JPS6311890Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric motor, and more particularly to an electric motor in which a stator is integrated by resin molding.

Conventionally, as this type of electric motor, a motor as shown in FIG. 1 using a cylindrical magnet 1 has been known.
This generally used a cylindrical surface to cause the stator 2 and rotor 3 to act magnetically. However, this inevitably causes the problem that the output shaft 4 becomes longer in the axial direction. To solve this problem, an electric motor is constructed in which a stator consisting of an annular excitation coil surrounded by a yoke is placed facing each other, and a rotor having a donut plate-shaped permanent magnet is placed between the facing surfaces. is proposed. In this electric motor, the permanent magnets are located between the opposing surfaces of the left and right annular stators, so
The magnetically active surface has a circular shape perpendicular to the axis, which has the advantage that the length in the axial direction can be shortened. However, in this flat type electric motor, in order to hold the excitation coil inside the stator yoke while maintaining insulation, the coil is wound around a coil bobbin and is housed inside the yoke. Problems remained, such as the space within the yoke being taken up by the thickness of the yoke, which reduced the winding capacity of the coil, and the number of assembly steps required during assembly.

The present invention solves these conventional problems by integrating the stator yoke and the excitation coil housed inside the yoke using an insulating synthetic resin mold, and further integrating the stator and rotor. The purpose of the present invention is to provide an electric motor in which the winding capacity can be increased by eliminating the need for a coil bobbin by integrating the rotor bearing between the two parts, and in which the stator can be assembled as a single component and the number of assembly steps can be reduced. shall be.

The present invention will be explained below with reference to an embodiment of a linear output type electric motor shown in the drawings. In FIG. 2, the left and right stators 10a, 10b have respective annular excitation coils 11a, 11b and these excitation coils 11a, 1.
Synthetic resins 12a and 12b insulating 1b, respectively
and yokes 13a, 13b surrounding both excitation coils 11a, 11b. Furthermore, yoke 1
3a and 13b have magnetic pole tooth plates 14a and 1 on one side.
It is said to be 4b. The magnetic pole tooth plates 14a and 14b are each made of a donut-shaped soft magnetic plate, and as shown in FIGS. 3 and 4, the starting point is the outer peripheral edge 15 and the tip is connected to the inner peripheral edge 16 via a connecting strip 17. A radial row of magnetic pole teeth 18 to which are connected, and conversely a connecting strip 1 starting from the inner peripheral edge 16 and connecting to the outer peripheral edge 15.
In this configuration, radial rows of magnetic pole teeth 20 whose tips are connected via teeth 9 are arranged adjacent to each other alternately. The angle between adjacent magnetic pole teeth 18 and 20 is equal in the circumferential direction, and in this embodiment is set to 22.5 degrees, which is equal to the angle between the N and S poles of a donut plate-shaped permanent magnet 22, which will be described later. Reference numerals 24a and 24b are synthetic resin rotating bearings extending from the inner peripheral surfaces of the yokes 13a and 13b of the respective stators 10a and 10b. As shown in FIG. 5, the stators 10a and 10b having this configuration are first made of an annular excitation coil 11a that is wound in a predetermined shape in cup-shaped yokes 13a and 13b that are open on one side and have a U-shaped cross section. , 11b, and then fit donut-shaped magnetic pole tooth plates 14a, 14b in which rows of magnetic pole teeth 18, 20 are formed into the opening edges of the yokes 13a, 13b, and then fit them into a mold. Insulating synthetic resin is injected into the inside of the yoke 13 using the resin injection port 40 and the holes between the magnetic pole teeth.
a, 13b and excitation coils 11a, 11b are integrated with synthetic resins 12a, 12b, and rotor bearings 24a, 24b are integrally molded into the shape shown in FIG. Synthetic resins are not particularly limited in type, but include polyphenylene sulfide resin, polyacetal resin, polyamide resin, polyethylene terephthalate resin, and those mixed with fluorine or carbon fiber to increase lubricity. is used.

