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Rotorhead
In helicopters the rotorhead is the part of the rotor assembly that joins the blades to the shaft, cyclic and collective mechanisms. It is sometimes referred to as the rotor "hub". The rotorhead is where the lift force from the rotor blades act. The rotorhead is connected to the main drive shaft via the jesus bolt, and houses several other components such as the swash plate, flight control linkages and fly-bars. The rotor hub is also where the centre of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ... acts on the helicopter. Types Rotorheads can be classified into 3 main types: * Articulated * Semi-Rigid * Rigid Articulated Rotorhead An articulated rotorhead system is one where the individual blades are free to flap, lag and change pitch. This is done by mounting t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Rotor
A helicopter main rotor or rotor system is the combination of several rotary wings (rotor blades) with a control system, that generates the aerodynamic lift force that supports the weight of the helicopter, and the thrust that counteracts aerodynamic drag in forward flight. Each main rotor is mounted on a vertical mast over the top of the helicopter, as opposed to a helicopter tail rotor, which connects through a combination of drive shaft(s) and gearboxes along the tail boom. The blade pitch is typically controlled by the pilot using the helicopter flight controls. Helicopters are one example of rotary-wing aircraft (rotorcraft). The name is derived from the Greek words ''helix'', helik-, meaning spiral; and ''pteron'' meaning wing. Design principles Overview The helicopter rotor is powered by the engine, through the transmission, to the rotating mast. The mast is a cylindrical metal shaft that extends upward from—and is driven by—the transmission. At the top of the mast i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopters
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of STOL (Short TakeOff and Landing) or STOVL (Short TakeOff and Vertical Landing) aircraft cannot perform without a runway. In 1942, the Sikorsky R-4 became the first helicopter to reach full-scale production.Munson 1968.Hirschberg, Michael J. and David K. Dailey"Sikorsky". ''US and Russian Helicopter Development in the 20th Century'', American Helicopter Society, International. 7 July 2000. Although most earlier designs used more than one main rotor, the configuration of a single main rotor accompanied by a vertical anti-torque tail rotor (i.e. unicopter, not to be confused with the single-blade monocopter) has become the most common h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Flight Controls
A helicopter pilot manipulates the helicopter flight controls to achieve and maintain controlled aerodynamic flight. Changes to the aircraft flight control system transmit mechanically to the rotor, producing aerodynamic effects on the rotor blades that make the helicopter move in a deliberate way. To tilt forward and back (pitch) or sideways (roll) requires that the controls alter the angle of attack of the main rotor blades ''cyclically'' during rotation, creating differing amounts of lift (force) at different points in the cycle. To increase or decrease overall lift requires that the controls alter the angle of attack for all blades ''collectively'' by equal amounts at the same time, resulting in ascent, descent, acceleration and deceleration. A typical helicopter has three flight control inputs—the cyclic stick, the collective lever, and the anti-torque pedals. Depending on the complexity of the helicopter, the cyclic and collective may be linked together by a ''mixing uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jesus Nut
''Jesus nut'' is a slang term for the main rotor retaining nut or mast nut, which holds the main rotor to the mast of some helicopters. The related slang term Jesus pin refers to the lock pin used to secure the retaining nut. More generally, ''Jesus nut'' (or ''Jesus pin'') has been used to refer to any component that is a single point of failure which results in catastrophic consequences, and the only thing left to do is pray to Jesus, hence the name. Origin of name The term ''Jesus nut'' may have been coined by American soldiers in Vietnam; the Vietnam War was the first war to feature large numbers of soldiers riding in helicopters. The term may also have originated with the PBY Catalina, which had two ''Jesus bolts'' holding the wing onto the fuselage. If the Jesus nut were to fail in flight, the rotor would detach from the helicopter and the only thing left for the crew to do would be to "pray to Jesus." Real examples of the Jesus nut/pin failing are rare. However, the nut/p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swashplate (aeronautics)
A swashplate is a mechanical device that translates input via the helicopter flight controls into motion of the main rotor blades. Because the main rotor blades are spinning, the swashplate is used to transmit three of the pilot's commands from the non-rotating fuselage to the rotating rotor hub and mainblades. Assembly The swashplate consists of two main parts: a stationary swashplate and a rotating swashplate. The stationary (outer) swashplate is mounted on the main rotor mast and is connected to the cyclic and collective controls by a series of pushrods. It is able to tilt in all directions and move vertically. The rotating (inner) swashplate is mounted to the stationary swashplate by means of a bearing and is allowed to rotate with the main rotor mast. An anti-rotation link prevents the inner swash from rotating independently of the blades, which would apply torque to the actuators. The outer swashplate typically has an anti-rotation slider as well to prevent it from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Center Of Mass
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force may be applied to cause a linear acceleration without an angular acceleration. Calculations in mechanics are often simplified when formulated with respect to the center of mass. It is a hypothetical point where the entire mass of an object may be assumed to be concentrated to visualise its motion. In other words, the center of mass is the particle equivalent of a given object for application of Newton's laws of motion. In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid. The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe. In the case of a dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sikorsky S-92 Rotor P1230176
Sikorsky or Sikorski may refer to: * Sikorsky (comics), a Marvel Comics character * Sikorsky (crater), a lunar crater * Sikorsky Aircraft, an American aircraft manufacturer People with the surname * Brian Sikorski (born 1974), Major League Baseball and Nippon Professional Baseball relief pitcher * Daniel Sikorski (born 1987), Austrian footballer * Igor Sikorsky (1889–1972), Russian-American inventor and founder of the Sikorsky Aircraft Corporation * Kazimierz Sikorski (1895–1986), Polish composer * Krystian Sikorski, Polish ice hockey player * Radosław Sikorski (born 1963), Polish Minister of Foreign Affairs, former Minister of National Defence * Roman Sikorski (1920–1983), Polish mathematician * Władysław Sikorski (1881–1943), Polish general and Prime Minister in exile during World War II Fictional * Rudolf Sikorski, a character in Boris and Arkady Strugatsky's series of novels See also * Sikorski * Hans Sikorski, a music publishing house in Hamburg, Germany * Polish I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
