Basic Structure of Makita Engines
As the maker of MAN B&W engine, which holds over an 80% worldwide share of marine low-speed engines, Makita Corporation mostly builds engines for 10,000 to 40,000 ton class ocean-going vessels. They are characteristically two-stroke crosshead diesel engines. Thanks to the reliability of our technology and impeccable track record over many years, the engines built by Makita Corporation have come to hold a worldwide top share for small bore engines.
The Mainstream of Low-Speed Two-Stroke Diesel Engines
For ocean-going vessels, diesel engines are mainstream. A diesel engine is an internal combustion engine where internal combustion is achieved by the compressed air in the cylinders acting on the fuel (heavy oil), and the resulting explosive power firing the pistons back and forth generating power. By changing the rotational movement of the crankshaft via the above-mentioned crosshead and connecting rod, the reciprocating motion of the pistons turns the propeller, driving the ship. To increase the propulsion efficiency of a ship, an engine with high output per fewer revolutions is necessary. In order to achieve this with marine engines, longer stroke engines evolved, and in order to reduce the increased amount of lateral pressure in the cylinders, what is known as the "crosshead" was developed and adopted, linking the piston and the connecting rod. All the engines built by Makita Corporation also come equipped with a turbo charger. By taking in more oxygen, high combustion energy is created, and as a result, a structure where even a small engine can have a large output is produced.
In this crosshead is the structure that connects the piston and the connecting rod.
These important parts are produced by Makita Corporation itself. A crankshaft is featured in the photograph.
Selection and adjustment of turbo chargers is important processes that directly affect the engine's performance.
- In this structure the piston and connecting rod are linked by this crosshead.
- The most important parts are made at Makita's own factories. The picture shows a crankshaft.
- The selection and adjustment of the turbo chargers is important processes that determine engine performance.
Meaning behind the Engine Names
The letters and numbers used in each engine's name signify the configuration and capabilities of the engine.
Process for Starting a Marine Engine
The engine first starts by moving the pistons. In the engine of a large ship, the weight of the pistons is also measured in tons. An automotive engine can be started with an electric motor, but this is not possible with a ship's engine. So what do you do? The answer is to use compressed air. With good timing on the feed of high-pressure compressed air into cylinders, the resulting pressure can even move the several ton pistons used in these engines, which then switch from inertial rotation to fuel operation. The motion of the pistons in the diesel engine creates a high-temperature state with the compressed air in the cylinders, and when fuel is injected it combusts (ignites), which is how the energy that allows for movement is generated. This is why the pistons have to start moving first. The initial motion comes from a push from compressed air.
Process for Stopping the Vessel
There is no actual brake on a ship. So how do you stop it? For the vast majority of ships, reducing speed involves reversing the rotation of the propeller. The propeller is directly connected to the engine. That is why to stop the engine a reverse rotation is necessary. This feature of switching the rotational direction of the engine using the transmission is not found in automotive engines.
