JP2602177Y2 - Rotating body structure for magnetic encoder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating body structure for a magnetic encoder, and more particularly to a novel improvement for easily obtaining a zero point for detecting a zero point position.

[0002]

2. Description of the Related Art Conventionally, a structure shown in FIG. 4 has been generally used as a rotating body structure for a magnetic encoder of this kind which has been used. That is, in the case of the configuration shown in FIG.
The entire circumference of the gear 2 having a large number of teeth 1 in the predetermined axial direction is cut while leaving only one tooth 1, and the residual tooth portion 1 b left on the single tooth 1 is used as a zero point portion 1 </ b> A.

[0003]

Since the conventional rotary body structure for a magnetic encoder has been constructed as described above,
The following issues existed. That is, since a part of the gear in the axial direction is cut all around except one tooth, the cutting operation requires a lot of time and cost, and there is a lot of waste in designing the gear.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a rotating body structure for a magnetic encoder which can easily obtain a zero point position.

[0005]

According to the present invention, there is provided a rotating body structure for a magnetic encoder comprising a gear having a large number of teeth and made of a magnetic body. A ring portion integrally provided at an end portion, a zero point portion provided on the ring portion and formed with a notch corresponding to the teeth, and a zero point portion formed on the peripheral surface of the gear and formed between the gear and the ring portion. With a ring-shaped groove,
The gear is formed in a hollow shape.

[0006]

In the rotary body structure for a magnetic encoder according to the present invention, a gear and a ring portion are integrally formed, a zero point portion is formed in the ring portion, and an annular groove is formed between the ring portion and the gear. Is formed, the positional tolerance in the thrust direction with respect to the magnetic detecting element when mounting the gear can be increased, and interference of the output waveform of the magnetic detecting element is reduced by the annular groove.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the rotary body structure for a magnetic encoder according to the present invention will be described in detail with reference to the drawings. The same or equivalent parts as in the conventional example will be described with the same reference numerals. FIG. 1 is a cross-sectional view showing a rotary body structure for a magnetic encoder according to the present invention, FIG.
FIG. 3 is a plan view of FIG.

In FIG. 1 to FIG. 3, reference numeral 1 denotes a large number of teeth formed at a predetermined pitch on the peripheral surface of a hollow gear 2, and an axial end of the gear 2 has a ring portion. 10 are integrally formed.

[0009] 1 of the gear 2 in the ring portion 10
At a position corresponding to each tooth 1, a zero point portion 1 </ b> A including a notch 11 is formed, and a ring-shaped groove portion 12 is formed between the gear 2 and the ring portion 10. Further, the gear 2 is formed in a hollow shape with a shaft center portion penetrating therethrough.

Therefore, in the above-described configuration, the rotating body 20 is mounted on a rotating shaft of a magnetic encoder (not shown), and each tooth 1 is detected by a magnetic detecting element (not shown). Get the signal. Further, the zero point, that is, the origin of the magnetic encoder can be detected by the zero point signal obtained by passing the zero point portion 1A through the magnetic detecting element.

Further, since the annular groove 12 is formed, the positional tolerance in the thrust direction when the gear 2 is mounted can be increased, and the annular groove 12 can interfere with the output waveform of the magnetic detecting element. , The interference between the incremental signal and the zero point signal is reduced, and the S / N ratio of the signal can be improved.

[0012]

The rotary body structure for a magnetic encoder according to the present invention is constructed as described above, so that the following effects can be obtained. That is, since the gear and the ring portion are integrally formed, the structure is greatly simplified,
The zero point can be easily obtained by the notch formed in the ring portion. In addition, since the annular groove portion is formed between the gear and the ring portion, the position tolerance in the thrust direction at the time of mounting the gear is enlarged, the position tolerance for the magnetoresistive element is enlarged, and at the same time, the output waveform of the magnetoresistive element is increased. , And an encoder signal having a good S / N ratio can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a rotary body for a magnetic encoder according to the present invention.

FIG. 2 is a perspective view showing a main part of FIG.

FIG. 3 is a plan view of FIG. 1;

FIG. 4 is a perspective view of a main part showing a conventional rotary body structure for a magnetic encoder.

[Explanation of symbols]

 Reference Signs List 1 tooth 2 gear 1A zero point 10 ring part 11 notch 12 annular groove

Claims (1)

(57) [Scope of request for utility model registration] 1. A gear having a number of teeth (1) and made of a magnetic material
In the rotary structure for a magnetic encoder constituted by (2), a ring portion (10) integrally provided at an axial end of the gear (2), and the teeth provided on the ring portion (10). (1)
A zero point (1A) consisting of a notch (11) formed corresponding to
The gear (2) and the ring (1) are formed on the peripheral surface of the gear (2).
0) a ring-shaped groove (12) formed between the gears (2)
Is a rotating body structure for a magnetic encoder, which is formed in a hollow shape.