JPH0592985U - Shaft grounding device - Google Patents

Abstract

(57) [Summary] [Purpose] Prevents spark erosion that occurs on the crankshaft of a marine main engine and prevents galvanic corrosion of ships. A shaft-side connecting portion formed by attaching a disk-shaped contact plate support seat 19 to which a contact plate 14 is fixed to a non-driving side end portion of a propeller shaft or an extension shaft end portion thereof via a shaft connecting pipe 18. The brush holder 21, which is formed integrally with the fixed plate 16 attached to the engine cover and comes into contact with the contact plate 14 via the brush 22, is housed inside, and the outer peripheral surface of the disk-shaped contact plate support seat 19 is provided. Rubber ring 2
The brush holder storage box 17 is provided with a fitting portion that comes into contact with the brush holder storage box 3 through the contact hole 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shaft grounding device for grounding a rotating shaft (propeller shaft, crank shaft) in order to prevent spark erosion mainly generated on a crankshaft of a marine main engine (engine) and to prevent galvanic corrosion of a ship. Is.

[0002]

[Prior Art]

 When a ship's propeller is subjected to galvanic protection, it is necessary to electrically connect (ground) the propeller and propeller shaft to the hull, but the propeller shaft in operation is insulated from the hull by the oil film of bearing lubricating oil. It is necessary to provide a connection circuit (ground circuit) between the hull and the hull by using a slip ring or the like provided on the shaft. This circuit is called the shaft grounding device because it considers the entire hull as grounding. This shaft grounding device is used to prevent spark erosion (corrosion due to a discharge phenomenon) that is often seen in bearings of main engines in addition to electrical corrosion protection.

Hereinafter, a conventional shaft grounding method and a conventional electrocorrosion method will be described with reference to the drawings. FIG. 4 is an explanatory view of an electric corrosion protection method using a conventional shaft grounding device. The external power supply method is used as a method for supplying corrosion protection current. The positive terminal of the external DC power supply 3 is connected to the electrode (anode) 2 installed at the tail of the hull 1, and the propeller 4 and the propeller 4 to be protected from the electrode 2 are connected. An anticorrosion current 5 is made to flow toward the metal surface of the hull 1. The propeller 4 is connected to one end of a shaft (propeller shaft) 8 arranged inside a shaft chamber 7 supported by an intermediate bearing 6, and the other end of the shaft 8 is connected to an engine 9. A shaft grounding device 10 is installed at an intermediate portion of the shaft 8, and the propeller 4 is grounded (electrically connected to the hull 1) via the shaft 8 and the shaft grounding device 10. The negative terminal of the DC power supply 3 is connected to the hull 1. Although various methods and materials have been used for the shaft earthing device 10 in the past, these methods are generally used in which a brush is brought into contact with a slip ring wound around the shaft peripheral portion having the highest peripheral speed or the shaft itself. Target. Various materials are used for slip rings and brushes, but the most effective one is silver.

[0004]

[Problems to be solved by the device]

 The shaft grounding method using the shaft grounding device 10 according to the prior art has the following problems. (1) It is expensive because a large amount of silver is used for the slip ring. (2) Since the shaft grounding device 10 is attached to the shaft 8 arranged in the shaft chamber 7, it is difficult to maintain a good condition for a long period of time due to the influence of ship vibration, oil, and humidity. .. (3) A somewhat skilled technique is required for construction. The present invention aims to provide a shaft grounding device that solves these problems.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the present invention, as shown in the schematic explanatory view of FIG. 3, the non-driving side of the propeller shaft (the side opposite to the shaft 8 to which the propeller 4 is attached) or the extension thereof. A shaft grounding device (a part corresponding to a conventional shaft grounding device) 13 is provided on an end face 12 of the shaft end portion 11 (hereinafter, referred to as a “shaft end face”), and a shaft 8 rotating through the shaft grounding device 13 is electrically grounded (electrical (Connected to the hull 1).

[0006]

[Action]

 According to the shaft grounding device of the present invention described above, as shown on the right side of the engine 9 shown in FIG. 3, the shaft grounding device 13 is provided on the shaft end face 12 outside the shaft chamber 7 (where there is little oil or moisture). Therefore, the silver contact plate (reference numeral 14 in FIGS. 1 and 2) provided on the shaft grounding device 13 may be small, and the mounting work of the shaft grounding device 13 can be simplified, and the contact portion Since the environmental conditions are improved, maintenance and management can be saved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view of a shaft grounding device according to the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG.

