JPH06284676A - Stepping motor - Google Patents

Abstract

PURPOSE:To prevent only a part into which a magnetic flux is concentrated from being saturated and at the same time to increase the output of a stepping motor. CONSTITUTION:This stepping motor comprises a rotor 20 composed of a rotor 3 with a permanent magnet 2 and a non-magnetic material and capable of being stepwise controlled, an output shaft 4 driven with the rotation of the rotor 20, a bobbin 8 on which a magnetic coil 7 is wound, yokes 9, 9a and 10, 10a to hold the bobbin having a bend part 11a therebetween from both sides, a shaft 5 for rotatably pivoting the rotor 20 and a housing 6 in which the shaft 5 and the yokes 9, 9a and 10, 10a are accommodated, wherein a thick part 11c is formed in the bent places of the bend part 11a provided in the yokes 9, 9a and 10, 10a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step motor, and more particularly to a step motor yoke.

[0002]

2. Description of the Related Art Conventionally, various types of devices have been proposed for driving an actuator by using a step motor as a driving source.

FIG. 4 is a sectional view showing an example of a conventional step motor 100. Rotor 101 made of non-magnetic material
A rotor 120 including a permanent magnet 102 and a bearing 103 to enable step control, a bobbin 105 around which the magnetic coil 104 is wound, an output shaft 106 rotatably driven by the rotor 101, and a bobbin 105 having a bent portion 107a on both sides. It is provided with a yoke 107 which is sandwiched from above, a shaft 108 and a housing 109 which houses the yoke 107. Further, since the magnetic flux is most likely to be concentrated on the bent portion 107a and is easily saturated, the yoke 107 is uniformly thickly press-molded to prevent saturation.

[0004]

However, in the prior art, in order to improve the output, it is necessary to strengthen the permanent magnet, and accordingly, the magnetic flux is also strengthened and the burden on the bent portion is increased.

Along with this, the yoke must be thickened so as not to be saturated, and therefore the portion where the magnetic flux is not concentrated is also processed thickly, so that the machining is performed with the same thickness as the portion where the magnetic flux is concentrated. This leads to waste of material and space.

Therefore, it is a technical object of the present invention to prevent the saturation of only the portion where the magnetic flux concentrates and to improve the output of the step motor.

[0007]

[Constitution of the invention]

[0008]

In order to solve the above-mentioned technical means, the technical means taken in the invention of claim 1 is a rotor and a magnetic coil which are made of a permanent magnet and a non-magnetic material and which enable step control. A bobbin around which the coil is wound, a yoke that has a bent portion and sandwiches the bobbin from both sides, an output shaft that is driven to rotate by a rotor, a shaft that rotatably supports the rotor, and a housing that houses the shaft and the yoke. The step motor has a thick portion formed at a bent portion of a bent portion provided on the yoke.

The technical means taken in the invention of claim 2 is a rotor which is made of a permanent magnet and a non-magnetic material and enables step control, an output shaft which is rotationally driven by the rotor, a bobbin around which a magnetic coil is wound, In a step motor having a yoke that has a bent portion and sandwiches a bobbin from both sides, an output shaft that is rotationally driven by a rotor, a shaft that rotatably supports the rotor, and a housing that houses the shaft and the yoke, It is characterized in that the second yoke is arranged at the bent portion of the bent portion provided on the yoke.

[0010]

The operation of claim 1 will be explained. Since the thick portion is formed only in the portion where the magnetic flux is easily concentrated, that is, in the bent portion of the bent portion of the yoke, and the portion where the magnetic flux is difficult to concentrate is made thin. Not only can the bent portion be prevented from being saturated, but many magnetic coils can be wound around the thinned portion, and the output can be improved.

Explaining the operation of claim 2, the second yoke is arranged only in the portion where the magnetic flux is easily concentrated, that is, in the bent portion of the bending portion of the yoke, and the portion where the magnetic flux is difficult to concentrate is made thin. Not only can the bent portion be prevented from being saturated, but many magnetic coils can be wound around the thinned portion, and the output can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a permanent magnet type step motor 1. In the step motor 1, the rotor 20 is composed of a combination of the permanent magnet 2 and the rotor 3 having a non-magnetic material. The output shaft 4 is the rotor 20.
It is driven to rotate by.

