Planar and cylindrical oscillating pneumatodynamic bearings

Abstract

An oscillating pneumatodynamic bearing takes the form of a laminated transducer disk cooperating with a flat surface or a tubular transducer cooperating with a rod or an enclosing tube. Such bearings are also known as squeeze bearings. At least one piezoelectric, magnetostrictive or electrostrictive material is laminated with another material to provide oscillation of the transducer portion of the bearing so that the transducer portion is able to fly above a bearing surface on a fluid which is usually ambient air compressed by the mechanical oscillation of the transducer portion at an ultrasonic frequency. The disk or the tube is connected mechanically to supports and to its electrical sources of energy or signals at points along the loci of zero oscillation or minimal oscillation. With a laminated disk, a nodal circle is the locus of zero oscillation. In the case of the tube, a number of parallel strips of reversed polarity transducer material are alternately connected together by an interdigitated electrode design of spacing grooves between an enveloping conductive layer which overlies the piezoelectric layer laminated to a metallic base. Bearings for armatures of linear motor types of actuators for reciprocating magnetic recording heads within magnetic recording disk files can employ a set of disk type bearings or a combination of a tubular bearing with at least one disk type bearing.