JPH07227076A - Forward/reverse rotation stepping motor - Google Patents

Abstract

PURPOSE:To provide a forward/reverse rotation stepping motor which is simple in structure and can easily set the forward rotation stable position of a rotor in a magnetic offset state. CONSTITUTION:The title motor comprises a rotor 11 made of a permanent magnet magnetized to N and S poles and a stator 12 for magnetically driving the rotor 11, a cylindrical space 13 is formed at the stator 12, at the same time the dynamic magnetic center line is nearly perpendicular to the cylindrical space 13, and an overhang part is formed at the stator 12, thus biasing the static stable position of the rotor 11 for the dynamic magnetic center line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a simple structure,
The present invention relates to a stepping motor capable of forward and reverse rotation.

[0002]

2. Description of the Related Art A conventional forward / reverse rotation stepping motor will be described below.
The data will be described with reference to FIG. FIG. 4A shows 18
Forward / reverse rotation stepping motor that rotates in steps of 0 °
1 shows an example, and 1 has a cylindrical space 1a
The stators 2 are the N and S poles provided in the cylindrical space 1a.
A rotor 3 composed of a magnetized permanent magnet, and a coil 4 ₁，
Four₂Is wound and is connected to the stator 1 by an iron core 5 is a magnet
Air offset (state where magnetism is not generated in the stator)
Positioning of rotor 2 to set static stable position
It is a permanent magnet for.

In this forward / reverse rotation stepping motor, a magnetic flux along the magnetic force lines 7a is generated by energizing the coil 4a, and a magnetic flux 7 is generated by energizing the coil 4b.
A magnetic flux along b is generated. Magnetic force as shown by arrows 7c and 7d is generated in the cylindrical space 1a. When the coil 4a is energized, the rotor 2 rotates in the direction of the arrow 8, and then the coil 4a is turned off and the coil 4b is energized, whereby the rotor 8 rotates in one direction and the permanent magnet 5 Due to the index torque due to, the rotor 2 comes to a static stable position and the rotor 2 makes one rotation.

FIG. 4 (b) shows the essential parts of another forward / reverse rotation stepping motor, 1 ₁ and 1 ₂ are stators, and 2
Is a rotor composed of permanent magnets magnetized to N and S poles. The stator 1 _1, 1 ₂ of the tip arcuate notch 1 ₃ respectively, 1 ₄ is formed, tip portions of the stator 1 _1, 1 ₂ are opposed at a predetermined gap. The cutout portions 1 ₃ and 1 ₄ are slightly displaced from each other, and when the rotor 2 is arranged in the space formed by the cutout portions 1 ₃ and 1 ₄ , the rotor 2 is fixed to the stators 1 ₁ and 1 _2. The part that is closest to is formed. When magnetically offset, the rotor 2 creates an index torque at this position and is constrained along the static stability line 9.

When a magnetic field is generated by the stators 1 ₁ and 1 ₂ , magnetic lines of force are generated along the dynamic magnetic center line 10b, and the rotor 2 rotates by obtaining an output torque and is rotated 180 degrees in the magnetic offset state. Rotate to °. Then, the stator 1
_{When the} magnetic lines of force are generated in the opposite directions by ₁ and 1 ₂ , the rotor 2 obtains a driving torque and rotates in the same direction, and rotates 180 ° in the magnetic offset state to rotate once.

[0006]

However, as shown in FIG.
The forward / reverse rotation stepping motor has a
The permanent magnet 5 is required to set the static stable position of the rotor 2.
There are some drawbacks. In addition, the forward / reverse rotation step of FIG.
The ping motor has a permanent magnet to set a static stable position.
No need for stones, but stator 1₁, 1₂And of rotor 2
The static stable position of the rotor 2 is set by the gap,
Stator 1₁, 1₂And high positioning accuracy of rotor 2 are required
Is required. In this type of forward / reverse rotation stepping motor,
Stator 1 ₁, 1₂And the rotor 2 are assembled individually
, Any one of the three components exceeded the tolerance.
If the drive torque is not sufficient, the probability of failure is extremely high.
It has a very high defect.

The present invention has been made in view of the above, and provides a forward / reverse rotation stepping motor having a simple structure and capable of easily setting a static stable position of a rotor in a magnetic offset state. The purpose is.

