Mikasa
Mikasa corporation is a company established in 1917. They are well known for their business in sport goods but also for their role in the industrial production.
WATER LUBRICATED BEARINGS (FF-BEARING)
FF-Bearing is a three-layer bearing with rubber and tetrafluoroethylene inside the outer cylinder.
FF-Bearing takes advantage of the elasticity that is a feature of rubber bearings, and uses slippery polytetrafluoroethylene on the sliding surface. Compared to conventional rubber bearings, FF-Bearing has ⅛ the frictional resistance and reduces energy loss. This bearing significantly reduces fuel consumption and contributes to reducing CO2, the main cause of global warming. Rubber bearings, which have excellent wear resistance, shock resistance, and vibration absorption, are commonly used as bearings for water lubrication. However, rubber bearings have poor self-lubricating properties, and there is a risk of seizing, especially when water runs out. , noise may occur in the low rotation range.
Mikasa offers FF-Bearing, which utilizes the advantages of rubber while reducing these risks with tetrafluoroethylene and has excellent self-lubricating properties.
Characteristics of Water Lubricated Bearings (FF-Bearing)
- Lower Fuel Consumption
The friction coefficient is extremely low, approximately 1/8th of that of conventional rubber bearings, resulting in significantly reduced energy loss and an expected energy-saving effect. For detailed data, please feel free to contact us.
- Resistance to Seizure
The low friction coefficient minimizes heat generation in sliding parts, making it less prone to seizure even with reduced seawater intake. Coolant requirements can also be set at a lower level compared to conventional rubber bearings.
- Quietness
With inherent self-lubrication and excellent friction characteristics at low rotational speeds, it effectively suppresses stick-slip phenomena during startup and shutdown. This feature results in extremely minimal noise generation, a common occurrence in rubber bearings.
- History and Reference
FF-Bearing was developed in 1981, and to date, it has a cumulative delivery record of over 700 vessels. With a long history and numerous successful adoptions, the technology and experience, enriched by abundant data and continuous improvements, provide confidence for safe usage.
- Suitable for Large Vessels
Its self-lubricating properties, coupled with a moderate softness even under high loads, enable the realization of self-alignment. It can be applied to large vessels operating under substantial weight conditions. The largest delivered size by our company is in the Antarctic observation ship "Shirase," with a bearing inner diameter of φ810.
WATER LUBRICATED BEARINGS (MR-BEARING)
Bearings for propeller shaft systems for ships can be broadly classified into water lubrication and oil lubrication. In the past, lignum vitae, which is a natural wood containing resin, had been used for water lubricated bearings. However, the depletion of raw wood in the production areas (Central and South America) has made it difficult to obtain materials with good quality, resulting in the frequent occurrence of irregular wear and swelling. In recent years, rubber bearings with stable quality are most commonly used instead of lignum vitae. Mikasa began developing rubber bearings in the early 1970s. They provide excellent rubber bearings that are strong and stable in the long-term by using rubber that has great sliding properties and wear resistance, as well as a special method for adhesion with the metal shell. At present, they have numerous achievements
Characteristics of Water Lubricated Bearings (MR-Bearing)
- No Damage to the Shaft and Sleeve
Even if sand or pebbles fall between the shaft and the rubber bearings, the lubricating water expels the debris along the ridge as the shaft rotates. At out company, we implement designs with rubber that take advantage of these properties.
- Low Power Loss
In general, wet rubber and metals have properties of sliding very well. At our company, we pay attention to these characteristics and implement designs with rubber that have a low coefficient of friction.
- Low Wear
Wear resistance is better compared to lignum vitae. There is an example of rubber bearings being used for over 10 years in a situation where lignum vitae had to be replaced every several months.
- Swelling resistance
We use a rubber with excellent swelling resistance that does not cause hydrolysis.