(In FIG. 5) 41 is the exciting coil 11a,
11b, and is for positioning the excitation coils 11a, 11b at accurate positions within the yokes 13a, 13b. The rotor 21 includes a permanent magnet 22 which has a donut plate shape and has north and south poles alternately magnetized at equal angles in the circumferential direction on both sides thereof, and a permanent magnet 22 provided on the inner circumference of the permanent magnet 22. It is composed of a shaft portion 23. The permanent magnet 22 is
When the material is magnetically anisotropic, the front and back sides are magnetized with opposite polarities, and when it is magnetically isotropic, the front and back sides are magnetized with the same polarity. In this embodiment, the number of poles is divided into equal parts of 22.5 degrees, with eight poles each for the north and south poles, but this number can be increased or decreased depending on the application. The shaft portion 23 is a metal cylindrical base 23a.
It has a structure in which a synthetic resin molded material 23b is outsert molded into an integrated structure. A female threaded shaft hole 23c is provided in the inner peripheral portion of the molded material 23b. Therefore, both excitation coils 11a of each stator 10a, 10b,
Magnetic pole tooth plate 1 arranged on opposing surfaces between 11b
The rotor 21 is assembled so that the donut plate-shaped permanent magnet 22 of the rotor 21 is located between 4a and 14b.
Through this assembly, the rotary bearings 24a and 24b are brought into contact with the outer circumferences of the left and right ends of the base body 23a of the shaft portion 23, respectively, and the rotor 21 is brought into contact with the outer peripheries of the left and right ends of the base body 23a.
Rotating bearings 24a, 24b each integrated with
It is rotatably supported by the shaft. Output shaft 2
5 includes a slide shaft portion 25a having a non-circular outer shape such as a spline, a male screw portion 25b, and a rear slide shaft portion 25c. Slide shaft part 25
a is supported by a central boss portion 26a of the case lid 26 so that it can only slide in the axial direction;
The male screw portion 25b is screwed into the female screw shaft hole 23c of the shaft portion 23 of the rotor 21, and the rear slide shaft portion 25c is slidably supported by the central boss portion 27a of the case 27. In the output shaft 25, reference numerals 28 and 29 are rotation regulating stoppers, each having contact protrusions 28a, 28b and 29a, 29b at 180 degrees opposite positions, as shown in FIG. The stoppers 28 and 29 abut against the protruding ends of stop pins 30 and 31 inserted near the inner peripheral edge of the shaft portion 23 of the rotor 21, and the rotation of the rotor 21 is stopped in order to stop further movement of the output shaft 25. It is designed to stop. 32 is a sealing gasket interposed between the case lid 26 and the case 27, since the electric motor of this embodiment requires sealing. 33 is a circular and wavy washer interposed to prevent rattling between the rotor 21 and the rotation bearing 24b, and 34 is the stator 10.
This is a wavy washer interposed between the yoke 13 and the case 27 to prevent rattling between the yoke 13 and the case 27.

The operation of the linear output type electric motor having the above configuration will be explained next. When an alternating current is applied to the excitation coils 11a, 11b to generate an alternating magnetic field, the yoke 13a, 1
3b and a magnetic circuit passing through the magnetic pole tooth plates 14a and 14b. Assuming that the stray magnetism of the magnetic pole tooth plates 14a and 14b at a certain moment is N pole on the outside and S pole on the inside as shown in FIG. 4, at this time, the row of magnetic pole teeth 18 is excited with N pole, The row of magnetic pole teeth 20 is energized with an S pole. At the next moment when the phase of the applied current is reversed, the row of magnetic pole teeth 18 has an S pole,
The row of magnetic pole teeth 20 is excited with N poles. Due to this alternating magnetism, each magnetic pole of the permanent magnet 22 of the rotor 21 facing the magnetic pole tooth plates 14a and 14b has an attractive force,
Rotation occurs due to repulsive force. When the rotor 21 starts rotating, the male threaded portion 2 of the output shaft 25 screwed into the female threaded shaft hole 23c of the shaft portion 23 of the rotor 21
A linear motion force is generated at 5b, and this force causes the output shaft 25 to start moving to the left or right. Now, if the output shaft 25 is driven to the right and reaches the state shown in Fig. 2, then the left stopper 2
Stopper pins 30 and 31 are attached to the abutting protrusions 29a and 29b (29b is not visible in the figure) of 9, respectively.
The left protruding end of the rotor 21 comes into contact with the rotor 21 to stop the rotation of the rotor 21, thereby stopping the rightward movement of the output shaft 25. When the output shaft 25 is moved to the left as shown by the imaginary line in FIG.
28b (28 is not visible in the figure), the rotation of the rotor 21 is stopped, and the leftward movement of the output shaft 25 is stopped. In this way, the rotational force of the rotor 21 is converted into a linear movement to the left or right corresponding to the distance between the stoppers 28 and 29 and is output to the output shaft 25.

