JP4033332B2 - Stepping motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small cylindrical motor.
[0002]
[Prior art]
Conventionally, this type of stepping motor is shown in FIG. A motor having this structure is disclosed in JP-A-10-075558.
[0003]
In FIG. 3, reference numeral 10 denotes a cylindrical connecting ring made of a non-magnetic material. Grooves 10a, 10b, 10c and 10d are provided inside the connecting ring 10, and the first stator 18 is provided in the grooves 10a and 10b. The outer magnetic poles 18a and 18b are fitted, the outer magnetic poles 19a and 19b of the second stator 19 are fitted into the grooves 10c and 10d, and these fitting portions are fixed with an adhesive, and the first stator is attached to the connecting ring. The second stator is attached and has a function of positioning the stator and a function of securing a coaxial by deformation of the connecting ring of the motor body.
[0004]
[Problems to be solved by the invention]
However, the conventional example has the following drawbacks because the outer periphery of the outer magnetic pole stator and the inner peripheral surface of the connecting ring are fitted. Since the outer magnetic pole stator must be smaller than the outer diameter of the motor by the thickness of the connecting ring, the torque is inferior to that of the motor with the outer magnetic pole stator having a larger diameter to the full outer diameter of the motor.
Further, the outer magnetic pole stator having a comb blade shape is likely to bend inward when fitted to the connecting ring, and may cause interference with the magnet.
[0005]
Accordingly, the first object of the present invention is to make the outer diameter of the outer magnetic pole stator equal to the motor outer diameter and obtain a torque larger than that of the same outer diameter motor of the conventional structure.
[0006]
Secondly, an object of the present invention is to prevent the outer magnetic pole stator having a comb blade shape from being bent inward when the outer magnetic pole stator having a comb blade shape is fitted to the coupling member.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a positioning member in which a coupling member for fitting a first outer magnetic pole and a second outer magnetic pole is formed by insert-molding an ultrathin nonmagnetic metal plate into a cylindrical shape on the inner periphery. It is configured.
[0008]
In the above configuration, the ultra-thin metal plate insert-molded in a cylindrical shape on the inner periphery works to prevent bending deformation to the inside of the outer magnetic pole stator having a comb blade shape, and the pole is insert-molded in the cylindrical shape. Since the thin metal plate is firmly supported by the molded member, it acts to bring out the coaxial of the motor. Further, the coupling member having a groove shape so as to be fitted to the outer magnetic pole stator having a comb blade shape acts so as to position the first outer magnetic pole and the second outer magnetic pole.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Example 1
FIG. 1 is an exploded perspective view of a motor according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a coupling member for positioning and coupling the first stator and the second stator. The coupling member 1 is formed by insert-molding an ultrathin nonmagnetic metal plate 1a on the inner periphery, and the molding member 1b is formed with positioning grooves for positioning the positions of the outer magnetic pole stators that form a comb blade shape. . Furthermore, the bottom surface of the groove of the molded member 1b is formed by an ultrathin nonmagnetic metal plate 1a. Reference numerals 5 and 6 denote a first stator and a second stator made of a soft magnetic material, and the phases of the first stator and the second stator are shifted by 18 °. The coupling member 1 functions as a positioning member for positioning the coaxiality and phase between the first outer magnetic pole and the second outer magnetic pole.
[0010]
In the above configuration, the permanent magnet rotor 3, the rotating shaft 4, the first stator 5, and the second stator 6 are incorporated into the coupling member 1. At this time, the outer magnetic pole stator having a comb blade shape of the first stator 5 and the second stator 6 is positioned with respect to each other along the groove formed by the molding member 1b of the coupling member 1, and the first The inner peripheral surface of the outer magnetic pole stator that forms the comb blade shape of the stator 5 and the second stator 6 and the outer peripheral surface of the insert-molded ultrathin nonmagnetic metal plate 1a are fitted so that the stators are coaxial. It is a motor. By adopting such a configuration, since the outer periphery of the stator can be made the same as the outer diameter of the motor, the outer diameter of the permanent magnet rotor 3 incorporated inside the stator can also be increased. Therefore, it is possible to generate a larger torque than a motor having a conventional structure having the same motor outer diameter.
