JPS59183140A - Variable output type vibration damper - Google Patents

Abstract

PURPOSE:To obtain any and easy control over exciting force in a vibration eraser to reduce vibration in a ship by providing in a flywheel casing a weight coupled by screw to an external thread shaft whose direction of rotation can freely be changed. CONSTITUTION:A pair of flywheels 21 and 22 driven by a driving motor 25 via a driving gear 24 are provided. Each of flywheel 21 and 22 is provided in its casing 31 with a balancing weight 32 coupled by screw to an external thread shaft 33. The inner end of the external thread shaft 33 is fixed to a bevel gear 34. And auxiliary bevel gears 34A and 34B, which are fixed to the inner ends of a pair of adjusting shafts 37A and 37B that are arranged in a hollow main shaft 36 at the both ends of a casing 31, are engaged with the bevel gear 34. Clutches 38A and 38B that can be engaged with the fixed shaft are provided at the outer ends of the adjusting shafts 37A and 37B. By operating either one of the clutch 38A and 38B, the weight 32 is moved up and down along the external thread shaft 33, thereby controlling the magnitude of the exciting force.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration-dampening rock that can offset vibrations of ships and the like.

BACKGROUND OF THE INVENTION Conventionally, as one measure against ship body vibration, an electric vibration damping rock 1 installed at the stern of a ship has been developed, as shown in FIG. The principle is that in response to the vibrations 5 of the hull 4 caused by the main engine 2 and propeller 3, the electric vibration damping rock 1 excites the hull, causing vibrations 6 that are 180 degrees out of phase with the vibrations 5 and have the same amplitude. be. As a result, vibration 5 and vibration 6
The two cancel each other out based on the principle of superposition, and this makes it possible to reduce hull vibration.

As a concrete structure, as shown in Fig. 2, when an unbalanced weight 12 is mounted on a rotating body 11, a centrifugal force 13 is generated in the radial direction connecting the center of the rotating body and the unbalanced weight, and this force is Rotates with the position of the weight.

At this time, if the rotating body 14 and the weight 15, which are exactly the same as the rotating body 11 and the unbalanced weight 12, are rotated symmetrically and in opposite directions, the horizontal components of the centrifugal force 13.16 always cancel each other out, and the vertical The component forces are always added together, resulting in an excitation force that changes periodically only in the upward and downward directions.

Note that by changing the way in which the two rotating shafts are installed, it is possible to obtain a horizontal vibrational force instead of a vertical vibrational force. In that case, the horizontal vibration of the hull will be reduced.

By the way, ship vibration is caused by the ship's swamp, loading condition, etc.
The phase 9 frequency and amplitude of vibration are changed in a complex manner according to its vibration characteristics.

However, in the conventional vibration damping mode, once the weight of the unbalanced weight is adjusted, the relationship between its rotational speed (frequency) and the excitation force is expressed by the following equation.

F=(W/g)Rω2...Equation (1) %Equation %: In other words, the excitation force is determined in proportion to the square of the number of rotations, so the phase and frequency of vibration 6 in Figure 1 The vibration 5
If the control is made to be the same, it is inevitable that the amplitudes will be made exactly the same at the same time. Therefore, in response to changes in hull vibration, excessive vibration damping may cause hull vibration, or vibration damping force may be insufficient.

In order to solve the above-mentioned problems with the conventional vibration damping system, it was necessary to stop and release the vibration damping system each time to adjust the weight of the unbalanced weight.

The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide a variable output vibration damper that allows the position of an unbalanced weight to be easily adjusted using simple means.

For this reason, the variable output vibration damper of the present invention is provided with a male threaded shaft disposed in the radial direction via a thrust bearing inside a flywheel casing that is rotationally driven via a main shaft fixed to both end faces. , equipped with a weight that is screwed onto the ME screw shaft and can move as the releasable screw shaft rotates,
In order to adjust the position of the weight, a main bevel gear is fixed to the inner end of the male shaft, and a pair of adjustment shafts are provided with auxiliary tone gears fixed to both sides of the main bevel gear. The adjustment shaft is disposed concentrically within the main shaft on both end faces of the flywheel casing, and a differential rotation (a hole groove is provided) for rotating the adjustment shaft relative to the main shaft is provided. It is characterized by

Hereinafter, a variable output vibration damper as an embodiment of the present invention will be explained with reference to the drawings. FIG. 3 is a plan view showing a schematic structure thereof, and FIG. 4 is a longitudinal sectional view thereof.

As shown in FIG. 3, this vibration damping system is composed of a pair of flywheels 21 and 22 each having a weight for unbalance inside, a bearing 23 thereof, a drive gear 24 and a drive motor 25. . Two flywheels 21.22
The unbalanced weights within are always kept in symmetrical positions by gears 24 and rotate in opposite directions.

The inside of one of the flywheels 21 is shown in FIG.

Inside the flywheel casing 31, a weight 32 for unbalance is supported by being screwed onto a male threaded shaft 33.

