Abstract: Methods and apparatus are provided for locking and releasing ends of a support strut coupled between a mounting platform and a load. In a preferred embodiment, the strut comprises a damping section coupled between the ends and having a gap therein when the strut is unlocked, a locking section coupled between the ends for closing the gap by applying stress to a portion of the damper section through a force transmitting member, and a releasing section coupled in parallel with part of the force transmitting member, the releasing section including a Shape Memory Alloy (SMA) and heater therefore. Heating the SMA relieves the stress and opens the gap. Release from the locked condition occurs gradually and without fracture or sudden shock and the heater can be actuated remotely. In a preferred embodiment, a worm drive turnbuckle arrangement is used to apply force to lock the strut.

Abstract: An apparatus for detecting and reducing excessive amplitude of oscillation of a free piston slidably mounted in a housing. The housing has a vibration absorber, including a mass mounted through a spring to the housing. The mass reciprocates relative to the housing along a path in a phase relationship to the piston. A sensor is mounted near the mass for detecting the amplitude of oscillation of the mass. A controller is connected to the sensor for reducing the amplitude of oscillation of the piston when the amplitude of oscillation of the mass reaches a predetermined maximum.

Abstract: A hydraulically damping mount contains a working chamber and a compensation chamber that are filled with a hydraulically damping liquid and are separated by an intermediate plate. The working chamber and the compensation chamber are interconnected by an overflow channel and a bypass channel that can be opened and closed by an actuator that can be electromagnetically actuated in the axial direction. Accordingly, the actuator is embodied as a sliding sleeve in the form of a hollow cylinder defining the bypass channel, and contains a radially protruding armature on its outer side. The armature is received in the compensation chamber. The armature co-operates with an electromagnetic coil received in the intermediate plate, and with a baffle plate for opening or closing the bypass channel. In this way, small regulating forces and a compact structure are produced.

Abstract: A damper main body of a dynamic damper comprises a long flat mounting plate portion, a rod-like central supporting metal member which is erected vertically in the center of a top face of the mounting plate portion, constituting a supporting member together with the mounting plate portion, cylindrical rubber bushings placed on the central supporting metal member in succession from its bottom side, a coil member, a magnet portion, a yoke and a cylindrical case mounted over the yoke. Grommets, which are cylindrical supporting portions made of rubber elastic bodies, are inserted into mounting holes in side plate portions of the mounting plate portion. The damper main body is fixed on a mating plate member through the compressed grommets such that it is floated over the mating plate member.

Abstract: The invention disclosed is a magnetorheological fluid device offering vibration isolation and broad modulation range damping in a high load carrying and compact form. A cylindrically shaped flexure structure has a bottom cap attached to one end and a top cap attached to the other end. A piston comprising a toroidal displacement body, a central shaft, and intermediate connecting plate, attaches to the top cap. A fluid chamber surrounding and generally conforming to the shape of the toroidal displacement body, is attached to the bottom cap. Two bellows attaching between the piston connecting plate and top and bottom portions of the fluid chamber complete an enclosed volume around the toroidal displacement body and allow frictionless motion of the toroidal displacement body relative to the fluid chamber.

Abstract: Magnetorheological devices, including damping devices, rotary devices, and haptic systems constructed with said devices are disclosed. The devices contain dry magnetically-responsive particles, or MR fluids containing the magnetically responsive particles. The magnetically soft particles characterized by a single process yield population of atomized particles having a cumulative 10%, 50% and 90% by volume, fraction within specified size, i.e., D10 of from 2 up to and including a D10 of 5 ?m, a D50 8 ?m up to and including a D50 of 15 ?m, a D90 of 25 ?m up to and including a D90 of 40 ?m, and characterized by a least squares regression of log normal particles size against cumulative volume % fraction of greater than or equal to 0.77.

