JPS59127570A - Small-sized dc motor - Google Patents

Abstract

PURPOSE:To obtain a brushless DC motor by forming a cylindrical coil of a stator in a structure that windings are wound back and forth between both axial ends in a circle of circumferential direction of the coil and associating it with a rotor magnet. CONSTITUTION:Parallel wires 4 formed of insulated square wires in a plate shape are wound on a core 5 to form a coil inner layer 2b, the wires 4 are wound reversely on the outside to form a coil outer layer 2a, they are engaged and connected at the end, thereby forming a cylindrical coil 2. A motor is formed in combination with a rotor which is composed of rotor magnets 3 magnetized at N- and S-poles by securing to the inside of the stator yoke 1, the coil 2 is divided into equal segments, which are connected to be sequentially excited at the coil, thereby rotating the coil. Therefore, the motor is brushless in a slender shape, thereby reducing the inertia moment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field J] The present invention relates to a small-sized DC Tanabata that is formed using conventional DC coreless Tanabata technology and is used for applications such as servo motors.

[Background technology] The characteristics of the conventional DC coreless Tanabata are that the rotor is light and has good responsiveness, and there is no stator core, so there is no so-called "synthetic torque", and the applied voltage, rotation speed, and torque are The relationship is proportional, and the relationship always maintains linearity.For this reason, it is used as a voltmeter, for example, and as a drive source for Pesci recorders. Also, the rotor is light,
Since the conventional t-method is small in relation to the output, it has good response and is often used as a servo motor. However, this type of DC coreless Tanabata is equipped with a commutator and brushes, and the friction loss there fluctuates, so when this DC coreless Tanabata is rotated at extremely low speeds, nonlinearity in friction loss appears. However, there remained problems with delicate movement when used as a display power source for measuring instruments. In the power supply system using brushes like this one, due to the ever-changing contact status and the lifespan of the brushes themselves, there were always subtle changes, which caused trouble.

From the above, it has become necessary to make DC coreless motors lazier-less in order to improve reliability and output characteristics. However, even if a conventional armature with an iron core is designed to be sagless, when rotating at extremely low speeds, the attraction force between the stator iron core and the rotor magnets will cause a slight kink torque (reluctance torque). This has caused a problem in that it is impossible to always generate a constant torque at each rotational position. [Objective of the Invention] It is an object of the present invention to provide a small DC motor that maintains the wide range of linearity of applied voltage, rotational speed, and output torque that are characteristic of conventional DC coreless motors, and also achieves brushless design. This is the purpose.

[Disclosure of the Invention] In an embodiment, the stator coil is a linear cylindrical coil (2
), this cylindrical coil (2) is fixed inside the stator yoke (1) made of iron pipe, and the rotor magnet (3) is arranged with an appropriate air supply inside the cylindrical coil (2). It shall be. The cylindrical coil (2) used here has a long length in the axial direction, and the primary rotor magnet (3) is also elongated and has a structure that outputs output in the length direction, thereby minimizing the inertia. - Avoid increasing the amount of ment. ′! l: The above cylindrical coil (2) is exactly the same as the rotor coil of a DC coreless motor, and this cylindrical coil (
2) is crimped and fixed to the stator yoke +11. The manufacturing method and structure of this cylindrical coil (2) will be briefly described below.0 First, a parallel wire body (4) in which a large number of insulated square wires are arranged in a plate shape is inserted into a core metal ( 5) in the direction shown in the figure to form a cylindrical coil inner layer part (2)', and then the outer diameter of the coil inner layer part (2b) is equal to the inner diameter of the coil outer layer part (2&,)t. The outer and inner coil parts (2a), (2b) and k are made into one and fixed by completely fitting into each other.

