Novel active air foil bearing based on PZTs and flexible hinges

Abstract

The invention discloses a novel active air foil bearing. The bearing comprises a shaft sleeve, the PZTs, the flexible hinges, rigid push rods, precompression exertion devices, wave foil and top foil; the shaft sleeve is machined through wire cutting, three PZT mounting through grooves circumferentially and evenly distributed, the corresponding flexible hinges and the corresponding rigid push rods are obtained, the top ends of the rigid push rods are flush with the inner cylindrical face of the shaft sleeve, the PZTs are mounted in the through grooves, the corresponding precompression exertion devices are designed for the PZTs, the wave foil is formed by pressing of elastic materials, and is arranged on the shaft sleeve and the inner cylindrical faces of the rigid push rods, one end of the wave foil is welded to the inner round face of the shaft sleeve, and the other end of the wave foil is free. The top foil is arranged on the wave foil in a covering manner. Through control over power supply signals of the PZTs, the PZTs mechanically deform, the flexible hinges are enlarged to deform, and are supported through the rigid push rods to be attached to the wave foil on the push rods and the inner wall of the shaft sleeve, a gap between a bearing and a supporting rotor is changed, the wedge space is increased, the crossed coupling effect is weakened, the bearing dynamic pressure effect is enhanced, the rigid characteristic of the bearing is improved, and finally the aims of actively controlling the rigidity characteristics of the bearing and improving the stability of the bearing are achieved.

Description

technical field [0001] The invention relates to the technical field of air bearings, in particular to a novel air foil bearing based on PZT (piezoelectric ceramics) and flexible hinges. Background technique [0002] The air foil bearing is composed of the top foil, the wave foil and the shaft sleeve. It uses the relative motion between the rotating rotor and the bearing to generate a wedge-shaped space to squeeze the gas with a certain viscosity to form a pressure with a certain stiffness and damping. Aerodynamic bearings that lubricate the air film to support the load. [0003] The traditional air foil bearing supports the loaded rotor through the wedge effect, and the high-speed rotation of the rotor squeezes the gas to generate a dynamic pressure effect; the elastic foil is used as a supporting structure to provide a certain stiffness and damping, so that the bearing has a certain load-bearing capacity and vibration reduction ability. However, due to the influence of ga...

AI Technical Summary

Problems solved by technology

However, the mechanical deformation of PZT is relatively small and the preload needs to be continuously applied during the working process, which has limitations in application.

Images