JP2002219414A - Electric rotary-type vibration generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an electric rotary-type vibration generator that can generate an excitation of quite a less strain up to a high frequency band by an electromagnetic induction. SOLUTION: This electric rotary-type vibration generator is featured by the following characteristics. In a magnetic circuit an air gap 2 is provided wherein a rotary vibrator 3 made up of a cylindrical conductor is inserted. The rotary vibrator 3 is fixed onto a rotary axis 5 supported by a bearing 4. Therefore, a relative motion can be generated in the circumferential direction with the rotary axis 5 as a center. In order to let a vibration torque generate to the rotary vibrator 3 by an electromagnetic induction, in a magnetic field facing the air gap 2, a drive coil 7 is fixed parallel with the rotary axis of the rotary vibrator 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rotary vibration generator which can be used as a power source for torsional vibration, rotational vibration, or a vibration source for vibration tests in those fields.

[0002]

2. Description of the Related Art Conventionally, when torsional vibration or torsional load is required, rotation of a motor or linear vibration is converted into torsional vibration or torsional load by combining an arm and a crank mechanism. On the other hand, there is a hydraulic torsional vibration generator that generates torsional vibration without using an arm or a crank mechanism.

[0003]

These prior arts which use arms and cranks are limited to low frequency applications because of their large inertial mass and moment of inertia. As the frequency increases, the collision occurring at the connection between the arm and the crank increases the waveform distortion and noise and adversely affects the driven side. However, it is difficult to eliminate this, and the inertia mass and inertia A lot of wasted energy is consumed to drive the moment. For these reasons, it cannot be used in high frequency bands. On the other hand, in a hydraulic torsional vibration generator,
Since the medium that generates vibration is a liquid, the frequency that can be generated naturally remains in a low frequency band.

[0004]

In order to solve the above-mentioned problem, as shown in FIG. 1, a magnetic circuit is constituted by a body 1, a magnetic pole 6, and an exciting coil 9 made of a magnetic material. An air gap 2 is provided therein. The cylindrical vibrator 3 made of a conductor is incorporated in the magnetic field in the air gap. The rotating vibrator 3 is fixed to a rotating shaft 5, and is supported by a bearing 4 so as to be able to move relative to the body 1 and the magnetic pole 6 in a circumferential direction about the rotating shaft 5. Drive the magnetic pole 6 facing the rotary oscillator 3 in the air gap.
The coil 7 is fixed. The drive coil 7 is for generating torque in the rotary vibrator 3 by electromagnetic induction, and its effective part is fixed in parallel with the rotary shaft 5.

[0005]

When a direct current is applied to the exciting coil 9 of the mechanism constructed as described above, a magnetic field is generated in a certain direction in the air gap. Next, when an alternating current is input to the drive coil 7 and the current is passed, the rotating vibrator 3 is driven by electromagnetic induction.
Rotational vibration occurs around the rotating shaft 5 in accordance with the magnitude and frequency of the current flowing. Furthermore, this phenomenon is caused by continuously changing the amplitude and frequency of the input current.
This means that the amplitude and frequency of the rotational vibration, which is the mechanical output, change continuously, and that frequency sweep can be performed. This rotational vibration can add torsional vibration to the driven side with a simple attachment using the end face of the rotary vibrator 3 as an output end.

[0006]

