic material, it is possible to use a plastic which is inexpensive and can be easily formed into a complicated shape. Furthermore, in the case of the present invention, plastics can be used because they are joined with an adhesive. The adhesive is applied to the second grooves 20k, 20m, 20n, and 20p.
Therefore, there is no variation in the outer diameter of the motor. In addition, since the assembling operator can also set the target at the position where the adhesive is applied, the workability is improved and a stable bonding process can be performed.

FIG. 2 is a sectional view of the step motor, and FIGS. 3 (a), 3 (b), 3 (c) and 3 (d) are sectional views taken along the line AA in FIG. ), (F), (g), (h)
Shows a cross-sectional view taken along line BB of FIG. FIG. 3 (a)
3E and 3E are sectional views at the same point, FIGS. 3B and 3F are sectional views at the same point, and FIGS. 3C and 3G are sectional views at the same point. It is sectional drawing, FIG.3 (d) and (h) are sectional views in the same point.

Next, the operation of the step motor will be described.
3 (a) and 3 (e), the coils 2 and 3 are energized, the outer magnetic poles 18a and 18b of the first stator 18 are set to N poles, the inner magnetic poles 18c and 18d are set to S poles, When the outer magnetic poles 19a and 19b of the stator 19 are set to the N pole and the second inner magnetic poles 19c and 19d are excited to the S pole, the magnet 1 as the rotor rotates 45 degrees in a counterclockwise direction, as shown in FIG. The state shown in FIG.

Next, the power supply to the coil 2 is reversed,
The outer magnetic poles 18a and 18b of the stator 18 are S poles,
The inner stator poles 18c and 18d are set to the N pole, and the second stator 1
9, the outer magnetic poles 19a and 19b are N poles,
When c and 19d are excited to the south pole, the magnet 1, which is a rotor, further rotates counterclockwise by 45 degrees, resulting in the state shown in FIGS. 3 (c) and 3 (g).

Next, the power supply to the coil 3 is reversed,
The outer magnetic poles 19a and 19b of the stator 19 are S poles,
The inner stator poles 19c and 19d are N poles, and the first stator 1
8, the outer magnetic poles 18a and 18b are S poles, and the inner magnetic pole 18
When c and 19d are excited to the N pole, the magnet 1, which is the rotor, further rotates counterclockwise by 45 degrees, resulting in the state shown in FIGS. 3 (d) and 3 (h).

Thereafter, the coil 2 and the coil 3
By sequentially switching the power supply direction, the magnet 1, which is a rotor, rotates to a position corresponding to the power supply phase.

Here, a description will be given of the fact that the step motor having such a configuration is the most suitable configuration for miniaturizing the motor. The basic configuration of the step motor is described as follows: (1) the magnet is formed in a hollow cylindrical shape; and (2) the outer peripheral surface of the magnet is divided into n parts in the circumferential direction and magnetized alternately at different poles. (3) the first coil and the second coil are arranged in order in the axial direction of the magnet; (4) the outside of the first and second stators excited by the first and second coils. The magnetic pole and the inner magnetic pole are opposed to the outer peripheral surface and the inner peripheral surface of the magnet,
(5) forming a notch and a groove including the notch at an end of the holding member fitted to the first and second outer magnetic poles;
The first and second outer magnetic poles and the periphery of the groove including the notch of the holding member opposed thereto are joined with an adhesive.

Therefore, the diameter of the step motor only needs to be large enough to provide the magnetic pole of the stator opposite to the diameter of the magnet, and the axial length of the step motor is equal to the length of the magnet. It suffices if the length is large enough to add the lengths of the first coil and the second coil. For this reason, the size of the step motor is determined by the diameters and lengths of the magnet and the coil. Therefore, if the lengths of the magnet and the coil are reduced, the step motor can be miniaturized.

Further, the joining of the holding member and the outer magnetic pole stores and fixes the adhesive in the groove including the notch provided at the end of the holding member, so that a very small step motor can be obtained.
Also, if the diameters and lengths of the magnet and the coil are made very small, it becomes difficult to maintain the accuracy as a step motor. This is because the magnet is formed in a hollow cylindrical shape, and this hollow cylindrical shape is formed. The problem of accuracy as a step motor is solved by a simple structure in which the outer magnetic pole and the inner magnetic pole of the first and second stators are opposed to the outer peripheral surface and the inner peripheral surface of the magnet. At this time, not only the outer peripheral surface of the magnet but also the inner peripheral surface of the magnet are magnetized in the circumferential direction, so that the output of the motor can be made more effective.

(Other Embodiments) In the above embodiment, when the adhesive is injected into the second groove, the notch formed in the second groove is used. However, instead of the notch, for example, Circular holes can be used. FIG. 4 is a plan view for explaining another embodiment, and corresponds to FIG. 1B. FIG.
In this embodiment, notches 20g, 20h, 20i, and 20j are not formed in the second groove, and a circular hole 20u is formed in a substantially central portion of the second groove in place of the notch. 2
0v, 20w, and 20x (20v and 20x are not shown) are formed. If the tip of the injector is circular,
Such a circular hole is suitable for injecting the adhesive and for use as a guide at the tip of the injector. In addition,
The shape of the hole is not particularly limited.

