Title page for etd-0912112-130547


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URN etd-0912112-130547
Author Min-Chun Hsieh
Author's Email Address simeng18@yahoo.com.tw
Statistics This thesis had been viewed 5331 times. Download 122 times.
Department Mechanical and Electro-Mechanical Engineering
Year 2011
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Prediction of lubrication starvation and its effect on the lubricating characteristics
Date of Defense 2012-07-28
Page Count 77
Keyword
  • starved
  • meniscus
  • over-flooded
  • supply flow rate
  • surface tension
  • Abstract Excess lubricant can be found as reservoirs on the sides of the rolling tracks when the oil flows through the Hertzian contact and the side leakage. Uniform lubricant layers adhered to both rolling surfaces can flow into the supply region by the action of surface tension. Uniform lubricant layers are separated by air so that they move with the surfaces the surface tension of the liquid-air interface and the velocity of the roller. Hence, it can be considered as the fixed flow rate conditions. Under the lubricant starvation and the fixed flow rate conditions, the meniscus in the film inlet is formed due to the action of the surface tension of the oil-air interface, where the fluid pressure in the oil layer is smaller than the ambient pressure.
    An empirical formula to predict the thickness of the oil layer is derived based on the theoretical analysis and the experimental results of Cann et al. [10]. Results show that this thickness increases the amount of oil in the track and the surface tension of the liquid-air interface, but it decreases with the surface velocity and the oil viscosity. Moreover, the starved, fully flooded, over-flooded regimes are established based on the theoretical analysis. Under the lubricant starvation and the fixed flow rate conditions, the central film thickness in the pressure region increases with increasing the supply flow rate, so that the location of the meniscus moves to upstream. When the supply flow rate is more than 98% flow rate of fully flooded condition, the central film thickness achieves a saturated value. Hence, when the supply flow rate is between 98% and 100% flow rate of fully flooded condition, it is called the fully flooded regime. When the supply flow rate is more than the flow rate of fully flooded condition, the central film thickness remains constant, and the excess oil accumulates in the inlet region, so that the film thickness in the inlet region increases with time. When the supply flow rate is larger than the flow rate of fully flooded condition, it is called the over-flooded region.
    Advisory Committee
  • Jen-Fin Lin - chair
  • Y.R. Jeng - co-chair
  • Rong-Tsong Lee - advisor
  • Yuang-Cherng Chiou - advisor
  • Files
  • etd-0912112-130547.pdf
  • Indicate in-campus at 5 year and off-campus access at 5 year.
    Date of Submission 2012-09-12

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