The present invention relates to an apparatus for reducing a swinging motion of a ship such as a rolling motion, a pitching motion and a yawing motion.
Japanese Patent No.
An object of the present invention is to prevent a swinging motion reducing apparatus for a ship from being damaged.
In an aspect of the present invention, a swing motion reducing apparatus for a ship includes a flywheel, a gimbal mechanism configured to rotatably support the flywheel, a motor configured to rotate the flywheel based on a drive power to be supplied; and a motor driver configured to supply the drive power to the motor. A damper section is configured to brake a swing motion of the gimbal mechanism. A safety unit controls the motor driver to stop the supply of the drive power to the motor when a temperature of the damper section is equal to or higher than a predetermined temperature.
According to the present invention, damage of a swinging motion reducing apparatus for a ship is prevented.
Hereinafter, a swinging motion reducing apparatus for a ship according to the present invention will be described with reference to the attached drawings.
As shown in
The safety unit 40 includes a bimetal switch 41A provided for the damper 15A and a bimetal switch 41B provided for the damper 15B. The bimetal switches 41A and 41B are in a close state initially, and monitor temperatures of the dampers 15A and 15B, respectively. The bimetal switch 41A opens to set an OFF state when a temperature of the damper 15A increase to a temperature equal to or higher than a predetermined temperature. The bimetal switch 41B opens to set an OFF state when the temperature of the damper 15B increase to a temperature equal to or higher than a predetermined temperature. The CM terminal 23 is connected to the X1 terminal 24 via the bimetal switches 41A and 41B. Since the bimetal switches 41A and 41B are connected to each other in series, the connection between the CM terminal 23 and the X1 terminal 24 is in an ON state (a conduction state) when both of the bimetal switches 41A and 41B close, and the connection between the CM terminal 23 and the X1 terminal 24 is in an OFF state (a non-conduction state) when at least one of the bimetal switches 41A and 41B opens.
The relay 25 turns the connection between the input terminal 21 and the output terminal 22 to be in the ON state (closes the connection between the input terminal 21 and the output terminal 22) when the connection between the CM terminal 23 and the X1 terminal 24 is in the ON state. Also, the relay 25 turns the connection between the input terminal 21 and the output terminal 22 to be in the OFF state (opens the connection between the input terminal 21 and the output terminal 22) when the connection between the CM terminal 23 and the X1 terminal 24 is in the OFF state.
The motor driver 20 supplies a drive power to the motor 13 when the relay 25 keeps the connection between the input terminal 21 and the output terminal 22 in the ON state, and stops the supply of the drive power when the relay 25 turns the connection between the input terminal 21 and the output terminal 22 to be in the OFF state.
As shown in
A principle that the swinging motion reducing apparatus according to the present embodiment reduces the swinging motion of a ship will be described by exemplifying a case that a left or right direction axis (Pitch axis) of the hull is parallel to the swing axis S2. The flywheel 11 is driven by the motor 13 at a high speed so as to have angular momentum H. When the hull receives a wave in a direction of a roll axis to roll at an angular velocity Q, a gyrotorque T1 represented by an exterior product of the angular momentum H and the angular velocity Ω acts to the gimbal mechanism 12, and the gimbal mechanism 12 rolls around the swing axis S2. At this time, since the flywheel 11 works to maintain the angular momentum H, a counter torque T2 acts to the hull via the gimbal mechanism support section 14. When an angular velocity of the swinging motion of the gimbal mechanism 12 is ω, the counter torque T2 is represented by an exterior product of the angular momentum H and the angular velocity ω. Because the counter torque T2 acts to a direction opposite to the roll direction of the hull, the rolling motion in the roll direction of the hull is reduced.
For example, when the swinging motion reducing apparatus is used under an overload circumstance such as a case where a ship having the swinging motion reducing apparatus according to the present embodiment sails a high wave area, the gimbal mechanism 12 heavily swings so that the temperatures of the dampers 15A and 15B become high, and thus a seal member for sealing the hydraulic oil may be damaged. Since the gimbal mechanism 12 cannot be broken when the hydraulic oil leaks, the swinging motion reducing apparatus may be damaged.
Referring to
Additionally, in case of occurrence of a failure of the damper 15A or 15B, the temperatures of the damper 15A or 15B becomes high. The present embodiment prevents the swinging motion reducing apparatus from continuing to operate under the condition of occurrence of the failure of the damper 15A or 15B. Accordingly, the damage of the damper 15A or 15B can be prevented and the damage of the swinging motion reducing apparatus body 10 is prevented.
Moreover, when an atmosphere temperature around the swinging motion reducing apparatus body 10 is high, the damper 15A or 15B cannot release the heat to circumference, and accordingly a braking performance of the damper 15A or 15B deteriorates. When the swinging motion reducing apparatus continues to operate in a state that the braking performance of the damper 15A or 15B deteriorates, the swinging motion reducing apparatus body 10 may be damaged. According to the present embodiment, since the swinging motion reducing apparatus is stopped in the case of a high atmosphere temperature, the damage of the swinging motion reducing apparatus body 10 can be prevented.
Since the bimetal switches 41A and 41B are respectively arranged on the outer sides of the dampers 15A and 15B, the swinging motion reducing apparatus can be easily assembled. Meanwhile, the bimetal switches 41A and 41B may be arranged in the dampers 15A and 15B, respectively.
Referring to
When the temperature sensors 51A and 51B are arranged on the outer sides of the dampers 15A and 15B, the swinging motion reducing apparatus can be easily assembled. Meanwhile, the temperature sensors 51A and 51B may be arranged in the dampers 15A and 15B, respectively.
In the above-mentioned respective embodiments, the generator 30 and the motor 13 may be a single-phase generator and a single-phase motor, respectively. In addition, the dampers 15A and 15B may be a frictional damper, a linear damper, or a hydraulic pump.
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