Abstract: A hydraulic mount provides active control through the use of a rotary track assembly connecting a primary pumping chamber of the mount to a secondary fluid chamber. With low amplitude vibrations the fluid path remains open, providing low dynamic stiffness. For high amplitude vibrations, the fluid flow path is closed, providing a high level of dynamic stiffness. The rotary track assembly control is continuously variable offering a wide range of active control of hydraulic mount stiffness.

Abstract: According to the present invention, electrorheological fluid is deaerated after it is sealed in a closed device which is operated by the electrorheological fluid. Thus, it is possible to control the operation of the closed device in accordance with an electric field. Additionally, the control of viscosity is not affected by repetitive operations of the closed device, thereby obtaining a closed device having a smooth operation and good repeatability. The deaeration is achieved under a predetermined reduced pressure, for example, of not more than 100 torr. In addition thereto, a suitable heating process is carried out as required.

Abstract: A method and system for calculating a control function for a structural system (10) that can be used to determine an appropriate control force to apply to an active member (18) within a stationary member (12) on the structural system (10). An active member (18) and a stationary member (12) are defined as a two-mass system in which the active member (18) and the stationary member (12) move in opposite directions. The stationary member (12) is mounted to an isolation subsystem (14) that is composed of six isolators (28) at multiple degrees of freedom. The isolation subsystem (14) is softer than the stationary member (12), active member (18) and a spacecraft surface (16) due to a damping element (32) of the isolation subsystem (16). The isolation subsystem (16) is mounted to the spacecraft (16) and decouples the spacecraft (16) from the stationary member (12) and thus the active member (18). An accurate control force for the active member (18) can be determined based upon the above structure (10).

Abstract: A process is provided for operating a hydraulic bearing and a bearing is provided designed for carrying out the process. The process makes it possible to directly affect the complex transmission characteristic of a hydraulic bearing and to provide a bearing suitable for this. A defined force is directly introduced into the bearing in a contactless manner into the oscillatory system, namely, in the area of the overflow channel or the overflow channels. The direction vector of this force is superimposed in parallel as well as in phase or antiphase to the direction vector of the damping agent moving through the overflow channel or overflow channels. In the bearing at least one overflow channel accommodates a mass element, which is displaceable in the overflow channel by a force generated by means of a magnetic field and can thus be affected concerning its force which comes to act in addition to the restoring force of the buckling springs of the oscillatory system.

Abstract: An apparatus for detecting and reducing excessive amplitude of oscillation of a free piston slidably mounted in a housing. The housing has a vibration absorber, including a mass mounted through a spring to the housing. The mass reciprocates relative to the housing along a path in a phase relationship to the piston. A sensor is mounted near the mass for detecting the amplitude of oscillation of the mass.

Abstract: A powertrain mount comprises an orifice plate including two tracks, a control track and an isolation track. The control track is spirally formed within the orifice plate, which has an exit and entrance on either side of the plate. The control track provides damping to control damping from engine bounce; whereas, the isolation track controllably provides dynamic rate dip. The isolation track is formed between an alignment plate and rotatable track member, each having an exit and entrance, respectively. The rotatable track member and the alignment plate are sealingly engaged and affixed to a decoupler and an annular area disposed about the orifice plate of the powertrain mount. The exit of the alignment plate is adjacent the decoupler. The rotatable track member forms a cavity with the molded body of the powertrain mount, with the entrance exposed to fluid within the cavity for controlling and minimizing vibrations within the powertrain.

Abstract: A fluid filled engine mount including: a pressure-receiving chamber and an equilibrium chamber connected via a first orifice passage tuned to excite resonance of fluid flowing therethrough to engine shakes; a partition rubber plate partially defining a pressure receiving chamber and tuned to perform absorption of a fluid pressure fluctuation in the pressure-receiving chamber to booming noises; an oscillating chamber connected to the pressure receiving chamber via a second orifice passage tuned to excite resonance of the fluid flowing therethrough to idling vibrations; an oscillating rubber elastic plate having an expansion spring smaller than that of the partition rubber plate and defining the oscillating chamber; a working air chamber applied with air pressure fluctuation with a frequency corresponding to the idling vibration during idling, and to make the working air chamber atmospheric pressure during running.

