Patent ID: 7350977

Claim:
A ball bearing with double raceway, which rotatably supports a pinion shaft having a pinion gear on one end thereof in an axial direction, comprising: an outer ring member having a large-diameter raceway surface and a small-diameter raceway surface that are spaced from each other in the axial direction; an inner ring member having a large-diameter raceway surface and a small-diameter raceway surface that are spaced from each other in the axial direction so as to be respectively positioned inside the large-diameter raceway surface and the small-diameter raceway surface in a radial direction; a large-diameter-side row of balls that are interpolated between the two large-diameter raceway surfaces; a small-diameter-side row of balls that are interpolated between the two small-diameter raceway surfaces, wherein internal clearances on the two large-diameter raceway surfaces side as well as on the two small-diameter raceway surfaces side are designed to have respectively different sizes in such a manner that upon applying a load on the pinion shaft, the row of balls on the anti-pinion gear side of the two rows of balls is subjected to the load prior to the row of balls on the pinion gear side.