Double-row ball bearing and bearing device for supporting pinion shaft

A pinion-shaft-supporting bearing device comprising:

• a plurality of rolling bearings that support a pinion shaft having a pinion gear at one end in an axial direction at predetermined positions on the pinion gear side and the anti-pinion gear side,
• wherein at least the rolling bearing on the pinion gear side is prepared as a ball bearing with double raceway that comprises:
• an outer ring member having a large-diameter raceway surface and a small-diameter raceway surface that are placed in a separate manner 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 placed in a separate manner from each other in the axial direction;
• a large-diameter-side row of balls and a small-diameter-side row of balls that are respectively interpolated between the raceway surfaces of the outer ring member as well as between the raceway surfaces of the inner ring member, the ball bearing with double raceway being arranged so that 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.

A pinion-shaft-supporting bearing device comprising:

• a plurality of rolling bearings that rotatably support a pinion shaft having a pinion gear at one end in an axial direction at predetermined positions on the pinion gear side and the anti-pinion gear side,
• wherein the rolling bearing on the pinion gear side is prepared as a ball bearing with double raceway that comprises:
• 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;
• and a large-diameter-side row of balls and a small-diameter-side row of balls that are respectively interpolated between the raceway surfaces of the outer ring members as well as between the raceway surfaces of the inner ring members, and the rolling bearing on the anti-pinion gear side is prepared as a ball bearing with single raceway that comprises:
• an outer ring member, an inner ring member and a single row of balls that are interpolated between an outer ring raceway surface formed on the outer ring member and an inner ring raceway surface formed on the inner ring member, the ball bearing with double raceway being arranged so that an internal clearance on the anti-pinion gear side is made smaller than an internal clearance on the pinion gear side 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, the ball bearing with single raceway being arranged so that an internal clearance in the ball bearing with single raceway being made virtually equal to an internal clearance on the anti-pinion side in the ball bearing with double raceway.