FIG. 1 shows an embodiment. As shown, a magnetic circuit is formed by a body 1 made of a magnetic material, a magnetic pole 6, and an exciting coil 9, and an air gap 2 is provided in the magnetic circuit. The rotating vibrator 3 made of a cylindrical conductor is incorporated in the magnetic field in the air gap. The rotary vibrator 3 is fixed to a rotary shaft 5 and is supported by a bearing 4. Thus, the rotary vibrator 3 can move relative to the body 1 and the magnetic pole 6 in the circumferential direction around the rotation shaft 5. The drive coil 7 is fixed to the magnetic pole during the air gap. The drive coil 7 is for generating a vibration torque on the rotary vibrator 3, and its effective part is fixed in parallel with the rotation axis of the rotary vibrator 3. The effective portion of the drive coil 7 is arranged so that current flows in the same direction on the same magnetic pole as shown in FIG. This mechanism has the following five variations. 1. Configuration of Magnetic Circuit In order to obtain the magnetomotive force, a method using an exciting coil as shown in FIG. 1 and a method using a permanent magnet as shown in FIGS. 3, 4 and 5 are conceivable. FIG. 1 shows a method using an exciting coil 9 FIG. 3 shows an outer magnetic type magnetic circuit using a permanent magnet at the position of symbol 10 FIG. 4 shows an inner magnetic type magnetic circuit using a permanent magnet at the position of symbol 11 FIG. This is a magnetic circuit using a permanent magnet at the position of symbol 12. 2. Regarding the number of magnetic poles If an air gap is provided in a magnetic circuit, magnetic poles are inevitably generated. In the example of FIG. 1, there are four poles, but two, three, four
It is also possible to have a multi-pole configuration with poles, five poles, six poles, and so on. 3. 1. Position and Configuration of Drive Coil In FIG. 1, the drive coil 7 is fixed on the inner magnetic pole, but may be fixed on the outer magnetic pole.
Further, it is also possible to fix them on the inside and outside and on both poles to make a parallel connection. Further, the drive coil 7 may be provided with a groove parallel to the rotation axis on the magnetic pole and accommodated therein. 4. Rotating Vibrator 3 Supporting Method I As shown in FIG. 1, the rotating vibrator 3 is fixed to a rotating shaft 5 supported by bearings 4, and is fixed to the body 1 and the magnetic pole 6 with respect to the rotating shaft 5. Relative movement is possible in the circumferential direction. The bearing 4 may be an air bearing, a hydraulic bearing, a magnetic bearing, or the like in addition to the ball bearing shown in FIG. The rotating vibrator 3 moves with respect to the circumferential movement.
It is supported by an elastic body 8 having a restoring force so as to maintain a neutral point. The elastic body 8 includes a leaf spring, a spiral spring,
Coil springs, ring springs, rubber, sponges, etc. can be used. In FIG. 1, the elastic body 8 supports the rotary vibrator 3 from inside, but this can be done from outside or from both inside and outside. In this configuration, the rotary vibrator 3 can generate a rotary vibration having an angular displacement as shown in FIG. 6 based on the neutral point of the elastic body 8. 5. 2. Method of Supporting the Rotating Vibrator 3 If the elastic body 8 shown in FIG.
Can rotate freely in the air gap 2. In this configuration, as shown in FIG. 7, vibration having an angular displacement can be superimposed on an arbitrary number of rotations.

[0007]

When an alternating current is applied to the drive coil 7 of the mechanism assembled as described above, a vibration torque is generated in the rotary vibrator 3 by electromagnetic induction. The rotational vibration caused by the vibration torque has the following advantages because the torsional vibration can be applied directly to the driven side without passing through the crank or the arm. 1. Since it is driven directly without using an arm or a crank, it can be excited to a high frequency range. 2. Since the arm and the crank are not used, the adverse effect of the distorted wave and noise generated at the connection portion on the driven side is eliminated. 3. Energy for driving the inertial mass and moment of inertia of the arm and the crank is not wasted. 4. As in the fifth embodiment, in the configuration excluding the elastic body 8 in FIG. 1, the shaft on the driven side rotating at an arbitrary number of revolutions is
A vibration having an angular displacement as shown in FIG. 5. Vibration can be applied to a frequency band several steps higher than that of a hydraulic torsional vibration generator.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a mechanism showing one embodiment of the present invention. The figure on the left shows a sectional view taken along line AA of the figure on the right.

[Explanation of symbols]

ω: Direction of rotational vibration 1… Body, 2… Air gap, 3… Rotating vibrator, 4… Bearing, 5… Rotating shaft,
6 magnetic pole 7 drive coil 8 elastic body 9 excitation coil

FIG. 2 is a side view of a part of the magnetic poles of FIG. 1, showing the drive coil 7 and the direction of current. Shaded area N: N pole face, i: Current

FIGS. 3, 4, and 5 show three types applicable to the magnetic circuit of FIG. Fig. 3 10: Position of permanent magnet in outer magnet type magnetic circuit Fig. 4 11: Position of permanent magnet in inner magnet type magnetic circuit Fig. 5 12: Position of permanent magnet in magnetic circuit with magnet fixed in air gap Are shown respectively.

FIG. 6 shows the angular displacement of the rotational vibration on the time axis. φ… · Angular displacement, t… · Time

FIG. 7 shows the angular displacement of rotational vibration superimposed on an arbitrary number of rotations on a time axis. N: rotation speed, t: time

Claims (1)

[Claims] 1. An exciting coil and a magnetic material,
A magnetic circuit having an air gap, a cylindrical rotating electric vibrator supported by a rotating shaft and incorporated in a magnetic field in the air gap, and a torque generator for generating torque. An electric rotary vibration generator characterized by electrical-mechanical energy conversion by electromagnetic induction of a mechanism constituted by a drive coil fixed to a magnetic pole facing an air gap in parallel with a rotation axis of a rotary vibrator.