JPH05141984A - Rotary encoder - Google Patents

Abstract

PURPOSE:To shorten the fitting size in the rotary shaft direction with a simple structure when a rotary encoder is fitted to an AC motor. CONSTITUTION:A rotary encoder 1 is constituted of a rotation section 4 rotated interlockingly with the rotary shaft 3 of an AC motor 2, an AB-phase detecting magnetic sensor 5 magnetically detecting the rotation position of the rotation section 4 located near and faced to the radial side section, and a UVW-phase detecting magnetic sensor 6 arranged below the rotation section 4. A magnetic shield plate 13 and a UVW-phase signal magnet 14 are stored in a storage recess 12 opened to the lower side of a magnetic drum 11, and the depth size (rotary shaft direction size) of the storage recess 12 of the magnetic drum 11 is set equal to the height size Y from the lower periphery section of the magnetic shield plate 13.

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 electric motor (AC motor) such as FA equipment, and more particularly, to a rotary encoder for effectively reducing the mounting distance in the motor axial direction. Regarding the structure.

[0002]

2. Description of the Related Art Conventionally, F of robots, NC machine tools, etc.
As a rotary encoder used to detect the position of the AC motor of the device A, for example, a rotary encoder having a structure shown in FIG. 3 is known. That is, the rotary encoder 101 is
The rotating portion 103 fixed to the rotating shaft 102 of the C motor 100 so as to be able to rotate integrally, the AB phase detecting magnetic sensor 104 arranged in proximity to the peripheral portion of the rotating portion 103, and the lower surface side of the rotating portion 103 in close proximity to each other. The magnetic sensor 105 for detecting the UVW phase is arranged in the above. The rotating unit 103 is
A disk-shaped magnetic drum 111 around which magnetic field position information corresponding to the A phase and the B phase is magnetically recorded, and the magnetic drum 11
1 and a magnetic shield plate 112 fixed to the lower surface of the motor 1. The magnetic shield plate 112 is fixed below the magnetic drum 111 via the magnetic shield plate 112 so as to rotate integrally with the rotary shaft 102.
The UVW-phase signal magnets 113 (the number of which is one) are magnetized at equal intervals in the circumferential direction according to the number of zero phases. With this configuration, the rotary encoder 101 detects the change in position due to the rotation of the magnetic drum 111 by the AB-phase detecting magnetic sensor 104 arranged close to and facing the recording surface of the magnetic drum 111, and also the UVW. The position of the phase signal magnet 113 is set to the UVW phase detection magnetic sensor 105.
This is the configuration to be detected by.

[0003]

However, in the above-mentioned conventional structure, the magnetic shield plate 11 is provided on the lower surface of the magnetic drum 111.
Since the magnet for the UVW phase signal is fixed via 2 as described above, the length of the rotary encoder 101 in the direction of the rotary shaft 102 becomes long, and there is a problem that the mountability in the device is poor. That is, since the AC motor 100 protrudes in the direction of the rotary shaft 102 by the distance Z that is the sum of the height dimension X of the magnetic drum 111 and the height dimension Y from the lower peripheral edge of the magnetic shield plate 112, the rotary encoder is rotated. In order to attach 101 to the AC motor 100, a mounting distance of the distance Z is required in the rotation axis direction, which leads to an increase in size of the device. As described above, the above-mentioned conventional technique 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 It is an object of the present invention to solve the above-mentioned problems of the prior art all at once, and to provide a rotary encoder having a simple structure and capable of shortening the mounting dimension in the rotation axis direction when mounting an AC motor.

[0005]

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

[0006]

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

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described in detail with reference to the drawings. First Embodiment A rotary encoder that is a first embodiment of the present invention will be described based on FIG. As shown in FIG. 1, the rotary encoder 1 includes a rotary unit 4 that rotates in conjunction with a rotary shaft 3 of an AC motor 2, and a rotary unit 4 that closely opposes a radial side portion of the rotary unit 4.
From the AB phase detecting magnetic sensor 5 for magnetically detecting the rotational position of the UV phase, the UVW phase magnetic sensor 6 for detecting the UVW phase, that is, the phase position of the AC motor 2 disposed below the rotating part 4. It is configured.

