JP2512627Y2 - Stepping motor - Google Patents

Description

[Detailed Description of the Invention] a. Industrial field of application The present invention relates to an inner rotor type hybrid type or VR (variable reluctance) type stepping motor, and particularly to a rotation effective for reducing magnetic noise when the motor is driven. Regarding the improvement of the child structure.

b. Prior Art As a structure of a stepping motor of this type, for example, there is a hybrid type structure as shown in the sectional view of FIG. 6 and the conceptual view of FIG.

In the figure, a two-phase hybrid type stepping motor 1 is composed of a stator 2 and a rotor 3. Stator 2
The salient pole 2a has a plurality of small teeth 2b, and the rotor 3 is also provided with a large number of small teeth 3a.
To output mechanical power at a predetermined step angle.

In the stator 2, in addition to the case 5, the brackets 6 and 7, and the motor windings (two-phase, bi-ferrar winding in the figure) 8, bearings 9 and 10 that rotatably support the rotor 3 are provided on the brackets 6. , 7 and both are assembled by screws.

The rotor 3 has its respective structures shown in FIG. 8 and FIG.
Shown in the cross-sectional view of the figure. The figure shows rotors 3 _-1 , 3 _-2 of the hybrid type stepping motor, and the rotor 3 _-1 , or 3 _-2 has a plurality of small teeth 3 _a-1 , or 3 _{a-2 on the} outer peripheral surface. A cup-shaped rotary iron core 11 _-1 , 11 _-2 , or a disk-shaped rotor iron core 11 _-3 , 11 _-4 , and the rotor iron core 11
_-1 , 11 _-2 , or 11 _-3 , 11 _-4 and the permanent magnet 12 _-1 or 12 _-2 which is magnetized in the axial direction of the rotary shaft 4 is passed through the rotary shaft 4 respectively. Are assembled. And
The iron cores 11 _-1 , 11 _-3 are magnetized to, for example, the N pole, and the iron cores 11 _-2 , 11 _-4 are magnetized to the S pole, and the respective small teeth are electrically separated by a half pitch (electrically.
180 °) deviated. Figure 10 is a sectional view of the VR stepping rotor 3 _-3, the rotor 3 _-3 cylindrical rotor core in which a plurality of small teeth 3 _a-3 on the outer peripheral surface disposed 11 _{- 5} , the rotary shaft 4 is penetrated and fixed.

c. Problems to be Solved by the Invention However, in such a conventional rotor structure of a stepping motor, the radial rigidity of the rotor core is configured to be stronger than the rigidity of the stator core. , When the motor is driven, the magnetic attraction force or repulsive force acting in the radial direction of the rod between the stator 2 and the rotor 3 causes
Mainly, the stator 2 periodically causes minute deformation. For this reason, there is a problem that the stator 2 vibrates when driving the stepping motor to generate a magnetic sound.

The present invention has been made in view of the above points, and an object thereof is to solve the above-mentioned problems, to reduce the periodic deformation of the stator in the radial direction during driving of the motor, and to reduce the magnetic noise generated thereby. It is to provide a stepping motor.

d. Means for Solving the Problems The configurations of the present invention for achieving the above object are as follows (1) and (2).

(1) A rotor having a cup-shaped iron core in which a plurality of small tooth poles are arranged on the outer peripheral surface at an equal pitch, and a plurality of protrusions arranged so as to face the outer peripheral surface of the rotor through a gap. In a stepping motor of hybrid type or VR type comprising a stator having poles, in a cup-shaped iron core of the rotor, a portion having an iron core thickness thinner than the radial iron core thickness excluding the small tooth poles, The cup-shaped iron core is formed periodically or at equal pitches along the inner or outer circumference thereof, whereby the rigidity of the iron core is relatively weakened as compared with that of the stator.

