JPH0324399B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diesel engine propulsion system for ocean-going and ice-breaking ships, especially commercial ships, having at least one screw.

Known diesel engine systems have used only medium speed engines with rotational speeds of about 500 to 600 rpm and power outputs of 500 to 800 horsepower per cylinder. The maximum rotational speed of the screw is approx.
170 rpm, an electric unit consisting of a generator connected to the diesel engine, and a low-speed electric motor driven by electricity from the generator and connected to the screw shaft connects the medium-speed diesel engine and the screw shaft. It was interposed between the shaft and the shaft.

Another known possible way of adjusting the difference in rotational speed between the diesel engine and the screw shaft is to interpose a reduction gear.

This type of propulsion device requires the aforementioned electric unit or reduction gearing, resulting in considerable power transmission losses. Since medium-speed diesel engines have very high fuel consumption per horsepower, this has negative consequences for the running costs of the ship. These diesel engines can never be operated economically if they are to be used for long periods of time in ocean navigation as well as ice-breaking operations. The engine output ratio for ice-breaking navigation and ocean navigation that should be input by the diesel engine is approximately 3:1 to 2:
1, and its limits vary depending on the operating conditions of the ship.An object of the present invention is to improve the above-mentioned type of diesel engine propulsion system, thereby reducing the power transmission loss for the screw drive and the running cost of the ship. The object of the present invention is to significantly reduce the amount of damage caused by the diesel engine, thereby making it possible to operate the diesel engine economically both during ice-breaking voyages and during ocean voyages.

For this purpose, according to the invention, at least two low-speed two-stroke diesel engines are installed in the hull for each screw and in a common row in longitudinal succession parallel to the longitudinal axis of the ship. the screw is directly connected to the screw via a shaft system, and a clutch is interposed in the shaft system of the row between the two engines; It is provided that each joint of the series of shafts connected by a clutch can only be connected when it is in a certain precisely positioned position.

A low-speed two-stroke diesel engine was placed inputting a common single-row shaft system to which the screws were attached, so that the screws could be rotated directly. That is, the rotational speed of the diesel engine and the rotational speed of the screw are the same. In this manner, the present invention eliminates the need for an electric unit or reduction gear, thereby eliminating the power transmission loss. Since low-speed diesel engines consume less fuel per horsepower than medium-speed engines, the running costs of ships are also significantly reduced. Using two engines allows the propulsion to be split. That is, during ice-breaking operations all engines are running, while during ocean-going operations, where very little horsepower is required, only the engine closest to the screw is operated, with the other engines being clutched. separated from the shaft system by In this way, each engine can be operated economically. Surprisingly,
It has been found that the torque characteristics of a low speed diesel engine arranged according to the invention are optimal under various ship operating conditions.

An exemplary embodiment of the invention will be described in detail below with reference to the drawing, which is a simplified schematic diagram of a propulsion device with two diesel engines.

Two low-speed diesel engines 11, 12 are arranged successively and parallel to the longitudinal axis 10 of the ship and are fixed in a known manner to the hull 18. The drawing shows only the stern section. The two engines 11, 12 are two-stroke engines with crossheads and the same power output, and feed directly into a common single-row shaft system 21. At its bottom end in the drawing of the common shaft system 21 is fixed a ship's screw with fixed vanes, which is adapted to propel the ship for both ice-breaking and ocean-going navigation.

A clutch 13 of known construction is inserted in the shaft system 21 between the two diesel engines 11, 12. The clutch 13 is adapted to be able to engage only when each joint of the series of shafts connected by the clutch is in a certain precisely positioned position.

A thrust bearing 19 is attached to each of the two engines 11 and 12 by a well-known method.
Each thrust bearing 19 is adapted to receive the axial thrust force of an associated crankshaft. Separately, a thrust bearing 15 is disposed on a portion of the shaft supporting the screw 16 and is fixed within the hull 18 so as to receive a very large axial thrust force generated from the screw 16. Thrust bearing 15 of shaft system 21 and engine 12
A clutch 14 is interposed between the clutches 14 and 14 to receive relative axial movement of the respective joint shaft portions it connects.

When the ship is ice-breaking, the clutch 13 is engaged and the outputs of the two engines 11, 12 are input to the screw 16 via a common shaft system 21. On the other hand, during ocean voyage, clutch 13
is cut off and only the output of engine 12 is output from screw 1.
6 is input. The total output of the two engines 11 and 12 and the output of only the engine 12 are balanced so that cruising is always possible with the output of the engines involved being maximized.

The fixed vane screw 16 may alternatively be replaced by a screw with adjustable vanes, which allows a better adaptation of the engine power to the speed of the ship. Instead of a 1:1 engine power ratio acting on a single row of shafts, e.g.
ie in this case the larger engine may be arranged adjacent to the screw.

The invention also provides two or three units operated in parallel.
It is also applicable to ships propelled by multiple screws. In this case, each screw is
Each has its own in-line shaft system, two low-speed diesel engines input to the shaft system, and a clutch interposed between the two engines. More than one engine per row of shafts can also be used.

[Brief explanation of the drawing]

The drawing shows a simplified schematic diagram of a commercial marine diesel engine propulsion system illustrating an exemplary embodiment of the invention. 10... Longitudinal axis, 11, 12... Diesel engine, 13, 14... Clutch, 15...
...Thrust bearing, 16...Screw, 18...
Hull, 21... shaft system.

Claims (1)

[Scope of Claims] 1. In a diesel engine propulsion system for a ship capable of ocean navigation and ice-breaking navigation, especially a merchant ship, having at least one screw, at least two low-speed two-stroke diesel engines are installed in the ship for each screw. attached to and connected to said screw so as to directly drive said screw through a common series of shafts located in longitudinal succession parallel to the longitudinal axis of said merchant vessel; A clutch is interposed in the row of shafts between the two engines, and the clutch is configured to ensure that each joint of the row of shafts connected by the clutch is precisely positioned. A diesel engine propulsion device for a merchant ship, characterized in that the device can be connected only when the diesel engine is in a fixed position. 2. The apparatus according to claim 1, wherein the screw has adjustable vanes. 3. In the device according to claim 1 or 2, a thrust bearing fixed within the hull and adapted to receive a force in the axial direction of the screw is located between the screw and the screw closest to the screw. A clutch is interposed between the thrust bearing and the engine, and each of the shaft systems connected by the clutch is interposed between the thrust bearing and the engine. A commercial marine diesel engine propulsion system adapted to allow axial movement of joints.