JPH0713419Y2 - Coupling structure of rotating machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is for connecting an output shaft of a rotating machine such as an AC servomotor and a rotating shaft of a position detector such as a rotary encoder. The present invention relates to an effective rotating machine coupling structure.

[Prior art] In recent years, for example, rotating machines such as AC servo motors have been applied to ultra-precision processing machines and the like that require high accuracy and high reliability such as high-speed rotation, high-frequency start / stop, and maintenance-free. There is. In order to improve the control accuracy of such a rotating machine, it is necessary to couple a position detector that detects the rotational position of the rotor of the rotating machine, such as an absolute rotary encoder, to the rotor. Conventionally, for example, the following techniques have been known as a technique for coupling the rotating machine and the position detector. (1) As shown in FIG. 2, the output shaft 101 of the AC servomotor 100 and the rotary shaft of the absolute rotary encoder 102.
103 is connected to the coupling 104, and the coupling 10
4 and the above-mentioned output shaft 101 and the above-mentioned rotary shaft 103 by means of a bolt 1 with a hole.
Technology to fix at 05.

(2) As shown in FIG. 3, the output shaft 201 of the AC servomotor 200 is provided with a tapered hole 202 and a slit 203 for preventing rotation. On the other hand, the tip 206 of the rotary shaft 205 of the absolute rotary encoder 204 also has the tapered hole 2
Process so that it has a taper with the same gradient as 02. Further, a detent spacer 207 is interposed between the detent slit 203 of the output shaft 201 and the rotating shaft 205, and the case 208 of the absolute rotary encoder 204 and the
Leaf spring 2 arranged in the case of AC servo motor 200
09 is tightened with a bolt 210 via a sleeve 210a, and the outer peripheral surface of the tapered tip portion 206 of the rotating shaft 205 and the inner peripheral surface of the tapered hole 202 of the output shaft 201 by the urging force of the plate spring 209. A technology for fixing and contacting and with a predetermined pressing force.

[Problems to be Solved by the Invention] However, the above-mentioned conventional techniques have the following problems and are not yet sufficient. That is, (1) When the rotary machine and the position detector are coupled by a coupling or a leaf spring, it is necessary to accurately perform precise centering between the output shaft of the rotary machine and the rotary shaft of the position detector. However, this precise centering is extremely difficult and
If it is not correctly centered, it will not be possible to completely eliminate the looseness of the joint, which will reduce the assembling accuracy of the joint and is inappropriate when precise rotational positioning or high-speed rotation is required. was there.

(2) Also, if sudden acceleration and deceleration are repeated frequently, or if the machine is operated for a long time in an environment where vibration is transmitted from the outside, the bolts will loosen or the leaf spring will deform during rotation. Therefore, there is a problem in that the detection accuracy of the rotational position of the rotating machine is significantly deteriorated and reliability + durability is reduced.

(3) Further, the coupling or the leaf spring is a torque transmission system between the rotary machine and the position detector due to a misalignment or play between the output shaft of the rotary machine and the rotary shaft of the position detector. There is also a problem that the control accuracy of the rotating machine is deteriorated because it acts as a time delay element in.

Each of the above-mentioned disadvantages is caused when a rotating machine is used as an actuator and a servo system having a position detector as a sensor is configured.
Since the rotational position detection accuracy is lowered due to the poor accuracy of the joint portion between the both, and the joint portion behaves as a high-order delay element, it becomes impossible to realize precise control, which is a particularly remarkable problem.

An object of the present invention is to provide a connecting structure for a rotating machine, which can suitably improve both the assembly accuracy of the connecting section of the rotating machine and the position detector and the suppression of the action of the connecting section as a time delay element.