[0031]

As described above, according to the present invention,
A magnet formed in a cylindrical shape and having at least its outer peripheral surface divided into n portions in the circumferential direction and alternately magnetized to different poles, and a first coil and a second coil are arranged in the axial direction of the magnet. A first outer magnetic pole and a first inner magnetic pole that are excited by the first coil are opposed to an outer peripheral surface and an inner peripheral surface at one end of the magnet, and a second outer magnetic pole and a first inner magnetic pole that are excited by the second coil. The outer magnetic pole and the second inner magnetic pole are arranged so as to face the outer peripheral surface and the inner peripheral surface on the other end side of the magnet, and the tip of the first outer magnetic pole and the tip of the second outer magnetic pole face each other. A holding member that holds the first outer magnetic pole and the second outer magnetic pole, and a first groove that fits the first and second outer magnetic poles is formed on both inner end surfaces of the holding member; Cut out the end face of the first groove. A second groove including a notch is formed, and the periphery of the second groove including the notch and the first and second outer magnetic poles are bonded with an adhesive. It can be a motor, and is an optimal configuration for miniaturizing and rubbing the motor. Further, the magnet is formed in a hollow cylindrical shape, and the first and second magnets are formed on the outer peripheral surface and the inner peripheral surface of the hollow cylindrical magnet.
By making the outer magnetic pole and the inner magnetic pole face each other, an effective output as a motor can be obtained.

The adhesive is applied to the second grooves 20k, 20m,
Since it accumulates at 20n and 20p, it does not flow to other outer circumferences, and there is no variation in the outer diameter of the motor. In addition, since the assembling operator can also set the target at the position where the adhesive is applied, the workability is improved and a stable bonding process can be performed.

[Brief description of the drawings]

FIG. 1 is a view showing a step motor of the present invention, wherein FIG. 1a is an exploded perspective view of the step motor, and FIG. 1b is an arrow in the direction of arrow D of FIG. 1a after the step motor is assembled. FIG. 1c is a view in the direction of arrow E in FIG. 1a after the step motor is assembled.
d is a view in the direction of arrow F in FIG. 1b.

FIG. 2 is an axial sectional view after assembling of a step motor.

FIG. 3 is a sectional view taken along line AA of FIG. 2 and FIG.
It is sectional drawing in B.

FIG. 4 is a plan view for explaining another embodiment of the present invention, and substantially corresponds to FIG. 1b.

FIG. 5 is an axial sectional view of a conventional small cylindrical step motor.

FIG. 6 is a cross-sectional view for explaining magnetic flux of a conventional step motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Magnet 2 1st coil 3 2nd coil 7 Output shaft 18 1st stator 19 2nd stator 20 Holding member 20g, 20h, 20i, 20j Notch 20k, 20m, 20n, 20p 2nd groove (adhesion Groove) 21 adhesive

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Kazufumi Suzuki, Inventor 1248 Shimokagemori, Chichibu City, Saitama Prefecture Inside Canon Electronics Co., Ltd. In company

Claims (4)

[Claims] 1. A magnet formed in a cylindrical shape and having at least its outer peripheral surface divided by n in a circumferential direction and alternately magnetized to different poles, and a first coil and a second magnet in an axial direction of the magnet. And the first outer magnetic pole and the first inner magnetic pole excited by the first coil are opposed to the outer peripheral surface and the inner peripheral surface on one end side of the magnet, and the second coil The second outer magnetic pole and the second inner magnetic pole to be excited are configured to face the outer peripheral surface and the inner peripheral surface on the other end side of the magnet, and the tip of the first outer magnetic pole and the second outer magnetic pole A holding member for holding a first outer magnetic pole and a second outer magnetic pole with their ends facing each other, and a first groove for fitting the first and second outer magnetic poles to both inner end surfaces of the holding member. Is formed on the end face of the first groove. A motor, wherein a notch and a second groove including the notch are formed, and a periphery of the second groove including the notch and the first and second outer magnetic poles are joined with an adhesive. 2. A magnet formed in a cylindrical shape and having at least an outer peripheral surface thereof divided into n portions in a circumferential direction and alternately magnetized to different poles, wherein a first coil and a second coil are arranged in the axial direction of the magnet. And the first outer magnetic pole and the first inner magnetic pole excited by the first coil are opposed to the outer peripheral surface and the inner peripheral surface on one end side of the magnet, and the second coil The second outer magnetic pole and the second inner magnetic pole to be excited are configured to face the outer peripheral surface and the inner peripheral surface on the other end side of the magnet, and the tip of the first outer magnetic pole and the second outer magnetic pole A holding member for holding a first outer magnetic pole and a second outer magnetic pole with their ends facing each other, and a first groove for fitting the first and second outer magnetic poles to both inner end surfaces of the holding member. Is formed, and contacts the inside of the first groove. A motor, wherein a second groove for receiving an adhesive is formed, and guide means for injecting an adhesive into the second groove are provided. 3. The motor according to claim 2, wherein said guide means is a notch formed in a part of said second groove. 4. The motor according to claim 2, wherein said guide means is a hole formed substantially at the center of the second groove.