Abstract: A hydraulic mount provides active control of dip rate performance through use of an orifice track connecting a primary pumping chamber of the mount to a secondary fluid chamber having a movable wall, and an actuator for regulating pressure applied to the movable wall for controlling movement of the movable wall. With little or no pressure applied to the movable wall, the mount provides significant isolation and very little damping in a predetermined and designed frequency range. As pressure is applied to the movable wall, the stiffness of the mount is increased significantly, to thereby provide substantial damping.

Abstract: The liquid-sealing type vibration isolating apparatus of the present invention includes a coupler attached to a vibrating body, a holder, an insulator for absorbing and isolating vibration from the vibrating body at a position between the coupler and the holder, and a vibration isolating mechanism directly following the insulator and including liquid chambers sealing an incompressible fluid. This vibration isolating mechanism has a main chamber sealing a liquid, having a part of wall thereof formed by the insulator, an auxiliary chamber communicating with the main chamber via an orifice, and an equilibrium chamber provided in a portion of the main chamber via a diaphragm and having a varying volume in the chamber. The vibration isolating apparatus further includes switching means for introducing a negative pressure and the atmospheric pressure continuously or in synchronization with vibration of the vibrating body, and control means for controlling this switching operation.

Abstract: A method for reducing vibration in an instrument panel structure is achieved by introducing one or more piezoelectric actuator and sensor assemblies between various structures contained within the instrument panel structure. The assembly has a sensor component that senses vibrations between the structures and an actuator component that is activated to produce a reverse sine pulse that dampens the vibrations. The assembly also has an electronic control module, located integrally or as a separate component, electrically to the sensor and actuator for precisely controlling the actuation of the actuator. In alternative embodiments, multiple assemblies may be coupled to a single electronic control module for achieving total system vibration control.

Abstract: A shock and vibration isolation system for mounting equipment to a base wall uses a semi-active damper in parallel with a spring arrangement to provide optimum isolation with respect to both shock and vibration. The system comprises a load plate configured for attachment of the equipment thereto and a base plate configured for attachment to the base wall. The base plate is substantially parallel to the load plate with a spring arrangement disposed intermediate the load plate and the base plate. The spring arrangement engages the load plate and the base plate to bias the load plate and the base plate in a separated relationship. The system also comprises a damping arrangement disposed intermediate the load plate and the base plate. The damping arrangement is adapted for providing a selectively variable reaction force to the load plate and the base plate responsive to a relative displacement of the load plate with respect to the base plate.

Abstract: A “passive-active” mount includes an emanator-securement plate, a foundation-securement plate, at least one elastomeric “streamlined resilient element,” and at least one collocated motion sensor-vibratory actuator pair. The mount brings to bear, sequentially and complementarily, passive vibration control followed by active vibration as control. The passive vibration control is effectuated by one or more “streamlined resilient elements,” each attributed with a “constant natural frequency” (CNF) property whereby such element is naturally predisposed to passively reducing vibration at a particular frequency band regardless of the extent of the loading, within certain limits, to which such element is being subjected.

Abstract: A control section outputs a reference signal which corresponding to a frequency and an amplitude of signals sent from a vibration generation source. The pulse width modulation section generates a drive control signal to, an electromagnetic valve, connection of an air chamber and is alternately switched between the side of an inlet port and the side of the atmosphere. The drive control signal corresponds to an amplitude of the reference signal and is composed of at least the same number of pulses corresponding to a duty ratio-changed frequency as that of each one period of the standard signal. The drive control signal is synchronized with the standard signal. The number of pulses of the drive control signal for each period of the reference signal is changed corresponding to a control frequency of the standard signal so that the number of pulses and the control frequency is not larger than a responding frequency of the electromagnetic valve.

