The significance of economical exploitation of resources has brought a need for compact and efficient electromechanical systems and electrical machines. The electrical machines such as bio-generators need to be featured with high power densities and high efficiencies with lower excitation losses, magnetizing currents and rotor losses. However, the research progress has often been challenged by the ultrahigh-speed bio-generator knowhow as the design must be dealt with factors: i) “DN” rating of value 1.5X 106 and above ii) high value of “kW/speed” rating. Furthermore, the thermal management of ultrahigh-speed bio-generator is difficult and complicated as the temperature rise in high-speed bio-generator facilitates demagnetization cascading to the reduction of the output power. The output of research portrays the use of pressurized oil-air particles as a lubrication method on an ultrahigh speed bio-generator to avoid thermal damage and starvation at the rolling element and to address the predominant concern which is effective cooling of ultra-precision ball bearings even at elevated speeds. The ultrahigh-speed generator was designed and developed to operate at a maximum speed of 30000 RPM to deliver 10kW output power and expected to 8092C temperature rise with 2 kW idle power consumption enough to cause a severe impact to the rolling elements of the bearing. The newly developed oil-air mist lubrication arrangement enables to control the temperature rise at the rolling element and ensures the use of ultrahigh speed conditions for the bio-generator.
Kuppuswamy, R., Richmond, C., & Khan, A. (2019). A Study on the role of oil-air mist lubrication on an ultrahigh-speed bio-generator. In Procedia Manufacturing (Vol. 33, pp. 107–114). Elsevier B.V. https://doi.org/10.1016/j.promfg.2019.04.015