Patent ID: 7305330

Claim:
A method to predict a life using a computer of a rolling bearing having a basic dynamic rated load C and a basic static rated load C 0 , comprising calculating the rated correction life L nm of a rolling bearing at a reliability coefficient a 1 according to the relationship: L nm =a 1 ×a xyz ×( C/P ) p a xyz ∝f(α) where P represents an equivalent load, p represents a load index, a xyz represents a life correction coefficient, and α represents a ratio between a dimension for a portion of a bearing to be in contact with a mixed foreign substance and a characteristic quantity showing a size of the mixed foreign substance, wherein the ratio α is calculated according to the relationship: α= d/√ S where √ S represents the dimension assuming a diameter of the mixed foreign substance as d, and a contact ellipse area in the bearing as S, and presenting the calculated rated correction life.