WHEEL SUPPORTING ROLLING BEARING

摘要

PROBLEM TO BE SOLVED: To provide a wheel supporting rolling bearing capable of maintaining good water resistance and sealing performance even in severer circumstances for a long period while securing lubricity.SOLUTION: The wheel supporting rolling bearing includes a bearing part and a seal device. The bearing part includes an outer ring equivalent member having an outer ring raceway on the inner peripheral face and a plurality of rolling elements which are arranged in a freely rollable manner between the outer ring equivalent member and an inner ring equivalent member having an inner ring raceway on the outer peripheral face, and which are retained by a cage. The seal device blocks a space formed between the outer ring equivalent member and the inner ring equivalent member. A seal lip constituting the seal device and its sliding contact surface are lubricated with a first grease composition which uses at least one type of mineral oil and synthetic hydrocarbon oil as base oil and contains at least one type of metal soap and metal composite soap as thickening agent at a rate of 50 mass% or more of the total amount of the thickening agent, and the bearing part is filled with a second grease composition using a urea compound as a thickening agent.