An apparatus for vibration reduction in a linear actuator includes one or more sets of counterweights, one or more enclosures configured to receive one set of counterweights for each enclosure, and a driving shaft configured to mount the one or more sets of counterweights. The one or more sets of counterweights are disposed symmetrically with respect to a plane that extends perpendicularly and longitudinally through a longitudinal axis of the linear actuator. The driving shaft extends perpendicularly and transversely through the longitudinal axis and the plane. A portion counterweight of a given set of counterweights may rotate clockwise and another portion counterweight of the given set of counterweights may rotate counterclockwise.

Provided is a balancer device for an internal combustion engine capable of effectively decreasing gear rattle between gears of a drive mechanism. A balancer drive gear and a balancer driven gear are arranged on a second end side of a drive-side balancer shaft and a second end side of a driven-side balancer shaft, respectively, and an oil pump is arranged on a first end side of the driven-side balancer shaft via the drive mechanism.

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.

A vibration suppression unit for an aircraft comprising a vibration control frame adapted to be mounted to the aircraft and to rotate about a central axis, a first motor configured to rotate the vibration control frame about the central axis, a second motor configured to rotate a first and second center of mass about a first and second axis or rotation, a third motor configured to adjust a variable distance between the first and second centers of mass and the first and second axis of rotation, respectively, and a controller for receiving input signals and outputting command signals to the first, second and third motors.

A vibration attenuator for an aircraft has first and second coaxial spinners configured for rotation about a mast axis and relative to a rotor. Upper and lower weights of each spinner are spaced radially from the axis and positioned 180 degrees from each other about the axis. The weights of each spinner are spaced from each other a distance parallel to the mast axis, each weight rotating about the mast axis in a different plane. The spinners rotate together relative to the rotor at a selected angular rate and are selectively rotatable relative to each other between a minimum-moment configuration, in which the upper weight of each spinner is angularly aligned with the lower weight of the other spinner, and a maximum-moment configuration, in which the upper weights are angularly aligned and the lower weights are angularly aligned, producing a whirling moment about the mast axis as the spinners rotate.

An oscillatory driving device for a hand-held power tool includes at least one input shaft, at least one output shaft, and at least one gearing unit. The gearing unit operatively connects the input shaft to the output shaft and includes at least one eccentric element configured to drive the output shaft in an oscillatory manner. The gearing unit includes at least one further eccentric element configured to drive the output shaft in an oscillatory manner.

An oscillatory driving device for a hand-held power tool includes at least one input shaft, at least one output shaft, and at least one gearing unit. The gearing unit operatively connects the input shaft to the output shaft and includes at least one eccentric element configured to drive the output shaft in an oscillatory manner. The gearing unit includes at least one further eccentric element configured to drive the output shaft in an oscillatory manner.

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.

Provided is a dynamic force generator having a supporting shaft, a first rotor including an internal bore housing the supporting shaft and bearings arranged between the supporting shaft and the internal bore so that the first rotor is mounted rotatably in relation to the supporting shaft, an external bore having an inner face provided with a first set of permanent magnets. A first unbalanced mass is within the internal bore of the first rotor and mounted opposite an outer face of the external bore of the first rotor. A second rotor is mounted rotatably in relation to the first rotor, via an antifriction component provided between the first rotor and the second rotor, and includes an internal bore housing the internal bore of the first rotor so that the internal bores of the first and second rotors are concentric, and an external bore with a second set of permanent magnets.

A motor control device of a vehicle including an engine and a motor generator, a transmission transmitting an engine torque and/or a motor torque to a wheel, and a damper reducing vibration of a crankshaft of the engine includes: a damper torque calculation unit calculating a damper torque generated by the damper according to fluctuation in engine torque based on a difference between a crank angle and a motor angle; a reverse-phase torque calculation unit calculating a reverse-phase torque with a reverse phase to the damper torque; a correction amount calculation unit calculating a first value calculated at least based on the crank angle and the motor angle; and a motor torque command output unit outputting a motor torque command given to the motor generator based on the reverse-phase torque corrected by the correction amount.