As described above, the present invention arranges the donut plate-shaped permanent magnet of the rotor between the opposing sides of the two annular excitation coils, and rotates this permanent magnet with the magnetism induced by the excitation coil. Since the female threaded shaft hole provided on the inner circumference of the permanent magnet is screwed together with the male threaded part of the output shaft, the magnetically active surface becomes a circular shape perpendicular to the shaft, unlike the conventional cylindrical surface parallel to the shaft. The length in the axial direction can be made shorter and shorter than that of other types. Also, since a magnetic circuit can be formed on the side of the excitation coil,
The rotation moment generated in the permanent magnet of the rotor has a long arm with respect to the central axis,
Thrust can be improved.

In the above embodiment, a linear output type electric motor was explained, but the present invention can also be easily applied to a rotary output type electric motor. For example, as shown in Fig. 2, the output shaft is fixed to the shaft of the rotor and the This can be realized by interposing a rotary bearing between the output shaft and each stator, and also by making the case lid and each boss part of the case have a rotary bearing structure.

As described above, the present invention integrates the yoke that makes up the stator and the excitation coil housed inside using a synthetic resin mold, eliminating the need for a bobbin for the excitation coil and increasing the coil winding capacity. It has the advantage of increasing the Furthermore, since the stator is integrated, the entire stator can be handled as one component, which has the advantage of reducing the number of assembly steps. Furthermore, since the rotary bearing is molded and integrated into the stator to support the shaft of the rotor, the two parts can be assembled by simply fitting the rotor into the stator, making handling easier. It has the advantage of being extremely easy to use.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional example, Fig. 2 is a sectional view of an embodiment of the present invention, Fig. 3 is a side view of a part of the magnetic pole tooth plate of the yoke in the above, and Fig. 4 is a stator in the same as above. Fig. 5 is a partially cutaway perspective view showing the state before molding in the manufacture of the stator used in the above, and Fig. 6 is the same as the above. FIG. 3 is a perspective view of a stopper of the output shaft in FIG. 10a, 10b...Stator, 11a, 11b...
...Exciting coil, 12a, 12b...Synthetic resin, 1
3a, 13b...Yoke, 18...Magnetic pole teeth, 20...
...Magnetic pole teeth, 21...Rotor, 22...Permanent magnet,
23... Shaft portion, 24a, 24b... Rotating bearing.

Claims (1)

[Scope of utility model registration request] An annular excitation coil, a yoke surrounding the excitation coil, magnetic pole teeth extending inward from the outer periphery and magnetic pole teeth extending outward from the inner periphery, which are formed on a circular plane portion on one side of the yoke. and a stator having two types of magnetic pole teeth arranged alternately at equal angles along the circumferential direction; Consists of a donut plate-shaped permanent magnet whose N and S poles are magnetized at equal angles in the circumferential direction and alternately, and a shaft formed on the inner circumference of this permanent magnet. It consists of a rotor, two stators are arranged so that the surfaces on which the rows of magnetic pole teeth of each yoke are formed face each other, and the permanent magnets of the rotor are positioned between the opposing surfaces. In an electric motor in which a rotor bearing is interposed between the inner circumferential surface of each stator and the shaft of the rotor, the excitation coil and yoke of the stator have insulation injected into the yoke. 1. An electric motor characterized in that the rotor bearing is integrally formed with a synthetic resin and the rotor bearing is further formed integrally with the synthetic resin.