JPH0663897B2 - Yaw inertia moment measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a yaw moment of inertia measuring device for measuring a yaw moment of inertia of a model of a ship, a marine structure, or the like.

[Prior Art] Generally, the yaw moment of inertia of a model such as a ship or an offshore structure is obtained from its cycle by suspending the model with a wire and yawing. However, even if it is called a model, it can weigh several hundred kilograms, and there was a safety problem with this method.

Therefore, a method has been devised in which the model is placed on a measuring table that is supported by the yaw axis and has a yaw restoring force to measure the model.

[Problems to be Solved by the Invention] However, in the case of such a method, the yaw damping is quick because the bearing friction of the yaw shaft supporting the measuring table is large.
It was difficult to measure accurately.

The present invention reduces the bearing friction of the yaw axis to enable accurate measurement.

[Means for Solving Problems] In the present invention, the upper and lower portions of a yaw shaft that supports a measuring table having a yaw restoring force are supported by a support frame on a base frame via bearings each having a double structure. A race located between the race on the yaw axis side of each of the bearings and a race on the support frame side is fixed to a cylindrical body arranged concentrically with the yaw axis, and a yaw axis is formed on the outer circumference of each cylindrical body. Concentric gears are provided respectively, and a pinion of a drive motor attached to the support frame side is meshed with each gear.

[Operation] When the motor is driven, the cylindrical bodies are rotated in the opposite directions through the meshing between the pinion and the gear, and the cylindrical bodies are further rotated.
Rotate the race located in the middle of the heavy structure bearing. Therefore, the bearing friction becomes dynamic friction, and the bearing friction during yawing becomes small.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1 to FIG. 3, reference numeral 1 is a measuring table for mounting a model 2 such as a ship or a marine structure, and a frame grid in which, for example, nine space portions 3 are formed when seen from a plane. It has a structure. The center of the measuring table 1 is supported by a yaw shaft 4 from the lower surface, and the yaw shaft 4 is supported by a support frame 6 provided on a base frame 5 by upper and lower bearing mechanisms 7a and 7b. The upper and lower bearing mechanisms 7a and 7b are the support frame 6
Inside and outside the shaft box 13 that is fixedly installed via the support plate 12
It has radial bearings 8 and 9 and thrust bearings 10 and 11 in a heavy structure, and the inner race of the radial bearing 8 and the upper race of the thrust bearing 10 are fixed to the yaw shaft 4, and the outer race and thrust of the radial bearing 9 are fixed. The lower race of the bearing 11 is fixed to the axle box 13, and the outer race of the radial bearing 8 and the radial bearing 9 are fixed.
The inner race, the lower race of the thrust bearing 10 and the upper race of the thrust bearing 11 are fixed to a cylindrical body 14 arranged concentrically with the yaw shaft 4. A ring-shaped external gear 15 is fixed to one end of the cylindrical body 14, and
A pinion 16 is meshed with the gear 15, and the pinion is
Reference numeral 16 is provided on a shaft of a drive motor 17 attached to the support frame 6 via a support plate 12. The base frame 5 is movable by a caster 26 with a stopper, and the position of the base frame 5 is fixed during the yaw moment of inertia measurement to receive the load of the entire apparatus, and the horizontal state of the model 2 is adjusted. Threaded rods 18 are provided at the four corners.

An elevating frame 19 is arranged on the base frame 5 so as to surround the supporting frame 6. A female screw block 20 is provided at each of four corners of the elevating frame 19, and each female screw block 20 is screwed onto a male screw 22 provided on an upper portion of a jack shaft 21 provided so as to vertically penetrate the base frame 5 to form a jack. The shaft 21 is a bevel gear mechanism 23 and a connecting rod 24.
Is connected to the jack drive motor 25 via. Therefore,
A jack 32 is formed by the female screw block 20 and the jack shaft 21, and the lifting frame 19 can be raised and lowered by the jack 32.