At this time, the winding direction of the first layer outside the coil (2) is reversed as shown in Fig. 1(b) compared to that of Fig. 1(a), and these core metals (5) The parallel wire body (4) is wound around and formed into a long continuous pipe shape, so cut it to an appropriate length and cut the inside and outside N (2b) as shown in Figure 2(a). )(2a), t=fit. Then, on the end face of the product formed by fitting, each strand is lined up in the circumferential direction as shown in FIG. As shown in Figure (b), when the connection piece (6) is connected by welding, the inner and outer #
(2'b) By connecting all the strands of (2a), the winding m
This winding (7), which becomes f71, forms a cylindrical coil (2) in which the number of strands is equal to the number of wires. Since the cylindrical coil (2) is manufactured by such a processing method, it is easy to make a considerably long and slender coil. If the winding wire (7) with a full circumference made in this way is connected into three equal parts as shown in Fig. 4, five coil bodies L+ are formed as shown in Fig. 5.
% A cylindrical coil (2) for the stator is made by star-connecting L2-.... Here, the stator of the embodiment of the present invention is completed by fitting and fixing this cylindrical coil (2) inside the stator yoke (1), which is the outer periphery of the motor, which forms the entire magnetic path. Thus, this stator yoke +11 and the cylindrical coil (
A cylindrical rotor magnet (3) magnetized with the outer circumferential layer KNS is rotatably attached to the center of the stator cylinder (8) which is fully integrated with the stator cylinder (8) as shown in FIG. At this time, the rotor magnet (3) has a small energy density in order to lower the rotor inertia, and in order to increase the output, a rare earth magnet such as samarium steel is used, and a rare earth magnet with a high energy density is used. The Tanabata of the above embodiment is assembled as shown in FIG.
It is magnetized. Also, (9) is the output shaft, (10) is a 7-wheel bearing fixed to the stator yoke fi+, which is the Tanabata outer body, and (ll) is the rotor (3) fixed to the output shaft (9). (2) is the inner and outer layer (2bH2
a).As shown in Figs. 4 and 5 above, in this example, this cylindrical coil (2) is composed of three-phase coil bodies Ll, L2, and L5. This example shows the case where In addition, (8) is a connecting piece when connecting the outer and inner layer wires at their ends, and the cylindrical coil (2
) is the terminal of each coil body L1 to □Ls, which corresponds to the terminal LI'-Ia in FIG. 5, and the 0 point in the center of FIG. The terminals are combined into one terminal, which is also led out to the outside as the terminal 0, and a total of 6 terminals 02) are led out to the outside.

Thus, in the Tanabata of the above embodiment, each coil body Lt-Lr.

Collect the beginning of the volume and set it as 0 point, this C point? : heavy weight.

and the end terminal L+'-(i' of each winding is connected to the other end of the power supply via an electronic switch.
By sequentially turning on these electronic switches, the rotor magnet (3) rotates and rotates in that order, and the number of phases of the coil and the method of the electronic switch are designed as necessary. An example of this will be explained below. %
As shown in Figure 7, connect one side of the five-phase coil body Ll-Lg to the positive power supply, and connect the other terminal Lr''
Lr't'' are connected to the negative power supply via thyristors SCR+~5CRs, respectively, and each of the above thyristors SCR,~
Saturable reactor SR, ~5 in the gate circuit of S CRs
R=Jr are connected respectively, and these saturable reactors S
By bringing a permanent magnet close to the iron core of R+" S Rs, the iron core is saturated and these saturable reactors S R
The interface of SRs itself is reduced, and at this time, the output of the oscillator O8C is input to the gate of the thyristor SCR+ to turn on the thyristor 5CRI. For example, in FIG. 7, when the thyristor SCR1 turns on, the coil body L1 is excited, and at the same time, the capacitor C1 is charged in the forward direction.

