JPS6335160A - Stepping motor - Google Patents

Abstract

PURPOSE:To enlarge the diameter of a rotor so as to increase the torque and to make finer control possible, by providing two coils against a rotor on one side of the axial direction of rotor and on the other side of it. CONSTITUTION:On both sides of a rotor 7 stators 5 and 6 are provided. The stators 5 and 6 are equipped with iron cores 10, over which a coil 14 is wound. When pulse signals are given to each coil 14 of stators 5 and 6, the flux generated by each coil 14 is given to pole teeth 23 and 28 through iron cores 10 and substrates 21 and 26 in yokes 20 and 25, by which the pole teeth 23 and 28 are magnetized respectively. The rotor 7 pivots in accordance with the change of polarity in magnetization of pole teeth 23 and 28 of respective stators 5 and 6.

Description

[Detailed description of the invention] The present invention aims to solve the following problems.

(Industrial Application Field) The present invention relates to a stepping motor that converts electrical pulse signals into mechanically intermittent step motions.

(Conventional technology) In a conventional stepping motor,
In the case where two annular coils are placed side by side on the same axis, and a large number of pole teeth are provided on the inner periphery of the coils, and a rotor is further provided on the inner side, the diameter of the rotor is compared due to the presence of the outer coil. There was a problem in that it was limited to small dimensions.

This is because the circumference of the rotor is short and limited, so the number of magnetic poles that can be arranged there is small, and as a result, the rotor's 36
There was a problem that the number of steps in 0'1 rotation was small and only rough control was possible. Also, as mentioned above, the small diameter of the rotor means that when the force generated between the pole teeth and the magnetic poles is extracted to the rotating shaft of the rotor, only a relatively small torque is obtained on the rotating shaft. I was also worried about not being able to do it.

(Problems to be Solved by the Invention) This invention eliminates the above-mentioned conventional problems and allows the diameter of the rotor to be increased without being restricted by the coils.As a result, fine control of step feed is possible. The present invention aims to provide a stepping motor that can obtain a large torque on its rotating shaft.

The configuration of the present invention is as follows.

(Means for Solving the Problems) The present invention takes the measures as described in the claims above, and its effects are as follows.

(Operation) When a pulse signal is applied to each of the two coils, a large number of pole teeth arranged on the outer circumferential side of the rotor are respectively magnetized. The rotor is then moved in steps in the rotational direction by the magnetic attraction and repulsion forces between the magnetized pole teeth and the magnetic poles on the circumferential surface of the rotor.

(Embodiments) The drawings showing the embodiments of the present application will be explained below. In Figures 1 to 3, 1 is a hollow case;
It is made of non-magnetic material such as synthetic resin. 2 is a storage space, which has a cylindrical shape.

Reference numeral 3 indicates a positioning recess, and reference numeral 4 indicates a mounting portion for attaching the motor to any machine.

Next, 5 indicates a first stator, 6 a second stator, and 7 a rotor. In the first stator 5, lO is an iron core made of an oil-impregnated magnetic material. 11.12 is the fastening part,
13 indicates a bearing hole. Reference numeral 14 indicates an annular coil disposed on the outer peripheral side of the iron core 10. In this, 15 is a bobbin,
16 is a winding made of copper wire, 17 is v5vA1
Insulating tape to protect the outer circumferential side of 6, 18 is the winding 16
The lead wires connected to are shown respectively. Next, 20 indicates an outer yoke, which is formed by punching and press-forming a magnetic material, such as an iron plate. In this yoke 20, reference numeral 21 is a yoke substrate, and after the running hole 22 is fitted into the fastening part 11, the end edge of the fastening part 11 is caulked so that the iron core can be fixed.
It is fixed at 0.

Reference numeral 23 indicates a pole tooth, and 24 indicates a positioning piece. Next, 25 is an inner yoke, which is formed in the same manner as the outer yoke 20 and is fastened to the fastening portion 12 in the same manner. In this yoke 25, 2
Reference numeral 6 indicates a yoke substrate, 27 indicates a stop tag, and 2B indicates a pole tooth. The pole teeth 23 on the outer yoke 20 and the pole teeth 28 on the inner yoke 25 are positioned such that their respective tips are arranged alternately in the circumferential direction on the outer circumferential side of the rotor. Further, the total number of these pole teeth 23°2 is the same as the number of magnetic poles (described later) in the rotor (for example, 12). In both yokes 20 and 25, the yoke substrate and the pole teeth may be formed separately and then integrated by means such as welding.

Next, since the second stator 6 has the same configuration as the first stator 5, each member is given the same reference numeral as the first stator 5, and redundant explanation will be omitted.

Next, in the rotor, reference numeral 31 denotes a rotation shaft provided at the axis, which is rotatably supported by the bearing holes 13 of both stators. Reference numeral 32 denotes a rotor magnet, which has an annular configuration, and has a large number of N-pole and S-pole magnetic poles 33. on its outer peripheral surface.
34 are arranged alternately in the circumferential direction. Reference numeral 35 denotes a stopper, which is used to integrate the magnet 32 and the rotating shaft 31, and is made of a non-magnetic material such as plastic.

