A power train for an amphibian operable in land and marine modes includes a prime mover having an integral speed change transmission, at least a first land propulsion unit, at least a first marine propulsion unit, and a power transmission unit including a drive member configured to couple the prime mover to the at least first marine propulsion unit, wherein the prime mover is arranged to drive the at least first land propulsion unit through/via the integral speed change transmission in the land mode, and the prime mover is arranged to drive the at least first marine propulsion unit through/via the power transmission unit in both the marine mode and the land mode.

An actuator includes housing having a reciprocation axis, drive gear configured to couple to the motor, and electromagnetic clutch configured to couple to the motor and coupled to the drive gear. The clutch engages first and second clutch plates responsive to being powered and disengages the clutch plates responsive to not being powered. Actuator includes a ball screw including a nut and a threaded shaft. The nut is coupled to the drive gear and rotation of the drive gear induces rotation of the nut about the reciprocation axis. Rotation of the nut induces motion of the threaded shaft along the reciprocation axis. Actuator includes a fluid damper having a piston coupled to the threaded shaft and disposed within a chamber containing a fluid. Piston includes a port that couples a first chamber portion to a second chamber portion. A brake assembly limits rotation of the nut responsive to the assembly being engaged.

Disclosed is an apparatus (100) for an aerial transportation of a payload. The apparatus (100) includes a propeller unit (10) to provide a primary thrust whereas a plurality of propellers (50) is fitted around a body of the apparatus (100) to help in maneuvering and orientation control. The apparatus (100) employs gasoline as a primary source of energy that has a higher energy density than lithium polymer batteries. The apparatus (100) facilitates longer flight times. The apparatus (100) is useful for safe transportation of higher payloads and has vertical takeoff and land capability.

A balanced motorcycle powertrain is described. Embodiments of the balanced motorcycle powertrain include components mounted to a frame of a motorcycle such that the powertrain can be evenly balanced about a centerline of the frame. The balanced motorcycle powertrain can include, but is not limited to, a motor, a transmission, a pair of clutches, a clutch shaft, a crank shaft, a pair of superchargers, a pair of chains, a pair of rear sprockets, and a rear wheel. Each of the components can be oriented such that the powertrain is substantially balanced about the centerline of the frame.

A clutch system configured to transmit torque between an input shaft and an output shaft. The clutch system includes a clutch. The clutch includes: an input portion disposed at an end of the input shaft; an output portion disposed at an end of the output shaft; a sliding component that slides axially between the input and output portions to engage the clutch; and swirl breaks. The input portion, the output portion, and the sliding component each comprises walls. The swirl breaks are affixed to a one of the walls.

Embodiments of systems and methods for operating a gas turbine engine defining a bowed rotor condition are generally provided. The systems and methods include rotating a rotor assembly defining a bowed rotor condition from approximately zero revolutions per minute (RPM) to within a bowed rotor mitigation speed range, in which the bowed rotor mitigation speed range is defined by a lower speed limit greater than zero RPM and an upper speed limit less than or equal to an idle speed condition of the gas turbine engine; applying a load at the rotor assembly via an energy storage device; adjusting the load to limit rotational speed or acceleration of the rotor assembly to within the bowed rotor mitigation speed range for a period of time; and removing the load to enable rotation of the rotor assembly to the idle speed condition following the period of time.

A clutch system configured to transmit torque between an input shaft and an output shaft. The clutch system includes a clutch. The clutch includes: an input portion disposed at an end of the input shaft; an output portion disposed at an end of the output shaft; a sliding component that slides axially between the input and output portions to engage the clutch; and swirl breaks. The input portion, the output portion, and the sliding component each comprises walls. The swirl breaks are affixed to a one of the walls.

A power train for an amphibian operable in land and marine modes includes a prime mover having an integral speed change transmission, at least a first land propulsion unit, at least a first marine propulsion unit, and a power transmission unit including a drive member configured to couple the prime mover to the at least first marine propulsion unit, wherein the prime mover is arranged to drive the at least first land propulsion unit through/via the integral speed change transmission in the land mode, and the prime mover is arranged to drive the at least first marine propulsion unit through/via the power transmission unit in both the marine mode and the land mode.

Provided is a portable brush cutter with reduced weight and size due to its simple structure with a small number of components that is capable of improving durability and the like as well as effectively suppressing torsional vibration of a transmission shaft. In the portable brush cutter, a one-way clutch to prevent generation of torsional vibration in a rotation transmission path is interposed between an output shaft and a transmission shaft, and bearings are adjacently mounted on the opposite sides of the one-way clutch.

A safety coupling has a driving coupling member engaged with a driven coupling member by a frictional connection. The frictional connection can be disconnected by activation of a release element. The release element can be activated by a centrifugal device wherein a centrifugal unit of the centrifugal device is radially moveable to interact with a shift gate in dependence of the revolution speed of the centrifugal unit and the slip between the driving coupling member and the driven coupling member. The centrifugal device includes a stop to limit the centrifugal force applied to the centrifugal unit.