Abstract: A shaft has a seal journal with a plurality of raised spherical bumps. These microscopic spherical bumps provide a smooth, edge-free contact surface for the seal which is positioned around the seal journal of the shaft. The valleys or spaces between these bumps serve to retain lubricant, thereby promoting hydrodynamic lubrication between the seal and seal journal, reducing friction and reducing or eliminating wear on the seal.

Abstract: A plug for insertion through the wall of a vessel filled with fluid to be monitored has an extension immersed in the fluid which has a pair of wire electrodes helically wound thereon in spaced arrangement. The electrodes are wound at a uniform pitch in one embodiment and wound with regions of closely and widely spaced pitches in another embodiment. In a third embodiment, the electrodes are helically wound in spaced parallel arrangement at a pitch greater than the spacing of the pair. A thermistor is disposed on the extension for providing a fluid temperature signal. The electrodes are excited sequentially by a low voltage at a fractional Hertz (low) frequency and a (high) frequency of at least one Hertz and the current and temperature are measured. The impedance and differential impedance are computed from the measured currents.

Abstract: A fluid condition monitor suitable for real time monitoring of a fluid in a fluid system such as on-board vehicle monitoring of engine oil and transmission fluid to determine contamination. A capacitive spaced array electrode probe is immersed in the fluid and an oscillating voltage is applied at a first frequency of at least one hertz and the current IB measured as an analog of the bulk fluid impedance. The voltage is also applied to the probe at a second frequency of less then one hertz and the current Is measured as an analog of the electrode surface impedance. The difference in measured currents &Dgr;I is determined electrically compared with a predetermined threshold value; and, the measured first frequency current IB is compared with an upper and lower limit value for IB determined empirically for the known baseline fluid.