The rotating part 4 magnetically records the rotational position information of the A phase and the B phase on the recording surface 11A, which is the peripheral side surface of the rotating part 4, and also has a storage recess 1 which opens downward inside.
2, a hollow cylindrical magnetic drum 11, a magnetic shield plate 13 fixed inside the storage recess 12 of the magnetic drum 11 by adhesion or the like, and a storage recess of the magnetic drum 11 via the magnetic shield plate 13. The UVW phase signal magnets 14 are fixed to the inside of the rotary shaft 12 by gluing or the like so that they can rotate integrally with the rotary shaft 3 and are magnetized at equal intervals in the circumferential direction according to the number of phases of the AC motor 2. ..

With this configuration, the rotary encoder 1
Indicates a change in position due to the rotation of the magnetic drum 11, which is arranged in close proximity to the recording surface 11A of the magnetic drum 11.
The magnetic sensor for phase detection 5 detects the position of the magnet 14 for the UVW phase signal and the magnetic sensor 6 for UVW phase detection. The AB phase detecting magnetic sensor 5 is arranged at one side of the magnetic drum 11, and the UVW phase detecting magnetic sensors 6 are arranged at three places on the upper surface of the AC motor 2 at 120 ° intervals in the circumferential direction. ing.

The recording portion around the magnetic drum 11 is formed of a material such as Spinex (FeCrCo) or Plamag, or formed by applying ferrite. The magnetic shield plate 13 is made of a non-magnetic material.

Here, both the magnetic shield plate 13 and the UVW-phase signal magnet 14 are housed inside a housing recess 12 which is open 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 to be equal to the height dimension Y from the lower peripheral edge of the magnetic shield plate 13. Therefore, the protrusion distance of the rotary encoder 1 in the direction of the rotating shaft 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 mounting the rotary encoder 1 on the AC motor 2, the mounting distance in the axial direction can be shortened to the height dimension X of the magnetic drum 11. Therefore, the rotary encoder 1 can be widely applied to various FA devices having a limited mounting space.
The versatility of will also increase.

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 both 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 adhesion or the like, and the central portion of the magnetic shield plate 33 is fitted and fixed so as to rotate integrally with the rotating shaft.
A UVW-phase signal magnet 34 is fixed inside the magnetic shield plate 33 by adhesion or the like. The UVW-phase signal magnets 34 are magnetized by equal numbers to the number of poles of the AC motor 2 with their polarities reversed at equal intervals in the circumferential direction.

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

As described above, according to the second embodiment, the rotary encoder 21 can be effectively utilized by effectively utilizing the internal space of the magnetic drum 31 when mounting it on the AC motor 2.
The mounting distance in the direction of the rotation axis of can be shortened, and its mountability can be improved. Further, since the mass of the rotary portion of the rotary encoder 21 attached to the rotary shaft of the AC motor 2 can be concentrated, it becomes easy to adjust the dynamic balance of the rotary shaft and the versatility is enhanced.

Although some embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be implemented in various modes without departing from the technical idea thereof. Of course 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 housed in the housing section which is a space internally provided around the rotation axis of the position recording section along the rotation axis direction. With this configuration, there is an excellent effect that the mounting dimension of the AC motor in the rotation axis direction can be shortened 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 electric motor, the size can be reduced by shortening the protrusion distance in the rotation axis direction, so that the versatility can be improved. Further, it is possible to sufficiently reduce the mounting distance with a simple structure.

[Brief description of 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 ... AB phase detection magnetic sensor, 6 ... UVW phase detection magnetic sensor, 11 ... Magnetic drum, 11A ... AB phase recording surface, 12 ... Storage recess, 13 ... Magnetic shielding plate, 14 ...
・ UVW phase signal magnet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Hayashi 10-1 Nakazawa-machi, Hamamatsu-shi, Shizuoka Yamaha Stock Company (72) Masayoshi Yamashita 10-1 Nakazawa-machi, Hamamatsu-shi, Shizuoka Yamaha Stock Company

Claims (1)

[Claims] 1. A position recording unit, which is fixed so as to be rotatable integrally with a rotating shaft of an AC electric motor, and magnetically records a rotational position along a circumferential direction, and is disposed so as to be rotatable integrally 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 shield member interposed between the position recording unit and the phase recording unit; and a magnetic recording member close to the position recording unit. In a rotary encoder comprising position detecting means arranged so as to face each other and phase detecting means arranged so as to closely face the phase recording portion, the position recording portion is configured to rotate around the rotation axis. A rotary encoder having a storage portion which is a space internally provided along the axial direction, and wherein the phase recording portion and the magnetic shielding member are stored in the storage portion.