An added inertia resonant system (12) for a power toothbrush (10) comprises a drive shaft (16), a drive system (22), and at least one inertial weight member (24). The drive shaft (16) has a principal axis (26) that defines a center of rotation. The drive system (22) imparts a reciprocating motion to the drive shaft (16) about the principal axis (26). The at least one inertial weight member (24) couples to the drive shaft (16) and comprises a planar material having a complex shape balanced along an x-, y- and z-axis to enable the drive system (22) to achieve low power, high amplitude motion of the drive shaft (16) when placed under user loading. A method for providing added inertia in a resonant system for a power toothbrush is also disclosed.

An added inertia resonant system (12) for a power toothbrush (10) comprises a drive shaft (16), a drive system (22), and at least one inertial weight member (24). The drive shaft (16) has a principal axis (26) that defines a center of rotation. The drive system (22) imparts a reciprocating motion to the drive shaft (16) about the principal axis (26). The at least one inertial weight member (24) couples to the drive shaft (16) and comprises a planar material having a complex shape balanced along an x-, y- and z-axis to enable the drive system (22) to achieve low power, high amplitude motion of the drive shaft (16) when placed under user loading. A method for providing added inertia in a resonant system for a power toothbrush is also disclosed.

The invention relates to a flywheel for stabilising the position of a spacecraft, comprising a hub means (1) for fastening the flywheel, a flywheel ring (4), which externally surrounds the hub means (1) circumferentially at a distance, a support means (3) for supporting the flywheel ring (4) on the hub means (1), and a vibration damping device (6, 8) having a tuned mass damper means (8) which is axially movable back and forth relative to the flywheel ring with respect to a rotation axis of the flywheel.

The invention relates to a flywheel for stabilising the position of a spacecraft, comprising a hub means (1) for fastening the flywheel, a flywheel ring (4), which externally surrounds the hub means (1) circumferentially at a distance, a support means (3) for supporting the flywheel ring (4) on the hub means (1), and a vibration damping device (6, 8) having a tuned mass damper means (8) which is axially movable back and forth relative to the flywheel ring with respect to a rotation axis of the flywheel.

Disclosed is a device for lubrication of a unit turning under vacuum, such as a flywheel, where the unit includes an axle rotating relative to a fixed bearing structure, via at least one bearing or roller, and where the unit is placed in an enclosure connected to a vacuum, with: a lubricant reservoir connected by pipes both to the bottom of the enclosure and also to the bearing; and fluid suitable circulator for connecting the reservoir either to the vacuum, for filling the reservoir from the enclosure by gravity, or to the atmosphere for lubricating the bearing. The fluid circulator includes a three-way valve connecting the reservoir either to the vacuum or to the atmosphere.

Disclosed is a device for lubrication of a unit turning under vacuum, such as a flywheel, where the unit includes an axle rotating relative to a fixed bearing structure, via at least one bearing or roller, and where the unit is placed in an enclosure connected to a vacuum, with: a lubricant reservoir connected by pipes both to the bottom of the enclosure and also to the bearing; and fluid suitable circulator for connecting the reservoir either to the vacuum, for filling the reservoir from the enclosure by gravity, or to the atmosphere for lubricating the bearing. The fluid circulator includes a three-way valve connecting the reservoir either to the vacuum or to the atmosphere.

A system for providing dynamic force comprises a solar cell, an engine, a transmission module, two motors, two one-way fly wheels, and an electrical energy storage device. The solar cell is configured to drive the two motors. The transmission module comprises an input terminal and two output terminals. The input terminal of the transmission module is driven by the engine, and the output terminals of the transmission module are configured to drive the two motors respectively. The electrical energy storage device is configured to store electrical energy generated by the solar cell and drive the two motors. The two one-way fly wheels are driven by the two motors respectively.

A system for providing dynamic force comprises a solar cell, an engine, a transmission module, two motors, two one-way fly wheels, and an electrical energy storage device. The solar cell is configured to drive the two motors. The transmission module comprises an input terminal and two output terminals. The input terminal of the transmission module is driven by the engine, and the output terminals of the transmission module are configured to drive the two motors respectively. The electrical energy storage device is configured to store electrical energy generated by the solar cell and drive the two motors. The two one-way fly wheels are driven by the two motors respectively.

A power transmission device includes a flywheel and a torque limiter unit fixed to the flywheel. The flywheel includes an annular portion and an accommodation portion provided on an inner peripheral side of the annular portion to accommodate the torque limiter unit. The torque limiter unit includes a first plate, a second plate, a friction disc disposed between the first and second plates, and a pressing member. A torque is inputted to the first plate. The first plate includes first engaging portions. The second plate is axially opposed to and non-rotatable relative to the first plate. The second plate includes second engaging portions engaged with the first engaging portions. The pressing member presses the second plate onto the friction disc. The annular portion of the flywheel is provided with recesses on the inner peripheral surface thereof. The recesses are recessed radially outward in opposed positions to the second engaging portions.

A power transmission device includes a flywheel and a torque limiter unit fixed to the flywheel. The flywheel includes an annular portion and an accommodation portion provided on an inner peripheral side of the annular portion to accommodate the torque limiter unit. The torque limiter unit includes a first plate, a second plate, a friction disc disposed between the first and second plates, and a pressing member. A torque is inputted to the first plate. The first plate includes first engaging portions. The second plate is axially opposed to and non-rotatable relative to the first plate. The second plate includes second engaging portions engaged with the first engaging portions. The pressing member presses the second plate onto the friction disc. The annular portion of the flywheel is provided with recesses on the inner peripheral surface thereof. The recesses are recessed radially outward in opposed positions to the second engaging portions.