A top drive for well operations having a gearbox, a traction motor connected to the gearbox so that a motor shaft of the traction motor extends into the gearbox, a quill extending into the gearbox, a gear train positioned within the gearbox and mechanically connected between the traction motor shaft and the quill, and a connector positioned in the gear train, wherein in a coupled configuration the connector communicates torque through the gear train, and wherein in a decoupled configuration the connector does not communicate torque through the gear train. A method for operating a top drive by applying a first torque to a quill with two traction motors, disconnecting one of the traction motors from the quill, and applying a second torque less than the first torque to the quill with the non-disconnected traction motor.

A drive shaft is formed by welding two spline shaft heads to a hollow middle section of tubing. The spline shaft head includes teeth which are crowned to permit an angular offset of the drive shaft relative to cylindrical splines of connectors, such that the end faces of the teeth define a barrel shape. The teeth of the spline shaft head include a side face curvature, defining a football-shaped tooth cross-section. Torque is rotationally transmitted across a permitted angular offset of the drive shaft relative to cylindrically arranged linear splines of drive and driven connectors (i.e., relative to the engine output axis of rotation and the differential input axis of rotation), thereby avoiding the use of prior art universal joints.

A planetary gear train for a wind power plant includes a planetary stage rotating in a gear train housing, a spur gear stage downstream of the planetary stage, a sun wheel shaft which is non-rotatably connected to a sun wheel of the planetary gear stage, and a hollow shaft which is coaxially surrounded by a spur gear of the spur gear stage and is non-rotatably connected to the spur gear. The sun wheel shaft and the hollow shaft are non-rotatably connected to each other by a toothed coupling, with an outer toothing of the sun wheel shaft meshing with an inner toothing of the hollow shaft. The planetary gear train includes oil-guide ducts which produce a connection between an oil inlet connected to the gear train housing, on the one hand, and the toothed coupling and the axial contact surface, on the other hand.

A planetary gear train for a wind power plant includes a planetary stage rotating in a gear train housing, a spur gear stage downstream of the planetary stage, a sun wheel shaft which is non-rotatably connected to a sun wheel of the planetary gear stage, and a hollow shaft which is coaxially surrounded by a spur gear of the spur gear stage and is non-rotatably connected to the spur gear. The sun wheel shaft and the hollow shaft are non-rotatably connected to each other by a toothed coupling, with an outer toothing of the sun wheel shaft meshing with an inner toothing of the hollow shaft. The planetary gear train includes oil-guide ducts which produce a connection between an oil inlet connected to the gear train housing, on the one hand, and the toothed coupling and the axial contact surface, on the other hand.

A rotor assembly includes a fan rotor shaft coupled to a fan rotor, a low pressure turbine rotor shaft coupled to a low pressure turbine rotor, and a joint device configured to connect the fan rotor shaft to the low pressure turbine rotor shaft, to allow torsion, shear and bending to be transferred between the fan rotor shaft and the low pressure turbine rotor shaft under normal operation, and allow torsion and shear but prevent bending to be transferred between the fan rotor shaft and the low pressure turbine rotor shaft under a fan blade-out event.

A rotor assembly includes a fan rotor shaft coupled to a fan rotor, a low pressure turbine rotor shaft coupled to a low pressure turbine rotor, and a joint device configured to connect the fan rotor shaft to the low pressure turbine rotor shaft, to allow torsion, shear and bending to be transferred between the fan rotor shaft and the low pressure turbine rotor shaft under normal operation, and allow torsion and shear but prevent bending to be transferred between the fan rotor shaft and the low pressure turbine rotor shaft under a fan blade-out event.

An electric vehicle and a range extender engine are shown including the controls to operate the same.

An electric vehicle and a range extender engine are shown including the controls to operate the same.

A telescopic shaft is provided. The telescopic shaft includes a first shaft including a first coupler having an inner circumferential surface including an external straight groove and an external inclination groove formed thereon, the external straight groove having a semi-circular cross section and being formed in parallel to a rotation axis and the external inclination groove having a semi-circular cross section, being inclined with respect to the external straight groove at a predetermined angle, and being shaped like a spiral, a second shaft including a second coupler inserted into the first coupler and having an outer circumferential surface including an internal straight groove and an internal inclination groove formed thereon, the internal straight groove having a semi-circular cross section and corresponding to the external straight groove and the internal inclination groove having a semi-circular cross section, being inclined in an opposite direction to the external inclination groove at a predetermined angle with respect to the internal straight groove, and being shaped like a spiral, and a plurality of balls arranged in a line in an axial direction between the external straight groove and the internal straight groove, one ball being arranged between the external inclination groove and the internal inclination groove, wherein the first shaft and the second shaft are coupled to extend and retract in an axial direction, thereby preventing play from occurring in a circumferential direction and preventing separation of balls.

A telescopic shaft is provided. The telescopic shaft includes a first shaft including a first coupler having an inner circumferential surface including an external straight groove and an external inclination groove formed thereon, the external straight groove having a semi-circular cross section and being formed in parallel to a rotation axis and the external inclination groove having a semi-circular cross section, being inclined with respect to the external straight groove at a predetermined angle, and being shaped like a spiral, a second shaft including a second coupler inserted into the first coupler and having an outer circumferential surface including an internal straight groove and an internal inclination groove formed thereon, the internal straight groove having a semi-circular cross section and corresponding to the external straight groove and the internal inclination groove having a semi-circular cross section, being inclined in an opposite direction to the external inclination groove at a predetermined angle with respect to the internal straight groove, and being shaped like a spiral, and a plurality of balls arranged in a line in an axial direction between the external straight groove and the internal straight groove, one ball being arranged between the external inclination groove and the internal inclination groove, wherein the first shaft and the second shaft are coupled to extend and retract in an axial direction, thereby preventing play from occurring in a circumferential direction and preventing separation of balls.