2410 results about "Torsional vibration" patented technology

An ultrasonic calculus treatment apparatus includes a longitudinal-vibration piezoelectric oscillator for vibrating in the axial direction of an ultrasonic transmitting member and a torsional-vibration piezoelectric oscillator for vibrating about the axial direction, and further includes driving circuits for driving the piezoelectric oscillators at respective resonance frequencies and a mode selection switch for permitting the oscillators to vibrate independently or in combination, so that lithotripsy can be performed effectively in accordance with the size of a calculus or a function of an operating tool.

To conduct a fluid, the transducer has a flow tube which in operation vibrated by an excitation assembly. Inlet-side and outlet-side vibrations of the flow tube are sensed by means of a sensor arrangement. To produce shear forces in the fluid, the flow tube is at least intermittently excited into torsional vibrations about a longitudinal flow-tube axis. An internal portion of the transducer, formed at least by the flow tube, an antivibrator, the sensor arrangement, and the excitation assembly and mounted at least on the inlet and outlet tube sections, has a centroid which is located inside the flow tube. The transducer is suitable for use in viscometers or Coriolis mass flowmeter-viscometers. In spite of using only a single straight flow tube, it is dynamically well balanced in operation, and the development of bending moments by the torsionally vibrating flow tube is largely prevented. This also effectively prevents the transducer case or the connected pipe from being excited into sympathetic vibration. Measurement signals representative of mass flow rate are readily distinguishable from measurement signals representative of viscosity, particularly if the sensors used for the viscosity measurement are also used for the mass flow measurement.

A torsional vibration damper having a hub carrying a radially projecting flange and an annular inertia mass defining an annular channel encompassing the radially projecting flange and an elastomeric member. An annular compression ring is attached to the opening of the annular channel to axially compress and extrude the elastomeric member to fill the annular channel around the radial flange within the inertia ring. Projections defining an intermittent annular inner rim of the inertia mass extend through openings between the spokes of the hub and cooperate with an annular outer rim of the inertia mass to retain the compression ring.

A hybrid vehicle drive for a motor vehicle includes an internal combustion engine and an electric machine which is selectively coupled with the internal combustion engine. The electric machine can be operated as a generator and as a motor. Regulation device which responds to a reference signal predetermined by a reference signal preset device are provided for the active damping of vibrations, especially torsional vibrations in the torque transmission path between the internal combustion engine and wheels of the motor vehicle driven by the latter. The regulation device also respond to sensing device which deliver an actual-value vibration signal containing vibration information about a rotating structural component of the motor vehicle and control the load torque exerted on the internal combustion engine by the electric machine for reducing or eliminating the vibrations of the structural component. An analysis device for determining a frequency spectrum of the actual-value vibration signal is associated with the regulation device. The reference signal preset device establishes a reference signal with predetermined frequency spectrum. The regulation device control the frequency spectrum of the load torque exerted on the internal combustion engine by the electric machine such that excessive spectral vibrations of the actual-value vibration signal are reduced or eliminated.

The present invention provides an apparatus and a method for an ultrasonic medical device operating in a torsional mode and a transverse mode. An ultrasonic probe of the ultrasonic medical device is placed in communication with a biological material. An ultrasonic energy source is activated to produce an electrical signal that drives a transducer to produce a torsional vibration of the ultrasonic probe. The torsional vibration produces a component of force in a transverse direction relative to a longitudinal axis of the ultrasonic probe, thereby exciting a transverse vibration along the longitudinal axis causing the ultrasonic probe to undergo both a torsional vibration and a transverse vibration. The torsional vibration and the transverse vibration cause cavitation in a medium surrounding the ultrasonic probe to ablate the biological material.

An integrated torsional mode damping method for a current source converter, including a rectifier, an inverter, and a DC link inductor coupled between the rectifier and the inverter, includes sensing a signal representative of torque on a shaft coupled to the inverter or rectifier; using the sensed signal for detecting a presence of a torsional vibration on the shaft; and damping the torsional vibration by modulating active power through the respective inverter or rectifier.