[0011]
Further, in the conventional structure, since the inner peripheral surface of the connecting ring and the outer peripheral surface of the outer magnetic pole stator are fitted, the tip of the outer magnetic pole stator having a comb blade shape is easily bent inward at the time of assembly, and is in contact with the permanent magnet rotor 3. Therefore, the gap between the inner surface of the outer magnetic pole stator and the outer peripheral surface of the permanent magnet rotor 3 cannot be reduced.
[0012]
However, in this embodiment, since the outer peripheral surface of the ultrathin nonmagnetic metal plate 1a insert-molded on the molded member 1b and the inner peripheral surface of the outer magnetic pole stator are fitted, the tip of the outer magnetic pole stator having a comb blade shape is inward. Since there is no bending, the gap between the inner surface of the outer magnetic pole stator and the outer peripheral surface of the permanent magnet rotor 3 can be reduced.
[0013]
Therefore, in the present invention, despite the presence of the ultrathin metal plate 1a between the outer magnetic pole stator and the outer peripheral surface of the permanent magnet rotor 3, the inner surface of the outer magnetic pole stator and the permanent magnet rotation equivalent to those of the conventional motor are provided. It can be set as the gap of the outer peripheral surface of the child 3.
[0014]
(Example 2)
In the second embodiment, the outer peripheral surface of the ultrathin nonmagnetic metal plate 1a insert-molded in the coupling member 1 in the first embodiment and the comb blade shape of the first stator 5 and the second stator 6 fitted thereto are used. This is a motor in which the inner peripheral surface of the outer magnetic pole stator formed has a press-fit tolerance and the co-axiality between the first stator 5 and the second stator 6 is improved.
[0015]
As in the first embodiment, the outer peripheral surface of the comb member is formed even if press-fitting is performed because the outer peripheral surface of the ultrathin nonmagnetic metal plate 1a insert-molded on the molded member 1b and the inner peripheral surface of the outer magnetic pole stator are fitted. Since the tip of the magnetic pole stator does not bend inwardly, the inner surface of the outer magnetic pole stator is accurately formed into a cylindrical shape along the outer peripheral surface of the ultrathin nonmagnetic metal plate 1a insert-molded in the coupling member 1. The variation in the gap between the inner surface of each outer magnetic pole stator and the outer peripheral surface of the permanent magnet rotor 3 is smaller than in the conventional structure. Therefore, a smoother rotation can be obtained.
[0016]
Further, in the conventional structure, even if the tip of the outer magnetic pole stator having a comb blade shape is incorporated without bending inwardly, the variation in the thickness of the soft magnetic plate forming the stator becomes permanent with the inner surface of each outer magnetic pole stator. Since this occurs as a variation in the gap with the outer peripheral surface of the magnet rotor 3, the effect of the present invention cannot be obtained.
[0017]
(Example 3)
In the third embodiment, the comb of the first stator 5 and the second stator 6 fitted to the outer peripheral surface of the ultrathin nonmagnetic metal plate 1a insert-molded in the coupling member 1 in the first or second embodiment is used. This is a motor that is fastened by bonding the inner peripheral surface of an outer magnetic pole stator having a blade shape.
[0018]
The outer magnetic pole stator having a comb-blade shape composed of the ultra-thin non-magnetic metal plate 1a insert-molded on the coupling member 1 and the soft magnetic plate is bonded to each other, so that a stable strength can be obtained. In addition, the coupling member 1, the first stator, and the second stator are in a fitting relationship as shown in FIG. 2, and the ultrathin nonmagnetic metal plate 1 a insert-molded on the coupling member 1 serves as the permanent magnet rotor 3. Since it covers, there is an effect that the protrusion to the inner surface of the adhesive, which has been a problem in the conventional structure, does not occur structurally.
[0019]
Furthermore, the outer magnetic pole stator having a comb-blade shape made of a soft magnetic plate is very soft and easily deformed because it is subjected to magnetic annealing in order to satisfy its magnetic characteristics. As a result, the adhesive resin is cured and the deformation strength is dramatically improved. As a result, there is an effect that the motor is integrated with the coupling member 1 and has a high rigidity.
[0020]
In addition, since the outer magnetic pole stator having a comb blade shape is firmly bonded and fixed, the excitation vibration of the outer magnetic pole stator having a comb blade shape generated to rotate the motor is extremely small, and the rotational noise is very small. A motor can be provided.