(2) A rotor having a cup-shaped iron core in which a plurality of small tooth poles are arranged on the outer peripheral surface at an equal pitch, and a plurality of protrusions arranged so as to face the outer peripheral surface of the rotor with a gap. A hybrid type having a pole and a stator having a plurality of small tooth poles on a surface of the salient pole facing the rotor, or
In a VR-type stepping motor, the cup-shaped iron core of the rotor is configured such that a portion having an iron core thickness thinner than the radial iron core thickness excluding the small tooth poles is cycled along the inner or outer circumference of the cup-shaped iron core. It is characterized in that the iron core is formed to have a desired pitch or a uniform pitch, thereby making the rigidity of the iron core relatively weaker than that of the stator.

e. Operation Since the present invention is configured as described above, the thickness of the cup-shaped iron core of the rotor in the radial direction excluding the small tooth poles is made to be periodic or equal pitch along the inner or outer circumference. By making it thinner than other parts, the rigidity of the rotor core is weakened,
When the motor is driven, deformation due to the attractive force or repulsive force that acts between the stator and rotor is generated not only on the stator side but also on the rotor side, so that the deformation on the stator side is relatively reduced, and the motor Reduce the magnetic sound of.

f. Embodiment Hereinafter, a preferred embodiment of the present invention will be illustratively described in detail with reference to the drawings.

1 and 2 show an embodiment of the present invention.
FIG. 2 is a sectional view of the rotor of the hybrid stepping motor, and FIG. 2 is a sectional view taken along the line II-II of FIG. In the figure, a rotor 20 includes two cup-shaped rotor cores 21 _-1 , 21 _-2 , a disk-shaped permanent magnet 22 held by the rotor cores 21 _-1 , 21 _-2 , and a rotary shaft. It is composed of 23 and. The rotor core 21 _-1, 21 _-2, its outer peripheral surface a plurality of small teeth 24 are disposed at an equal pitch, iron heart 21 _-1, 21 _-2
In the radial core portion 25 excluding the portion of the small teeth 24 of
A plurality (five in this embodiment) of groove portions 26 are provided along the inner circumference at equal pitches (every 72 ° in the center angle) and in parallel with the rotary shaft 23, and the thickness of the iron core portion 25 in the radial direction is set. The iron core portion 27 having a thinner thickness is formed at a plurality of places. In addition,
The permanent magnet 22 is magnetized in the axial direction of the rotating shaft 23, and the small teeth 24, 24 of the iron cores 21 _-1 , 21 _-2 are displaced from each other by a half pitch (electrically 180 °).

3 and 4 show a modification of the above-described embodiment, FIG. 3 is a sectional view of the rotor of the hybrid stepping motor, and FIG. 4 is a sectional view taken along the line IV-IV of FIG. is there. In the figure, a rotor 28 is similar to the above-mentioned cup-shaped rotor core 2 arranged in a direction opposite to that of FIG.
1 _-1, and 21 _-2, iron heart 21 _-1, pinched 21 _-2 is fixed, and is composed of a cylindrical permanent magnet 29 which is magnetized in the axial direction of the rotary shaft 23 and the rotary shaft 23 There is. Each part shown in FIG.
The core 21 _-1 differs from the one shown in the figure to 21 _-2 , but is otherwise the same.

FIG. 5 is a sectional view of a cup-shaped rotor core of a stepping motor according to another embodiment of the present invention and corresponds to FIGS. 2 and 4 of the above-described embodiment. In FIG. 5, the cup-shaped rotor core 30 has a plurality of small teeth on its outer peripheral surface.
31 are arranged at equal pitches, and the small teeth 31 of the iron core 30.
A plurality of (five in the present embodiment) tooth grooves, which are deeper than the plurality of small teeth 31, or slots 33, are provided in the radial iron core portion 32 excluding the portion of No. Angle) and in parallel with the rotary shaft 23, and an iron core portion 34 having a thickness smaller than the thickness of the iron core portion 32 in the radial direction is formed.