Above the elevating frame 19, there is disposed a positioning table 27 having a shape that allows each pedestal 33 to penetrate through the respective space portions 3 on the outer peripheral portion of the measuring table 1 and project above the measuring table 1. Is horizontally slidably mounted on the elevating frame 19 via an adjusting ball 28 provided as a caster at the lower part of the four corners and a ball receiver 29 mounted on the elevating frame 19 to receive the ball 28. .

In the figure, 30 is a spring stretched between the yaw shaft 4 and an appropriate place on the base frame 5 via an auxiliary member 31 so as to give a yaw restoring force to the measuring table 1, and 34 is a fixing device for the positioning table 27. .

When the yaw moment of inertia of the model 2 is measured by using the measuring device having such a configuration, first, the jack 32 is operated by driving the motor 25 to operate the pedestal 33 of the positioning table 27 via the elevating frame 19. As shown by the chain double-dashed line in FIG. 1, it is raised so as to project above the measuring table 1. Then, the model 2 hung by a hoist or a crane is placed on the pedestal 3. In this state, the positioning table 27
Is moved horizontally using the ball 28 and the ball receiver 29, and the model 2 is adjusted (centered) so that it can be placed at a predetermined position with respect to the measuring table 1, and the positioning table 27 is moved in the horizontal direction. The position is fixed by the fixing device 34. Positioning stand 27
After fixing the position of
The positioning table 27 is lowered via the and the model 2 is placed on the measuring table 1. At this time, the pedestal 33 is lowered to a position below the measuring table 1 through the space 3 of the measuring table 1. Then, by driving the upper and lower motors 17, the upper and lower bearing devices 7a, 7b
To rotate. That is, the upper and lower cylindrical bodies 14, 14 are rotated in opposite directions through the meshing between the pinion 16 and the gear 15. By the rotation of the cylindrical bodies 14,14, the races and balls of the bearings 8,9,10,11 fixed to the cylindrical bodies 14,14 are rotated.
In this state, the measuring table 1 is horizontally swung around the yaw axis 4 and the yaw moment of inertia of the model 2 is measured.

In the above, each bearing 8,9,10, in the bearing device 7a, 7b
Since 11 is in the rotating state, the bearing friction of the yaw shaft 4 becomes dynamic friction and becomes small, and as a result, the yaw axial moment can be measured with high accuracy. By the way, in the above case, the yaw shaft 4 is rotated by the rotation of the bearings 8, 9, 10 and 11.
Although it is possible that a rotational force acts on the yaw axis 4, the race rotation in the middle part of the bearings 8, 9, 10, 11 is opposite in the upper and lower parts of the yaw axis 4, so the rotational force of the yaw axis 4 is canceled out. It

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the yaw moment of inertia measuring device of the present invention, the bearing friction of the yaw axis becomes dynamic friction and becomes small, so that the yaw moment of inertia can be measured with high accuracy. The excellent effect of saying, can be produced.

[Brief description of drawings]

1 is a cutaway front view of a yaw moment of inertia measuring device of the present invention, FIG. 2 is a side view, and FIG. 3 is a schematic plan view. 1 is a measuring stand, 2 is a model, 4 is a yaw axis, 5 is a base frame, 6 is a support frame, 7 is a bearing mechanism, 8 and 9 are radial bearings, 10 and 11 are thrust bearings, 14 is a cylindrical body, and 15 is Gears, 16 are pinions, 17 is a drive motor, 27 is a positioning base, and 30 is a spring.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Uchida Kenshin Uchida, Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industries, Ltd. Technical Research Institute (72) Inventor Koshiro Fukuda 6-15 Shimorenjaku, Mitaka City, Tokyo No. 29 Electronic Industry Co., Ltd.

Claims (1)

[Claims] 1. A yaw shaft supporting upper and lower portions of a yaw shaft for supporting a measuring table having a yaw restoring force is supported by a support frame on a base frame via bearings each having a double structure, and the yaw shaft side of each of the bearings is supported. A race located between the race and the race on the side of the support frame is fixed to a cylindrical body arranged concentrically with the yaw axis, and gears concentric with the yaw axis are provided on the outer circumference of each cylindrical body, and A yaw moment of inertia measuring device characterized in that a pinion of a motor mounted on a support frame side is meshed with each gear.