JP2605536B2 - Rotary 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 rotary encoder used for detecting the position of an AC motor (AC motor) such as FA equipment, and more particularly, to a rotary encoder for effectively reducing the mounting distance in the motor axis direction. Regarding the structure.

[0002]

2. Description of the Related Art Conventionally, robots, NC machine tools, etc.
As a rotary encoder used for detecting the position of the AC motor of the A device, for example, a rotary encoder having a structure shown in FIG. 3 is known. That is, the rotary encoder 101
A rotating part 103 fixed to the rotating shaft 102 of the C motor 100 so as to be integrally rotatable, an AB-phase detection magnetic sensor 104 disposed close to and opposed to a peripheral edge thereof, and a closely facing lower surface of the rotating part 103. And a magnetic sensor 105 for UVW phase detection arranged in the same manner. The rotating unit 103
A disk-shaped magnetic drum 111 around which position information corresponding to the A-phase and the B-phase is magnetically recorded;
And a magnetic shield plate 112 fixed to the lower surface of the AC motor 10 via the magnetic shield plate 112 so as to be rotatable integrally with the rotating shaft 102 below the magnetic drum 111.
A UVW phase signal magnet 113 (the number of magnets is one) is magnetized at equal intervals in the circumferential direction by a number corresponding to the number of phases of 0. With this configuration, the rotary encoder 101 detects a change in position due to the rotation of the magnetic drum 111 by the AB-phase detection magnetic sensor 104 disposed in close proximity to the recording surface of the magnetic drum 111, and outputs a UVW signal. The position of the phase signal magnet 113 is determined by the UVW phase detection magnetic sensor 105.
This is a configuration for detecting by:

[0003]

However, in the structure of the prior art, the magnetic shield plate 11 is provided on the lower surface of the magnetic drum 111.
2, the length of the rotary encoder 101 in the direction of the rotating shaft 102 is increased, and there is a problem that the mountability to the device is poor. In other words, the rotary encoder 102 protrudes from the AC motor 100 in the direction of the rotary shaft 102 by a distance Z obtained by adding the height X of the magnetic drum 111 and the height Y from the lower peripheral edge of the magnetic shielding plate 112. In order to attach the 101 to the AC motor 100, a mounting distance of the distance Z is required in the direction of the rotation axis, which has led to an increase in the size of the apparatus. As described above, the above-described prior art uses a relatively large mounting dimension in the rotation axis direction when mounted on an AC motor.
There was still room for improvement.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary encoder which solves the above-mentioned problems of the prior art at once, and which has a simple structure and can be mounted in an AC motor and can be reduced in mounting dimension in a rotating shaft direction.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a position which is fixed so as to be integrally rotatable with a rotating shaft of an AC motor, and whose rotational position is magnetically recorded along a circumferential direction. A recording unit, a phase recording unit disposed so as to be integrally rotatable with the rotating shaft, and magnetically recording a phase position determined according to the number of poles of the AC motor; and a position recording unit and the phase recording unit. A magnetic shielding member interposed therebetween, position detecting means disposed in close proximity to the position recording section, and phase detecting means disposed in close proximity to the phase recording section. In the rotary encoder, the position recording section has a storage section which is a space provided along the rotation axis direction around the rotation axis, and furthermore, the phase recording section and the magnetic shielding member are stored in the storage section. Rotary characterized by being stored It is an gist the encoder.

[0006]

According to the present invention having the above-described structure, the phase recording section and the magnetic shielding member are accommodated in a storage section which is a space provided along the rotation axis direction around the rotation axis of the position recording section. That is, the mounting dimension in the rotation axis direction of the AC motor is limited to the rotation axis direction dimension of the position recording unit. Therefore, the rotary encoder of the present invention works to suitably reduce the mounting dimension in the rotation axis direction when the AC motor is mounted. As described above, the technical problems of the present invention are solved by the operation of each component of the present invention.

[0007]

Next, preferred embodiments of the present invention will be described in detail with reference to the drawings. First Embodiment A rotary encoder according to a first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the rotary encoder 1 includes a rotating unit 4 that rotates in association with a rotating shaft 3 of an AC motor 2, and the rotating unit 4 that is closely opposed to a radial side portion thereof.
An AB phase detection magnetic sensor 5 that magnetically detects the rotational position of the AC motor 2, and a UVW phase, that is, a UVW phase detection magnetic sensor 6 that is disposed below the rotating unit 4 and detects the phase position of the AC motor 2. It is configured.

The rotating portion 4 magnetically records the A-phase and B-phase rotational position information on a recording surface 11A, which is a peripheral side surface thereof, and has a storage recessed portion 1 which is opened downward inside.
2, a magnetic drum 11 having a hollow cylindrical shape, a magnetic shield plate 13 fixed by adhesion or the like inside the storage recess 12 of the magnetic drum 11, and a storage recess of the magnetic drum 11 via the magnetic shield plate 13. It is composed of UVW-phase signal magnets 14 fixed to the inside of the rotating shaft 3 by adhesive or the like so as to be integrally rotatable with the rotating shaft 3 and magnetized at equal intervals in the circumferential direction by a number corresponding to the number of phases of the AC motor 2. .

