US Patent 7954790 Composite shaft aspirator assembly

A composite hollow aspirator shaft is formed of fiberglass-reinforced phenolic resin that resists abrasion and reduces the amount of vibration that is transferred to the motor rotating the shaft, and the motor's bearings to extend motor and bearing life. An aspirator tip is adhesively attached to the composite aspirator shaft and includes an access hole for cleaning inside the hollow aspirator shaft. The hole is in axial alignment with the hollow aspirator shaft and a selectively-removable plug is used to seal the hole during aspirator use. When the aspirator tip is rotated in a liquid, fluidic forces are transferred to the shaft where they are attenuated. A splined hub is used to attach a foam restrictor near the other end of the shaft. The composite shaft material has a flexural modulus, or ratio, within the elastic limit of any applied stress.