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:
Jul. 20, 1993
Filed:
Apr. 16, 1991
Keizou Yamamoto, Tokorozawa, JP;
Takahiro Ichihashi, Tachikawa, JP;
Kanehiro Hanayama, Tachikawa, JP;
Shunichi Bandoh, Kakamigahara, JP;
Asao Kakinuma, Kakamigahara, JP;
Tadashi Wakatsuki, Seki, JP;
Abstract
A bearingless hub structure for a rotary-wing aircraft is provided, the structure including a hub body adapted to be securely connected to a rotor mast, a plurality of flexible beam members provided integrally with the hub body to extend radially outwardly, a pitch housing encircling each of the flexible beam members, and having a radially outward end portion which is rigid with a radially inward end portion of a rotor blade, a spherical bearing positioned adjacent to a radially inward end portion of the flexible beam member for supporting the pitch housing, a lead-lag damper positioned between the flexible beam member and the pitch housing, and the flexible beam members each having a flexible plate portion which is of a low bending rigidity in a flapping direction, a flexible portion provided radially outwardly of the flexible plate portion having a low bending rigidity in the lead-lag direction, and a twist-flex portion provided radially outwardly of the flexible portion. The flexible portion has two beam sections which have radially outward end portions integrally connected with a radially inward end portion of a twist-flex portion, with the radially inward end portions of the beam sections being removably connected to a radially outward end portion of the flexible plate portion at a plurality of circumferentially spaced positions.