Advanced Technology Institute of Commuter-helicopter, Ltd.

Eiichi Yamakawa

Hiroki Nishimura

Makoto Aoki

Tatsuhiko Goi

Natsuki Kondo

Tatsuro Hongu

Atsushi Murashige

Noriaki Katayama

Kouji Kawakami

Noboru Kobiki

Tomoka Tsujiuchi

Eiji Shima

Tetsuya Hori

Shun-ichi Bandoh

Nobuyoshi Yamauchi

Takaki Amano

Akihiko Tsuchihashi

Kenjiro Inagaki

Mitsumasa Sato

Displacements of output portions of a pair of piezoelectric actuators arranged spanwise in a flap drive apparatus are magnified by a displacement magnification mechanism so that a swing arm is driven in swinging fashion with large amplitude. A flap attached to the trailing edge of a blade by way of a connecting rod connected to a tip of the swing arm is driven in vertical angular displacement fashion. The displacement magnification mechanism possesses an eccentric shaft has a first shaft and second shaft with offset axes. An output portion is coupled to the first shaft , and an output portion is coupled to the second shaft . The swing arm is fixed to the eccentric shaft . Displacement of the output portions of the actuators in opposite phase results in a stable swing of the swing arm

Rotor blade flap drive apparatus

A flap support mechanism for attachment of a flap to a rotor blade so as to permit angular displacement with respect thereto has a tension-torsion member disposed coaxial with a hinge axis of the flap. One end at the blade root side of the tension-torsion member is secured to the rotor blade. The other end at the blade tip side of the tension-torsion member is secured to the flap. The tension-torsion member is placed such that it passes through a narrow cavity formed at the interior of the rotor blade. Such construction permits smooth flap motion in spite of a large centrifugal force.

Flap support mechanism and a flap-equipped rotor blade

Helicopter blade aerofoil and helicopter blade

A constant speed drive apparatus for an aircraft generator comprises an input shaft for receiving drive torque from an aircraft engine, a traction speed change mechanism of continuously-variable speed change ratio which is coupled to the input shaft, an output shaft for supplying the aircraft generator with drive torque which is changed in speed by the traction speed change mechanism, and a control computer for controlling the speed change ratio of the traction speed change mechanism to maintain the output shaft at a predetermined rotational frequency. With such constitution it is possible to achieve a small and lightweight constant speed drive apparatus having a high transmission efficiency.

Constant speed drive apparatus for aircraft generator and traction speed change apparatus

An actuator and first to fourth links constitute a first displacement magnifying mechanism. An input shaft which is fixed in a basal end of the first and second links, a support shaft which is fixed in a basal end of the third and fourth links, and a displacement magnifying lever constitute a second displacement magnifying mechanism. In the displacement magnifying lever, an intermediate portion is angularly displaceably coupled to a tip end of the support shaft, a tip end of the input shaft is angularly displaceably coupled to one end, and an output rod is angularly displaceably coupled to another end. The expansion and contraction of the actuator are magnified by the first and second displacement magnifying mechanisms so as to drive a flap angularly via output rod. According to this configuration, the displacement of the actuator can be largely magnified so that the flap can be sufficiently angularly displaced in the vertical direction and in a reciprocal manner.

Rotor blade flap driving apparatus

A flight path display apparatus provided in a cockpit of an aircraft has a head-up display unit. An image combining panel of the head-up display unit displays a flight path image projected from projecting system which is superimposed on the outside view. Computing system for calculating the image to be projected to the image combining panel calculates a display position of the target flight path based on data from storage system in which predetermined flight paths are stored and from aircraft flight data measuring system for measuring the position and attitude of the aircraft. When the display position of the target flight path is outside a display area of the image combining panel, a target mark indicative of a direction toward the flight path from the center of the display area blinks on the image combining panel. With the above construction, a flight path display apparatus which allows a pilot to keep sight on a target flight path is realized.

Flight path indicated apparatus

In a variable mode of operation in which clutches are locked and a clutch and a brake are unlocked, the power of an input shaft is branched to a traction transmission mechanism. By contrast, in a fixed mode of operation in which the clutches are unlocked and the clutch and the brake are locked, the power of the input shaft is not branched to the traction transmission mechanism. In this way, the fixed mode and the variable mode are selectively used, whereby noise reduction and enhanced fuel efficiency can be attained. According to this configuration, it is possible to provide a power transmission apparatus for helicopters in which the number of rotations of a main rotor or a tail rotor is continuously varied while maintaining the number of rotations of an engine constant.

