Coupled aircraft rotor system

US6616095B2 · kind B2 · utility

Assignee

• Bell Helicopter Textron Inc. · US

Inventors

• Frank B. Stamps · Colleyville, US
• James L. Braswell, Jr. · Colleyville, US
• David A. Popelka · Colleyville, US
• Richard Bennett · Southlake, US
• Thomas B. Settle, Jr. · Arlington, US
• Charles Eric Covington · Colleyville, US
• Cecil E. Covington · Hurst, US

Key dates

• Filing date: Jan 18, 2002
• Grant date: Sep 9, 2003
• Expiry date: Mar 26, 2022

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B64C29/0033
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

The subject tiltrotor aircraft has three modes of operation: airplane mode, helicopter mode, and transition mode. A tilting mast, which transitions the aircraft between airplane mode and helicopter mode, is controlled by systems that allow selective movement of the rotor blades between the flight modes. A hub couples the rotor blades to the tilting mast such that torque and thrust are transferred, while allowing rotor thrust vector tilting. A main swash plate controls rotor thrust vector direction. Pitch horns are coupled to the rotor blades and the main swash plate via pitch links such that swash plate inputs are communicated to the rotor blades. The pitch links are coupled at “delta-3” values that are not optimum. A feedback swash plate and feedback links receive disk tilting inputs from the rotor blades, and supply inputs to the main swash plate, which compensates for the less than optimum delta-3 coupling.