Abstract: Disclosed is a pneumatically controlled vibration damper that includes: an elastic connector disposed between and secured to a mounting member and a mass member for elastically connecting the mass member to the mounting member, and partially defining a working air chamber closed from an external area; an air passage connected to the working air chamber for regulating an air pressure in the working air chamber from the external area; and a static pressure-regulating system operable for substantially statically regulating the air pressure in the working air chamber via the air passage, so as to induce a substantially static elastic deformation of the elastic connector for changing a spring characteristic of the elastic connector.

Abstract: There is provided a liquid filled type vibration isolator in which damping action for both engine idling vibration and engine shake is carried out with the use of a single orifice. In the liquid filled type vibration isolator comprising a rubber-like insulator for absorbing and isolating vibration transmitted from an oscillating body, a main chamber having a chamber wall formed by a part of the insulator, and hermetically charged therein with liquid, an auxiliary chamber connected to the main chamber through the intermediary of an orifice and having a chamber wall a part of which is formed by a first diaphragm, a partition member partitioning between the main chamber and the auxiliary chamber, a working chamber defined and formed with respect to the main chamber by means of a second diaphragm, wherein the second diaphragm has a deforming stiffness which is higher than that of the first diaphragm. The liquid in the orifice effects resonant oscillation with a vibration input during engine idling operation.

Abstract: A method for controlling the drive of an actuator of an active vibration isolation support system is provided in which one cycle of the actuator moving a movable member out and back is divided into a plurality of micro time regions, a voltage applied to the actuator is duty-controlled in each micro time region, and the duty ratio in at least the last micro time region is set to 0%. As a result, the current passing through the actuator can be made 0 in the final stage of the out and back movement cycle before the movable member moves back to the original position. This can minimize the current passing when the movable member moves back to its original position at the end of the cycle, thus suppressing the needless generation of heat in a coil of the actuator. Therefore, it is possible to prevent an increase in the electrical resistance of the coil which would otherwise hinder the achievement of a required value of current, and to prevent thermal damage to equipment surrounding the coil.

Abstract: To eliminate vibrations and noise in higher-order components of explosive vibrations of an engine in its idling revolution range, an insulator and a vibration-absorbing mechanism formed in line with the insulator are provided between an upper coupling member to be mounted on a vibratory body and a lower coupling member to be mounted on the car body. The vibration-absorbing mechanism comprises a main chamber sealed with liquid, a subsidiary chamber connected to the main chamber through a first orifice, an air chamber provided below the subsidiary chamber, a third liquid chamber connected to the main chamber through a second orifice, and a balance chamber partitioned and formed to the third liquid chamber through a second diaphragm. The balance chamber is provided with a changeover means introducing a negative pressure or atmospheric pressure and a control means controlling the actuation of the changeover means so as to synchronize it to vibration frequencies of higher-order components.

Abstract: The liquid-sealing type vibration isolating apparatus of the present invention includes a coupler attached to a vibrating body, a holder, an insulator for absorbing and isolating vibration from the vibrating body at a position between the coupler and the holder, and a vibration isolating mechanism directly following the insulator and including liquid chambers sealing an incompressible fluid. This vibration isolating mechanism has a main chamber sealing a liquid, having a part of wall thereof formed by the insulator, an auxiliary chamber communicating with the main chamber via an orifice, and an equilibrium chamber provided in a portion of the main chamber via a diaphragm and having a varying volume in the chamber. The vibration isolating apparatus further includes switching mechanism for introducing a negative pressure and the atmospheric pressure continuously or in synchronization with vibration of the vibrating body, and a control mechanism for controlling this switching operation.

