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:
Mar. 23, 1993
Filed:
Dec. 13, 1990
Anders O Andersson, Seattle, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
Apparatus for continuously actively balancing rotors by controlling the mass-distribution of a rotor (24) relative to an axis-of-rotation (27) about which the rotor rotates in a stator (26) is disclosed. The mass-distribution of the rotor is adjustable via a hydraulic subsystem (23) that can move the rotor relative to the axis-of-rotation. An electronic subsystem (22) controls the hydraulic subsystem (23) with control signals. More specifically, the sensors (100) of a sensor subsystem (21) sense the repetitive vibrations caused by an unbalanced rotot. The electronic subsystem (22) cyclically updates the control signals applied to the hydraulic subsystem (23) so as to reduce the sensed vibrations, i.e., to balance the rotor (24). The hydraulic subsystem (23) adjusts the position of the rotor (24) by varying the flow of a viscous fluid between the perimeter of a portion of the rotor (24) and an annular sleeve (34) encompassing that portion of the rotor. The annular sleeve (34) rotates with the rotor (24). The rotor (24) is suspended in the annular sleeve by the flowing viscous fluid (40). Ducts (66,70,72,74) in the rotor (24) lead to ports (42,60,62,64) on the rotor through which the fluid (40) between the rotor (24) and the sleeve (34) is supplied and drained. The flow of the fluid (40) through the ducts is controlled by a hydraulic pressure source (75) which is directly coupled to the rotor ducts (66,70,72,74) or through a hydraulic commutator. The flowing fluid (40) may be confined in a single elastic bladder (88) separating the rotor and the sleeve, or the fluid can be contained in four individual bladders in which the pressures are varied to adjust the position of the rotor. Alternatively, rather than using fluid flow or pressure to control the position of the rotor, the rotor can contain cavities (90,92,94,96) in which a mass of fluid is housed. The amount of fluid in the cavities is controllable to control the balance of the rotor.