The shaft grounding device according to the present invention is roughly formed integrally with a shaft side connecting portion provided with a contact plate (made of silver) 14 and a fixed plate (made of copper) 16 attached to an engine cover 15. A shaft connecting pipe 18 which is divided into a brush holder storage box 17 is attached to the center of the shaft end face 12, and a disc-shaped contact plate support seat (copper) 19 is brazed to the shaft connecting pipe 18. This part rotates with the shaft 8. The contact at the rotating portion is performed by a contact plate (made of silver in this embodiment) 14 attached to the center of the disk-shaped contact plate support seat 19 with a conductive resin (not shown) and a screw 20, and a brush holder. It is held by a brush (made of silver alloy in this embodiment) 22 attached to 21. In order to protect the rotary contact part from oil and moisture, the side of the disk-shaped contact plate support 19 to which the contact plate 14 is fixed has a recess in the center to facilitate the diffusion of oil and water drops. The gap between the disc-shaped outer peripheral surface and the fitting portion provided in the brush holder storage box 17 is structured to be kept airtight by a rubber ring 23 attached to the peripheral portion of the fitting portion. .. The brush 22 is pressed against the contact plate 14 by the pressing lever 25, and the brush holder 21 is fixed to the brush holder storage box 17 by the holder support rod 24.

The corrosion current 5 that has flowed into the propeller 4 or the corrosion current that occurs when corrosion is not performed passes through the shaft 8 and is connected to the shaft grounding pipe 18, the contact plate support seat 19, the contact plate 14, the brush 22, the brush holder 21, and the holder. It flows to the hull 1 via the support rod 24, the brush holder storage box 17, and the engine cover 15. In the above description, silver and silver alloy are used for the contact plate 14 and the brush 22, but if the effect can be expected even if the potential difference between the shaft 8 and the hull 1 is slightly higher than 50 mV, the contact plate 14 is made of copper or silver. The brush 22 can be changed to brass, and carbon can be changed to a low price.

[0010]

[Effect of the device]

 As described above, the shaft grounding device according to the present invention is provided at the shaft end portion of the propeller shaft, and the propeller shaft is grounded via this shaft grounding device, so that the following effects can be obtained. (1) The amount of silver used for the contact plate is reduced to 1/5 to 1/20 of the conventional amount, and the manufacturing cost can be significantly reduced. (2) The conductive contact part is protected from oil, moisture, etc., and maintenance and management labor can be saved. (3) Installation work is simplified and no skilled technique is required. (4) Since the same shape can be used regardless of the shaft diameter, it can be applied to large vessels as well as small vessels. (5) The present invention is not limited to the propeller shaft and crank shaft of a ship, but can be widely used when the rotating shaft is grounded.

[Brief description of drawings]

FIG. 1 is a front view of a shaft grounding device according to the present invention.

2 is a sectional view taken along line AA in FIG.

FIG. 3 is a schematic explanatory view of this device.

FIG. 4 is an explanatory diagram of electrical corrosion protection using a conventional shaft grounding device.

[Explanation of symbols]

 1 Hull 2 Electrode (Anode) 3 DC Power Supply 4 Propeller 5 Corrosion Protection Current 6 Intermediate Bearing 7 Shaft Chamber 8 Shaft 9 Engine 10 Shaft Grounding Device 11 Shaft End or Its Extended Shaft End 12 Shaft End Face 13 Shaft Grounding Device 14 Contact Plate 15 Engine cover 16 Fixed plate 17 Brush holder storage box 18 Pipe for connecting shaft 19 Contact plate support seat 20 Screw 21 Brush holder 22 Brush 23 Rubber ring 24 Holder support rod 25 Push lever

Claims (1)

[Scope of utility model registration request] 1. A disk-shaped contact plate support seat having a silver contact plate fixed to the center thereof is provided with a shaft connecting pipe at the center of the non-driving side end of the propeller shaft or the end face of the extension shaft end thereof. And a shaft holder connected to the engine cover and a fixing plate attached to the engine cover are integrally formed, and a brush holder that comes into contact with the silver contact plate via a silver alloy brush is stored inside and A brush holder storage box having a fitting portion that comes into contact with the outer peripheral surface of the disk-shaped contact plate support seat via a rubber ring, and makes contact between the silver contact plate and the silver alloy brush. A shaft grounding device characterized by grounding between the propeller shaft and a hull via the shaft.