The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
A typical pinion shaft and bearing assembly uses various mechanisms to maintain sufficient friction between the pinion shaft and the bearing to prevent the bearing from spinning free from or walking off the pinion shaft. These mechanisms include various mechanical methods of coupling the bearing to the pinion shaft such as, for example, press-fitting the bearing to the pinion shaft. The effectiveness of these mechanisms may be enhanced by the addition of an anaerobic adhesive between the pinion shaft and the bearing.
Typically, the anaerobic adhesive is applied to the pinion shaft or bearing prior to assembly and is cured in situ. The adhesive fits within gaps formed on the surfaces due to surface roughness. In general applications the cure time for the anaerobic adhesive is a function of the gap between the pinion shaft and the bearing. The cure times are shorter when the anaerobic adhesive is applied to a smaller gap. Also, the relationship between retention strength of the adhesive and surface roughness is integral in the robustness of the assembly where the rougher the surface finish the higher the retention strength achieved.
However, the location accuracy (i.e., the radial and axial position) of the bearing on the pinion shaft improves when tight dimensional controls are employed. One result of tight dimensional controls is smooth surface finish. In balancing the needs for tight location accuracy and high bearing retention strength, location accuracy is typically favored. Alternative solutions for preventing bearing spin or walk while maintaining location accuracy include integrated bearing sleeves or mechanical retention of the bearing. However, these alternative solutions may increase cost and may not be practical due to packaging restraints. Accordingly, there is a need in the art for a pinion shaft and bearing assembly that increases the effectiveness of anaerobic adhesives without increasing cure time and without decreasing locational accuracy.