Configuration of the Invention [Means for Solving the Problems] The present invention made to solve the above problems is to combine a rotor of a rotating machine and a rotation shaft of a position detector that detects a rotation position of the rotor. In the connecting structure of the rotating machine described above, the rotor has a hollow portion having an opening at an end, and a can-shaped fitting member having an outer peripheral portion that fits in the hollow portion, and a center of rotation of the fitting member. A tubular body with a fitting hole provided so as to extend into the hollow portion and fitted into the rotary shaft of the position detector; and the rotary shaft of the position detector inserted in the fitting hole, And a fastening portion that fastens to the fastening portion, and an elastic portion that is provided between the fastening portion and the outer peripheral portion and exhibits at least greater elasticity than the outer circumferential portion and the fastening portion. The gist is the connecting structure of the rotating machine.

The fitting member has a can shape having an outer peripheral portion that fits inside the hollow portion of the rotor. Here, the rotor is, for example, a rotor such as an AC servo motor and a DC servo motor. For example, it can be realized by a can-shaped bracket sleeve made of carbon steel for machine structure, which is press-fitted into the rotor.

The fitting hole is formed in a cylindrical body provided so as to extend into the hollow portion of the rotor at the center of rotation of the fitting member, and is fitted into the rotary shaft of the position detector. The fastening portion is for fastening the rotary shaft of the position detector inserted in the fitting hole to the fitting member via the tubular body. For example, the rotation shaft of the position detector may be fixed to the fitting hole by an inner sleeve and a nut. In this case, fixing the nut with a pin can prevent the nut from loosening. Further, for example, a configuration in which the rotary shaft is bonded to the fitting hole with an adhesive, a configuration in which the rotary shaft is press-fitted into the fitting hole, or a shrink fit may be adopted.

The elastic part is provided between the fastening part and the outer peripheral part, and exhibits at least greater elasticity than the outer peripheral part and the fastening part. For example, it can be realized by providing an escape groove or a thin portion in the outer peripheral portion of the fitting member between the fastening portion and the outer peripheral portion. Further, for example, it can be realized by connecting the fastening portion and the outer peripheral portion with rubber, synthetic resin, a metal material having high elasticity, a composite material, or the like. Furthermore, for example, a material exhibiting great elasticity against external force such as bending, twisting, and compression may be interposed between the fastening portion and the outer peripheral portion.

[Operation] According to the coupling structure of the rotating machine of the present invention, the outer peripheral portion of the can-shaped fitting member is inserted and fitted through the end opening of the hollow portion provided in the rotor of the rotating machine, and The rotation shaft of the position detector is inserted into the fitting hole provided at the center of rotation, and is fixed to the fitting member via the cylindrical body at the fixing portion.

That is, the rotary shaft of the position detector is fixed so as to enter the hollow portion provided in the rotor of the rotary machine. At this time, since the fitting portion is fitted in the hollow portion of the rotor via the outer peripheral portion, the center of rotation thereof coincides with the center of rotation of the rotor. Moreover, since the fitting hole is provided in the cylindrical body extending toward the inside of the hollow portion, the rotary shaft of the position detector inserted therein can be inserted straight by being guided by the cylindrical body. Therefore, the rotary axis of the position detector is essentially aligned with the rotor of the rotary machine in a precisely aligned state.

Since the elastic portion is provided between the fastening portion and the outer peripheral portion, a predetermined degree of freedom is maintained in the coupling between the rotor of the rotating machine and the rotating shaft of the position detector. . As a result, even if a slight misalignment occurs between the rotor and the rotating shaft and vibration occurs, this elastic part absorbs it, so loosening or deformation of the connection does not occur. Suppressed.

In this way, the rotary shaft of the position detector is coupled so that it fits inside the rotor of the rotary machine, thereby facilitating the axial alignment, and moreover, between the rotor of the rotary machine and the rotary shaft of the position detector. Since the elastic portion is interposed in the structure, vibration absorption or the like is performed, and it is possible to favorably improve the assembling accuracy of the coupling portion between the rotating machine and the position detector and suppress the action of the coupling portion as a time delay element. .

[Embodiment] Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial vertical sectional view of a coupling mechanism according to an embodiment of the present invention.

As shown in FIG. 1, the coupling mechanism 1 includes a rotor 4 rotatably supported inside a case 3 of an AC servomotor 2.
And the rotary shaft 6 of the absolute rotary encoder 5 are connected by a bracket sleeve 7 made of carbon steel for machine structure,
The inner sleeve 8 and the nut 9 are fixed by fastening.