Abstract: A vibration-damping device including: an elastic body connecting a first and a second mounting member: a pressure receiving and equilibrium chambers partially defined by the elastic body and a flexible diaphragm, filled with a non-compressible fluid and held in fluid communication through a first orifice passage and a second orifice passage that is tuned higher than the first orifice passage. A shut-off valve mechanism operable to selectively allow and inhibit fluid flows through the second orifice passage, an elastic oscillation plate partially defining the pressure-receiving chamber so that a fluid pressure in the pressure-receiving chamber acts on one surface of the elastic oscillation plate, and a working air chamber partially defined by the other surface of the elastic oscillation plate and oscillated by a periodic air pressure change in the working air chamber, are also incorporated. A method of controlling the same is also disclosed.

Abstract: The invention relates to a hydraulic bearing, especially for supporting motor vehicle assemblies, that includes a supporting connection, a buttress connection which lies axially opposite the supporting connection and a bearing spring element which is located between these two and which includes (i) an elastomer radial spring, (ii) an expanding spring which is configured as a separate molded elastomer part in the form of a bell-type rolling membrane and which forms part of a hydraulic damping system between the supporting connection and the buttress connection, and (iii) an axially upright steel helical spring. The hydraulic damping system includes a working chamber, a throttle channel and a compensation chamber. A bearing housing radially surrounds the bearing spring element and the hydraulic damping system and is supported by the buttress connection.

Abstract: A powertrain mount comprises an orifice plate and a track member. The orifice plate has an exit, a first surface sloping toward the exit, and an inner surface. The track member has an outer surface proximate the first surface of the orifice plate, and the outer surface of the track member has an entrance. A containment plate forms an orifice track with the first and inner surfaces of the orifice plate and with the outer surface of the track member.

Abstract: A damper main body 11 of a dynamic damper 10 comprises a long flat mounting plate portion 12, a rod-like central supporting metal member 15 which is erected vertically in the center of atop face of the mounting plate portion 12, constituting a supporting member together with the mounting plate portion 12, cylindrical rubber bushings 17 placed on the central supporting metal member in succession from its bottom side, a coil member 24, a magnet portion 28, a yoke 33 and a cylindrical case 38 mounted over the yoke 33. Grommets 41, which are cylindrical supporting portions made of rubber elastic bodies, are inserted into mounting holes 13c in side plate portions 12c of the mounting plate portion. The damper main body is fixed on a mating plate member 45 through the compressed grommets such that it is floated over the mating plate member.

Abstract: It is an object of the present invention to make a damping force variable in a damping device that uses a magnetic fluid. In a damping device using a magnetic fluid as an operating oil, the present invention includes a groove portion 34a as a leakage magnetic field generating portion that is provided in one appropriate place or more of a pair of flow path forming members forming a fluid flow path 22b and that generates a strong leakage magnetic field to the fluid flow path 22b. Accordingly, the use of only a permanent magnet enables the behavior of magnetic particles in the magnetic fluid to be changed according to a relative position of a casing 20 and a movable portion 30 and enables a damping force to be variable, without using an electromagnet.

Abstract: A pneumatically controlled vibration damper that includes: an elastic connector disposed between and secured to a mounting member and a mass member for elastically connecting the mass member to the mounting member, and partially defining a working air chamber closed from an external area; an air passage connected to the working air chamber for regulating an air pressure in the working air chamber from the external area; and a static pressure-regulating system operable for substantially statically regulating the air pressure in the working air chamber via the air passage, so as to induce a substantially static elastic deformation of the elastic connector for changing a spring characteristic of the elastic connector.

Abstract: A magnetic spring device with negative stiffness contains at least one first pole body combination composed of at least one first, at least one second and at least one third pole body, which each have opposite magnetic poles, with the pole bodies in the combination being aligned such that opposite poles are opposite one another and the first and the third pole bodies assume a defined distance from one another, in which the second pole body is arranged, with the pole bodies being arranged such that they can move relative to one another.

