A swivel device with rotation damping, adapted to rotationally couple a hoist cable to a hoist hook, the device including: a first disc fixedly mounted on a central axle and adapted to be operationally coupled to a distal end of the cable by a non-rotating coupling; a second disc rotationally mounted on said central axle and spaced apart from said first disc, said second disc adapted to be operationally coupled to the hoist hook by a non-rotating coupling; a first set of magnets mounted on said first disc; and a second set of magnets mounted on said second disc, magnetic fields of said first set of magnets interacting with magnetic fields of said second set of magnets to damp rotation of said second disc about said central axle.

A swivel device with rotation damping, adapted to rotationally couple a hoist cable to a hoist hook, the device including: a first disc fixedly mounted on a central axle and adapted to be operationally coupled to a distal end of the cable by a non-rotating coupling; a second disc rotationally mounted on said central axle and spaced apart from said first disc, said second disc adapted to be operationally coupled to the hoist hook by a non-rotating coupling; a first set of magnets mounted on said first disc; and a second set of magnets mounted on said second disc, magnetic fields of said first set of magnets interacting with magnetic fields of said second set of magnets to damp rotation of said second disc about said central axle.

A rolling vibration reduction device for an internal combustion engine includes: a main inertial system configured to rotate with a crankshaft of the internal combustion engine; a driving force transmission mechanism configured to transmit a rotational driving force of the crankshaft, a direction of the rotational driving force being reversed by the driving force transmission mechanism; and a sub-inertial system configured to rotate by the rotational driving force transmitted from the driving force transmission mechanism and to reduce rolling vibration of the internal combustion engine associated with rotation of the crankshaft by rotating in an opposite direction to the crankshaft. A torsional resonance frequency in the rolling vibration reduction device is set to a value higher than an explosion primary frequency at a maximum engine speed in a preset operating region of the internal combustion engine.

A highly-efficient new-energy vibration controller integrating passive, semi-active and active control, including a multi-cavity beam, a battery assembly, a wound magnetic device, a damping piezoelectric device and an inertia mass assembly. The wound magnetic device includes a connecting rod, an electromagnetic wire wound on a bottom end of the connecting rod and a magnetic box arranged at a bottom of the inertia mass assembly. A top end of the connecting rod is fixedly connected to a bottom of the multi-cavity beam. The bottom end of the connecting rod passes through a center through hole of the inertia mass assembly and arranged in the magnetic box. The magnetic box is provided with a magnetic field. The damping piezoelectric device is sleevedly arranged on an outer wall of the connecting rod. The damping piezoelectric device and the wound magnetic device are both electrically connected to the battery assembly.

A bolt catcher and extractor for use with a separation nut and an attaching preloaded bolt that secure a payload to a launch vehicle or spacecraft. The bolt catcher extracts the attaching bolt from the separation nut, pulls it clear of the interface between the launch vehicle or spacecraft and the released payload, and captures it within the bolt catcher housing. The released bolt may have kinetic energy due to the strain energy stored by the pre-release bolt preload. The bolt catcher may have a magnetic eddy current damper that controls the bolt velocity during bolt extraction and dissipates the bolt kinetic energy as heat. The bolt may be magnetically non-impact captured within the bolt catcher. Bolt momentum at the end of the bolt extraction is less than 2% of that of bolt catchers of the prior art. Shock to the released payload or deployable equipment is near zero.

Described and shown are passive variable stiffness devices, which are of compact design and configured to produce a restoring force that varies optimally with the isolator displacement when subjected to vibration-inducing loading.

An electric motor control device includes a feedforward controller, a feedback controller, and an adder-subtractor. The feedforward controller receives a position command signal to specify a target position of a control target load and outputs signals representing a target position, target speed and torque of the electric motor. The feedback controller outputs a feedback torque command signal representing a torque command to perform feedback control in such a manner that an electric motor position signal and a feedforward position command signal coincide with each other. The adder-subtractor subtracts a load acceleration feedback torque signal obtained by multiplying a load acceleration signal representing acceleration of the control target load by a load acceleration feedback gain from a torque command signal obtained by adding a feedforward torque command signal and the feedback torque command signal, and outputs a result of the subtraction as a torque command correction signal.

An electric motor control device includes a feedforward controller, a feedback controller, and an adder-subtractor. The feedforward controller receives a position command signal to specify a target position of a control target load and outputs signals representing a target position, target speed and torque of the electric motor. The feedback controller outputs a feedback torque command signal representing a torque command to perform feedback control in such a manner that an electric motor position signal and a feedforward position command signal coincide with each other. The adder-subtractor subtracts a load acceleration feedback torque signal obtained by multiplying a load acceleration signal representing acceleration of the control target load by a load acceleration feedback gain from a torque command signal obtained by adding a feedforward torque command signal and the feedback torque command signal, and outputs a result of the subtraction as a torque command correction signal.

A suspension device includes: a hydraulic damper including a rod provided with a valve for generating a hydraulic pressure when the rod is displaced between a first liquid chamber and a second liquid chamber; and an electric damper configured to electrically displace the rod by an actuator. The electric damper includes: an outer cylinder; an inner cylinder; a piston provided on the rod and configured to stroke in the inner cylinder; and a communication passage disposed inside the inner cylinder at a central portion where the piston strokes. The communication passage establishes communication between the first liquid chamber at one axial end side of the piston and the second liquid chamber at another axial end side of the piston.

A suspension device includes: a hydraulic damper including a rod provided with a valve for generating a hydraulic pressure when the rod is displaced between a first liquid chamber and a second liquid chamber; and an electric damper configured to electrically displace the rod by an actuator. The electric damper includes: an outer cylinder; an inner cylinder; a piston provided on the rod and configured to stroke in the inner cylinder; and a communication passage disposed inside the inner cylinder at a central portion where the piston strokes. The communication passage establishes communication between the first liquid chamber at one axial end side of the piston and the second liquid chamber at another axial end side of the piston.