Abstract: A helicopter is described comprising a motor member comprising an output shaft and a first stator rotatably supporting the output shaft around a first axis; a main rotor adapted to provide the lift necessary for the support and the thrust necessary for the movement of the helicopter; a transmission interposed between the motor member and the main rotor; the transmission comprises, in turn, an input shaft rotatable around a second axis and a second stator rotatably supporting the input shaft around the second axis; the helicopter also comprises a joint interposed between the first and second stator, angularly fixed with respect to the first axis, and configured to allow an inclination between the first and second stator in a plane parallel to said first axis; the joint comprises a first corrugated element made of an elastically deformable material, interposed between said first and second stator, and adapted to allow the inclination through elastic deformation.

Abstract: A rotor for an aircraft is described, comprising an input shaft rotatable around a first axis; an output member rotatable around a second axis; a coupling element functionally interposed between the input shaft and the output member and adapted to transmit the motion from the input shaft to the output member; the coupling element is configured to allow, in use, a fixed or variable inclination between the respective first and second axes; the coupling element comprises at least a first corrugated element made of an elastically deformable material; the first corrugated element allows the inclination through elastic deformation.

Abstract: A hover-capable aircraft is described that comprises a drive unit, a rotor and a transmission interposed between the drive unit and the rotor; the transmission comprises a gear; the gear, in turn, comprises a main body rotatable about a first axis and a plurality of first teeth projecting in a cantilever fashion from the main body; the gear comprises a first pair of first rings axially opposite to each other and cooperating with the gear so as to exert a radial force on the gear.

Abstract: A hover-capable aircraft is described that comprises a drive unit, a rotor and a transmission interposed between the drive unit and the rotor; the transmission comprises a gear; the gear, in turn, comprises a main body rotatable about a first axis and a plurality of first teeth projecting in a cantilever fashion from the main body; the gear comprises a first pair of first rings axially opposite to each other and cooperating with the gear so as to exert a radial force on the gear.

Abstract: A test bench for screwdrivers comprises a hydraulic brake unit (11) provided with a coupling (12) for a screwdriver to be tested and angle and torque measurement transducers (15). The brake unit (11) comprises a disk (40) axially connected to the coupling (12) so as to be rotated by a screwdriver to be tested, and braking plates (42, 43) pushed in a controllable manner with their braking surfaces (44, 45) against the disk (40) by means of a plurality of pistons (46, 47) supplied with fluid by an electrovalve (16). The pistons (46, 47) of the plurality can be selectively activated under the control of the control unit (26) so as to select a maximum braking torque of the brake. The control may be performed by means a PID controller (19) which receives an electrovalve control signal (22) from a control unit (26) so as to follow braking curves depending on the angle of rotation and/or torque measured and has parameters which can be set using different sets of parameters.

Abstract: A test bench for screwdrivers comprises a hydraulic brake unit (11) provided with a coupling (12) for a screwdriver to be tested and angle and torque measurement transducers (15). The brake unit (11) comprises a disk (40) axially connected to the coupling (12) so as to be rotated by a screwdriver to be tested, and braking plates (42, 43) pushed in a controllable manner with their braking surfaces (44, 45) against the disk (40) by means of a plurality of pistons (46, 47) supplied with fluid by an electrovalve (16). The pistons (46, 47) of the plurality can be selectively activated under the control of the control unit (26) so as to select a maximum braking torque of the brake. The control may be performed by means a PID controller (19) which receives an electrovalve control signal (22) from a control unit (26) so as to follow braking curves depending on the angle of rotation and/or torque measured and has parameters which can be set using different sets of parameters.

Abstract: Described herein is a planetary gear train, comprising: a sun gear that can turn about an axis and comprises a plurality of first teeth; a fixed crown wheel comprising a plurality of second teeth; and two planetary gears, each comprising a plurality of third teeth, the planetary gears each meshing with the crown wheel and the sun gear and able to turn about second axes, which are in turn able to turn about the first axis; at least two third teeth simultaneously mesh with second teeth and further two third teeth simultaneously mesh with first teeth; the third teeth comprise a first and a second side, which have, respectively, a first and a second pressure angle different from one another; and the number of the third teeth is different from the absolute value of the semidifference between the number of the first teeth and of the second teeth.

Abstract: Described herein is a planetary gear train, comprising: a sun gear that can turn about an axis and comprises a plurality of first teeth; a fixed crown wheel comprising a plurality of second teeth; and two planetary gears, each comprising a plurality of third teeth, the planetary gears each meshing with the crown wheel and the sun gear and able to turn about second axes, which are in turn able to turn about the first axis; at least two third teeth simultaneously mesh with second teeth and further two third teeth simultaneously mesh with first teeth; the third teeth comprise a first a second side, which have, respectively, a first and a second pressure angle different from one another; and the number of the third teeth is different from the absolute value of the semidifference between the number of the first teeth and of the second teeth.

Abstract: There is described a helicopter having a transmission for transmitting motion from a driving member to a driven member; the transmission has at least a first gear driven by the driving member, and a second gear meshing with the first gear and in turn driving the driven member; the first and second gear have teeth shaped so that the gears mesh with one another at at least two pairs of respective simultaneously meshing teeth; the teeth of at least one of the gears have a profile having an end portion relieved with respect to a starting theoretical involute; and the pattern of the distance between the points of the end portion and the starting involute along an axis of the tooth has at least a first and a second segment sloping with respect to each other.

Abstract: There is described a helicopter having a transmission for transmitting motion from a driving member to a driven member; the transmission has at least a first gear driven by the driving member, and a second gear meshing with the first gear and in turn driving the driven member; the first and second gear have teeth shaped so that the gears mesh with one another at at least two pairs of respective simultaneously meshing teeth; the teeth of at least one of the gears have a profile having an end portion relieved with respect to a starting theoretical involute; and the pattern of the distance between the points of the end portion and the starting involute along an axis of the tooth has at least a first and a second segment sloping with respect to each other.