Patent ID: 8397872

Claim:
A lubricant recovery device for the recovery of lubricant supplied together with carrier air as one of oil air lubrication and oil mist lubrication, the recovery device comprising: a vertical main spindle; a bearing that supports the main spindle and through which one of oil air lubrication and oil mist lubrication is passed, the bearing having a lower portion; a space formed below the bearing into which oil air lubrication or the oil mist lubrication passed through the bearing is discharged; an oil reservoir; a housing including: an air discharge passage extending vertically upwardly from the oil reservoir, the air discharge passage having a peripheral inner wall with lower and upper ends and an intermediate portion intermediate the lower and upper ends, wherein the lower end is valveless and opens into the oil reservoir, the upper end opens into the air outside the housing, and the intermediate portion has an opening through the peripheral inner wall, the peripheral inner wall providing a surface to which the lubricant in the oil air lubrication or the oil mist lubrication partly adheres and on which the lubricant liquefies, wherein the liquefied lubricant collects in the oil reservoir, a lubricant discharge passage extending vertically upwardly from the oil reservoir in parallel with the air discharge passage, the lubricant discharge passage having lower and an upper ends, the lower end opening into the oil reservoir, and a through hole which connects the lower portion of the bearing and the opening in the intermediate portion of the air discharge passage; and a suction unit connected to the upper end of the lubricant discharge passage for sucking the lubricant collected in the oil reservoir through the lubricant discharge passage such that the lubricant is recovered at a position outside the housing, wherein the air of the oil air lubrication or the oil mist lubrication passing through the bearing is discharged into air from the air discharge passage and the lubricant collected at the oil reservoir is sucked and recovered through the lubricant discharge passage.