JPS5980146A - Structure of pulse motor - Google Patents

Abstract

PURPOSE:To reduce the rotating angle per step and to enhance the output torque and the responding speed of a pulse motor by exciting an electromagnet to attract the corresponding part of a rotor, and meshing to two gears with the corresponding part, thereby removing the transient vibration during rotation. CONSTITUTION:Four stators 2 are provided on a frame 1 which is formed of a magnetic material, a coil 2 is wound on the stators 2 to form four electromagnet 4. Part 6 of a gear is integrally formed with a coil frame 5. Accordingly, the four coil frames 5 are form a gear 7 as a whole. A gear-shaped hole 15 is formed at the center and a magnetic unit 12 is formed on the outer periphery of a plastic rotor plate 14, a rotor gear 13 is formed in the vicinity of the magnetic unit, thereby forming a rotor as a whole. The electromagnets 4 are excited to mesh the gears 7 and 13, thereby rotating the rotor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a motor structure suitable for a pulse motor.

The objects of the present invention are to produce smaller and cheaper pulse motors than conventional pulse motors, to eliminate transient vibrations during rotation, to reduce the rotation angle per step and achieve high division, and to provide output (especially These include increasing the torque) and increasing the response speed.

An embodiment of the present invention will be explained below based on the drawings.

1 and 2, four stators 2 are provided on a frame 1 made of magnetic material, and each stator has a coil 3.
The winding is four electromagnets 4 (Ml, M2, M8, M4)
Nasu. A part 6 of a gear is integrally formed with the coil frame 5. Therefore, the four coil frames collectively form one gear 7. A plastic rotor plate 14 is provided with a gear-shaped hole 15 in the center and a magnetic part 12 on the outer periphery, and a rotor gear 18 is provided in the vicinity thereof, thereby forming the rotor 11 as a whole. (In this embodiment, 12 and 18 are integrated.) Also, the bearing 8 is installed in the frame so that the motor shaft 9 passes through it, and one end 10 of the motor shaft is shaped like a gear, and a hole 15 of the same shape at the center of the rotor. Engage with a slight gap. Therefore, the rotation of the rotor is transmitted to its -1 axis, and at the same time, the rotor can freely tilt with respect to the axis. Further, since the rotor position is determined by the motor shaft stage 16, when the motor is tilted, the two gears are partially engaged and the other gears are disengaged.

Still, the stator gear and rotor gear have different numbers of teeth (normally there is a difference of one tooth, but when there are a large number of electromagnets, the difference in number increases), so the whole gear does not mesh, but only partially. For example, there are 36 rotor gears and 8 stator gears.
There will be 5 pieces.

Next, the operation will be explained using two-phase excitation as an example.

Now, electromagnet MLM2 is excited. (Ml is M2 at the N pole
It is convenient if the winding direction of the coil is set so that it becomes the south pole, since the magnetic flux forms a closed magnetic path from M1 to rotor to M2 to stator to M1. ) The areas near Ml and M2 of the rotor are attracted, and the rotor gear and stator gear are also engaged near the center of Ml and M2.

In order to advance the pulse motor one step, M2, M8 (
When the N pole is excited, the meshing part of the gear moves to the vicinity of the center of M2 and M3.

However, since the rotor gear and the stator gear differ in number by one tooth, the movement of the meshing portion causes the rotor gear to rotate by approximately one-fourth of a phase. (Figure 8)
Similarly, switch the phases sequentially to M8, M4~M4, M1~M.
1, M2), it makes one electrical revolution and the rotor rotates by one phase (1/86 revolution). It will be easily understood that if the phases are switched in the opposite direction, the rotor will rotate in the opposite direction.

The effects of the invention regarding the above motor will be described.

PM where the rotation angle of one step is determined by the number of poles of the permanent magnet
In type pulse motors, VR type motors, etc. which are determined by the number of magnetic poles of the rotor, the poles are part of the magnetic circuit, and the magnetic circuit cannot be made smaller in relation to the output.

That is, it is difficult to unnecessarily increase the number of poles, and the rotation angle will not become small. On the other hand, the rotation angle of the pulse motor of the present invention is determined by the number of teeth of the rotor and has nothing to do with the magnetic circuit, so it can be set much smaller. In this example, the number of teeth is 86, but another motor (rotor diameter 20jff,
With 100 teeth, 8 electromagnets, and 2-phase excitation, we achieved 800 steps per rotation.

Also, a pair of gears has the function of converting the axial force coming from the electromagnet into rotational force, but because the input and output directions are different in this way, and after step feeding, the pair of gears Because the gears are tightly meshed at the bottom of the teeth and have a deep stable point, stable step response was achieved with little rotational unevenness (vibration) caused by overshoot, which is typical of pulse motors.

Considering the magnetic circuit, the pair of gears are in contact with each other and there is only a small gap. As an electromagnet, it is highly efficient, and combined with the small rotation angle of the step per step, it was possible to increase the output ()/ref and the response speed.

Compared to other motors, the simple structure and low cost will be easily understood from the explanation given here. There are big effects as mentioned above.

Although the present invention has been described for the case where four electromagnets are provided,
There is no restriction in principle as long as there are eight or more. Further, as for the driving method, conventional methods such as 1-phase, 1-2-phase, 2-phase, etc. can be widely applied as they are.

The shaft and rotor can also be fixed by a flexible leaf spring, and is not limited to the embodiment.

[Brief explanation of the drawing]

The drawings show one embodiment of the pulse motor of the present invention, in which Fig. 1 is a sectional view, Fig. 2 is an explanatory view showing the state with the rotor removed, and Fig. 8 is an explanatory view showing the meshing state of gears. 4: Electromagnet 7: Stator gear 11: Rotor 13: Rotor gear Patent applicant Yasushi Morinaga Figure 1

Claims (1)

[Claims] A rotor consisting of at least 8 or more electromagnets arranged in a circle, a stator gear with 2 teeth fixed nearby, and a rotor gear with a different number of teeth than 2, and a rotor that engages with the motor shaft in a freely tiltable manner. A structure of a pulse motor in which the corresponding part of the rotor is attracted by the excitation of the electromagnet, and the two gears mesh at the corresponding part.