Patent ID: 8436292

Claim:
A lubricant deterioration detecting device which comprises: a single light source having linear shape; a plurality of light detecting components, arranged in line in correspondence with the linear shape of the light source, for detecting rays of light emitted from the light source and subsequently transmitted through a lubricant, wherein each of the plurality of light detecting components includes only a single detector and only a single light guide element having one end in the form of a base end connected with the detector and the other end in the form of a free end forming a light detecting face, each of the light detecting faces faces a same direction of travel of the rays of light, and the light guide elements have respective lengths different from each other so that the light detecting faces are sequentially displaced in position by a distance relative to the direction of travel of rays of light; and a determining unit operable to compare respective signal strengths of outputs from the detectors connected respectively with the light guide elements having respective lengths different from each other to thereby detect a status of deterioration of the lubricant, wherein the lubricant deterioration detecting device is provided within a bearing assembly for detecting a status of deterioration of a lubricant filled within the bearing assembly.