JPH1183541A - Bonding structure for rotating disk in encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a bonding structure in which a rotating disk can be bonded and fixed precisely to a face at right angles to the axial direction of a shaft by a method wherein a nonplanar part is formed on the end face of the shaft and an adhesive which is used in a bonding operation is made to escape into the nonplanar part. SOLUTION: A nonplanar part which is composed of a ring-shaped groove 1b and of a recessed part 1c is formed on the end face 1a of a shaft 1. The nonplanar part is constituted to be a hollow shape by plane parts 1d which are formed in parts other than the nonplanar part. By this constitution, after the respective plane parts 1d are coated with an adhesive, a rotating disk 3 is bonded. Then, the adhesive which is excessive in the respective plane parts 1d can escape into the nonplanar part (the ring-shaped groove 1b and the recessed part 1c), and the adhesive in the plane parts 1d becomes a constant thickness. Consequently, when the rotating disk 3 is bonded, the face of the rotating disk 3 is bonded and fixed in a state which is precisely at right angles to the axial direction of the shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary disk bonding structure in an encoder, and more particularly to a rotary disk bonding structure in which a non-planar portion is formed on an end face of a rotary shaft to release an adhesive during bonding. The present invention relates to a novel improvement for accurately bonding and fixing to a surface orthogonal to the axial direction of the horn.

[0002]

2. Description of the Related Art Conventionally, in a rotary disk bonding structure in this type of encoder used, bonding is performed as shown in FIGS. That is, what is indicated by reference numeral 1 in FIGS. 4 and 5 is the rotation shaft of the encoder, and the end surface 1 a of the rotation shaft 1 is provided with a rotation code (not shown) via an adhesive 2. The disk 3 is adhered and fixed. Therefore, the rotation shaft 1 and the rotating disk 3 are rotated, and rotation is detected by using, for example, an optical rotation detector (not shown).

[0003]

Since the rotary disk bonding structure in the conventional encoder has the above-described structure, there are the following problems. That is,
Since the entire end surface of the rotating shaft is a flat surface, if the rotating disk is bonded and fixed via an adhesive, the adhesive is not necessarily formed with the same thickness on the flat surface. In this case, the rotating disk cannot be accurately mounted on a surface orthogonal to the axial direction of the rotating shaft. In such a state, since a rotation detector is provided at a fixed distance to the surface of the rotating disk and a rotation detection signal is obtained,
When the rotating disk rotates, the distance between the surface of the rotating disk and the rotation detector is deviated depending on the rotation angle. In such a case, even if the rotation detector is a light transmission type or a light reflection type, there is a problem that the intensity of light varies, and a highly accurate rotation detection signal cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. In particular, a non-planar portion is formed on an end face of a rotating shaft to allow an adhesive used for bonding to escape into the non-planar portion. Accordingly, an object of the present invention is to provide a rotary disk bonding structure in an encoder in which a rotary disk is accurately bonded and fixed to a surface orthogonal to an axial direction of a rotary shaft.

[0005]

According to the present invention, there is provided a rotary disk bonding structure in an encoder according to the present invention, wherein a rotary disk having a rotary code is bonded and fixed to an end face of a rotary shaft with an adhesive. The disc bonding structure has a flat portion formed on the end face, and a non-planar portion having a shape depressed from the flat portion, wherein the adhesive escapes into the non-flat portion, The non-planar part is formed of a ring-shaped groove, and the non-planar part is formed of a stepped part.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a rotary disk bonding structure in an encoder according to the present invention will be described below with reference to the drawings. The same or equivalent parts as those in the conventional example will be described with the same reference numerals. 1 and 2, a reference numeral 1 denotes a rotary shaft of the encoder, and an end surface 1a of the rotary shaft 1 is provided with a non-planar portion including a ring-shaped groove 1b and a concave portion 1c formed in a ring shape. In addition to the non-planar portion, a ring-shaped flat portion 1d is formed. This non-planar part is formed in a shape depressed from the flat part 1d.

When the rotating disk 3 is bonded to the end surface 1a of the rotating shaft 1 having the above-described configuration, an adhesive (not shown) is applied to each flat portion 1d, and then the rotating disk 3 is bonded. The adhesive remaining in 1d can escape into each of the non-planar portions 1b and 1c, so that the flat portion 1d
Becomes an adhesive having a constant thickness, and the surface of the rotating disk 3 when the rotating disk 3 is bonded can be bonded and fixed in a state exactly perpendicular to the axial direction of the rotating shaft 1. The non-planar portion is not limited to the above-described annular groove 1b and concave portion 1c, but may be an annular step portion 1e as shown in FIG. Although not shown, the same effect as described above can be obtained when a large number of concave holes are formed in the end face 1a.

[0008]

The rotary disk bonding structure in the encoder according to the present invention is configured as described above.
The following effects can be obtained. That is, since a non-planar portion such as an annular groove or a step portion is formed on the end surface of the rotating shaft, an uneasy portion of the adhesive adhered to the flat portion at the time of bonding the rotating disk escapes into the non-planar portion, so that the flat surface is formed. The thickness of the adhesive in the portion becomes much more uniform than before, and the surface of the rotating disk after bonding and fixing can be mounted in a direction exactly perpendicular to the axial direction of the rotating shaft.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a rotary disk bonding structure in an encoder according to the present invention.

FIG. 2 is a cross-sectional view of the rotation shaft of FIG.

FIG. 3 is a sectional view showing another example of FIG. 2;

FIG. 4 is a perspective view showing a rotary disk bonding structure in a conventional encoder.

FIG. 5 is a cross-sectional view showing a rotation shaft of FIG.

[Explanation of symbols]

 Reference Signs List 1 rotating shaft 1a end face 1b annular groove (non-planar part) 1c concave part (non-planar part) 1e step (non-planar part) 1d flat part 3 rotating disk

Claims (3)

[Claims] 1. A rotary disk bonding structure in an encoder in which a rotary disk (3) having a rotation code is bonded and fixed to an end surface (1a) of a rotary shaft (1) by an adhesive. 1a) has a flat portion (1d) and a non-planar portion (1b, 1c, 1e) having a shape depressed from the flat portion (1d),
A rotary disk bonding structure in an encoder, wherein the adhesive is configured to escape into the non-planar portions (1b, 1c, 1e). 2. A rotary disk bonding structure according to claim 1, wherein said non-planar portion comprises a ring-shaped groove. 3. The rotary disk bonding structure according to claim 1, wherein the non-planar portion (1e) comprises a step.