A vibration control device of a plate-like member 11 includes: a piezoelectric element actuator 14 and a piezoelectric element sensor 15 fixed to a surface of a plate-like member 11; and a control circuit 17 that performs feedback control of operation of the piezoelectric element actuator 14 based on an output voltage of the piezoelectric element sensor 15 so as to suppress vibration of the plate-like member 11. The control circuit 17 applies any voltage in a range where a vibration frequency of the plate-like member 11 is equal to or less than a predetermined value based on characteristics of an output voltage of the piezoelectric element sensor 15 so as not to generate noise in a range of 100 Hz or less. Therefore, by increasing a feedback gain, vibration can be suppressed, and noise generated by the vibration can be reduced.

A torque impact mitigator including a housing assembly having a hydraulic cylinder. A piston is disposed within the hydraulic cylinder. A piston rod is mounted at a first end to the piston and having a second end extending out from the compression end. A compression spring is disposed between the piston and an end of the hydraulic cylinder. A rod clevis is secured to the second end of the piston rod. A plug is disposed within an upper end of the compression spring and having a bore extending therethrough to receive the piston rod. One or more bores are disposed through the piston to allow passage of hydraulic fluid into the hydraulic cylinder. A damper tube connecting the compression end and the rebound end of the hydraulic cylinder to direct the hydraulic fluid therethrough to further control the speed of the piston.

To provide a gas-driven type valve device that is capable of mounting various electronic devices, and includes a power generation function that solves problems involving wiring or battery replacement. The problem is solved by a valve device including an actuator including a housing part, and a movable part housed in the housing part and driven by a driving fluid to move a valve element in a closing direction or an opening direction, a spring member that presses the movable part in a direction against a driving force of the driving fluid, and a power-generating and vibration-damping unit including that uses a piezoelectric effect of a piezoelectric element to exercise a power generation function of converting a vibration generated in a vibration system by an activation of the actuator into electric power, and a vibration-damping function of suppressing a vibration applied to a device.

The vibration control system configured to control vibration of a vibration-controlled object is disclosed. The vibration control system comprises: (i) actuator units each including a piezoelectric element configured to expand and contract; (ii) a drive power source configured to supply drive voltages to the piezoelectric elements of the actuator units for causing the piezoelectric elements to expand and contract; (iii) a vibration detector configured to detect a status of vibration of the vibration-controlled object; and (iv) a vibration controller configured to control the vibration of the vibration-controlled object by controlling the voltages supplied by the drive power source to the piezoelectric elements of the actuator units based on the status of vibration detected by the vibration detector, respectively.

A microelectromechanical membrane transducer includes: a supporting structure; a cavity formed in the supporting structure; a membrane coupled to the supporting structure so as to cover the cavity on one side; a cantilever damper, which is fixed to the supporting structure around the perimeter of the membrane and extends towards the inside of the membrane at a distance from the membrane; and a damper piezoelectric actuator set on the cantilever damper and configured so as to bend the cantilever damper towards the membrane in response to an electrical actuation signal.

A compliant structure including a frame and a shuttle distant from the frame mounted on a cantilever that is supported by the frame. The cantilever and shuttle together are movable transversely to and out of a plane of the frame. The structure also includes one or more flexures that connect the cantilever with the frame. The cantilever includes a body at least in part extending in a first direction which points to the shuttle. The one or more flexures connect to the shuttle and/or to the cantilever in the vicinity of the shuttle. The flexures are oriented in a second direction, which second direction is generally transverse with respect to the first direction.

A system for passive damping of mechanical vibrations generated by a vibrating structure supported by a support, including a transducer interposed between the vibrating structure and the support to transform mechanical energy of vibrations into electrical energy. The transducer includes a flextensional structure having a first axis perpendicular to a second axis, a stack of piezoelectric elements adapted to produce electrical energy when stressed, the stack stressed in compression by the flextensional structure along the first axis so that deformation of the structure modifies the compressive stress applied to the stack, two peripheral fasteners are secured to the flextensional structure, each fastener disposed along the second axis, a first fastener for securing the flextensional structure to the vibrating structure, a second fastener for securing the flextensional structure to the support, at least one fastener integrates an elastic suspension, a shunt connected to the piezoelectric stack to dissipate electrical energy.

An apparatus for attenuating vibration transmission between first and second structures includes a rod extending entirely through, and being mechanically connected to, both of the first and second structures. The rod defines a central longitudinal axis. A piezoelectric sensor senses vibrations in at least one of the first and second structures and responsively generates a voltage. The piezoelectric sensor is disposed entirely longitudinally between the first and second structures. A piezoelectric actuator actively attenuates the vibrations sensed by the piezoelectric sensor. The piezoelectric actuator is at least partially driven responsive to voltage generated by the piezoelectric sensor. The piezoelectric actuator is disposed entirely longitudinally between the first and second structures. At least one of the piezoelectric sensor and the piezoelectric actuator has a throughhole through which the rod entirely extends.

The invention relates to a lifting system, comprising a piezoelectric actuator (5), a support (15), and a hydraulic stroke multiplier (10) having an input and an output side, wherein the input side of the hydraulic stroke multiplier is connected to the piezoelectric actuator (5), and the output side of the hydraulic stroke multiplier is connected to the support (15). In the method for electrically testing an electronic component, the component is placed on the support of such a lifting system and is lifted for positioning relative to a test contact. The vibration damper comprises such a lifting system. The machine assembly has a machine and such a vibration damper.

The vibration control system configured to control vibration of a vibration-controlled object is disclosed. The vibration control system comprises: (i) actuator units each including a piezoelectric element configured to expand and contract; (ii) a drive power source configured to supply drive voltages to the piezoelectric elements of the actuator units for causing the piezoelectric elements to expand and contract; (iii) a vibration detector configured to detect a status of vibration of the vibration-controlled object; and (iv) a vibration controller configured to control the vibration of the vibration-controlled object by controlling the voltages supplied by the drive power source to the piezoelectric elements of the actuator units based on the status of vibration detected by the vibration detector, respectively.