The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 31, 1996
Filed:
Aug. 28, 1995
Kerry G Geringer, Ames, IA (US);
Sauer Inc., Ames, IA (US);
Abstract
An attenuator for a variable displacement hydraulic unit having a servo connected to a swashplate includes an oscillator connected to the servo. The oscillator includes a pipe constituting an inertial portion connected to the servo and a hose defining a hydraulic spring portion connected the other end of the pipe. The pipe has a fixed length and diameter. The pipe and hose combine to attenuate vibration and output pressure in the hydraulic unit by introducing a phase change in the pressure fluctuations within the fluid. A linearized model assists in sizing the components and tuning the oscillator to the troublesome frequency of the hydraulic unit. A method for using the oscillator to attenuate periodic pressure fluctuations due to swashplate vibrations includes fluidly connecting the oscillator to the servo piston bore and introducing a phase change to the periodic component of the fluid pressure by routing the fluid through the oscillator then returning it to the servo piston bore.