A variable speed transmission is disclosed, with a transmission apparatus which includes a planetary gear set having a ring gear and a sun gear. The variable speed transmission further includes a primary engine for powering the sun gear, a braking device engaging the ring gear, and a controller configured to alter the rotational speed of the ring gear by adjusting the braking device.

Embodiments are directed to a double Hooke's joint gimbal in a rotor system. An upper Hooke's joint has four arms extending radially outward to define first and second axes, and a lower Hooke's joint has four arms extending radially outward to define third and fourth axes. A pair of connectors couple the upper Hooke's joint and the lower Hooke's joint. A first set of bearings are positioned between arms on the upper and lower Hooke's joints and the connectors. The first set of bearings comprise an elastomer, such as elastomeric journal bearings. The upper Hooke's joint is coupled to a yoke and rotor blades by a driver assembly that allows rotor blade flapping. The lower Hooke's joint is coupled to and driven by a mast. A spherical bearing allows the upper Hooke's joint to move laterally along the mast.

A variable speed transmission is disclosed, with a transmission apparatus which includes a planetary gear set having a ring gear and a sun gear. The variable speed transmission further includes a primary engine for powering the sun gear, a braking device engaging the ring gear, and a controller configured to alter the rotational speed of the ring gear by adjusting the braking device.

Embodiments are directed to a double Hooke's joint gimbal in a rotor system. An upper Hooke's joint has four arms extending radially outward to define first and second axes, and a lower Hooke's joint has four arms extending radially outward to define third and fourth axes. A pair of connectors couple the upper Hooke's joint and the lower Hooke's joint. A first set of bearings are positioned between arms on the upper and lower Hooke's joints and the connectors. The first set of bearings comprise an elastomer, such as elastomeric journal bearings. The upper Hooke's joint is coupled to a yoke and rotor blades by a driver assembly that allows rotor blade flapping. The lower Hooke's joint is coupled to and driven by a mast. A spherical bearing allows the upper Hooke's joint to move laterally along the mast.

A mechanical system for transmitting rotary motion between at least two shafts movable in rotation respectively about a first axis and a second axis, the first and second axes intersecting, the mechanical system including a bevel gear set made up of a first bevel gear having teeth and movable in rotation about the first axis and a bevel wheel having teeth and movable in rotation about the second axis, the teeth of the first bevel gear and of the bevel wheel respectively being suitable for co-operating in complementary manner with one another, the first bevel gear, referred to as a power gear, presenting a first defining pitch surface of conical shape, and the bevel wheel presenting a second defining pitch surface of conical shape.

A hub planetary belt transmission (2) has a platform body (50) supporting a motor drive (8) having a motor drive shaft (6) coupled to a distributing and a collecting pulley (4, 18) attached to a first output shaft (22) coupled to a first propulsion element (40, 44). A housing (30) coupled to peripheral shafts (24) attached to tension arms (26) is concentrically rotatable about a common axis of the distributing and collecting pulleys and is coupled to a second propulsion element (42, 45). Transmitting pulleys (12, 14) are driven by distributing belts (10) and collecting belts (20) for rotating together with the peripheral shafts and tension arms about a common axis of the distributing and collecting pulleys so as to create a centripetal force which stretches the distributing belts and the collecting belts, thus regulating the coupling force between the belts and pulleys based on the rotation velocity.

A fairing system for a rotary wing aircraft is provided including a shaft fairing mounted for rotation about a first axis of rotation. A de-rotation system contained with the shaft fairing includes a toroidal continuously variable transmission configured to control the rotation of the shaft fairing about the first axis of rotation. A position control system includes at least one position sensor and a controller. The at least one position sensor is configured to monitor a position of the shaft fairing relative to the first axis of rotation. The controller is operably coupled to the at least one position sensor and the de-rotation system. The controller is configured to adjust a gear ratio of the toroidal continuously variable transmission in response to a sensed position of the shaft fairing.

A mechanical system for transmitting rotary motion between at least two shafts movable in rotation respectively about a first axis and a second axis, the first and second axes intersecting, the mechanical system including a bevel gear set made up of a first bevel gear having teeth and movable in rotation about the first axis and a bevel wheel having teeth and movable in rotation about the second axis, the teeth of the first bevel gear and of the bevel wheel respectively being suitable for co-operating in complementary manner with one another, the first bevel gear, referred to as a power gear, presenting a first defining pitch surface of conical shape, and the bevel wheel presenting a second defining pitch surface of conical shape.

A drive system for a helicopter includes a main drive for driving a rotor the helicopter, a flywheel mass battery including at least one flywheel, a first transmission coupling the flywheel mass battery with the main drive such that, during operation of the main drive, output can be transferred from the main drive to the flywheel mass battery, and a second, variable transmission connecting the flywheel mass battery to the rotor of the helicopter such that a predetermined output can be transferred to the rotor through adjustment of a transmission ratio of the variable transmission.

A hub planetary belt transmission (2) has a platform body (50) supporting a motor drive (8) having a motor drive shaft (6) coupled to a distributing and a collecting pulley (4, 18) attached to a first output shaft (22) coupled to a first propulsion element (40, 44). A housing (30) coupled to peripheral shafts (24) attached to tension arms (26) is concentrically rotatable about a common axis of the distributing and collecting pulleys and is coupled to a second propulsion element (42, 45). Transmitting pulleys (12, 14) are driven by distributing belts (10) and collecting belts (20) for rotating together with the peripheral shafts and tension arms about a common axis of the distributing and collecting pulleys so as to create a centripetal force which stretches the distributing belts and the collecting belts, thus regulating the coupling force between the belts and pulleys based on the rotation velocity.