Reference numerals 7 and 7a denote magnetic coils. The magnetic coil 7 is wound by a cylindrical bobbin 8 and 8a. The bobbins 8 and 8a are made of iron yokes 9, 9a and 1.
It is fitted from both sides by 0, 10a.

The yokes 9, 9a and 10, 10a are formed so as to have the same shape as the bobbins 8, 8a, and the permanent magnet 2
It is formed of a plurality of protrusions 11 having bent portions 11a formed to collect the magnetic flux from and a flange portion 11b attached to the bobbins 8 and 8a.

After the yokes 9, 9a and 10, 10a are fitted on the bobbins 8, 8a, the rotor 20 is housed.

As a method of processing the yokes 9, 9a and 10, 10a, it is possible to form the yoke 9, 9a by sintering or the like. Further, the bobbin 8 includes the yokes 9, 9a, 10, 10
The magnetic coil 7 is wound on the magnetic coil 7 along the line a. Therefore, the flange portion 11b which is hard to be saturated can be made thin, and an arbitrary magnetic coil 7 according to the desired output can be obtained.
Can be wound.

Another embodiment is shown in FIG. Since the configuration of the step motor 1 has been described above, detailed description will be omitted.

A second member formed on the bent portion 11a of the yokes 9, 9a and 10, 10a is the same member as the yokes 9, 9a and 10, 10a, and is formed along the bent portion 11a.
Mount the yoke 30. Also, the bobbin 8 is a yoke 9, 9
The magnetic coil 7 is formed along a, 10, 10a and 30 and is wound along the stepped shape. Therefore, the thickness of the yokes 9, 9a and 10, 10a, 30 can be processed to a certain degree of thinness in a state where the press stroke does not saturate, and an arbitrary magnetic coil 7 is wound according to the desired output. It will be.

[0020]

As described above, according to the first aspect of the present invention, the thick portion is formed only in the portion where the magnetic flux is easily concentrated, that is, the bent portion of the bending portion of the yoke, and the portion where the magnetic flux is difficult to concentrate is thinned. As a result, not only it is possible to prevent the bent portion from being saturated, but also many magnetic coils can be wound around the thinned portion so that the output can be improved.

According to the second aspect of the present invention, the second yoke is arranged only at the portion where the magnetic flux is easily concentrated, that is, at the bent portion of the bent portion of the yoke, and the portion where the magnetic flux is difficult to concentrate is made thin. Not only is it possible to prevent the bent portion from being saturated, but more magnetic coils can be wound around the thinned portion to improve the output.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a step motor of this embodiment.

FIG. 2 is a sectional view showing a step motor according to another embodiment.

FIG. 3 is a cross-sectional view showing a conventional step motor.

[Explanation of symbols]

 1 Step Motor 2 Permanent Magnet 3 Rotor with Non-Magnetic Material 4 Output Shaft 5 Shaft 6 Housing 7 Magnetic Coil 8 Bobbin 9, 9a, Yoke 10, 10a Yoke 11 Projection 11a Bend 11b Flange 11c Thick 20 Rotor 30 Second yoke

Claims (2)

[Claims] 1. A rotor made of a permanent magnet and a non-magnetic material that enables step control, an output shaft that is rotationally driven by the rotor, a bobbin around which a magnetic coil is wound, and a bobbin that has a bent portion and is provided from both sides. A step motor provided with a yoke to be sandwiched, an output shaft rotatably driven by the rotor, a shaft rotatably supporting the rotor, and a housing for accommodating the shaft and the yoke. A step motor, wherein a thick portion is formed at a bent portion of the bent portion. 2. A rotor made of a permanent magnet and a non-magnetic material that enables step control, an output shaft that is rotationally driven by the rotor, a bobbin around which a magnetic coil is wound, and a bobbin that has a bent portion and is provided from both sides. A step motor having a yoke to be sandwiched, an output shaft rotatably driven by the rotor, a shaft for rotatably supporting the rotor, and a housing for accommodating the shaft and the yoke, the step motor being provided on the yoke. A step motor, wherein a second yoke is arranged at a bent portion of the bent portion.