Abstract: A planetary screw actuator is provided which includes a stator; a rotor; a lead screw having external threads thereon; an ovoidal planet screw that meshes with the external threads on the lead screw; an end plate; and a grooved roller bearing (GRB) race disposed between the end plate and the ovoidal planet screw. The GRB race has at least one GRB roller disposed therein.

Abstract: A rotary actuator (101) is provided which includes a crankshaft (103), first and second eccentric gears (121), first and second end plates (123), a first crosslink (117) which is disposed between the first eccentric gear and the first end plate, a second crosslink which is disposed between the second eccentric gear and the second end plate, a stator (113) disposed between the first and second eccentric gears, and a rotor (109). Preferably, the rotary actuator further includes first and second support plates (115) which are disposed concentrically about the crankshaft and which are attached to first and second surfaces of the stator, respectively. The foregoing configuration allows the stator to serve as a major structural element, which may enhance the stiffness and reduce the weight of the actuator, while simplifying many of its active components.

Abstract: An orthotic device is provided which includes a first structural element; a second structural element which is rotatably attached to the first structural element across a joint; a first rotary actuator which imparts rotational motion to the first structural element relative to the second structural element about a first axis; and a second rotary actuator which imparts rotational motion to the first structural element relative to the second structural element about a second axis. Each of the first and second rotary actuators is selected from the group consisting of parallel eccentric actuators and rotary actuators.

Abstract: A rotary actuator (101) is provided which includes a crankshaft (103), first and second eccentric gears (121), first and second end plates (123), a first crosslink (117) which is disposed between the first eccentric gear and the first end plate, a second crosslink which is disposed between the second eccentric gear and the second end plate, a stator (113) disposed between the first and second eccentric gears, and a rotor (109). Preferably, the rotary actuator further includes first and second support plates (115) which are disposed concentrically about the crankshaft and which are attached to first and second surfaces of the stator, respectively. The foregoing configuration allows the stator to serve as a major structural element, which may enhance the stiffness and reduce the weight of the actuator, while simplifying many of its active components.

Abstract: A parallel eccentric electro-mechanical actuator provides motive power and includes an electric prime mover that drives the reducer's pinion gear. This pinion drives minimum three star gears with stationary shaft bearings. Each shaft contains an eccentric which are completely in parallel with each other. These eccentrics can be thought of as parallel/in-phase driven crankshafts. Each eccentric drives the parallel eccentric (PE) gear through a bearing. The PE gear exhibits a circular motion (without rotation) which in itself is unbalanced. The crankshafts have another eccentric which create an opposite inertia force to balance that of the PE gear. The PE gear contains an external toothed gear on its periphery. It meshes with the internal teeth of the output ring gear. The relative motion between the PE gear and the ring gear is that the PE gear rolls inside the ring gear. This relative motion is called hypo-cycloidal motion.

Abstract: A multi-speed hub drive wheel is provided which includes a wheel equipped with a hub; a star compound gear train having first and second stages; a motor disposed in the hub which drives the wheel by way of the star compound gear train; and a clutch which switches the hub drive wheel between a first mode of operation in which the motor engages the first stage of the star compound gear train, and a second mode of operation in which the motor engages the second stage of the star compound gear train.

Abstract: A rotary actuator is provided which includes a prime mover including a rotor and a stator; a front-end star compound gear equipped with a first pinion, a first plurality of star gears arrayed concentrically around said first pinion, a first clutch, a first clutch shift motor, an output shaft, and first, second and third gears, wherein said third gear is attached to said output shaft; a back-end star compound gear; and a wheel interface including a principal bearing and a brake disk. The first pinion drives said the clutch. The first clutch shift motor shifts the first clutch between a first position in which the first clutch engages the first gear, and a second position in which the first clutch engages the second gear. When the first clutch engages the first gear, the first gear drives the first plurality of star gears. When the first clutch engages the first gear, the first plurality of star gears drive the third gear, or the first clutch engages the third gear to drive the output shaft directly.

Abstract: A rotary actuator (101) is provided which includes first and second opposing endplates (107); a stator (105) having a first end which is attached to said first endplate, and a second end which is attached to said second endplate; a rotor (103) having first and second eccentrics (125) on a surface thereof; an output attachment ring gear (135) disposed about the periphery of said first and second opposing endplates; a first parallel eccentric gear (131) which is disposed between said first eccentric and said output gear and which meshes with said output gear; a second parallel eccentric gear which is disposed between said second eccentric and said output gear and which meshes with said output gear; a first crosslink (113) which engages said first endplate and said first eccentric gear by way of a first set of surface features (143, 153); and a second crosslink which meshes with said second endplate and said second eccentric gear by way of a second set of surface features.

Abstract: A rotary actuator is provided which includes an internal gear, first and second parallel eccentric gears which mesh with said internal gear, a crankshaft equipped with first and second eccentrics which are 180° out-of-phase and which drive said first and second parallel eccentric gears, respectively, a prime mover which drives said crankshaft, first and second crosslinks which prevent the rotation of said first and second parallel eccentric gears, respectively, and first and second sets of splines which engage said first and second parallel eccentric gears, respectively.

