Lubricating structure of bearing

A lubricating structure of a bearing for lubricating a bearing by supplying oil air which is transmitted with pressure through respective distribution passages of an oil air distributor from an oil air supply apparatus to the bearing, comprising:

• a first lubrication route for supplying said oil air to the bearing to lubricate inner portion of the bearing;
• and
• a second lubrication route for supplying said oil air to the bearing, and leading this oil air to a fit portion between the internal diameter surface of the inner race and the shaft portion through a seal member having a predetermined void portion, thereby lubricating this fit portion, wherein
• said bearing comprising a plurality of outer race elements juxtaposed each other to compose a bearing outer race, a plurality of inner race elements disposed radially distant from the outer race elements and juxtaposed each other to compose a bearing inner race, and a plurality of rolling elements disposed in a bearing space formed between said outer race elements and said inner race elements;
• a first outer race spacer disposed between the neighboring outer race elements and extending radially inwardly to said bearing space, said first outer race spacer being formed with a first lubricating passage communicating with one of said distribution passages and opening to said bearing space;
• the first lubricating passage forming said first lubricating route;
• a second outer race spacer disposed between the other neighboring outer race elements and extending radially inwardly to the neighborhood of said inner race, said second outer race spacer having a second lubricating passage which communicates with the other of said distribution passage and opens radially inwardly;
• seal element disposed between said second outer race spacer and said inner race element radially opposed thereto to form a sealed space separated from said bearing space;
• said inner race being formed with a third lubricating passage which communicates with said sealed space and opens to said fit portion;
• and
• said second lubricating passage of said second outer race spacer, said sealed space and said third lubricating passage formed through said inner race composing of said second lubricating route, and
• wherein a cross-section area A of a lubricating passage composing the second lubricating route satisfies the following formula:
• V=Q/A≧6 m/s
• where V is a velocity of the oil air in the lubricating passage;
• and
• Q is an amount of supply of the oil air.