PURPOSE: To secure a damper effect by means of an oil film and prolong the service life of a rolling bearing owing to the separation prevention of a raceway surface by forming this oil film with sufficient thickness and buffering capacity, in space between the raceway surface and a rolling surface by means of grease.
CONSTITUTION: Grease is filled up in an inner ring 2 with an inner ring raceway track 1 on an outer circumferential surface, an outer ring 4 with an outer ring raceway track 3 on an inner circumferential surface, plural rolling elements 5 installed between the inner ring raceway track 1 and the outer ring raceway track 3, and a rolling element setup part in an interspace 8 between both these tracks 1 and 3. At least one side raceway ring of both these inner and outer rings 2 and 4 is manufactured by a rigid material of less than 6ppm in oxygen content in steel, and at least a raceway surface of the raceway ring satisfied the condition is hardened by heat treatment. This grease is amde up of using synthetic fluid of more than 60cst and less than 90cst in kinematic viscosity at 40°C. In this connection, this grease contains a thickening agent of 18 to 28wt.% consisting of an urea compound.
GOSHIMA FUSASUKE
AOKI NORIHIRO
IMAMURA YOICHI