The grooves 26 provided in the rotor cores 21 _-1 , 21 _-2 , 30 and the tooth groove portions or slot portions 33 having a deep depth in each of the above-described embodiments are straight grooves or slots. Alternatively, it may be an oblique slot. Further, the cross-sectional shape is not limited to the groove or slot shape, and the thickness of the rotor core in the radial direction excluding the small teeth is formed periodically thinner along the inner or outer circumference than other portions. Any shape can be used.

Further, although the above-described embodiments have mainly been described with respect to the hybrid type stepping motor, they can be similarly applied to the VR type stepping motor.

Note that the technology of the present invention is not limited to the technology in the above-described embodiment, and may be implemented by means of another mode having the same function.The technology of the present invention may be variously modified within the scope of the configuration. Addition is possible.

g. Effect of the Invention As is apparent from the above description, according to the stepping motor of the present invention, the cup-shaped iron core of the rotor is provided with a portion having an iron core thickness thinner than the radial iron core thickness excluding the small tooth pole. The cup-shaped iron core is periodically formed along the inner or outer circumference, and the rigidity of the iron core is weakened by this, so that a suction force acting in the radial direction between the stator and the rotor when the motor is driven, By causing structural deformation due to repulsive force not only on the stator side but also on the rotor side, the deformation on the stator side is relatively reduced, and the magnetic noise generated from the stepping motor can be reduced. it can.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a sectional view of a rotor of a hybrid type stepping motor, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, Third
4 and 5 show a modification of the above embodiment, FIG. 3 is a sectional view of a rotor of a hybrid type stepping motor, FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3, and FIG. FIG. 4 is a sectional view of a cup-shaped rotor core of a stepping motor according to another embodiment of the present invention.
FIGS. 6 and 7 show the structure of a conventional stepping motor, FIG. 6 is a sectional view thereof, FIG. 7 is a conceptual view thereof, and FIGS. 8 to 10 are conventional stepping motors. It is sectional drawing which shows the structure of the rotor of a motor. 21 _-1 , 21, _-2 , 24,31 …… Small teeth, 30 …… Rotor core, 25, 32…
… Iron core part excluding small teeth, 26 …… Groove part, 33 …… Deep tooth groove part, 27, 34 …… Iron core part with thin thickness.

Claims (4)

(57) [Scope of utility model registration request] 1. A rotor having a cup-shaped iron core in which a plurality of small tooth poles are arranged on the outer peripheral surface at an equal pitch, and a plurality of rotors arranged so as to face the outer peripheral surface of the rotor with a gap. Hybrid type with a stator having salient poles, or VR
In a stepping motor of the shape, in the cup-shaped iron core of the rotor, a portion having an iron core thickness thinner than the radial iron core thickness excluding the small tooth poles is periodically arranged along the inner or outer circumference of the cup-shaped iron core. The stepping motor is characterized in that the rigidity of the iron core is weakened thereby. 2. A rotor having a cup-shaped iron core in which a plurality of small tooth poles are arranged on the outer peripheral surface at an equal pitch, and a plurality of rotors arranged so as to face the outer peripheral surface of the rotor with a gap. A stepping motor of hybrid type or VR type, which has a salient pole and a stator having a plurality of small tooth poles on a surface of the salient pole facing the rotor, wherein a cup of the rotor is provided. The core-shaped iron core forms a portion having an iron core thickness smaller than the radial iron core thickness excluding the small tooth poles periodically along the inner or outer circumference of the cup-shaped iron core, thereby increasing the rigidity of the iron core. A stepping motor characterized by being weakened. 3. The utility model registration claim 1 or claim 2, wherein the thin core thickness portion is formed by a groove provided in the inner peripheral surface of the cup-shaped core parallel to the rotation axis. The stepping motor according to item 2. 4. The utility model registration claim 1 wherein the thin core portion is formed by a deep tooth groove provided on the outer peripheral surface of the cup-shaped core in parallel with the rotation axis.
Alternatively, the stepping motor according to item 2.