Method and apparatus for measuring bearing friction

A method for testing bearings, the bearing having an inner race and an outer race, comprising:

• (a) coupling the outer race of the bearing to a strain gauge;
• (b) rotating the inner race of the bearing in a first direction and measuring the torque exerted on the outer race;
• and
• (c) rotating the inner race of the bearing in a second direction and measuring the torque exerted on the outer race.

An apparatus for testing bearings, comprising:

• means for moving a first race of the bearing in a first direction and a second direction relative to a second race;
• a strain gauge;
• means for coupling the outer race of the bearing to the strain gauge;
• and
• means, coupled to the strain gauge, for measuring the force applied to said strain gauge when said inner race is rotated;
• and
• means for clamping the bearing during testing, wherein said means for clamping may be positioned between an unclamped position and a clamped position.

A method for measuring the running friction of a bearing, comprising:

• coupling the outer race of a bearing to a strain gauge, the gauge including a load beam;
• rotating the inner race of the bearing in a first direction and simultaneously measuring the force applied to the load beam by the outer race;
• rotating the inner race of the bearing in a second direction and simultaneously measuring the force applied to the load beam by the outer race;
• and
• comparing the forces applied by the outer race to the load beam.

An apparatus for measuring the running friction of a bearing, the bearing having an inner race and an outer race, comprising:

• a housing;
• a spindle, mounted on the housing, having a central shaft and base, the shaft extending from the base and having a diameter sufficient to accommodate the inner race of a bearing under test;
• a motor mounted under the housing for rotating the spindle;
• a bearing holder, having a cylindrical bore of sufficient diameter to receive the outer race of a bearing under test;
• a clamp, positioned adjacent the spindle, being rotatable between a first, unclamped position, and a second clamped position;
• a load beam, positioned adjacent the spindle and in a position to engage the holder when the holder is mounted on a bearing and the bearing is mounted on the spindle, the load beam having a strain gauge at one end;
• and
• control means, coupled to said motor, clamp and load beam, for controlling the rotation of the spindle, and for measuring the force applied by the housing to the strain gauge when the spindle is rotated.