Precision spindle unit for low friction performance

A precision spindle unit for low friction performance comprising:

• an elongated shaft;
• a tubular housing surrounding the shaft and having an interior, the tubular housing having a larger inner diameter than the diameter of the shaft and having a first annular shoulder projecting inwardly from an inner surface of the housing;
• a first rolling bearing positioned in the interior of the housing and mounted on the shaft, the first rolling bearing having an inner race ring and an outer race ring, the inner race ring of the first rolling bearing having a first side and an oppositely located second side, the first side of the inner race ring of the first rolling bearing abutting against a shoulder provided on the shaft;
• a first locking washer affixed to the shaft with an interference fit and provided with an axially extending annular flange which engages the second side of the inner race ring of the first rolling bearing so that the first rolling bearing is axially arrested between the shoulder on the shaft and the annular flange on the first locking washer;
• a second rolling bearing provided in the interior of the housing and having a loose fit on the shaft, the second rolling bearing having an inner race ring and an outer race ring, the inner race ring of the second rolling bearing having a first side facing axially outwardly and an oppositely located second side;
• a second locking washer fitted with an interference fit to the shaft;
• a resilient member provided between the second locking washer and the first side of the inner race ring of the second rolling bearing;
• the outer race ring of the second rolling bearing having an axially inwardly directed side engaging the first annular shoulder that projects inwardly from the inner surface of the housing;
• the second bearing being biased, under influence of the resilient member, between the resilient member and the first annular shoulder in the housing;
• and
• the first and the second locking washers being arranged to extend radially along at least a portion of the tubular housing at a short distance from respective end faces of the housing that face the first and second locking washers to form a slot seal at each axial end of the housing, whereby each of the first and second rolling bearings at their outwardly facing sides are provided with a seal.