The bracket sleeve 7 and the rotor 4 of the AC servomotor 2 are fixed by press-fitting the outer peripheral surface 10 of the bracket sleeve 7 onto the inner peripheral surface 11 of one end of the rotor 4 in the rotation axis direction.

Further, the bracket sleeve 7 and the rotary shaft 6 of the absolute rotary encoder 5 are through-holes formed at substantially the rotation center position of the bracket sleeve 7 corresponding to the rotation center position of the rotor 4. The rotating shaft 6 is inserted into the inner sleeve 8 and the nut 9 is fastened and fixed by the inner sleeve 8 and the nut 9. A screw portion 13 having a screw is formed on the outer peripheral portion of the bracket sleeve 7 so as to be screwed with the nut 9.

Further, in the vicinity of the rear end of the screw portion 13 of the bracket sleeve 7, a relief groove 14 is engraved over the entire circumference in order to exert a predetermined elasticity.

In the coupling mechanism 1 having the above-described configuration, the outer peripheral surface 10 is AC
The rotary shaft 6 of the absolute rotary encoder 5 inserted into the through hole 12 is press-fitted into the rotor 4 of the servomotor 2, and the distal end portion of the rotary shaft 6 is tightened and fixed by the inner sleeve 8 and the nut 9, and further the escape is performed. Groove 14
Has a predetermined elasticity, the rotor 4 of the AC servomotor 2 and the rotary shaft 6 of the absolute rotary encoder 5
While maintaining the flexibility that can absorb vibration during rotation due to misalignment of the cores, etc., a highly accurate coupling that both can be integrally rotated without time delay is realized.

In this embodiment, the bracket sleeve 7 corresponds to the fitting member, the through hole 12 corresponds to the fitting hole, the inner sleeve 8 and the nut 9 correspond to the fastening portion, and the escape groove 14 corresponds to the elastic portion.

As described above, according to this embodiment, since the relief groove 14 of the bracket sleeve 7 causes a predetermined elasticity, the centering work of the rotor 4 of the AC servomotor 2 and the rotary shaft 6 of the absolute rotary encoder 5 is easy. At the same time, since the rotational position detection error caused by the backlash of the coupling mechanism 1 is eliminated, it is possible to improve the assembly accuracy of the coupling portion using the coupling mechanism 1 and realize the precise rotational position detection with a simple configuration. It can be suitably compatible.

Further, even if the vehicle is repeatedly driven by sudden acceleration and sudden deceleration or is operated for a long time in an environment where vibration is transmitted from the outside, the vibration is absorbed by the escape groove 14 of the coupling mechanism 1. Since the coupling mechanism 1 is not loosened or deformed during rotation, detection accuracy of the rotational position of the AC servomotor 2 is improved, and reliability + durability + environmental resistance is improved.

Further, since the coupling mechanism 1 is unlikely to be adversely affected by the misalignment of the core position, backlash, etc., it does not act as a time delay element in the rotational force transmission system between the AC servo motor 2 and the absolute rotary encoder 5. The motor control accuracy is improved.

Each of the above effects can be coupled with high accuracy because the AC servomotor 2 and the absolute rotary encoder 5 and the servo system including these control devices can be coupled to the AC servomotor 2 and the absolute rotary encoder 5 with high accuracy. Accurate detection of rotational position is possible, and since the coupling mechanism does not act as a high-order delay element,
Precise control of AC servo motor can be realized, which is especially effective.

In this embodiment, the rotor 4 of the AC servomotor 2 and the rotary shaft 6 of the absolute rotary encoder 5 are fixed by the inner sleeve 8 and the nut 9. However, for example, the rotor 4 and the rotary shaft 6 are
They may be fixed by an adhesive, or, for example, both of them may be fixed by shrink fitting or press fitting.

