Lubrication system and its modification method

A lubrication system for a bearing of a machine, the lubrication system comprising:

• an oil tank for storing lubricant oil so that a tank oil level may be formed in the tank, the tank oil level positioned below the bearing:
• an oil supply pipe for supplying the lubricant oil from the oil tank to the bearing;
• an outlet pipe for guiding the lubricant oil from the bearing substantially vertically downward so that an outlet pipe oil level may be formed in the outlet pipe;
• an oil returning mother pipe for guiding the lubricant oil from the outlet pipe to the tank, the oil returning mother pipe including a substantially horizontal part and a flow resistance disposed close to the tank so that substantially all portion of the substantially horizontal part may be maintained full of lubricant oil;
• and
• a vent pipe for communicating the outlet pipe above the outlet pipe oil level and the tank above the tank oil level.

A method for modifying an existing lubrication system and reconstructing a new lubrication system for a bearing of a machine, the existing lubrication system comprising:

• an oil tank for storing lubricant oil so that a tank oil level may be formed in the tank, the tank oil level positioned below the bearing:
• an oil supply pipe for supplying the lubricant oil from the oil tank to the bearing;
• an outlet pipe for guiding the lubricant oil from the bearing substantially vertically downward so that an outlet pipe oil level may be formed in the outlet pipe;
• an oil returning mother pipe for guiding the lubricant oil from the outlet pipe to the tank, the oil returning mother pipe covering part of the oil supply pipe;
• and
• a vent pipe for communicating the outlet pipe above the outlet pipe oil level and the tank above the tank oil level;
• the method comprising:
• separating the existing oil returning mother pipe from the existing outlet pipe and the existing tank, while the existing oil returning mother pipe is maintained to cover part of the oil supply pipe;
• and
• disposing a new oil returning mother pipe outside of the existing oil returning mother pipe and connecting the new oil returning mother pipe to the existing outlet pipe and the existing tank, wherein the new oil returning mother pipe including a substantially horizontal part and a weir or a flow resistance disposed close to the tank so that substantially all portion of the substantially horizontal part may be maintained full of lubricant oil.