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 force transmission device, in particular or power transmission between a drive engine and an output, comprising a damper assembly with at least two dampers, which can be connected in series, and a rotational speed adaptive absorber, wherein the rotational speed adaptive tuned mass damper is disposed between the dampers at least in one force flow direction through the force transmission device.

A variable inertia flywheel having revolute joint assemblies, a roller guide, a first actuator and a second actuator. The revolute joint assemblies are in engagement with a primary mover and include a first member, a second member and a roller. The roller guide is disposed about the revolute joint assemblies. An inner surface of the roller guide is in contact with the rollers and defines cam profiles that cause the rollers to extend and contract, creating a torque disturbance opposed to a primary mover torque ripple. The first actuator is in engagement with the roller guide and moves the roller guide, changing the amplitude and/or the phase angle of the torque ripple. The second actuator is in engagement with the roller guide and rotates the roller guide, changing the phase angle of the torque ripple.

A vehicle vibration reducing apparatus includes: an inertial mass body; a first engagement device that is switched between a state where a running power source engages with a damper of a power transmission device so as to enable power transmission and a state where the engagement is released; a second engagement device that is switched between a state where the power transmission device engages with the inertial mass body so as to enable power transmission in a power transmission pass different from that of the first engagement device and a state where the engagement is released; and a third engagement device that is switched between a state where the running power source engages with the inertial mass body so as to enable power transmission in a power transmission path different from those of the first engagement device and the second engagement device and a state where the engagement is released.

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 torque fluctuation inhibiting device includes a mass body, first and second centrifugal elements, and first and second cam mechanisms. The mass body is rotatable with a rotor and is also rotatable relatively to the rotor. Each of the first and second centrifugal elements receives a centrifugal force to be generated by rotation of the rotor and the mass body. When a relative displacement is produced between the rotor and the mass body in a rotational direction, the first cam mechanism converts the centrifugal force that acts on the first centrifugal element into a first circumferential force directed to reduce the relative displacement. When the relative displacement is produced between the rotor and the mass body in the rotational direction, the second cam mechanism converts the centrifugal force that acts on the second centrifugal element into a second circumferential force directed to reduce the relative displacement.

A torque fluctuation inhibiting device includes a mass body, a centrifugal element and a cam mechanism. The mass body is disposed to be rotatable with a rotor and be rotatable relatively to the rotor. The centrifugal element is disposed to receive a centrifugal force to be generated by rotation of the rotor and the mass body. When a relative displacement is produced between the rotor and the mass body in a rotational direction, the cam mechanism converts the centrifugal force that acts on the centrifugal element into a circumferential force directed to reduce the relative displacement. Additionally, when the torque fluctuations inputted to the rotor have a predetermined magnitude or greater, the cam mechanism makes the mass body freely rotate with respect to the rotor.

A torque fluctuation inhibiting device inhibits torque fluctuations in a rotor to which a torque is inputted. The torque fluctuation inhibiting device includes a mass body, a centrifugal element and a cam mechanism. The mass body is disposed to be rotatable with a rotor and be rotatable relatively to the rotor. The centrifugal element is disposed to receive a centrifugal force to be generated by rotation of the rotor and the mass body. The cam mechanism converts the centrifugal force acting on the centrifugal element into a circumferential force when a relative displacement is produced between the rotor and the mass body in a rotational direction. The circumferential force is directed to reduce the relative displacement.

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 motor-driven centrifugal pump for circulating a coolant in a primary circuit of a nuclear reactor comprises a sealed motor unit, a hydraulic part and a shaft which is immersed in the coolant, turned by the sealed motor unit and pumping the coolant by an impeller of the hydraulic part secured to the shaft. The motor unit comprises a dry stator and an immersed rotor, mounted securely on the shaft. The motor-driven pump also comprises an immersed flywheel mounted securely on the shaft between the rotor of the motor unit and the impeller of the hydraulic part, allowing a minimum slowing-down time after the electrical power supply is cut; and an immersed anti-backspin device, configured to mechanically block the rotation of the shaft in a predetermined direction.