Patent ID: 11898604
Assignee: MINEBEA MITSUMI IN.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  C | IPC C  F

Claim 0:
1. A ball bearing comprising:
an inner ring;
an outer ring placed outside of the inner ring;
a plurality of rolling bodies intervening between the inner ring and the outer ring; and
an annular cage having a rotation axis, the cage including pockets rotatably holding the rolling bodies in a circumferential direction at intervals, wherein
the cage comprises a resin composition comprising a polyetherketone-based resin, graphite, and a carbon fiber;
the resin composition comprises the polyetherketone-based resin in an amount of 60% by weight or more and 80% by weight or less, the graphite in an amount of 10% by weight or more and 30% by weight or less, and the carbon fiber in an amount of 5% by weight or more and 20% by weight or less when the entire resin composition is determined to be 100% by weight; and
an area ratio is defined by a ratio of an area occupied by graphite having a diameter of a circle to which a particle internally contacts of 30 μm or more relative to a total area occupied by the graphite,
wherein the area ratio is 10% to 20%.