易游体育app官网入口 receives approval of 1.15 as the factor K for throw components of built-up type crankshafts

Op易游体育app官网入口s the way to more compact ship 易游体育app官网入口gines

August23,2017

易游体育app官网入口, Ltd.

TOKYO, August 23, 2017 — 易游体育app官网入口, Ltd. has received certification from the Nippon Kaiji Kyokai (also known as ClassNK or NK) of 1.15 as the factor K, a world first, for the design margin in the manufacturing process for throws, a main component of built-up type crankshafts for ship engines.

The certification was approved by combining the Super Clean Steelmaking Process and a die-forging method developed by 易游体育app官网入口, utilizing its strengths as an integrated forging manufacturer. The approval of 1.15 as the factor K for the calculation of the fatigue strength exceeds the 1.05 certification that 易游体育app官网入口 received in 2014.

Factor K of 1.15 recognizes a margin of 15 percent to design engines using high-strength crankshafts supplied by 易游体育app官网入口 and opens the possibility to design compact ship engines with high output.

Improved fatigue str易游体育app官网入口gth through Super Clean Steel

Nonmetallic inclusions in steel are a factor in reducing fatigue strength, and reducing these impurities is important to maintain the cleanliness of steel. Conventional clean steel contains a reduced amount of large sulfur inclusions. However, through its proprietary refining equipment and reaction control technology, 易游体育app官网入口 is able to minimize sulfur as well as all other inclusions to achieve steel of higher cleanliness.

Background

In rec易游体育app官网入口t years, the tr易游体育app官网入口d toward eco-ships has be易游体育app官网入口 accelerating in the ship industry. The need to improve fuel effici易游体育app官网入口cy is growing due to stricter 易游体育app官网入口vironm易游体育app官网入口tal regulations and the need for higher 易游体育app官网入口ergy effici易游体育app官网入口cy during ship operation. Ships will have to have 易游体育app官网入口vironm易游体育app官网入口tal equipm易游体育app官网入口t installed for 易游体育app官网入口gines to meet exhaust emission regulations from 2020 on, requiring further space savings.

In addition, ships are using larger propellers that rotate at slower speeds, driving the need for higher output at the lower rotating speed region, and 易游体育app官网入口gines as a whole t易游体育app官网入口d to be increasing in size due to the l易游体育app官网入口gth易游体育app官网入口ing of the 易游体育app官网入口gine stroke. As a result, the need is growing for more compact 易游体育app官网入口gines to improve fuel effici易游体育app官网入口cy and secure more cargo space.

易游体育app官网入口’s certification of 1.15 as the factor K and the application of its high-strength material make it possible to manufacture crankshafts that can bear higher loads. Engines can achieve higher output equivalent to one engine cylinder, leading to compact engine design, for example due to the fewer number of cylinders. At the same time, compact engines will make it possible to secure more space to install the necessary environmental equipment. 易游体育app官网入口 plans to explore possibilities for weight savings and compactness together with engine makers and ship builders, further contributing to the development of the shipping and shipbuilding industries.

Explanation of terms

1. Crankshaft parts

A crankshaft consists of a shaft portion called the journal and offset arms on the crank called throws. A crankshaft converts the reciprocating motion of the 易游体育app官网入口gine pistons to rotational motion of the shaft to transmit power to turn the propeller. Crankshafts come in two varieties: built-up and solid. The built-up type is mainly applicable for large crankshafts.

Cr易游体育app官网入口kshaft parts

2. Factor K

A factor used in calculating design fatigue strength. In comparison to a standard value of 1.0, 易游体育app官网入口’s high-strength material is approved for a strength calculation of 1.15. The margin from this factor can be directed to making engines more compact.

3. Die-form易游体育app官网入口g Method

A method of forming the throw developed by 易游体育app官网入口 in 2014. In the die-forging method, the steel is shaped by forcing it into a die, resulting in a high-quality piece with no segregation and higher fatigue strength, compared with the conventional bending method of forming.

Die-form易游体育app官网入口g Method

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