JPS63191020A - Hollow shaft encoder - Google Patents

Abstract

PURPOSE:To reduce deviation of a shaft along with a low cost, by connecting a disc holding body direct to an inner ring while a hollow part of the disc holding body is connected direct to a shaft hole of a bearing body. CONSTITUTION:A bearing body 2 comprising an inner ring 14, an outer ring 15 and a ball 16 is provided into a casing 1 having openings 13 at the top and the bottom thereof. A disc holding body 5 having a hollow part 5a is provided integral at the upper end of the inner ring 14 of the bearing body 2 and the hollow part 5a communicates with a shaft hole 2a of the bearing body 2. A rotary disc 4 having numerous rotary slits is fixed at a step 5b on the circumference of the disc holding body 5. Light emitted from a light emitting body 12 enters a light receiving body 9 through a rotary slit of the rotary disc 4 and a fixed slit of a stationary slit 10.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a hollow shaft encoder, and more particularly to a novel improvement for obtaining an encoder having a structure that is low in cost and has extremely little shaft wobbling.

a. Conventional technology There are various configurations of this type of optical encoder that have been used in the past, but a typical configuration is the one described in the document No. 3, although the name of the document is not disclosed here. The configuration shown in the figure can be mentioned.

In the figure, a casing designated by the reference numeral 1 is generally box-shaped and has openings 13 at its upper and lower parts. A bearing body 2 made of a ball bearing is provided.

A hollow shaft 3 is provided within the inner ring 14, and this hollow shaft 3 is tightly fitted into the inner ring 14 and projects upward from the upper end of the bearing body 2 to form a protrusion 3a. , the outer diameter of this protrusion 3a is configured to be small.

A disc holder 5 is integrally attached to the upper end of the inner ring 14 in such a manner that it is held at the outer peripheral position of the protrusion 3a. A rotating disk 4 having a rotating slit (not shown) is fixed thereto, and the disk holder 5 and the hollow shaft 3 are configured in a non-contact state.

A base plate 17 and a mounting body 18 are formed integrally with the casing 1 at the upper end of one edge of the casing 1, and the base plate 17 and the mounting body 18 are configured to sandwich the rotating disk 4. has been done.

A light emitter 12 is provided on the substrate 17, and the light emitter 1
On the mounting body 18 in the lower position corresponding to 2,
Fixed slit plate 1 with fixed slits (not shown)
0 and a photoreceptor 9 are arranged.

Therefore, the light emitted from the light emitter 12 enters the light receiver 9 through the fixed slit (not shown) of the rotating disk 4 and the fixed slit (not shown) of the fixed slit plate.

A conventional hollow shaft encoder is constructed as described above.

The light emitted from the light emitting body 12 passes through the rotating slit of the rotating disk 4 and the fixed slit l- (not shown) of the fixed slit plate 10, enters the light receiving body 9, and is transmitted through the rotating slit and the fixed slit. By detecting the magnitude of the amount of light, a pulse signal corresponding to the rotation of the hollow shaft 3 can be obtained.

C1 Problems to be Solved by the Invention Since the conventional hollow shaft encoder was constructed as described above, the following problems existed.

(1) Since a disc holder with a rotating disc is integrally provided on the outside of the hollow shaft provided inside the bearing body, when a drive shaft is connected inside the hollow shaft, shaft vibration is prevented. This shaft wobbling easily causes insufficient rotational precision of the rotating disk, causing deterioration of the output characteristics of the encoder.

Furthermore, in order to prevent such shaft runout from occurring, extremely high-precision machining is required, leading to a significant increase in costs and making it impossible to fully meet the demand for lower prices. Ta.

(2) Since an independent hollow shaft is used separately from the bearing body, there is a significant increase in cost and not only deterioration of output characteristics, but also
It was virtually impossible to reduce costs.

The present invention has been made in order to solve the above-mentioned problems, and in particular, it is an object of the present invention to obtain a hollow shaft encoder having an inexpensive structure that is low in cost and has extremely little shaft wobbling.

Means for Solving the d0 Problem The hollow shaft encoder according to the present invention includes a bearing body provided in a casing and having a shaft hole, and a disc having a hollow portion directly provided in the inner ring of the bearing body and penetrating in the axial direction. This configuration includes a holder, a rotating disk provided at one end of the disk holder and having a large number of rotating slits, and a light emitting element and a light receiving element disposed to sandwich the rotating disk.

