Composite-film hydrodynamic bearings

From time-to-time, experts endeavor to estimate the amount of energy lost due to friction and wear. According to one such estimate, over 4.22 × 1018 J of energy were lost in the United States in 1978 alone – enough to supply New York city for the entire year. A major factor in limiting our energy efficiency is energy loss through friction in tribo-elements is [1]. In recognition of this, there have been significant efforts made during the past decades towards increasing the efficiency of bearing operations. The major influencing aspects of hydrodynamic lubrication are the structure of the lubricant film, the properties of the bearing surfaces, and the properties of the lubricant. Major past approaches for seeking efficiency improvement focused on the latter two of these aspects and concerned surface modification techniques and modification of lubricant properties. Here we advocate the third approach, modification of the structure of the lubricant film; this approach leads to what we call composite-film bearings (CFB). Composite-film bearings rely on a double layer, composite lubricant film to separate the load-bearing surfaces. We show in this paper that, while maintaining safe film dimensions, composite-film bearings perform with considerably lower frictional losses then do traditional bearings.In designing the CFB scheme, we rely on nature to seek out and maintain a configuration that minimizes viscous dissipation [4]. This will be achieved in our case by the localization of deformation, and thus of viscous dissipation, to the low-viscosity component of the film. The CFB construction appears to be particularly suitable to power generating equipment. The journal bearings of these large rotating apparatus dissipate considerable energy [5]; the CFB has the potential to cut these losses.