均匀磁场中铁磁流体润滑的平板滑块的性能

On Performance of Ferrofluid-Lubricated Plane Slider in Uniform Magnetic Field

计算结果表明 ,铁磁流体润滑的平板滑块的性能与牛顿流体或Bingham塑料润滑的平板的性能显著不同 .屈服应力引起粘附核的发生 ,并且增加滑块的承载能力 .在低速润滑中 ,高磁场强度对承载能力是有好处的 ,因为它可以提高铁磁流体的粘度和在润滑膜中引起粘附核 .当出现粘附核时 ,铁磁流体润滑的平板滑块的最佳膜厚比的值大于 2 .2 ,并随外磁场强度增加而增大 .在高速润滑中 ,可能没有粘附核出现 ,在此情况下 ,为了得到最大承载能力而采用膜厚比的值为 2 2是可取的 .在高磁场强度或高剪切速率下 ,铁磁流体润滑的平板滑块的摩擦系数增大 .

The calculated results show that the performance of the ferrofluid lubricated plane sliders is different obviously from the performance of plane sliders lubricated with Newtonian fluid or Bingham plastic. The yield stress causes the attached cores and increases the load carrying capacity of plane slider. In the case of a low velocity lubrication, the high applied magnetic field strength is of benefit to the load carrying capacity, since it can increase viscosity of a ferrofluid and can cause the attached cores in the lubricating film. When the adhered cores occur, the magnitude of optimum film thickness ratio of a plane slider lubricated with ferrofluid is much larger than 2.2 and increases with increasing applied magnetic field strength. In the case of a high speed lubrication, it is possible that no adhered cores appear and the film thickness ratio of 2.2 is advisable to reach a maximum load carrying capacity. The friction coefficient of a ferrofluid lubricated plane slider is larger under the condition of a high magnetic field strength and a high shear rate.