JPH0121492Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shaft system grounding device for grounding a propulsion shaft system of a ship.

In ships, the propulsion shaft system is sometimes grounded for cathodic protection of propeller blades, etc. The conventional shaft-based grounding device used in such cases is one in which a slip ring is fitted and fixed to the middle of the shaft, a solid brush is pressed against the slip ring, and the brush and the hull are connected with a grounding wire. It was hot. However, in such conventional devices, since the brush and the slip ring are in sliding contact, the contact resistance of the sliding part is large, and the contact resistance is increased due to oil, dirt, oxide film, etc. adhering to the sliding part. This increases the grounding stability, and requires frequent maintenance and inspection to remove this oil, dust, oxide film, etc., which is very troublesome.

This invention solves the above-mentioned conventional drawbacks, and has low contact resistance, stable grounding, and easy maintenance.
The purpose of the present invention is to provide a shaft grounding device that can reduce the number of inspections.

In order to achieve the above object, the shaft-based grounding device of the present invention has a metal casing that stores a highly conductive liquid fixed to the ship's hull, and a flexible structure with one rod-shaped end vertically immersed in the liquid. The other end of the conductor is fixed to the center of the shaft end of the ship's propulsion shaft system.

According to this configuration, the rotating side and the stationary side can be electrically connected through contact between the flexible conductor and the liquid, rather than through sliding contact between the brush and the slip ring as in the conventional case, so that the contact resistance is reduced. It is small, has a stable grounding, and can reduce maintenance and inspection efforts.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, 1 is a crankshaft of a propulsion diesel engine mounted on a ship, 2 is a ship's hull, and 3 is a metal casing that is fixed and electrically connected to the ship's hull 2 via a fixed base 4. The casing 3 stores mercury 5 as an example of a highly conductive liquid. A flexible conductor 6 is made of, for example, a copper wire processed into a coil shape, and one end is formed into a rod shape, and this one end is immersed in the mercury 5. The other end of the flexible conductor 6 is fixed to the center of one end surface of the crankshaft 1,
The entire body is covered with a bent tubular cover 7. This cover 7 has flanges at both ends and a middle part, and the flange at one end is attached to the casing 3.
The flange at the other end is fixed to the engine casing 9 via a bracket 8, and the flange at the middle part is fixed directly to the engine casing 9 by bolts or the like not shown.

In the above configuration, the crankshaft 1 is grounded to the hull 2 via the flexible conductor 6, the mercury 5, the casing 3, and the fixed base 4. When the crankshaft 1 rotates, the flexible conductor 6 also rotates, but one end of the flexible conductor 6 is immersed in the mercury 5, and the contact between the flexible conductor 6 and the mercury 5 is always good. is maintained. At this time, since the flexible conductor 6 is housed within the cover 7 and the other end is fixed to the center of one end surface of the crankshaft 1, it rotates extremely smoothly. In this way, the contact is not through sliding contact as in conventional devices, but through the liquid mercury 5, so the contact resistance is low and there is no problem with the adhesion of oil, dust, oxide film, etc. is stable and reduces maintenance and inspection effort.

As explained above, according to the present invention, the rotating side and the stationary side are electrically connected through a highly conductive liquid, so the contact resistance is low, the grounding is stable, and maintenance and inspection are easy. It can reduce the labor involved, and its industrial utility value is extremely large.

In addition, one end of the flexible conductor immersed in the liquid has a rod-like shape and is arranged vertically, so that stable conductivity can be obtained even at high speed rotation.

[Brief explanation of the drawing]

The drawing is a sectional view of a shaft-based grounding device according to an embodiment of the present invention. 1... Crankshaft, 2... Hull, 3... Casing, 5... Mercury, 6... Flexible conductor.

Claims (1)

[Scope of utility model registration request] A metal casing that stores a highly conductive liquid is fixed to the ship's hull, and one end of a rod-shaped flexible conductor is vertically immersed in the liquid, and the other end is connected to the center of the shaft end of the ship's propulsion shaft system. A shaft-based grounding device characterized by being fixed to the shaft.