83 Effects In the hollow shaft encoder according to the present invention, the disc holder is directly connected to the inner ring, and the hollow part of the disc holder is directly connected to the shaft hole of the bearing body, so that the central part of the encoder Since a hollow is formed and a rotating member such as a machine tool or a drive shaft can be directly connected to this shaft hole, the rotating member or drive shaft can be configured to directly pass through the hollow part of the disc holder. Therefore, it is possible to obtain a low-cost hollow shaft encoder with extremely little shaft wobbling.

Embodiments Hereinafter, preferred embodiments of the hollow shaft encoder according to the present invention will be described in detail with reference to the drawings.

1 and 2 are for showing a hollow shaft encoder according to the present invention; FIG. 1 is a side sectional view, and FIG. 2 is a perspective view showing the main part of FIG. 1.

The same or equivalent parts as in the conventional example will be described with the same reference numerals.

In the figure, a casing designated by the reference numeral 1 is generally box-shaped and has openings 13 at its upper and lower parts. A bearing body 2 made of a ball bearing is provided.

A disc holder 5 having a hollow portion 5a is integrally provided at the upper end of the inner ring 14 of the bearing body 2, and this hollow portion 5a communicates with the shaft hole 2a of the bearing body 2, and these shafts Hole 2a
The hollow portion 5a is formed to penetrate the bearing body 2 in the axial direction.

A rotating disk 4 having a large number of rotating slits 4a is fixed to a stepped portion 5b on the outer periphery of the disk holder 5, and a substrate is integrally attached to the upper end of one edge of the casing 1. 17 and a mounting body 18 are formed, and these substrate 17 and mounting body 18 are attached to the rotating disk 4.
It is configured to hold the

A light emitter 12 is provided on the substrate 17, and the light emitter 1
On the mounting body 18 in the lower position corresponding to 2,
A fixed slit plate 10 having a fixed slit 10a and a photoreceptor 9 are provided.

Therefore, the light emitted from the light emitter 12 enters the light receiver 9 through the rotating slit 4a of the rotating disk 4 and the fixed slit 10a of the fixed slit plate 10.

The hollow shaft encoder according to the present invention is constructed as described above, and its operation will be described below.

The light emitted from the light emitter 12 passes through the rotating slit 4a of the rotating disk 4 and the fixed slit 10a of the fixed slit plate 10.
By detecting the magnitude of the amount of light that enters the photoreceptor 9 and passes through the rotating slit 4a and the fixed slit 10a, a pulse signal corresponding to the rotation of the disc holder 5 can be obtained.

Note that the connection structure between the disk holder 5 and the inner ring 14 is as follows.
It goes without saying that the same effects can be obtained not only by using the structure shown in the figure but also by using other coupling structures not shown.

g0 Effects of the Invention Since the hollow shaft encoder according to the invention is configured as described above, it can produce various effects as described below.

(1) When connecting a rotating member or drive shaft of a machine tool or the like to an encoder, the bearing body of the rotating member or drive shaft is directly connected to the inner ring as shown by the dashed line in Fig. 1, and the disc holder is , the roundness of the rotating member or drive shaft and the disc holder can be achieved, and stable rotational characteristics of the rotating disc without shaft wobbling can be obtained.

(2) Compared to the conventional configuration, the number of parts is greatly reduced, the cost can be significantly increased, and a highly reliable hollow shaft encoder can be obtained with a simple structure.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing a hollow shaft encoder according to the present invention, FIG. 2 is an exploded perspective view showing the main parts of FIG. 1, and FIG. 3 is a cross-sectional view showing a conventional hollow shaft encoder. It is. 1 is a casing, 2 is a bearing body, 2a is a shaft hole, 4 is a rotating disk, 4a is a rotating slit, 5 is a disk holder, 5a is a hollow part, 9 is a photoreceptor, and 12 is a light emitter. Procedural amendment (voluntary) March 9, 1986

Claims (2)

[Claims] (1), a bearing body (2) provided in the casing (1) and having a shaft hole (2a), and an inner ring (14) of the bearing body (2)
a disc holder (5) having a hollow portion (5a) that is directly provided in the disc holder (5) and passing through in the axial direction; and a rotating circle that is provided at one end of the disc holder (5) and has a large number of rotation slits (4a). A plate (4), a light emitting body (12) and a light receiving body (9) disposed with the rotating disk (4) sandwiched therebetween, and A hollow shaft encoder characterized in that it is configured so that it can be connected to any other drive shaft. (2) The hollow shaft encoder according to claim 1, wherein the light emitter (12) and the photoreceptor (9) are held in the casing (1).