An apparatus and method for damping vibration, especially torsional vibration due to stick-slip, in a drill string, Sensors measure the instantaneous angular velocity of the drill string at one or more locations along the length of the drill string. One or more vibration damping modules are also spaced along the length of the drill string. When torsional vibration above a threshold is detected, the damping module imposes a reverse torque on the drill that dampens the torsional vibration. The reverse torque can be created by imparting a frictional resistance to the rotation of the drill string. The frictional resistance can be created externally, by extending friction pads from the damping module so that they contact the bore hole wall and drag along the bore hole as the drill string rotates, or internally by anchoring a housing mounted on the drill string to the wall of the bore hole and then imposing frictional resistance on a fluid, such as a magnetorheological fluid, flowing within the drill string.

A method and apparatus for sensing and displaying the magnitude of torsional vibrations. A transducer provides a signal indicative of the torsional vibrations being experienced by a rotating member. The magnitude of the frequency components of the signal are determined and displayed to an operator who may take corrective action.

A method for manufacturing a micromechanical device, in particular a micromechanical vibrating-mirror device, having the following steps: making available a three-layer structure having a first layer, a second layer and a third layer, the second layer lying between the first and the third layers; etching through the first layer up to the second layer to produce an island region, lying on the second layer, which is joined to region of the first layer surrounding the island region by way of one or more connecting webs, and etching through a region of the third layer up to the second layer and removing a region of the second layer below the island region in such a way that the island region can perform movements, preferably torsional vibrations, about the one or more connecting webs, the torsional vibrations having such an amplitude that a part of the island region extends into the etched-through region of the third layer.

A multi-clutch arrangement, especially a dual clutch for motor vehicles, comprising a first clutch area with a first pressure plate arrangement, with a first opposing support arrangement, and with a first clutch disk arrangement , which can be clamped between the first pressure plate arrangement and the first opposing support arrangement to transmit torque via the first clutch area; and a second clutch area with a second pressure plate arrangement, with a second opposing support arrangement, and with a second clutch disk arrangement, which can be clamped between the second pressure plate arrangement and the second opposing support arrangement to transmit torque via the second clutch area. A torsional vibration damper arrangement is assigned to at least one of the clutch areas, and where-relative to an axis of rotation (A)-the torsional vibration damper arrangement is arranged at least partially in the axial area of the first clutch area and/or of the second clutch area.

The invention discloses a longitudinal torsion composite supersonic vibration machining device. The longitudinal torsion composite supersonic vibration machining device comprises a longitudinal supersonic vibration energy converter and an ultrasonic amplitude transformer arranged at the front end of the longitudinal supersonic vibration energy converter and integrally connected with the longitudinal supersonic vibration energy converter. The longitudinal supersonic vibration energy converter comprises a back cover plate, a piezoelectric ceramic piece, an electrode plate, a front cover plate, an insulating sleeve and a pre-tightening bolt for connecting the back cover plate, the piezoelectric ceramic piece, the electrode plate, the front cover plate and the insulating sleeve. The ultrasonic amplitude transformer comprises an amplitude transformer index section and an amplitude transformer cylindrical section, the amplitude transformer index section and the front cover plate are designed into a whole, the amplitude transformer cylindrical section is used for being connected with a machining tool, the surface of the amplitude transformer index section is provided with four same spiral grooves, part of longitudinal vibration generated by the longitudinal supersonic vibration energy converter can be converted into torsion vibration through the spiral grooves, and therefore the longitudinal torsion composite supersonic vibration can be generated one the end face of the amplitude transformer cylindrical section. The longitudinal torsion composite supersonic vibration machining device has the advantages of being simple in structure, large in torsion component, high in converting efficiency and the like.

In a parallel hybrid vehicle, a controlling section controls an engine and a motor/generator, a torque from the engine and the motor/generator being transmitted to driven wheels via a transmission and a drive shaft. The controlling section comprises: an engine torque calculating section that calculates an engine torque and a torsional vibration suppression torque calculating section that calculates a torsional vibration suppression torque to suppress a torsional vibration developed on the drive shaft according to the engine torque calculated by the engine torque calculating section, the torsional vibration suppression torque calculated by the torsional vibration suppression torque calculating section being outputted from the motor/generator.