Assembling a stepping motor with the above configuration is as follows:
After assembling the first and second stators, for example, the second stator
The stator 6 is inserted into the space 2 from one side of the case 1 and fixed. In this case, the positioning piece 24 is made to fit into the positioning recess 3. Next, insert the rotor 7 into the space 2 from the other side.
and insert one end of the rotating shaft 31 into the bearing hole 13 of the second stator 6. Next, the first stator 5 is inserted into the space 2 from the other side. In this case, rotation axis 3
1 is inserted into the bearing hole 13 of the first stator 5, and the positioning piece 24 is fitted into the positioning recess 3. Then, the eight stator 5 is fixed to the case l by any means. This completes the assembly of the stepping motor. In the assembled state, the relationship between the pole teeth 23.28 on the first stator and the pole teeth 23.28 on the second stator 6 is as shown in FIG. The distance from the pole teeth 28 is one pitch, and the positional relationship is shifted by a half pitch in the circumferential direction of the rotor 7.

Next, FIG. 4 shows an example of a drive means for the stepping motor M, and shows an example of a unipolar drive circuit. In the figure, reference numeral 41 denotes a drive circuit, which is composed of a large number of transistors 42 and diodes 43. Reference numeral 44 indicates a power supply terminal, and 45a to 45d indicate input terminals, respectively. Note that the drive circuit may be bipolar drive.

Next, the operation of the stepping motor having the above configuration will be explained. By applying a pulse signal to each of the input terminals 453 to 45d, each coil 14.1 of each stator 5, 6 is activated.
A pulse signal is applied to the windings 4 and current flows through them. The magnetic flux generated by each coil due to the current is the iron core 1
0, is applied to the pole teeth 23.28 via the substrate 21.26 in each yoke 20.25, and the pole teeth 23.28 are respectively magnetized. The state of magnetization sequentially changes as shown in FIGS. 5(A) to 5(E) each time the direction of the current to the winding of the coil 14 of each stator 5.6 is reversed. As a result, the N-pole and S-pole magnetic poles 33.34 of the rotor 7 are magnetically attractive and repulsive with the pole teeth 23.28 magnetized to the N-pole and S-pole, respectively, and the magnetic poles 33.34 of the stators 5, 6 are In response to changes in the polarity of magnetization of the pole teeth, the rotor 7 is sequentially fed in steps as shown in FIGS. 5(a) to 5(e), and rotates. The rotational force is taken out via the rotation shaft 31 and operates various machines. As the excitation method for the coils of each of the stators 5 and 6, any known excitation method such as one-phase excitation, two-phase excitation, 1-2 phase excitation, etc. can be used.

When the rotor rotates as described above, since the radius of the rotor is formed to be large without being restricted by the coils, a large inertia can be obtained and smooth rotation can be performed.

Next, when the outer yoke and inner yoke of a stepping motor with the above structure are formed by bending means using a press, the pole teeth of each yoke are formed by bending from the outer circumferential side of the board, so the following There are also some advantages. That is, the rotor magnet 32 is
When the length in the axial direction of the rotor is made long, and the length of the tip of the pole tooth overlapping with the pole tooth tip is also made long, the pole tooth can be made arbitrarily long depending on the length of the rotor. This helps to solve the drawback that in conventional structures, the length of the pole teeth is limited because the pole teeth must be bent from the inner peripheral side of the substrate.

Next, FIG. 6 shows a different embodiment of the present application, in which the iron core 1
A recess 52 is formed in 0e, and a bearing 51 impregnated with oil (oil-impregnated bearing) is fixed therein by press-fitting means.
This shows an example in which the rotation shaft 31e is rotatably supported.

It should be noted that parts that are considered to have the same or equivalent configuration as those in the previous figure in terms of function are given the same reference numerals as in the previous figure with an e in the alpha character, and redundant explanations are omitted.

(Effects of the Invention) As described above, in the present invention, when it is desired to move the rotary shaft 31 in steps, by applying a pulse signal to the two coils 14, 14, a large number of pole teeth 2
3 and 28 are respectively magnetized, and as is well known, the rotor 7 can be rotated in steps corresponding to the above-mentioned pulse signal, and the movement can be extracted through the rotation shaft 31.

Moreover, the structure for rotating the rotor in steps as described above is such that two coils 14, 14 are arranged on one side and the other side in the axial direction of the rotor. The presence of the two coils has no relation to the size, so the diameter of the rotor 7 can be increased without being restricted by the coils.

This means that the circumference of the rotor 7 can be significantly longer than in conventional structures, allowing a large number of magnetic poles to be arranged there.As a result, the number of steps in one 360' rotation of the rotor can be increased, allowing fine control. This has the effect of making it possible to provide a stepping motor that can perform The radius also has the effect of making it possible to obtain a large torque on the rotating shaft.

[Brief explanation of drawings]

The drawings show an embodiment of the present application, and FIG. 1 is a longitudinal cross-sectional view;
Fig. 2 is a partially cutaway side view, Fig. 3 is an exploded perspective view, Fig. 4 is a circuit diagram for explaining the driving means of the stepping motor, and Fig. 5 is a diagram for explaining the step feed operation (many FIG. 6 is a partial vertical cross-sectional view showing a different embodiment. 1...Case, 7...Rotor, 33.34...M
1 pole, 14.14...coil, 23.28...pole tooth. Fig. 1 Fig. 4 Fig. 2 S Fig. S Fig. I2゜

Claims (1)

[Claims] Inside the case, a rotor having a rotating shaft at its axis and a plurality of magnetic poles arranged side by side in the circumferential direction on its outer circumferential surface is rotatably arranged. On one side and the other side of the rotor, annular coils are arranged approximately coaxially with the axis of the rotor, and on the outer circumferential side of the rotor,
A stepping motor characterized in that a number of pole teeth corresponding to the number of magnetic poles are arranged so that the rotor can be fed in steps in a rotational direction by applying a pulse signal to the two coils.