Next, when the saturable reactor i; S R2 is brought close to the magnet gold, the thyristor S CR2 is turned on, and the coil body L2 is excited, and at the same time, the electric charge stored in the capacitor C1 is passed through the thyristors S CR2 and S CR+k. is discharged, and this refined thyristor SCR+ is turned off. Thus, with the circuit configuration shown in FIG. 7, the coil bodies L1 to L5 are sequentially ignited in a so-called ring counter set, and the rotor magnet (3) rotates accordingly. By the way, the above-mentioned Noristar jCR+~
Precise rotational position detection device 03 for igniting S CRs
1, as shown in FIG. 6, a magnet plate 04) is fixed to a key point of an output shaft (9) to which a rotor magnet (3) is fixed and rotates together with the rotor magnet (3), and this magnet plate ( 14) the above-mentioned saturable reactor SR arranged to face the
It is composed of ~・SR5, and the magnetic plate (l rest is the 8th
As shown in the shaded area in the figure, it is partially magnetized, and in the case of the above-mentioned embodiment, magnetization is applied only in the range of 2π15, and the saturable reactor S
When R+-S Rs faces the magnetized part of this magnet plate (+4), its corresponding thyristor SCR+ ~ S CRs
will turn on. Accordingly, as the rotor rotates, currents as shown in FIGS. 9(A) to 9(E) sequentially flow through each coil body L+ to L. Furthermore, the ninth
The oscillation time of the thyristor 5CR1 in the figure can be freely changed by changing the angle of the magnetization range in the magnet plate 04.Also, as a method of sequentially exciting the coil body from 1 to Lst, - In addition to the above-mentioned method, the method of position detection using an encoder and other known methods can be freely used.

FIGS. 1O and 11 show another embodiment of the present invention, in which when the rotor magnet (3) is rotated at high speed in the embodiment described above, when the stator yoke m is made of iron, a vortex is generated. This method was developed with the focus on the problem of generating electric current and current and deteriorating efficiency, and is made by winding an iron wire with a rectangular cross section into a spring shape and crimping it into a cylindrical shape. This structure forms the stator yoke f1+.

Note that it is fitted and fixed into a groove Q7) formed in the iron wire (end part of 151, Holter 06 of bearing tlol), and fcQ9) is a protective cover for reinforcement. Therefore, in this embodiment, there arises a problem when using laminated iron plates as in the conventional AC Tanabata, namely, a cost problem due to the need to punch out the iron plates into ring shapes and laminate them. Moreover, even when the rotor magnet (3) is rotated at high speed, eddy current loss can be reduced and efficiency can be improved.

[Effects of the Invention] Since the present invention is configured as described above, it is possible to achieve a brushless design without reducing the effect of the conventional DC coreless Tanabata, and the application The linearity of rotational speed and output torque with respect to voltage can be maintained over a wide range from very low speeds to high speeds, and also has the effect of completely solving the problems caused by having brushes.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are diagrams showing the manufacturing process of winding the inner and outer layers of a cylindrical coil according to an embodiment of the present invention, and FIG. 2(a) is a diagram showing the fitting of the outer and inner layers of the same cylindrical coil. FIG. 8 is an explanatory diagram of the mated state, and FIG. 5 is an enlarged cross-sectional view of the main part showing the state in which the above cylindrical coil is fixed to the stator yoke, FIG. 5 is a wiring diagram of each coil body in the above cylindrical coil, FIG. 6 is a sectional view of the above embodiment, and FIG. The figure is a circuit diagram of the same coil and body excitation circuit, Figure 8 is an explanatory diagram of the installation relationship between the magnet plate for detecting the rotational position and the saturable reactor, and Figure 9 is the current of each coil body as above. 10 is a sectional view of another embodiment of the present invention, and FIG. 11 is a partially cutaway perspective view of the same, in which (1) is a stator yoke, (2) is a cylindrical coil, (3
) is a rotor magnet, (I5) is an iron wire, and L'+ to h are coil bodies. Agent Patent Attorney Ishi 1) Chief 7Figure 7Figure 10Figure 11

Claims (2)

[Claims] (1) A cylindrical coil is fixed to the inner circumferential surface of a cylindrical stator yoke, and all of the rotor magnets whose outer circumferential side is magnetized by NSK are arranged so as to rotate freely in the center of the cylindrical coil, and each turn of the cylindrical coil is The wire is structured so that it reciprocates once between both axial ends of the cylindrical coil in one circumferential direction, and each of these windings is divided into a plurality of equal parts and connected, so that each coil body is sequentially energized. Characterized by a small DC current generator. (2) A small DC motor according to claim 1, characterized in that a stator yoke is formed by winding a wire made of a magnetic material such as iron wire into a coil spring shape.