[0021]
Example 4
In the fourth embodiment, the coupling member 1 is formed from the ultrathin non-magnetic metal plate 1a by metal injection mold insert molding in the first to third embodiments. As a result, the material of the molded member 1b is a nonmagnetic metal. A motor using such a coupling member 1 is the fourth embodiment. When the molded member 1b is made of a nonmagnetic metal, not only the mechanical strength of the coupling member 1 is improved, but also there is an effect that the thermal conductivity is improved and the motor has a good heat dissipation.
[0022]
Also, the joint between the positioning groove for forming the position of the outer magnetic pole stator having the comb blade shape formed on the coupling member 1 and the outer magnetic pole stator having the comb blade shape fitted in the groove is butt-welded. Is possible. By performing the fastening by welding, it is possible to provide a motor that can be used even at higher temperatures.
[0023]
The ultra-thin nonmagnetic metal plate 1a is applied to the permanent magnet rotor 3 when laser welding or plasma spot welding is performed on the forming member 1b made of nonmagnetic metal and the outer magnetic pole stator having a comb blade shape by the structure of the present invention. It has the effect of preventing welding spatter from scattering.
[0024]
【The invention's effect】
As described above, the present invention has the following effects.
A larger torque can be generated than a motor having the same outer diameter of the conventional structure.
It is possible to provide a structure in which the outer magnetic pole stator having the comb blade shape does not fall into the motor.
It is possible to provide a motor capable of smooth rotation with less variation in the gap between the inner surface of the outer magnetic pole stator and the outer peripheral surface of the permanent magnet rotor than in the conventional structure.
When bonding the coupling member 1 and the outer magnetic pole stator, a motor structure can be provided in which no adhesive protrudes inside the permanent magnet rotor as in the conventional structure.
Since the outer magnetic pole stator having a comb blade shape composed of the ultrathin metal plate 1a and the soft magnetic plate of the coupling member 1 is bonded to each other, extremely stable adhesive strength can be obtained.
A highly rigid motor can be provided by bonding the coupling member 1 and the outer magnetic pole stator.
By bonding the coupling member 1 and the outer magnetic pole stator, it is possible to provide a motor with extremely low rotational noise.
By making the molding member 1b of the coupling member 1 into a nonmagnetic metal by metal injection molding, a motor with good heat dissipation can be provided.
When the molding member 1b of the coupling member 1 is made of a nonmagnetic metal by metal injection molding and the outer magnetic pole stator is laser welded or plasma spot welded, the ultrathin nonmagnetic metal plate 1a is weld sputtered onto the permanent magnet rotor 3. Since it has the effect of preventing scattering, it is possible to provide a motor that can be used easily even at high temperatures in a welded structure.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing all components for functioning as a motor of the present invention.
FIG. 2 is a view showing a fitting relationship between a first stator and a second stator and a positioning member of the motor of the present invention.
FIG. 3 is a diagram schematically showing the structure of a conventional stepping motor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Coupling member 1a ... Insert-molded ultra-thin metal plate 1b ... Insert molding member 2 ... Winding 3 ... Permanent magnet rotor 4 ... Rotating shaft 5 ... First 1 stator 6 ... second stator 10 ... connection ring 18 ... first stator 19 ... second stator

Claims (3)

The rotor is formed in a cylindrical shape and is divided into n pieces in the circumferential direction and alternately magnetized to different poles, and the first coil, the rotor, and the second coil are sequentially arranged in the axial direction of the rotor 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 of one end side of the rotor so as to sandwich one end side of the rotor and excited by the second coil. The second outer magnetic pole and the second inner magnetic pole to be opposed to the outer peripheral surface and the inner peripheral surface of the other end of the rotor so as to sandwich the other end of the rotor, and the first outer magnetic pole and the second outer magnetic pole In a motor having a coupling member that fits on the inner peripheral surface of a magnetic pole to ensure coaxiality and at the same time positions and connects the first outer magnetic pole and the second outer magnetic pole, the first outer magnetic pole and the second outer magnetic pole The coupling member that fits the magnetic pole is 0.1 m on the inner circumference. Motor, characterized by being composed of the following ultrathin nonmagnetic metal plate with a positioning member that is insert-molded. 2. The motor according to claim 1, wherein the first outer magnetic pole and the second outer magnetic pole are press-fitted into the coupling member in order to increase the positioning accuracy between the first outer magnetic pole and the second outer magnetic pole. . 3. The motor according to claim 1, wherein the first outer magnetic pole and the second outer magnetic pole are bonded to the coupling member.

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