Mechanical engineering active places, mostly of mountainous and desert areas away from human exploitation and life, such as site, sometimes even working at 2000 meters underground, This wide range of machinery, many construction machineries are various types of collaboration, which either machine fails, will give a large impact site of production, and due to the recent larger machinery, this will cause maintenance more difficult.
  Therefore, in terms of bearing working environment, " heavy load +impact force", "high speed+ light load", "heavy load + low-speed rotation" are very harsh conditions.So, the bearing desired by the user, is resistant to these harsh conditions of ruggedness, durability and high reliability.