An active balancer for dynamically balancing a rotating machine is provided. The active balancer has a balancer body which rotates with the rotating machine and at least one controllable position counter weight having a real-time adjustable position relative to the balancer body and the rotating machine inorder to produce an actively adjustable controllable counter weight balance force for dynamically balancing the rotating machine. The active balancer includes a spring with the balancer body mounted to the rotating machine through the spring wherein the balancer body mass resonates on the spring with a torsional vibration canceling frequency which cancels a torsional vibration of the rotating machine.

The present invention provides an apparatus and a method for an ultrasonic medical device operating in a torsional mode to treat a biological material. An ultrasonic probe of the ultrasonic medical device is placed in communication with the biological material. An ultrasonic energy source is activated to produce an electrical signal that drives a transducer to produce a torsional vibration of the ultrasonic probe. The torsional vibration produces a rotation and a counterrotation along the longitudinal axis of the ultrasonic probe that creates a plurality of torsional nodes and a plurality of torsional anti-nodes along a portion of the longitudinal axis of the ultrasonic probe resulting in cavitation along a portion of the longitudinal axis of the ultrasonic probe comprising a radially asymmetric cross section that ablates the biological material.

A composite flywheel has primary and secondary masses rotatable relative to each other against the resistance of a damper having arcuate coil springs and an abutment between neighboring end portions of such springs. The abutment can move in the circumferential direction of the masses and is preferably form-lockingly connected against loss to at least one of the springs. To this end, a portion of the abutment extends into the adjacent convolutions of the at least one spring and is engaged by such convolutions with a force which suffices to prevent unintentional separation of the at least one spring from the abutment in the axial direction of the at least one spring.

A torsional vibration damper of a hydrokinetic torque coupling device, comprises a driven plate rotatable about a rotation axis, an intermediate plate rotatably mounted about the driven plate coaxially with the rotation axis, a back plate rotatably mounted about the intermediate plate coaxially with the rotation axis, a plurality of circumferentially acting elastic members interposed between the driven plate and the intermediate plate, and a damper retainer plate non-moveably secured to the back plate coaxially with the rotation axis. The damper retainer plate is operatively connected to the elastic members. The driven plate, the intermediate plate and the back plate are aligned with each other along a radial axis perpendicular to said rotation axis.

The present invention provides a torsional energy control assembly and method for eliminating slip-stick and/or drill bit oscillations comprising axial and/or rotational oscillations. In one preferred embodiment, the assembly permits slippage between an upper portion of the drilling string and a lower portion of a drill string. The rotational control assembly may be installed at any desired position in the drill string. The rotational control assembly could also be utilized as a component of other drilling mechanisms such as a downhole drilling motor. The rotational control permits slippage while drilling for a selected time or selected rotational distance or other criteria to thereby release torsional energy in the drilling string which otherwise may produce damaging slip-stick torsional oscillations such as slip-stick. The rotational control assembly may, in one embodiment, comprise an on-off clutch whereby torque is either substantially completely transmitted or substantially not transmitted through the assembly for brief periods.

A torsional vibration damper mountable to a rotatable shaft. The torsional vibration damper is a composite structure including a body formed of a polymer, such as a glass-reinforced polyamide, that surrounds an insert formed of a structurally-rigid material, such as a metal. The insert includes one or more support flanges that extend radially outward into the polymer body. When the torsional vibration damper is removed from the rotatable shaft, axial forces applied to the damper are transferred by the support flanges to the insert such that the polymer body remains substantially stress-free. In addition to, or instead of, the support flanges, the insert may include torque-locking structure that locks the polymer annular body with the insert to prevent relative rotation therebetween.

A cushion sub for absorbing both axial and torsional vibration in a drill string and including an outer casing connectable at one end to a section of a drill string, and an inner piston reciprocally mounted in a cylinder within the casing, the piston having a shaft projecting from the other end of the casing connectable to another section of the drill string. The cylinder includes a first cushion device at opposite ends thereof for engagement by the piston to absorb axial vibrations. A spline type connection prevents relative rotation between the piston and the cylinder. The cylinder is mounted for arcuate turning in a chamber within the casing, but the cylinder has vanes which are interposed between vanes fixed to the casing, and elastomeric material between the vanes of the cylinder and the vanes of the casing absorbs torsional vibrations being transmitted between the cylinder and the casing. The elastomeric material is preferably formed in situ as an integral mass in the chamber of the casing by pouring the elastomeric material in a fluid state into the chamber.