JPH03168442A - Torsional vibration damping device for marine drive shaft - Google Patents

Abstract

PURPOSE:To surely damp torsional vibration in no relation to a rotational speed of a drive shaft by providing a torsional vibration sensor for detecting the torsional vibration of the drive shaft and a torque generating means for giving torsional vibration, in a phase reverse to that of the torsional vibration, to the drive shaft. CONSTITUTION:A torsional vibration sensor 8 for detecting torsional vibration of a drive shaft 3 is mounted on it. A control part 9 analyzes a detection signal of the torsional vibration sensor 8 to generate a current synchronized with a waveform of the torsional vibration. A torque generating means 10 is mounted on the drive shaft 3 in order to give torsional vibration, in a phase reverse to that of the torsional vibration, to the drive shaft 3 by an output signal of the control part 9. In this way, the torsional vibration can be effectively damped in no relation to a rotational speed of the drive shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a torsional vibration damping device for a marine drive shaft.

"Conventional technology" Figure 2 schematically shows the stern section of a large ship.

In this ship, torsional vibration is induced in the drive sleeve 3 for transmitting the rotational force of the prime mover 1 to the propulsion blower 2 due to uneven rolling due to intermittent combustion of fuel.

This torsional vibration contains high-order frequency components (harmonic components) in addition to the fundamental frequency component, and is transmitted to the accommodation room, deck, etc. via the attachment part of the engine III to the engine room. At the same time, noise is sometimes generated, and each 141. This becomes a factor that reduces the mechanical strength and fatigue strength of the eM material.

Conventionally, a torsional vibration damper as shown in FIG. 3 has been employed for the purpose of reducing torsional vibration. The torsional vibration damper has a drive shaft 3 with a protruding end on the bow side, a casing 5 attached to the drive shaft 3 via a plurality of partition walls 4 made of spring material, and a casing 5 connected to each partition chamber 6 and a casing song. It has a structure in which oil is sealed in a partition 6 surrounded by a drive shaft 3 and a swing arm 7 that is integrated with a drive shaft 3, and the drive shaft 3 rotates at a constant speed to prevent torsional vibration In the case without this, there will be no misalignment of the rotational peak between the canong 5 and the swing arm 7, but the drive $11
1 3 is accompanied by torsional vibration, the rotation f (+ is nif in the rotation direction
Later, a slight shift occurs and the partition wall 4 is deformed, and as shown in FIG. 4, the moment of inertia of the drive sleeve 3, etc.
If we consider a model in which the spring constant loss is K, the moment of inertia of the casing 5, etc. is m, and the spring constant of the partition 6, etc. is k, then the fixed lti'i of the m-k system is expressed as If it is made to vibrate It2 in accordance with the number of pulsations, it is possible to absorb the vibration of the MK system.

On the other hand, at 43 in FIG.
This shows a phenomenon in which the eigenvalues of the k system have a range.

"Problem to be Solved by the Invention" However, when making the m-k system resonate, it is effective only for one type of rotation speed of the drive shaft 3, so for example, the resonant frequency must be set to the resonance point of one mode. If it is adjusted to the above, problems remain, such as the vibration damping effect will be significantly reduced for vibrations in other modes.

The present invention solves these problems, and provides a marine drive shaft that reliably damps torsional vibrations, provides smooth rotation, exhibits a vibration damping effect, and is not affected by vibration frequency or vibration waveform. The purpose of the present invention is to provide a torsional vibration damping device.

"Means for Solving the Problem" The reflected vibration damping device for a marine drive shaft according to the present invention includes a torsional vibration sensor that is attached to the drive shaft and detects the torsional vibration, and a torsional vibration sensor that analyzes the detection signal of the torsional vibration sensor. The device is equipped with a control section that generates a current that is synchronized with a vibration waveform, and a torque generation means that is attached to the drive shaft and applies mirror vibration in phase opposite to the torsional vibration to the drive shaft in response to an output signal from the control section.

"Operation" The torsional vibration of the drive shaft is detected by the reflected vibration sensor, and analyzed by the control section.The control section outputs a control signal corresponding to the reflected vibration waveform to operate the torque generating means, thereby reducing the torsional vibration. By applying a vibration torque with an inverse phase to the drive shaft, the torsional vibration components are canceled out, the torsional vibration is damped, and the rotation of the drive shaft is made smooth.

"Embodiment" Hereinafter, an embodiment of the torsional vibration damping device for a marine drive sleeve according to the present invention will be described based on the drawings.

In the figure, numeral 8 is a torsional Fi motion sensor, 9 is a control unit,
10 is l.lux generating means.

The torsional vibration sensor 8, as shown in FIG.
The drive shaft 3 is equipped with a wireless transmitter 12 that amplifies the detection signal, converts it into a radio signal such as a PM wave, and transmits it as a radio wave, and outputs the radio signal around the drive shaft 3.

