A prime mover includes a stator fixed to a housing, and a rotor rotatable relative to the stator. The prime mover is capable of outputting torque from the rotor by being supplied with electric power. A speed reducer is capable of reducing the torque of the prime mover and outputting the reduced torque. The speed reducer includes a sun gear rotatable integrally with the rotor, and planetary gears capable of revolving in a circumferential direction of the sun gear while rotating in a state of meshing with the sun gear. A gear width of the sun gear is set such that a length in the axial direction by which the sun gear and the planetary gear are overlapped is smaller than a gear width of the planetary gear.

A prime mover includes a stator fixed to a housing and a rotor relatively rotatable relative to the stator. The prime mover outputs torque from the rotor by being supplied with electric power. A speed reducer reduces the torque of the prime mover and outputs the reduced torque. One bearing portion rotatably supports the rotor. The speed reducer includes an input portion that is coaxial and integrally rotatable with the rotor and receives the torque from the rotor.

A mechanical gearbox for turbomachine, in particular for aircraft. The gearbox includes a sun gear including an external toothing, a ring gear including an internal toothing, and planet gears which are meshed with the sun gear and the stationary ring gear. The planet gears are carried by a movable planet carrier and each having external toothings of different diameters. The movable planet carrier includes a movable ring gear which carries an internal toothing and which is independent of the stationary ring gear, each of the planet gears being meshed with the sun gear and the stationary and movable ring gears.

A planetary gear mechanism includes a sun gear attached to the motor rotation shaft to rotate about the central axis extending vertically, a fixed internal gear radially outside the sun gear, planetary gears radially outside the sun gear and radially inside the fixed internal gear to mesh with the sun gear and the fixed internal gear, a movable internal gear above the fixed internal gear and radially outside the planetary gears to mesh with the planetary gears and to rotate about the central axis, and a carrier that holds upper and lower surfaces of the planetary gears.

A battery-powered troweling machine is driven by an electric motor powered by a pair of twenty-four volt batteries coupled in series to drive a planetary gearbox to rotate a trowel blade assembly engageable with the surface of the poured concrete. The controls are carried by a detachable handle that is connectable with a receiver box that traps the handle between interior and exterior stops and uses over center clamps to maintain the handle in proper position within the receiver box. The controls at the rearward distal end of the handle can be used to vary the speed of rotation of the troweling assembly, to adjust the pitch of the individual trowel blades through an actuator and linkage assembly, to initiate actuation of the electric motor and to provide an emergency stop for the operation of the troweling machine.

A prime mover includes a stator fixed to a housing and a rotor relatively rotatable relative to the stator. The prime mover outputs torque from the rotor by being supplied with electric power. A speed reducer reduces the torque of the prime mover and outputs the reduced torque. One bearing portion rotatably supports the rotor. The speed reducer includes an input portion that is coaxial and integrally rotatable with the rotor and receives the torque from the rotor.

A planetary gear device configured by combining a plurality of planetary gear mechanisms includes first and second planetary gear mechanisms sharing a carrier, wherein each planetary gear mechanism is composed of an internal gear I.sub.k (k is an integer equal to or larger than 2) and a planetary gear P.sub.k which is engaged with the internal gear I.sub.k and revolves in a circumferential direction of the internal gear, the planetary gear P.sub.k of each planetary gear mechanism is composed of a spur gear in the form of an external gear, the planetary gears P.sub.k of the planetary gear mechanisms share a central axis or have central axes integrally connected to integrally rotate on a common rotation central axis line or are integrated with each other to integrally rotate on the common rotation central axis line in order to configure the entire planetary gear device as a two-stage gear mechanism, the planetary gear device is configured such that the number of teeth z.sub.p1 of a first planetary gear constituting the first planetary gear mechanism and the number of teeth z.sub.p2 of a second planetary gear constituting the second planetary gear mechanism are different from each other, the number of teeth on the internal gear I.sub.1 is z.sub.i1, and the number of teeth on the internal gear I.sub.2 is z.sub.i2, an addendum modification coefficient of the first planetary gear is x.sub.p1, an addendum modification coefficient of an internal gear which is engaged with the first planetary gear and constitutes the first planetary gear mechanism is x.sub.i1, an addendum modification coefficient of the second planetary gear is x.sub.p2, an addendum modification coefficient of an internal gear which is engaged with the second planetary gear and constitutes the second planetary gear mechanism is x.sub.i2, a power transmission efficiency of the planetary gear device having the addendum modification coefficients x.sub.p1, x.sub.i1, x.sub.p2, and x.sub.i2 is η, an addendum modification coefficient of the internal gear I.sub.1 is x.sub.i1, and an addendum modification coefficient of the internal gear I.sub.2 is x.sub.i2, and the addendum modification coefficients have relationships in which values selected from combinations of the addendum modification coefficients which maximize or submaximize the power transmission efficiency η within an allowable range of design specifications given in advance are combined.

An actuation mechanism for use in a vehicle. The actuation mechanism includes one or more motors having an output shaft with a sun gear. At least a portion of the sun gear is drivingly connected to at least a portion of one or more planetary gears. The one or more planetary gears are drivingly connected to at least a portion of a carrier, a fixed non-rotating ring gear and an output gear. The disclosure further relates to a method of operating an actuation mechanism that is drivingly connected to at least a portion of a vehicle parking mechanism. The method includes providing an actuation mechanism, providing a parking mechanism and one or more sensors that are operably configured to collect an amount of data to be analyzed. Based on the data analyzed, one or more failures within the parking mechanism may be determined and an alert may be sent.

A modular high precision gear box arrangement includes first and second gear boxes. The first gear box has a first rotatable hollow wheel, a second fixed hollow wheel and at least one double planet having a first planet and a second planet arranged on a planet shaft. The first planet meshes with the first hollow wheel, the second planet meshes with the second hollow wheel, and the first hollow wheel is coupled with an output. The second gear box includes a fixed hollow wheel that is the second hollow wheel of the first gear box and at least one planet that is the second planet of the at least one double planet of the first gear box. The second gear box further includes an input for driving the planet shaft, wherein the input is arranged centrically or eccentrically to a central rotation axis of the gear box arrangement.

A prime mover includes a stator fixed to a housing, and a rotor rotatable relative to the stator. The prime mover is capable of outputting torque from the rotor by being supplied with electric power. A speed reducer is capable of reducing the torque of the prime mover and outputting the reduced torque. The speed reducer includes a sun gear rotatable integrally with the rotor, and planetary gears capable of revolving in a circumferential direction of the sun gear while rotating in a state of meshing with the sun gear. A gear width of the sun gear is set such that a length in the axial direction by which the sun gear and the planetary gear are overlapped is smaller than a gear width of the planetary gear.