*4.3.4 Friction optimization*

Friction optimization solutions are intended to achieve better efficiency, lower losses in the bearing. Type of bearing and depending upon the application requirements bearing friction level can be achieved with the manufacturing process and tighter specification controls. Generally, bearing friction is a function of multiple factors like internal geometry, type of seals, material, lubricant, and the rolling element grade. Kinetics of bearing also plays a role in achieving the optimum friction of bearing. Adjustment in assembly, preload requirements, and assembly process influence final friction behavior of bearing in the application.

Lower friction of bearings directly contributes to wear performance as well as the efficiency of the system.

**Figure 16** depicts the typical wheel bearing friction rate. Conventionally, vehicle manufacturers were assembling different parts together including bearings into wheel hubs. However, this arrangement is not effective considering the performance parameters. Hub 1 bearing is integration of two bearing into one, so it provides 10 to 15% better friction rate, Hub 2 is further improvement having integration of out race of bearing into housing and it provided 10 to 15% friction reduction compare Hub 1. Currently most of the modern automobiles are using Hub3 which are complete integration of bearing and wheel mounting.

This arrangement provides 50 to 60% friction reduction compare to conventional arrangements and additional 10 to 12% improvement compare to hub 2 arrangement.

**Figure 16.** *Typical wheel bearing friction rate.*
