An actuator unit (1) includes a direct drive motor (2), a first magnetic gear (3) connected to a rotating shaft (6) of the direct drive motor (2), a second magnetic gear (4) configured to be magnetically engaged with the first magnetic gear (3), and a planetary reducer (5) connected to a rotating shaft of the second magnetic gear (4).

Mechanisms or apparatus convert a number of inputs via a number of input members into a number of output movements of an output structure, providing control in three degrees-of-freedom (DOF), for example control over roll, pitch and yaw of the output structure. Inputs may be rotations about a common axis of rotation, for example via a first ring, a second ring, and one or more plates, concentrically array. Rotation of the first ring may control a first DOF, rotation of the first ring may control a second DOF, and rotation of the plate may control all three DOF. Three concentrically arrayed tubular shafts may be employed, providing a through-passage or cable fluid conduit run to accommodate wires, optical fibers, fluid carrying conduits. Such may be particularly advantageous when employed as part of a robot, or other device with a tool or sensor or transducer located at or proximate a distal end thereof.

An electric drive hydraulic fracturing pump system includes one or more electric motors, with each electric motor electrically coupled to a dedicated dual inverter to control operation of the motor. A plurality of electric motors may be coupled to each end of a pump crankshaft and configured to provide rotational power to the power end of a hydraulic fracturing pump through a planetary gearset coupled to each end of the crankshaft. A hydraulic cooling circuit having a first and second cooling systems may be used to regulate the temperature of the electric motors and dual inverters.

An electric drive hydraulic fracturing pump system includes one or more electric motors, with each electric motor electrically coupled to a dedicated dual inverter to control operation of the motor. A plurality of electric motors may be coupled to each end of a pump crankshaft and configured to provide rotational power to the power end of a hydraulic fracturing pump through a planetary gearset coupled to each end of the crankshaft. A hydraulic cooling circuit having a first and second cooling systems may be used to regulate the temperature of the electric motors and dual inverters.

A drivetrain for coupling a motor to a mixer shaft within a mixer includes a sun gear connectable to a rotor of the motor. The drivetrain also includes a plurality of stepped planetary gears. Each of the stepped planetary gears includes a first tooth section and a second tooth section. A first ring gear is mounted such that the first ring gear is fixed. The first ring gear and the sun gear are meshed with the stepped planetary gears at the first tooth section. A second ring gear is meshed with the stepped planetary gears at the second tooth section. The sun gear, the stepped planetary gears, the first ring gear, and the second ring gear collectively form a single stage planetary gear set of the drivetrain.

A drivetrain for coupling a motor to a mixer shaft within a mixer includes a sun gear connectable to a rotor of the motor. The drivetrain also includes a plurality of stepped planetary gears. Each of the stepped planetary gears includes a first tooth section and a second tooth section. A first ring gear is mounted such that the first ring gear is fixed. The first ring gear and the sun gear are meshed with the stepped planetary gears at the first tooth section. A second ring gear is meshed with the stepped planetary gears at the second tooth section. The sun gear, the stepped planetary gears, the first ring gear, and the second ring gear collectively form a single stage planetary gear set of the drivetrain.

A turbomachine engine includes a fan assembly and a core engine comprising a turbine and an input shaft rotatable with the turbine is provided. A single-stage epicyclic gear assembly receives the input shaft at a first speed and drives an output shaft coupled to the fan assembly at a second speed. A sun gear rotates about a longitudinal centerline of the gear assembly and has a sun gear-mesh region along the longitudinal centerline of the gear assembly where the sun gear is configured to contact a plurality of planet gears. A ring gear-mesh region is provided along the longitudinal centerline of the gear assembly where a ring gear is configured to contact the plurality of planet gears. The sun gear-mesh region is axially offset from the ring gear-mesh region along the longitudinal centerline.

Currently, there is no efficient mechanism for speed increasing with very high transmission ratio. Therefore, a planetary mechanism is proposed, with two suns (0b, 3b), having teeth numbers: Z.sub.1,Z.sub.4, one stationary (0b) and one (3b) constituting the input of mechanism, a carrier (1a, 1b, 1c, 1d) constituting the output, and a planetic shaft (2b) with two planets (2a, 2c), cooperating with corresponding suns (0b, 3b) and having teeth numbers: Z.sub.2,Z.sub.3, where the term: Z.sub.1/Z.sub.2.Z.sub.3/Z.sub.4 is closest to 1, so the transmission ratio between moving sun (3b) and carrier (1a, 1b, 1c, 1d) is maximum possible. In a specific case, named “Three Successive Integers Mechanism”, this transmission ratio is equal to k.sup.2, where k is integer, easily taking high value. The applications are unlimited, while some are: —wind turbine, —electric assisted bicycle, —energy storage unit of enormous kinetic energy with k.sup.4 times increased moment of inertia, —mechanically driven supercharger for ICE or fuel cell, —robotic articulated arm (as speed reducer).

Currently, there is no efficient mechanism for speed increasing with very high transmission ratio. Therefore, a planetary mechanism is proposed, with two suns (0b, 3b), having teeth numbers: Z.sub.1,Z.sub.4, one stationary (0b) and one (3b) constituting the input of mechanism, a carrier (1a, 1b, 1c, 1d) constituting the output, and a planetic shaft (2b) with two planets (2a, 2c), cooperating with corresponding suns (0b, 3b) and having teeth numbers: Z.sub.2,Z.sub.3, where the term: Z.sub.1/Z.sub.2.Z.sub.3/Z.sub.4 is closest to 1, so the transmission ratio between moving sun (3b) and carrier (1a, 1b, 1c, 1d) is maximum possible. In a specific case, named “Three Successive Integers Mechanism”, this transmission ratio is equal to k.sup.2, where k is integer, easily taking high value. The applications are unlimited, while some are: —wind turbine, —electric assisted bicycle, —energy storage unit of enormous kinetic energy with k.sup.4 times increased moment of inertia, —mechanically driven supercharger for ICE or fuel cell, —robotic articulated arm (as speed reducer).

A planet carrier (213) for a speed reducer (210) of a turbomachine (1), this planet carrier (213) having a main axis X and comprising: a cage carrier (222) comprising an annular row of axial fingers (282) about the axis X, which comprises first connection elements, and a cage (220) comprising at its periphery housings (280) and second connection elements which are mounted in said housings and which cooperate with the first connection elements to form connections between the cage carrier (222) and the cage (220), which allow at least one degree of freedom,

characterised in that the cage (220) comprises two shells (220a, 220b) which are axially assembled to each other, said first or second connection elements comprising broaches (288) oriented radially with respect to said axis X and passing through radial orifices (220a, 220a2, 220b1, 220b2) of said shells (220a, 220b).