Abstract: A rotary actuator is provided which includes a crankshaft, a first eccentric gear disposed on a first end of the crankshaft, a second eccentric gear disposed on a second end of the crankshaft, first and second end plates, a first crosslink disposed between the first eccentric gear and the first end plate, and a second crosslink disposed between the second eccentric gear and the second end plate. The first crosslink has a first set of surface features on a surface thereof which engage a second set of surface features on the first eccentric gear, and at least one of the first and second eccentric gears is equipped with circular arc gear teeth.

Abstract: An engine and gear train combination is provided which includes an engine which drives a first crankshaft having a first gear disposed thereon; a second crankshaft having a second gear and a flywheel disposed thereon, wherein the second gear meshes with the first gear; and a pulse compensator having a central element which is pivotally connected on a first end thereof to a first set of lateral members and which is pivotally connected on a second end thereof to a second set of lateral elements. Each element of the first set of lateral elements is also pivotally connected to the second crankshaft, and each element of the second set of lateral elements is pivotally connected to a mount.

Abstract: A multi-speed hub drive wheel (MDW) is provided. The MDW includes first and second gears; a clutch shaft having a clutch collar disposed thereon, wherein the clutch shaft drives the clutch collar between a first position in which the clutch collar engages the first gear, a second position in which the clutch collar engages the second gear, and a third position in which the clutch collar maintains the MDW in neutral; a drive shaft having a first spline disposed thereon; a clutch disk equipped with a yoke, wherein the yoke and the clutch disk slidingly engage the first spline; and a clutch motor which drives the clutch shaft.

Abstract: An orthotic or prosthetic actuator is provided which includes a parallel eccentric gear train which terminates on a first end in a first plate, and which terminates on a second end in a second, rotatable plate which is adjacent to the first plate. The actuator further includes a spring which is disposed between these adjacent plates. The actuator preferably utilizes Oldham coupling, by way of a pair of crosslinks disposed on each side of the motor, to restrain rotation of the dual parallel eccentric gears in the actuator, while permitting their linear oscillation. The crosslinks are preferably equipped with a tongue/spline lubrication system to provide continuous lubrication to the mated and loaded crosslink tongue and groove surfaces.

Abstract: A hybrid vehicle (101) is provided which includes an internal combustion engine (109), an electric power source (115) and a plurality of multi-speed hub drive wheels (MDWs) (103, 105). Each MDW is transformable between a first state in which the MDWs are driven by the internal combustion engine, and a second state in which the MDW is driven by the electrical power source.

Abstract: A rotary actuator (101) is provided which includes a crankshaft (103), first and second eccentric gears (121), first and second end plates (123), a first crosslink (117) which is disposed between the first eccentric gear and the first end plate, a second crosslink which is disposed between the second eccentric gear and the second end plate, a stator (113) disposed between the first and second eccentric gears, and a rotor (109). Preferably, the rotary actuator further includes first and second support plates (115) which are disposed concentrically about the crankshaft and which are attached to first and second surfaces of the stator, respectively. The foregoing configuration allows the stator to serve as a major structural element, which may enhance the stiffness and reduce the weight of the actuator, while simplifying many of its active components.

Abstract: A rotary actuator is provided which includes a crankshaft, a first eccentric gear disposed on a first end of the crankshaft, a second eccentric gear disposed on a second end of the crankshaft, first and second end plates, a first crosslink disposed between the first eccentric gear and the first end plate, and a second crosslink disposed between the second eccentric gear and the second end plate. The first crosslink has a first set of surface features on a surface thereof which engage a second set of surface features on the first eccentric gear, and at least one of the first and second eccentric gears is equipped with circular arc gear teeth.

Abstract: A rotary actuator is provided which includes a first interface surface with a plurality of apertures defined therein; a plurality of interface modules, wherein each interface module includes a first portion which releasably engages one of said apertures, and a second portion which protrudes from said first interface surface; a second interface surface which releasably mates with said first interface surface; and a gear train which rotates said first interface surface about an axis.

Abstract: A method is provided for making a multi-speed hub drive wheel (MDW) for a vehicle. The method includes providing a set of standardized gear train modules which includes a first gear train module having a 2-speed star/epicyclic front end, a second gear train module having a 2-speed star compound back end, and a third gear train module having a single-plane star compound final stage reducer. A vehicle is selected having a set of gear train performance criteria associated therewith, and a module from the set of standardized gear train modules is incorporated into an MDW for the vehicle which meets the gear train performance criteria.

Abstract: A multi-speed hub drive wheel (MDW) is provided. The MDW includes first and second gears; a clutch shaft having a clutch collar disposed thereon, wherein the clutch shaft drives the clutch collar between a first position in which the clutch collar engages the first gear, a second position in which the clutch collar engages the second gear, and a third position in which the clutch collar maintains the MDW in neutral; a drive shaft having a first spline disposed thereon; a clutch disk equipped with a yoke, wherein the yoke and the clutch disk slidingly engage the first spline; and a clutch motor which drives the clutch shaft.

Abstract: A multi-speed hub drive wheel is provided which includes a wheel equipped with a hub; a star compound gear train having first and second stages; a motor disposed in the hub which drives the wheel by way of the star compound gear train; and a clutch which switches the hub drive wheel between a first mode of operation in which the motor engages the first stage of the star compound gear train, and a second mode of operation in which the motor engages the second stage of the star compound gear train.