With this configuration, the rotary encoder 1
AB indicates that a change in position due to the rotation of the magnetic drum 11 is detected by an AB arranged in close proximity to the recording surface 11A of the magnetic drum 11.
The position of the UVW phase signal magnet 14 is detected by the UVW phase detection magnetic sensor 6 while being detected by the phase detection magnetic sensor 5. The AB-phase detecting magnetic sensors 5 are disposed at one side of the magnetic drum 11, and the UVW-phase detecting magnetic sensors 6 are disposed at three positions on the upper surface of the AC motor 2 at intervals of 120 degrees in the circumferential direction. ing.

The recording portion around the magnetic drum 11 is made of a material such as spinex (FeCrCo) or pramag or formed by ferrite coating. The magnetic shielding plate 13 is made of a non-magnetically permeable material.

Here, the magnetic shield plate 13 and the UVW phase signal magnet 14 are both housed in the housing recess 12 opened to the lower surface side of the magnetic drum 11. That is, the depth dimension (dimension in the rotation axis direction) of the storage recess 12 of the magnetic drum 11 is set equal to the height dimension Y from the lower peripheral edge of the magnetic shielding plate 13. Therefore, the projecting distance of the rotary encoder 1 in the direction of the rotation axis 3 of the AC motor 2 is only the height dimension X of the magnetic drum 11.

As described above, according to the first embodiment, when the rotary encoder 1 is mounted on the AC motor 2, the axial mounting distance can be reduced to the height X of the magnetic drum 11. Therefore, the rotary encoder 1 can be widely applied to various types of FA equipment having a limited mounting space.
The versatility of is also increased.

Next, a second embodiment of the present invention will be described in detail with reference to FIG. Second Embodiment As shown in FIG. 2, the magnetic drum 31 of the rotary encoder 21 has a cylindrical shape, and is open in all directions of the rotation axis. The magnetic shield plate 3 is provided on the inner wall 32 of the magnetic drum 31.
3 is fixed by bonding or the like, and the central portion of the magnetic shielding plate 33 is fitted and fixed so as to be able to rotate integrally with the rotating shaft.
Further, inside the magnetic shielding plate 33, a UVW phase signal magnet 34 is fixed by bonding or the like. The UVW-phase signal magnets 34 are magnetized with the same polarity in the circumferential direction at equal intervals as the number of poles of the AC motor 2.

As described above, when the magnetic drum 31 is formed into a hollow cylindrical shape and the magnetic shield plate 33 and the UVW-phase signal magnet 34 are built therein, the rotation of the rotary encoder 21 when mounted on the AC motor 2 is performed. The axial projection distance can be reduced to the height dimension X of the magnetic drum 31.

As described above, according to the second embodiment, the rotary encoder 21 is mounted on the AC motor 2 by effectively utilizing the internal space of the magnetic drum 31.
Can be shortened in the rotation axis direction, and the mountability can be improved. In addition, since the mass of the rotating portion of the rotary encoder 21 attached to the rotating shaft of the AC motor 2 can be concentrated, adjustment of dynamic balance of the rotating shaft and the like is facilitated, and versatility is improved.

Although several embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and can be realized in various modes without departing from the technical idea thereof. Obviously you can get it.

[0017]

As described above in detail, according to the present invention, the phase recording section and the magnetic shielding member are stored in the storage section which is a space provided along the rotation axis direction around the rotation axis of the position recording section. With such a configuration, there is an excellent effect that the mounting dimension of the AC motor in the rotation axis direction can be reduced to the dimension of the position recording unit in the rotation axis direction. In this way, the mountability of the rotary encoder on the AC motor can be dramatically improved. Further, when the rotary encoder is mounted on the AC motor, downsizing by shortening the protruding distance in the rotation axis direction is possible, so that versatility can be improved. Further, there is an effect that the mounting distance can be sufficiently reduced with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a first embodiment of the present invention.

FIG. 2 is a side sectional view of a second embodiment of the present invention.

FIG. 3 is a side sectional view of the prior art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotary encoder, 2 ... AC motor, 4 ... Rotating part, 5 ... Magnetic sensor for AB phase detection, 6 ... Magnetic sensor for UVW phase detection, 11 ... Magnetic drum, 11A: AB phase recording surface, 12: storage recess, 13: magnetic shielding plate, 14 ...
・ Magnet for UVW signal

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masayoshi Yamashita Examiner, Yamaha Corporation 10-1 Nakazawacho, Hamamatsu City, Shizuoka Prefecture Masayuki Mori

Claims (1)

(57) [Claims] A position recording section fixedly rotatable integrally with a rotating shaft of the AC motor, and a rotational position magnetically recorded along a circumferential direction; a position recording section disposed so as to be integrally rotatable with the rotating shaft; A phase recording unit that magnetically records a phase position determined according to the number of poles of the AC motor; a magnetic shielding member interposed between the position recording unit and the phase recording unit; and a proximity to the position recording unit. A rotary encoder comprising: a position detection unit disposed to face the device; and a phase detection unit disposed to face and close to the phase recording unit. A rotary encoder having a storage portion which is a space provided along the axial direction, and further including the phase recording portion and the magnetic shielding member stored in the storage portion.