Abstract:
An anti-torque rotor (4) is described for a helicopter (1), comprising: a mast (6) rotatable about a first axis (A); a plurality of blades (8) hinged on the mast (6), extending along respective second axes (B) transversal to said first axis (A) and rotatable about respective said second axes (B) to alter the respective angles of attack; a control element (16) sliding and rotating with respect to the mast (6), and operatively connected to said blades (8) to cause the rotation of said blades (8) about respective second axes (B) following a translation of said element (16) along the first axis (A); a control rod (10) sliding axially along first axis (A) with respect to the mast (6) and angularly fixed with respect to the first axis (A); and a connection element (17) interposed between the control rod (10) and the control element (16), sliding along the first axis (A) with respect to the mast (6) and integrally with the control rod (10); the anti-torque rotor (4) further comprises an interface (18, 93) made of an antifriction material interposed between said control rod (10) and said connection element (17).
Abstract:
La présente invention porte sur un rotor pour hélice (6) de turbomoteur (1), à pales à calage variable, comprenant des pieds (8) de pale mobiles en rotation dans une structure supportant les pales et un dispositif (30) de mise en drapeau des pales. Ledit dispositif (30) de mise en drapeau comprend au moins une masselotte (40) solidaire d'une manivelle (39) reliée par un train d'engrenages à au moins un desdits pieds (8) de pale.
Abstract:
L'invention concerne un dispositif de commande de l'orientation des pales de soufflante d'un turbopropulseur comprenant au moins un ensemble (24a, 24b) de pales de soufflante à orientation réglable solidaire en rotation d'un anneau rotatif (28a, 28b) lié mécaniquement à un rotor (22a, 22b) de turbine. Chaque pale de l'ensemble est couplée à un support de pied de pale monté pivotant sur l'anneau rotatif au moyen d'un engrenage conique formé d'une première roue dentée solidaire du support de pied de pale et d'une seconde roue dentée (50) solidaire de l'anneau rotatif et portant un contrepoids (54) excentré par rapport à son axe de rotation. Un vérin (30a, 30b) solidaire en rotation du rotor de turbine et dont la tige (32a, 32b) est reliée à chaque contrepoids (54) par l'intermédiaire de bras de liaison permet de déplacer angulairement de façon synchronisée l'ensemble des contrepoids autour de l'axe de rotation de leur roue dentée respective.
Abstract:
Systems and methods related to passive variable pitch propellers are described. For example, an aerial vehicle may include one or more passive variable pitch propellers, and such propellers may include one or more passively movable propeller blades having respective hinges, flexible joints, or torsionally flexible joints. Based at least in part on current flight configurations, required thrust, and/or desired advance ratios, the passively movable propeller blades may modify their coning angles and/or pitches, such that the passive variable pitch propellers may operate with improved efficiency in two or more flight configurations. For example, in a VTOL flight configuration, the passive variable pitch propellers may have increased coning angles and decreased pitches, whereas in a horizontal flight configuration, the passive variable pitch propellers may have decreased coning angles and increased pitches.
