Westland Aircraft Limited

Westland Plc

James E Saunders

Kenneth Watson

Geoffrey John Humphrey

Richard G Buswell

Brian A Shotter

A helicopter transmission system is disclosed in which drive from three engines is transmitted to two output channels each of which is divided by dividing means to drive two output pinions meshed with a common combining gear rotationally fixed to a sustaining rotor drive shaft. Balancing means are provided to balance the torque transmitted by the respective pairs of output pinions and, in the described embodiment, the balancing means comprise a plurality of meshing spur gears arranged with one of the spur gears drivingly connected to one of the engines and a further two of the spur gears are drivingly connected respectively to the two output channels. Conveniently, a further one of the spur gears provides a power take off to an anti torque rotor drive shaft.

Helicopter transmission systems

A freewheel device for connecting a power input to a selected one of a plurality of outputs so as to transmit rotary motion in one direction of rotation and to over-run when the speed of the selected one of the outputs exceeds that of the input, includes a neutral condition in which the input is rotationally disengaged from any of the outputs. In a described embodiment, the freewheel device comprises a plurality of rollers retained circumferentially adjacent one end of an axially movable shaft in operative association with a plurality of wedge-shaped portions formed on the shaft, axial movement of the shaft serving to engage the rollers between the wedge-shaped portions and, selectively axially spaced-apart internal, cylindrical surfaces formed on each of the outputs and on a rotatable support. The freewheel device finds particular application in the transmission system of multi-engined helicopters.

Freewheel devices

This invention discloses oil purifying means suitable for installation in any gear assembly that includes a gear supported in a stationary housing for rotation about an axis and having a generally planar surface extending radially from the axis. The purifying means includes first means arranged during rotation of the gear, to direct a supply of lubricating oil onto the surface so that the oil is centrifuged outwardly and into second means forming an annular cavity adjacent the peripheral region of the gear. The cavity has an inwardly directed opening providing separate inlet and outlet fluid flow paths arrange so that, during rotation of the gear, lubricating oil is centrifuged through the inlet into the cavity wherein the direction of oil is reversed so that the oil exhausts through the outlet and contaminent particles in the oil are retained in the cavity due to centrifugal force. Thus, the purifying means of the present invention utilizes the energy of the rotating gear, and is automatically operational all the time that the gear is being rotated. Examples of embodiments suitable for both vertical and horizontal installations are disclosed, and the purifying means can be used either independently to provide the sole purification in a particular installation, or in combination with a conventional filter to further reduce the level of contamination. The purifying means can be incorporated in any number of suitable gears in a particular installation.

Centrifugal oil purifying means

This invention relates to freewheels comprising a plurality of rollers interposed between inner and outer races formed on driving and driven members respectively, one of said races having a plurality of wedge-shaped portions equal in number to the number of rollers. The invention is particularly concerned with cageless freewheels of this construction, and discloses a means for moving said rollers between a first position in which the rollers assume an engaged position to transmit rotation to the driven member, and a second position in which the rollers are retained in a disengaged position. This is accomplished by at least one actuating lever interposed in the rollers, and being capable of limited circumferential movement between said first and second positions. In one embodiment the actuating lever has parallel side portions for engagement with adjacent rollers, and in a second embodiment the actuating lever includes a circular section spindle portion rotatably mounted in an axial bore in one of the rollers.

Growing community of inventors

Sherborne, United Kingdom

James E Saunders