Fluid reaction surfaces (i.e. – impellers) – With means moving working fluid deflecting working member...
Reexamination Certificate
2000-03-02
2001-08-14
Ryznic, John E. (Department: 3745)
Fluid reaction surfaces (i.e., impellers)
With means moving working fluid deflecting working member...
C074S110000, C310S328000
Reexamination Certificate
active
06273681
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotor blade flap driving apparatus for driving a flap provided to a trailing edge of each rotor blade of a helicopter or the like.
2. Description of the Related Art
In recent years, there have been increasing demands for commuter helicopters which take off and land on heliports in urban areas. To realize this, noise reduction is highly required. As an effective anti-noise measure, a method has been considered in which a flap is attached to each rotor blade of a helicopter and the flap is driven at a high speed of approximately 30 Hz to 50 Hz and precisely controlled to thereby improve the aerodynamic characteristics of the rotor blades.
As an actuator for use in a flap driving apparatus of such a rotor blade is employed a small-size and lightweight one because the actuator must be housed in the rotor blade. For example, a stack-type piezo-actuator in which thin plates of piezoceramic elements are stacked is used, however, in such a stack-type piezo-actuator, since the amount of displacement is small, it is required to magnify the displacement to drive the flap.
In a configuration in which the displacement of the actuator is magnified simply with a lever or the like, however, it is difficult to obtain a magnification factor large enough to make an angular displacement to drive the flap.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a rotor blade flap driving apparatus provided with displacement magnifying means which makes it possible to achieve a magnification factor large enough to make an angular displacement to drive the flap.
The invention provides a rotor blade flap driving apparatus comprising:
a blade;
a flap angularly displaceably attached to a trailing edge of the blade;
an actuator housed in the blade, which expands and contracts in a spanwise direction of the blade thereof; and
displacement magnifying means for magnifying the displacements of the actuator and transmitting the magnified displacements to the flap to angularly displace the flap in a vertical direction thereof,
the displacement magnifying means including:
a first displacement magnifying mechanism having:
a first link disposed on one side portion of the actuator, one end of the first link being angularly displaceably coupled to one end of the actuator,
a second link disposed on the one side portion of the actuator, one end of the second link being angularly displaceably coupled to another end of the actuator, another end of the second link being angularly displaceably coupled to another end of the first link,
a third link disposed on the other side portion of the actuator, one end of the third link being angularly displaceably coupled to the one end of the actuator; and
a fourth link disposed on the other side portion of the actuator, one end of the fourth link being angularly displaceably coupled to the other end of the actuator, another end of the fourth link being angularly displaceably coupled to another end of the third link,
the first displacement magnifying mechanism being a mechanism for magnifying expansion and contraction displacements of the actuator by moving in a direction along which the coupling portion between the first and second links, and the coupling portion between the third and fourth links approach and separate from each other in accordance with expansion and contraction of the actuator; and
a second displacement magnifying mechanism having an input member which is coupled to the first displacement magnifying mechanism and output rod, one end of which is coupled to the flap for magnifying a displacement of the first displacement magnifying mechanism.
According to the invention, a triangular link mechanism is configured on the one side portion of the actuator by the first and second links, and, when the actuator expands or contracts, the coupling portion between the first and second links is displaced in a direction along which the coupling portion approaches or separates from the actuator. Similarly, a triangular link mechanism is configured on the other side portion of the actuator by the third and fourth links, and, when the actuator expands or contracts, the coupling portion between the third and fourth links is displaced in a direction along which the coupling portion approaches or separates from the actuator.
Therefore, by operating the actuator to expand or contract, the coupling portion between the first and second links, and the coupling portion between the third and fourth links are largely displaced in a direction along which the coupling portions approach or separate from each other, so that the amount of the displacement of the actuator can be magnified. The displacement which has been magnified by the first displacement magnifying mechanism is further magnified by the second displacement magnifying mechanism, and then transmitted to the flap via output rod. In this way, the displacement of the actuator is largely magnified by the two displacement magnifying mechanisms. Even when a piezo-actuator, which produces only small amounts of the displacement, is used, therefore, the flap can be largely displaced angularly.
In the invention it is preferable that the second displacement magnifying mechanism has an input member which is connected to one of the coupling portion between the first and second links, and the coupling portion between the third and fourth links;
a support member which is connected to another one of the coupling portion between the first and second links, and the coupling portion between the third and fourth links; and
a displacement magnifying member which is supported by the support member so as to be angularly displaceable about a predetermined support axis, and to which the input member is coupled so as to be angularly displaceable about an input axis that is separated from the support axis by a predetermined input arm length, and
another end of the output rod is coupled to the displacement magnifying member so as to be angularly displaceable about an output axis which is separated from the support axis by an output arm length which is larger than the input arm length.
According to the invention, the support member is connected to the coupling portion between the third and fourth links, the input member is connected to the coupling portion between the first and second links, a portion, for example, an intermediate portion of the displacement magnifying member is supported by a tip end of the support member, a tip end of the input member is coupled to one end of the displacement magnifying member, and the other end of the output rod is coupled to the other end of the displacement magnifying member. When the actuator expands, the coupling portions which constitute apexes of the triangular link mechanisms are displaced in a direction along which the coupling portions approach each other. In the displacement magnifying member, while the intermediate portion which is supported by the support member is considered as the fulcrum and the one end of the displacement magnifying member to which the input member is coupled, the displacement of the output portion of the displacement magnifying member to which the output rod is coupled is magnified by a magnification factor corresponding to a ratio of the input and output arm lengths, so that the output rod is largely displaced. In this way, the flap is driven angularly via output rod while the displacement of the first displacement magnifying mechanism is further magnified by the second displacement magnifying mechanism.
In the invention it is preferable that the first to fourth links, the coupling portions between the first to fourth links and the actuator, between the first and second links, and between the third and fourth links are continuously formed by a thin rigid plate made by composite material, and the coupling portions are constructed so as to be more flexible than the links and elastically deformable.
According to the invention, the links and the coupling portions are integrally and continuo
Hongu Tatsuro
Yamakawa Eiichi
Advanced Technology Institute of Commuter-Helicopter, Ltd.
Ryznic John E.
Wenderoth , Lind & Ponack, L.L.P.
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