Abstract:
Dispositif de commande du passage dans le mode réverse d'une turbomachine à hélices, par une action sur un axe de commande (13) du calage desdites hélices, ledit dispositif comprenant au moins une masselotte (14) agencée de façon à entraîner lesdites hélices vers leur position de drapeau sous l'action de la force centrifuge, le dispositif comprenant également un actuateur (9) apte à faire tourner ledit axe de commande (13) pour faire passer le calage des hélices d'un mode traction à un mode réverse, en traversant une position de calage à pas nul; il est caractérisé en ce que la masselotte (14) est dans une position d'équilibre instable vis-à-vis de l'action de la force centrifuge lorsque ledit axe de commande fait passer le calage des hélices (6) par la position de pas nul, il comporte par ailleurs un moyen d'actionnement (19) exerçant un couple sur ledit axe de commande (13) lorsque la masselotte est dans ladite position d'équilibre instable, de façon à l'empêcher de
Abstract:
A device for changing a pitch of a blade of an impeller/propeller is disclosed. It comprises at least one linear actuator. A first bearing is mounted to a non rotary mechanical element with the first portion, and a second bearing is mounted to the second portion, allowing a relative axial movement between the first bearing and second bearing. The first bearing is mounted between a supporting structure of the rotor shaft and the non rotary mechanical element, allowing a relative rotation between the supporting structure and the at least one linear actuator. The second bearing is mounted between the second portion and a lever means having a rotary point at the supporting structure. When operating the at least one linear actuator, the second portion is moved axially, leading to an angular movement of the lever means causing a change of the pitch of a blade, and when operating the at least one linear actuator, a force is generated that acts upon the non rotary element, so that the rotor shaft is unaffected by the force. Also, a fan comprising the device is disclosed.
Abstract:
The expense of a bearing employed at the interface of a yoke (22) and a propeller blade pin (14) in a variable pitch propeller assembly is reduced in a bearing construction (16) wherein a bearing race (48) includes a crowned surface (50) adapted to engage a slot (20) in the yoke (22) and having a profile (Pi) wherein the diameter at one side (88, 90) of the race (48) is less than the diameter at the opposite side (90, 88) of the race (48).
Abstract:
The phase control mechanism includes first gears (3, 4) coupled to the output shafts which are to be phase controlled. A transfer gear (5) is provided for rotation or operation independent of the input and is coupled to the first gears (3, 4) to allow rotary motion to be transferred between the first gear members and a phase adjuster (10) causes the first gears (3, 4) to advance on regress relative to one another to change the phase relationship between the outputs.
Abstract:
A motor for driving a propeller is disclosed which has a drive shaft (10) which is coupleable to a propeller shaft (20) by bevel gears (12 and 14) so as to rotate the shaft (20) to in turn rotate propeller blades P of an outboard motor. The drive shaft (20) has an internal concentric shaft (30) which enables the adjustment of the pitch of the propeller blades P by mounting the propeller blades P for rotation about a pitch axis and coupling the mounting (72') via an integral bevel gear (104) to a bevel gear (102) on the shaft (30). A phase adjustment mechanism (40) is provided for rotating the shaft (30) relative to the shaft (20) to in turn rotate the propeller blades P around the pitch axis to change the pitch of the propeller blades P. The phase adjustment mechanism comprises ring gears (48 and 50), together with planet gears (48) in engagement with a gear on the shaft (30) and planet gears (46) in engagement with a gear (26) on the shaft (20). An anti-backlash mechanism for preventing movement with propeller blades P about the pitch axis due to backlash within the gears of the phase adjuster mechanism (40), includes a screw-threaded section (252) coupled with the shaft (30) and the yoke (270) on the section (252) for movement on the section (252) in the longitudinal direction of the shaft (30). Engagement between the screw-threaded section (252) and the yoke (270) forms a rigid coupling of the shaft (30) to the propeller blades P so that any backlash in the phase adjusting mechanism (40) is not transmitted through the coupling to the propeller blades P.
Abstract:
L'invention concerne un système (40) de changement de pas des pales d'une hélice d'une turbomachine, chaque pale (25) étant montée pivotante suivant un axe de calage (A), le système comportant un moyen de commande et un mécanisme de liaison (50) reliant le moyen de commande à chaque pale de l'hélice, le mécanisme de liaison comportant pour chaque pale de l'hélice : - une biellette (54) ayant une première extrémité (56) reliée au moyen de commande; et - un excentrique (55) ayant une première extrémité (62) reliée à la pale pour l'entrainer en rotation autour de son axe de calage (A) et une deuxième extrémité (59) formant chape (60) reliée à une deuxième extrémité (58) de la biellette par une liaison pivot; La chape (60) de l'excentrique est orientée vers l'axe de calage (A) de la pale.