The control section 9 includes a torsional vibration sensor 8 and a torque generating means 1.
Therefore, the Ilt wave signal received by the antenna l3 is processed by amplification in the receiver l4, and the torsional vibrations contained in the signal are removed by the high-pass filter I5. Among the information, low frequency components such as steady torsion, which are not considered as reciprocating vibration components in the rotational direction, are removed, and the control unit 9, which receives the output signal of the high-pass filter l5, analyzes the torsional vibration waveform and In the drive current generation section 16 which performs calculations and outputs an electric signal synchronized with the torsional vibration waveform and receives the output signal of the control section 9,
A driving current of the required magnitude and polarity is generated in synchronization with the torsional vibration waveform and transmitted to the torque generating means 10.

The torque generating means 10 is, for example, a DC motor that can rotate in forward and reverse directions, and its rotor 17 rotates integrally with the drive shaft 3, and a drive current generator 16 supplies a winding of the stator 18 with a drive current generator 16.
Alternating current drive currents of positive and reverse polarity are supplied, and the stator l8 is attached to a support structure l9 in the engine compartment.

To give a supplementary explanation, the rotor l in the torque generating means 10
7 and the stator [the polarization number of 8 is the prime mover! Considering the specifications such as the number of cylinders and high-order vibrations, the number of polarizations should be increased, for example, to several times the high-order vibration frequency per rotation of the drive shaft, in order to reduce the unevenness of torque generation in the circumferential direction. Set.

In the reflected vibration damping device for a marine drive shaft configured as described above, when the drive shaft 3 is rotating and torsional vibrations accompanying the rotation are superimposed, the sensor section 1l of the torsional vibration sensor 8 , a torsional movement is detected, and the wireless transmitter 1
2 is output as an Asahi line signal, and this radio signal is sent to the control unit 9 via the receiver 14 and the high-pass filter 15, where it is analyzed and calculated, and the drive current generation unit l6 This generates an alternating current with the same frequency that is synchronized with the torsional vibration waveform, and supplies this to the winding of the stator 18 in the torque generating means lO, thereby causing the rotor l7 to rotate in the rotational direction of the drive shaft 3 or in the opposite direction. A rotational force (a reciprocating rotational force with a phase opposite to the initial torsional vibration) is applied to cancel out the torsional vibration. In other words, while the twist in the direction of accelerating the rotation is occurring, a twist in the opposite direction of deceleration is applied, and while the twist in the direction of decelerating the rotation is occurring, the twist in the acceleration direction is applied. It dampens torsional vibration, and performs cancellation using the original vibration waveform and a symmetrical vibration waveform that cancels it.

In this case, even if the torsional vibration waveform of the drive member 3 includes a high-defect component, the torsional vibration sensor 8 converts the displacement angle and angular acceleration change of the reflected vibration into a vibration waveform, so that the torsional vibration waveform is similar to the torsional vibration. I-[1 stage] can be performed in which eye movements are generated by the torque generating means 10 to attenuate recumbent movements. Note that the degree of {rotation (phase role ratio) can be set by the magnitude of the {J (supply current) and its waveform from the drive current generating section I6.

[Other Embodiments] The following embodiments can be employed in the present invention.

(a) Signal transmission from the torsional vibration sensor 8 to the non-rotating portion is carried out by optical signals or via a slip ring, brano, etc.

(b) Signal transmission and data processing from the torsional vibration sensor 8 to the drive current generator 16 are performed by analog/digital conversion or digital/analog conversion.

(c) Replace the control unit 9 with a microprocessor or the like through the digital conversion described above.

(2) Combined use with torsional vibration dampers, etc., as explained in the conventional column.

``Effects of the Invention'' As explained above, the torsional vibration damping device for a marine drive shaft according to the present invention has the following excellent effects.

■It detects the torsional vibration of the drive shaft and generates torsional vibration with the opposite phase to cancel out the vibration.
Torsional vibration can be effectively damped regardless of the rotation speed of the drive shaft.

(2) As a result of the above, torsional vibration can be reliably damped over the entire range of rotational speeds of the drive shaft without causing differences in the degree of damping due to vibration intensity.

■Since reflected vibrations are canceled by taking into consideration the vibration waveform, it is possible to cancel the reflected vibrations when higher-order vibrations are included.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view with a block diagram showing an embodiment of the torsional vibration damping device for a marine drive shaft according to the present invention, Fig. 2 is a side view schematically showing the stern portion of a large ship, and Fig. 3 4 is a front sectional view showing a conventional example of a torsional vibration damper, and FIG. 4 is a vibration model diagram of the example shown in FIG. Prime mover, propulsion propeller, ...drive shaft, partition wall, ...case song, ...partition chamber, ...swivel arm, -torsional vibration sensor, control unit, torque generation means, l...2...3 4 ... 5 6 7 8 ... 9 ・ lO... l2...81I (line transmitter, l3...antenna, 14...receiver, l5... High pass filter, 16... Drive current generating section, l7... Rotor, l8... Stator, 19... Support structure.

Claims (1)

[Claims] a torsional vibration sensor attached to the drive shaft to detect torsional vibration; a control section that analyzes the detection signal of the torsional vibration sensor and generates a current synchronized with the torsional vibration waveform; and an output of the control section attached to the drive shaft. 1. A torsional vibration damping device for a marine drive shaft, comprising: torque generating means for applying torsional vibration in phase opposite to the torsional vibration to the drive shaft in response to a signal.