Development and evaluation of the magnetic and journal bearing saving electric power using permanent magnet and ER fluid.

轴承是支撑旋转机械的重要机械元件。在保证轴承性能的前提下，如何降低摩擦损失是一个不可避免的问题。因此，我们尝试开发和评估的电力节省轴承使用ER流体（LC ;液晶）作为润滑流体的径向轴承，和永磁体作为元素的磁轴承。为了明确LC滑动轴承的节能性能和实现永磁轴承的可能性，本研究通过在轴颈和轴承之间施加电压来测量轴承性能，以明确LC滑动轴承的基本特性。我们阐明了相同的承载能力，可以获得最大减少40%的摩擦扭矩，轴颈中心的轨迹不同于传统的轴承。其原理是在最小膜厚区域局部增加液晶的粘度，提出了采用分布电极局部施加电压的方法，以提高承载能力，抑制摩擦力矩的增加。结果表明，与单电极情况相比，该方法能以更低的摩擦力矩获得相同的承载能力，且轴颈中心在有限区域内可控。从摩擦力矩的测量结果来看，压力朝流动方向增大的上游区域是施加电压的最佳位置，可以使摩擦力矩最小。我们阐明了磁体的布置，仅用永磁体支撑旋转轴。然而，轴承并没有实现。

Bearing is an important machine element, which supports rotating machinery. It is an inevitable problem to reduce the friction loss, while the performance of the bearing is kept. So we tried development and evaluation of the electric power saving bearings using ER fluid (LC ; Liquid Crystal) as a lubricating fluid of journal bearing, and permanent magnet as elements in magnetic bearing. The objective of this research is to clarify the energy saving performance of LC journal bearing and to examine the possibility of realizing a permanent magnetic bearing.In order to clarify the basic characteristics of LC journal bearing, the measurement of bearing properties by applying voltage between journal and bearing was carried out. We clarified that the same load capacity can be obtained with friction torque reduced maximum of 40%, and that the locus of journal center differs from the conventional bearing. The principle was that the viscosity of LC increased in the minimum film thickness area locally.The method of applying voltage partially using distributed electrodes was proposed for the purpose of increasing load capacity with suppressing the increase of friction torque. The results were that the same load capacity can be obtained with still lower friction torque compared with the case of using single electrode, and that the journal center is controllable in the limited area. From the measurement of friction torque, upstream region of the pressure increasing toward flow direction is the best location for applying voltage to minimize friction torque.We designed the magnetic bearing only using permanent magnet. We clarified the arrangement of the magnet to support the rotating shaft only by permanent magnet. However, the bearing has not come to a realization.