[0008]

In order to achieve the above object, a forward / reverse rotation stepping motor according to the present invention magnetically drives a rotor composed of permanent magnets magnetized to N and S poles. And a stator configured to form a substantially cylindrical space, and the dynamic magnetic center line is substantially orthogonal to the space, and the stator is provided with an overhang portion to form a dynamic magnetic center. The static stable position of the rotor is biased with respect to the line.

[0009]

In the forward / reverse rotation stepping motor of the present invention, the stator is constructed so that the dynamic magnetic center lines of the magnetic force lines that generate the drive torque are substantially orthogonal to each other, and the bulging portion is formed in the stator to dynamically move the magnetic field lines. The static stability line is biased with respect to the magnetic center line to create the index torque of the rotor in the magnetic offset state, and the magnetic flux along the dynamic magnetic center line in either direction of the orthogonal dynamic magnetic center lines. The rotation direction is controlled so as to generate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A forward / reverse rotation stepping motor of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an embodiment of a forward / reverse rotation stepping motor of the present invention.
In the figure, 11 is a rotor composed of permanent magnets magnetized to N and S poles, and 12 is a stator composed of stator members 12a to 12c composed of a ferromagnetic material such as iron. The stator member 12a has branch-shaped portions extending in all directions, and a substantially cylindrical space 13 in which the rotor 11 is arranged is formed at a crossing portion. The stator members 12b and 12c, on which the coils 14a and 14b are respectively wound, are provided at the respective ends of the stator member 12a with rivets 15a to 1c.
It is fixed by 5d or the like.

16a and 16b are dynamic magnetic center lines,
By energizing the coils 14a and 14b, the rotor 11
Shows the direction of the magnetic flux that gives the drive torque to the. The stator 12 has a shape such that the dynamic magnetic center lines 16a and 16b are substantially orthogonal to each other. Further, in the state where the coils 14a and 14b are not energized, that is, in the magnetic offset state,
The rotor 11 produces an index torque at a position along the static stabilization line 17 (static stabilization position).

Next, the main part of the stator 12 will be described in detail with reference to FIG. The stator member 12a has a predetermined thickness, a substantially cylindrical space 13 is provided to the center point of the intersection of dynamic magnetic center line 16a and 16b are orthogonal, stator tines 20 ₁ to 20 extending in all directions ₄ is stenosis 1
9a to 19d are connected to each other, and the narrowed portions 19b and 19d form arcuate grooves 18a and 18b on the inner wall surface of the cylindrical space 13 to form the narrowed portions 19a to 19d, thereby increasing the magnetic resistance. , The stator branch 20 ₁ ,
20 ₃ and the stator branches 20 ₂ and 20 ₄ are magnetically separated.

Stator branch 20₁, 20₃Is that
Recesses 20a and 20b are formed to reduce magnetic resistance.
However, the shape is such that the magnetic flux generated from the rotor 11 can easily pass through.
ing. In the magnetic offset state, it is emitted from the rotor 11.
The generated magnetic flux is the stator branch 20. ₁, 20₃Overhang 20
One that is easier to pass by forming a and 20b
Since it flows in the opposite direction, the magnetic force line 21 has a substantially inverted S shape.
Therefore, the rotor 11 moves from the dynamic magnetic center line 16a to the predetermined position.
The index torque is applied to the static stability line 17 having the angle θ.
Create and be restrained.

Next, based on FIG. 3, the rotation of the forward / reverse rotation stepping motor will be described with reference to FIGS. 1 and 2. Incidentally, FIG. 3A is a diagram for explaining the forward rotation,
FIG. 3B is a timing chart showing the power supply timing to the coil 14a, FIG. 3C is a diagram for explaining reverse rotation, and FIG. 3D is a timing chart showing the power supply timing to the coil 14a. . The case where the rotor 11 rotates forward will be described with reference to FIG.
In (a), the rotor 11 is in the magnetic offset state and is stopped at the static stable position. When the coil 14a is energized at time t ₁ , as shown in (b), the stator branch portions 20 ₁ ,
The N and S poles are generated at 20 ₃ , the N pole of the rotor 11 repels, the N pole of the rotor 11 is attracted to the S pole of the stator branch portion 20 _{3, and} a driving torque is applied to the rotor 11. The rotor 11 rotates 180 ° as shown in (c). Time t ₂
When the power supply to the coil 14a is cut off, the magnetic offset state is established, and the rotor 11 is in the static stable position as shown in (2). Next, when a current is applied to the coil 14a in the opposite direction at time t ₃ , as shown in FIG.
The S and N poles are generated at 0 ₁ and 20 ₃ , and the N pole of the rotor is attracted to the S pole of the stator and rotated by 180 °. By controlling the current supply to the coils 14a and 14b in this manner, the rotor 11 rotates once.

