JP3123375B2 - AC servo motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC servomotor used for driving a robot or a transfer machine used as industrial equipment.

[0002]

2. Description of the Related Art In recent years, in the field of industrial equipment, demands for simplification of equipment and miniaturization of space have been further increased, and similar demands have also been made for a driving AC servomotor used therein. Furthermore, with the progress of miniaturization and space saving of the equipment, the so-called built-in tendency to consider the motor as a part of the structure of the equipment has increased. In order to meet these demands, in the field of AC servomotors, the performance of the field magnet of the rotor has been improved, the space factor of the stator winding has been improved, and the rotation position detector has been downsized to achieve higher performance. Has been attempted. However, there were the following problems in promoting the built-in operation.

[0003]

FIG. 3 shows the basic structure of a conventional AC servomotor.

[0004] 21 is a stator, 22 is a rotor, 23 and 24
Is a motor casing, 25 and 26 are bearings, and 27 is a rotational position detector.

When such a structure is built in,
For example, in the case of a structure in which a ball screw is directly driven, it is necessary to penetrate and mount the ball screw in the motor. . For example, the same can be said for an example of a scalar type robot in which a rotation axis and a linear motion axis are concentrically configured. In another example, when the robot is incorporated in the arm of a robot, the power line to the working section at the tip,
Since the signal line protrudes outside and limits the working range,
It is necessary to penetrate and pass through the center axis of the motor, and this case also has the same problem as in the above-described example. Of course, the above problem can be solved by developing a new rotation detecting device and a new braking device.

[0006]

[Means for Solving the Problems] In order to solve this problem
In the present invention, the motor and the rotational position detecting device are provided side by side.
In AC servo motors, the rotation axis and rotation position of the motor
Provide a timing pulley on each rotating shaft of the detector
The timing bell between these timing pulleys
The signal phase of the rotational position detector.
The groove for synchronizing with the rotation
It is formed at the shaft end. The rotation of the rotation position detector
The rotation of the motor is controlled by the braking device provided on the turning shaft.
It was done.

[0007]

As described above, the rotation detector is separated from the rotation shaft of the motor and connected by the timing belt, so that a larger through hole can be formed in the motor shaft. Of course, the separately mounted rotation detector can be rotated on the same rotation axis as the conventional one, so that it is not necessary to change the shape. Further, it is possible to mount a braking device on the rotation shaft of the rotation detector by a method similar to the conventional one, and the shaft diameter can be made the same, so that the conventional shape can be used as it is.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an AC servomotor according to a preferred embodiment of the present invention. In FIG. 1, the motor body includes a stator 1, a rotor 2, casings 3, 4 and bearings 5,
6 and connected to a timing pulley 11 on a rotating shaft 10 of a rotation detector 9 by a timing pulley 7 and a timing belt 8 to rotate the rotation detector 9 synchronously. The rotating shaft 10 and the rotation detector 9 are supported by casings 12 and 13 and bearings 14 and 15 attached thereto, respectively, and are fixed to the motor casing 4 by an attaching plate 16. 17
Is a through hole formed in the rotating shaft.

With such a configuration, the through hole 17 is not affected by the inner diameter of the rotation detector 9, and is limited in dimensions, bearing size, and mechanical strength necessary for forming the magnetic path of the magnetic circuit of the rotor 2. Limited only to If the braking device 18 is required, it can be mounted on the rotating shaft 10 of the rotation detector 9 and is not affected by the inner diameter of the braking device. On the other hand, in order to function as an AC servomotor, it is necessary to synchronize the phases of the rotation detector 9 and the rotor 2 of the motor. This can be easily achieved by providing the rotation groove 19 shown in FIG. Of course, the detection accuracy is not impaired by the timing belt.

On the other hand, downsizing, in which the size is increased in the radial direction, has the disadvantage of going in the opposite direction.

[0012]

As described above, according to the present invention, the built-in system is easy and the size of the device is greatly reduced, and the rotation detector is separated from the motor drive shaft, so that the type of the rotation detector can be reduced. The size can be selected regardless of the size of the motor, and the frequency of the detection signal can be changed by changing the pulley size. In addition, since the motor rotation axis and the rotation axis of the rotation detector are separated, load fluctuations applied to the rotation axis and vibrations and shocks applied to the axis are not directly applied to the rotation detector, so that it is difficult to cause problems. There is also an effect.

[Brief description of the drawings]

FIG. 1 is a sectional view of an AC servomotor according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of a timing pulley portion of the rotation detector according to one embodiment of the present invention.

FIG. 3 is a sectional view of a conventional AC servo motor. 1,21 Stator 2,22 Rotor 3,4,23,24 Motor Casing 5,6,14,15,25,26 Bearing 7,11 Timing Pulley 8 Timing Belt 9 Rotation detector 10 Rotation shaft 12, 13 Casing 16 Mounting plate 17 Through hole 18 Braking device 19 Rotation groove 27 Rotation position detector

Claims (2)

(57) [Claims] 1. A motor and a rotational position detecting device are provided side by side.
In AC servo motors, the rotation axis and rotation position of the motor
Provide a timing pulley on each rotating shaft of the detector
The timing bell between these timing pulleys
The signal phase of the rotational position detector.
The groove for synchronizing with the rotation
AC servomotor formed at the shaft end . 2. A brake provided on a rotating shaft of a rotational position detecting device.
2. The AC servomotor according to claim 1 , wherein the rotation of the motor is controlled by a device .