Power transmission apparatus for helicopter

The root end is attached to the rotor head for rotationally driving. The central portion has aerodynamic characteristics depending on the leading and trailing edges and which extend linearly from the root end in parallel to each other, and the chord dimension therebetween. A planform shape of the blade tip portion is defined by the first leading edge which extends forwardly as the distance from the outboard end of the leading edge of the central portion outwardly increases, the second leading edge and the side edge which are rearwardly swept as the distance from the outboard end of the first leading edge toward outboard side outwardly increases, the first trailing edge which is curved forwardly as the distance from an outboard end of the trailing edge of the central portion outwardly increases, and the second trailing edge which is swept rearwardly as the distance from the outboard end point of the first trailing edge outwardly increases. This configuration makes it possible to eliminate the delocalization in the supersonic region and greatly reduce high-speed impulsive noises.

Rotor blade for rotary wing aircraft

A low-noise level landing apparatus for helicopters comprises a helicopter position calculator for calculating the position of the helicopter, a data input device, an air data sensor for measuring an airspeed and a descending angle, a rotor tachometer for detecting a rotor rotational speed, a memory and a fuel gauge for calculating the weight of the helicopter, a rotor rotational speed controller for controlling the rotor rotational speed, a BVI noise generating area database device for storing noise levels in accordance with parameters of descending speed, airspeed, descending angle, rotor rotational speed and weight of the helicopter. A computer selects a flight route, an airspeed, a descending angle and a rotor rotational speed wherein noise is reduced, by setting a plurality of flight routes on the basis of the helicopter position and landing point and by referring to the noise generating area database device. Low-noise level landing is then carried out by pilot manual control or automatic flight control. By modifying the selected flight route on the basis of ground noise data received by a data receiver, the optimal flight route is reselected. As a result, a flight route wherein noise reduction can be attained during landing can be selected more properly.

Low-noise level landing apparatus and system for helicopters

A blade root portion of a rotor blade is attached to a rotor head for rotating. A center portion linearly elongates from the blade root portion. A blade tip portion outward elongates from the center portion and has a shape which is defined by a leading edge, a side edge and a trailing edge, and has a predetermined aerofoil. In the leading edge of the blade tip portion, a swept-back angle &lgr;(r) at a distance r from the rotation center of a rotor satisfies relational expression (1) of a rotor blade length R of a rotorcraft, a maximum flight Mach number M,which is a flight limit speed of the rotorcraft, a blade tip Mach number M,which is a tip speed during hovering, and a drag divergence Mach number M,which is determined from the aerofoil of the blade tip portion. According to this configuration, it is possible to provide a rotor blade for a rotorcraft in which the performance in high-speed flying is improved, the high-speed impulsive noise can be reduced, and a high control performance is attained.

Rotor blade for rotorcraft

Upper and lower surfaces of an aerofoil are defined by the following coordinates given in the table below, and the configuration of a leading edge of the aerofoil is defined by the following leading edge radius and the center of circle. Thus drag divergence Mach number Mdd and maximum lift coefficient Clmax can be increased and the noise level can be reduced.

Helicopter blade aerofoil

A flap is attached to a rear end of a blade so as to be angularly displaceable. Displacement magnifying means magnifies the amount of displacement from an actuator to drive the flap. An input portion to which the displacement is applied from the actuator is expandably and contractibly supported by bellows. Likewise, an output portion to which the input amount of displacement is magnified is expandably and contractibly supported by a bellows. Consequently, displacement magnifying means is realized in which, compared with a existing piston with O ring which slides on the cylinder inner wall, no deterioration in response characteristic due to high friction occurs when the actuator is displaced at high speed, and no fluid leakage due to deterioration or wear of the O ring occurs. According to this structure, a rotor blade flap driving apparatus is obtained which has displacement magnifying means with fast response and no fluid leakage.

A main rotor torque compensation apparatus for a helicopter having a main rotor and a tail rotor includes vertical tails that are supported at a variable angle of attack. An actuator adjusts the angle of attack such that the main rotor torque is compensated by the torque of the tails together with the torque of the tail rotor.

Compensation apparatus for main rotor torque

The coordinates defining the upper surface, lower surface, leading edge configuration and center of circle for a helicopter blade airfoil are given to increase maximum lift coefficient and lift-to-drag ratio, and to reduce noise level.

Growing community of inventors

Kakamigahara, Japan

Eiichi Yamakawa