In order to prevent the nut 9 used to fix the rotary shaft 6 of the absolute rotary encoder 5 from being loosened in the bracket sleeve 7, a pin is inserted into the nut 9 or the nut 9 is bonded with an adhesive. It may be configured to fix with.

Furthermore, in this embodiment, the relief portion 14 constitutes the elastic portion, but, for example, the material between the outer peripheral surface 10 of the bracket sleeve and the screw portion 13 may be rubber, synthetic resin, composite material, or mechanical structure. Even if the material is changed to a metal material having a higher elasticity than the carbon steel for use, the same effect as in the above-described embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the scope of the present invention. .

Effect of the Invention According to the connecting structure of the rotating machine of the present invention, it is easy to center the output shaft of the rotating machine and the rotating shaft of the position detector, and the detection error due to the looseness of the connecting portion is eliminated. With a simple structure, it is possible to improve the assembling accuracy of the coupling portion and to perform precise rotational positioning.

In addition, even if the vehicle is repeatedly driven by sudden acceleration and sudden deceleration, or if it is operated for a long time in an environment where vibration is transmitted from the outside, the vibration is attenuated by the elastic part, so that the vibration of the coupling part may occur during rotation. Since looseness and deformation do not occur, the detection accuracy of the rotational position of the rotating machine is improved, and the reliability + durability is improved.

Further, since it is unlikely to be adversely affected by the misalignment of the core position, backlash, etc., it does not act as a time delay element in the rotational force transmission system between the rotary machine and the position detector, so the control accuracy of the rotary machine is enhanced.

Each of the above effects has the advantage that when the rotary machine is used as an actuator, the position detector is used as a sensor, and a servo system is configured by providing a control means for controlling these, the actuator and the sensor can be accurately coupled to each other. It is possible to detect with high precision, and since the coupling portion does not act as a high-order lag element, it is possible to realize precise control of the rotating machine, and a particularly remarkable effect is obtained.

As described above, according to the present invention, A. the rotary shaft of the position detector is inserted into the rotor of the rotary machine so that the rotary shaft can be easily and accurately aligned, and B. the rotor of the rotary machine. Since an elastic part is interposed between the position detector and the rotary shaft of the position detector, vibration is absorbed, etc. C. Assembling accuracy of the connecting part of the rotating machine and the position detector is improved and the time sending element of the connecting part It is possible to suitably achieve both suppression of action.

In addition, the above-mentioned A. configuration further reduces the entire length by inserting the rotary shaft of the position detector into the rotor of the rotary machine, and also has the effect of facilitating mounting in a narrow space. Play.

In addition, the shorter overall length and the insertion of the rotary shaft into the rotor make it possible to increase the rigidity of the joint in the direction perpendicular to the axis, and also to prevent the whirling motion from occurring at the joint. There is something expensive.

Vibration is reduced due to this whirling motion prevention effect, which improves the life of the device, improves the machining accuracy of the workpiece when applied to a processing machine, and improves measurement accuracy when applied to a measuring machine. This has the effect of improving accuracy.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view of an embodiment of the present invention, and FIGS. 2 and 3 are schematic configuration diagrams showing a prior art. 1 ... Coupling mechanism 7 ... Bracket sleeve 8 ... Inner sleeve 9 ... Nut 12 ... Through hole 14 ... Relief groove

Claims (1)

[Scope of utility model registration request] 1. A connecting structure of a rotating machine, wherein a rotor of a rotating machine and a rotating shaft of a position detector for detecting a rotating position of the rotor are connected to each other, wherein the rotor has a hollow portion opened at an end thereof. Then, a can-shaped fitting member having an outer peripheral portion that fits inside the hollow portion, and a fitting member that is provided at the center of rotation of the fitting member so as to extend into the hollow portion and that fits on the rotation shaft of the position detector. A tubular body with a fitting hole, a fastening portion for fastening the rotary shaft of the position detector inserted in the fitting hole to the tubular body, and between the fastening portion and the outer peripheral portion. A connecting structure for a rotating machine, comprising: an elastic portion that is provided and exhibits at least greater elasticity than the outer peripheral portion and the fastening portion.