Next, the case where the rotor rotates in the reverse direction will be described with reference to FIG. (A) shows the state where the rotor 11 is in the static stable position. As shown in (b), when the coil 14b is energized at time t ₁ , N and S poles are generated in the stator branch portions 20 ₃ and 20 ₄ , the S pole of the rotor 11 repels, and the N pole is the S pole of the stator. It is attracted to the pole and rotates 180 ° as shown in (c). When the magnetic offset state is set at time t ₂ , the rotor 11 is in the static stable position (the polarity of the rotor is reversed from that in the normal rotation) as shown in (2). When energized in the reverse direction to the coil 14b at time t _3, the polarity of the stator branches 20 _3, 20 ₄ is as shown in (e), N-pole of the rotor 11 is reversed,
The S pole is attracted and rotates 180 °, and the rotor 11 makes one rotation.

As described above, in the forward / reverse rotation stepping motor of the present invention, the stator obtains the driving torque by the magnetic fluxes which generate the forward rotation and the reverse rotation along the different dynamic magnetic center lines. . Further, each branch of the stator has a shape capable of generating an index torque by forming a narrowed portion so that each stator branch is magnetically insulated, and further forming an overhanging portion on the stator. . Therefore, the index torque is generated in the rotor only by aligning the rotation axis of the rotor with the central axis of the cylindrical space of the stator. Of course, the shape of the stator is not limited to the embodiment, and the stator branch may be bent upward and the stator member around which the coil is wound may be attached to the stator branch.

[0017]

As described above, in the forward / reverse rotation stepping motor of the present invention, the dynamic magnetic center lines of the magnetic fluxes that generate the drive torque for rotating the rotor in the cylindrical space of the stator are substantially orthogonal to each other. Of the stator arranged in such a manner that the statically stable position of the rotor can be set by forming the overhanging portion on the stator so that the statically stable line is biased with respect to the dynamic magnetic centerline. There is.

Further, the forward / reverse rotation stepping motor of the present invention comprises two main components, a stator having a coil wound around it and a rotor, and the rotation axis of the rotor is the central axis of the cylindrical space of the stator. The stepping motor can be configured only by adjusting the structure, which is an extremely simple structure, and has an advantage that the failure occurrence rate caused by variation in mounting accuracy can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a forward / reverse rotation stepping motor of the present invention.

FIG. 2 is a plan view showing a main part of the embodiment shown in FIG.

3A is a diagram showing an example for explaining forward rotation, FIG. 3B is a timing chart for explaining energization of a coil, and FIG. 3C is an example for explaining reverse rotation. FIG. 6D is a timing chart for explaining energization of the coil.

FIG. 4 is a plan view showing an embodiment of a conventional forward / reverse rotation stepping motor.

[Explanation of symbols]

11 rotor 12 stator 12a-12c stator member 13 cylindrical space 14a, 14b coil 15a-15d rivet 16a, 16b dynamic magnetic center line 17 static stabilizing line 18a, 18b arcuate groove 19a-19d constricted portion 20a, 20b overhang Part 20 _{1 to} 20 ₄ Stator branch part 21 Magnetic field line

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Claims (1)

[Claims] 1. A forward / reverse rotation stepping motor comprising a rotor composed of permanent magnets magnetized to N and S poles, and a stator for magnetically driving the rotor, wherein a substantially cylindrical space is formed. In addition, the stator is configured such that the dynamic magnetic centerline is substantially orthogonal to the space, and the projecting portion is formed in the stator to bias the static stable position of the rotor with respect to the dynamic magnetic centerline. A forward / reverse rotation stepping motor characterized by being made.