The male threaded shaft 33 is disposed in the radial direction inside the casing 31 via a thrust bearing 35, and is supported so as to be rotatable by being driven by a main bevel gear 34 fixed to its inner end.

The rotation of the weight 32 is restricted by a guide (not shown) so that it can only move in the radial direction, so when the male threaded shaft 33 rotates together with the main bevel gear 34, the weight 32 moves in the radial direction. It has become.

The main shaft 36 fixed to both end faces of the flywheel casing 31 has a hollow structure, and a pair of reinforcing shafts 37A and 37B installed therein have sub-shafts at their inner ends that mesh with both sides of the main bevel gear 34. To which the sound gears 3-4A and 34B are fixed, an electromagnetic type or other clutch 38 which can be engaged with a fixed shaft (not shown) is provided at the outer end protruding from both ends of the main shaft 36.
A, 38B, and these clutches work -
In the state in which the adjustment shafts 37A, 37B rotate at the same rotation speed as the main shaft 36 driven by the gear 39, the three shafts 3
6.37A and 37B are relatively stationary and each bevel gear 3.
! , 34A, and 34B do not rotate, and the weight 32 is kept at a constant position.

Then, when one clutch 38A is activated, the adjustment shaft 3
7A is forcibly stopped, so if the main shaft 36 is currently rotating clockwise when viewed from the end face on the adjustment shaft 37A side, the adjustment shaft 37A will rotate counterclockwise relative to the main shaft 36. I will do it. At this time, the main bevel gear 34 rotates clockwise, and if the male threaded shaft 33 is a right-handed thread, the weight 32 moves in the radial direction toward the center of the main shaft.

Conversely, when the clutch 38B is activated, even though the main shaft 36 remains rotating as before, it rotates counterclockwise when viewed from the end face on the adjustment shaft 37B side, so the adjustment shaft 37B rotates relatively clockwise. , the main bevel gear 34 turns counterclockwise, and the weight 32 moves in a direction away from the center of the main shaft.
' Note that a differential rotation (mechanism) that causes relative rotation between the main shaft 36 and each adjustment shaft 37A, 37B may include clutches 38A, 38B that can engage with the fixed shaft, a band brake, etc. Each adjustment shaft 37A as required.

A drive device that rotationally drives 37B may be used.

In this device, the excitation force of the pair of flywheels combined is based on the equation (1) shown above, but when the unbalance weight 32 is moved in the radial direction by the mechanism described above, the excitation force in equation (1) is R will be changed arbitrarily. That is, the main shaft 36
The magnitude of the excitation force can be freely controlled while keeping the rotational speed (frequency of the excitation force) constant.

Hereinafter, the effects and advantages obtained by the vibration-absorbing rock of the present invention are enumerated as follows.

(1) Even if the frequency-amplitude relationship changes in a complicated manner according to the vibration characteristics of the ship's vibration due to the ship's swamping, loading conditions, etc., the vibration-damping frequency and vibration-damping force can be determined separately without stopping the vibration-damping rock. Since the vibration can be controlled to the optimum point, each optimum point can be selected, and vibration damping force will not be insufficient or vibration excitation will not occur.

(2) Conventionally, the unbalanced weight was started with the unbalanced force still present, which required extra starting torque, and a correspondingly larger motor was installed.However, with the vibration-absorbing rock of the present invention, the unbalanced weight is centered on the main shaft. A small motor is used because it can move up to a certain point and start without imbalance.

(3) Since the rotational force of the flywheel itself can be used as the power to move the position of the weight, only one electric motor can be used as the drive source.

[Brief explanation of the drawing]

Figure 1 is a side view of a ship equipped with a damping beach, Figure 2 is an explanatory diagram showing the general structure of a conventional fishing rock, Figure 3 is a plan view showing its schematic structure, and Figure 4 is a side view of a ship equipped with a fishing rock. FIG. 21.22...Flywheel, 23...Bearing, 24...
- Drive gear, 25... Drive motor, 31... Flywheel casing, 32... Weight, 33... mt screw shaft, 34... Main bevel gear, 34A, 34B... Antistatic gear, 3
5. Thrust bearing, 36. Main shaft, 37A. 37B...Adjustment shaft, 38A, 38B...Differential rotation (brake clutch as a hole groove. Sub-Agent Patent Attorney Yoshihiko Iinuma Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] The inside of the seven-wheel casing, which is rotatably driven via main shafts fixed to both end faces, is equipped with a male threaded shaft arranged in the radial direction via a thrust Y bearing, and one opening fiber threaded shaft is screwed into the opening. It is equipped with a weight that can move with the rotation of the screw thread, and in order to adjust the position of the weight, it meshes with a main bevel gear fixed to the inner end of the male screw shaft, and both sides of this main bevel gear, respectively. A pair of adjustment shafts to which secondary bevel gears are fixed are provided, and the adjustment shafts are disposed concentrically within the main shaft on both end faces of the flywheel casing, and the adjustment shafts are rotated relative to the main shaft. A variable output two vibration damper characterized by being equipped with a differential rotation mechanism for rotating the vibration.