Abstract: The object of the present invention is to provide a vibration damping apparatus having 6 degrees of freedom using a magnetic circuit. Vibration transfer can be isolated by a vibration damping mechanism to set the spring constant utilizing a relative displacement of a movable magnet 37 to a stationary magnet 27 in an axial direction, and an elastic force of a metal spring 50 substantially to be zero. The displacement is quickly restored to an original position by a rubber 24a and the metal spring 50 composing a device to restore the displacement due to vibration not only in an axial direction (Z axis direction) but also in a horizontal direction (X or Y axis direction), in a rotational direction around each axis, or in a twisting direction which is an overlapping direction of these directions and is damped as a vibration in an axial direction. Accordingly, a vibration having 6 degrees of freedom can be controlled with a simple structure.

Abstract: A method for controlling the drive of an actuator of an active vibration isolation support system based on crank pulses detected by a crank pulse sensor, involves determination of a crank angular speed, a crank angular acceleration, an engine torque and an amplitude of the engine vibration from the detected crank pulses. When the amplitude is less than a predetermined value the actuator of the active vibration isolation support system is controlled based on the calculated amplitude and a preset phase. On the other hand, when the amplitude is equal to or greater than the predetermined value, an engine vibration phase is calculated from the phase at which the torque is a maximum, and the actuator of the active vibration isolation support system is controlled based on the calculated amplitude and the calculated phase. Thus controlled, the system exhibits an effective vibration isolation function in accordance with the vibration characteristics of individual engines.

Abstract: In a vibration isolator, stable liquid filling and assembling is obtained by reducing the effect of press-fitting a switching admission pipe. The vibration isolator including a partition having a partition main member and a partition plate member, a main liquid chamber, a first sub liquid chamber, a second sub liquid chamber and a switch chamber, orifices, and a switching admission pipe press-fit in a passage provided in the partition main member. A seal surface in contact with a seal rubber layer on an inner periphery of a cylindrical barrel is formed at around an opening end of a passage in an outer peripheral surface of the partition main member and a pressure-receiving surface broader than the other portion in the outer peripheral surface is provided on a side opposite to the seal surface sandwiching a device axis thereby effecting dispersal of external force during the press-fitting.

Abstract: A method for controlling drive of an actuator of an active vibration isolation support system allows the waveform of the lift of the actuator to be freely set, while avoiding the generation of heat in the actuator driver and a corresponding increase in the power consumption. Specifically, duty control of the voltage that is applied to the actuator is carried out in each of a large number of consecutive micro time regions such that the waveform of the lift of the actuator can be set freely, and by varying the number of consecutive micro time regions whose duty ratios change with a fixed pattern, the period over which the lift of the actuator changes can be set freely. Moreover, since electrical energy is not wasted as thermal energy in the actuator driver, the problems of heat being generated in the driver and increased power consumption can be avoided.

Abstract: A hydraulic mount for automotive engine and powertrain applications includes an elastomer body, a base and a partition interposed the body and the base to form a fluid-pumping chamber and a reservoir. Circumferentially spaced axial extending holes or slots or an annular orifice track are formed in the partition together with a magnetic coil operable to impose a magnetic field on the holes, slots or orifice track to control the shear properties of a magnetorheological (MR) fluid in the pumping chamber and reservoir. An elastomeric decoupler member is in communication with at least one of the pumping chamber and the reservoir to reduce the mount dynamic stiffness for isolating low-displacement relatively high-frequency vibrations. Vibrations of multiple frequencies may be isolated by tuning the mount with a controller.

Abstract: The invention relates to a damper device for damping vibration comprising a converter device for converting mechanical energy into electrical energy that is mounted on a baseplate for fixing to a structure for damping. Said converter device comprises an electrodynamic motor having a coil mechanically connected to the baseplate and a magnetic circuit suspended by at least one spring, the coil is coupled to an electrical load presenting a resistive component, and it presents a control device for causing the resistance of said resistive component to vary with at least two values.

Abstract: A magnetorheological fluid (32) having controlled-shaped particles (56,68), such as rod, prism, tetrahedral, and other regularly shaped particles. The regularly shaped particles (56, 68) increase the field yield and responsive to particle interaction forces. The magnetorheological material has particular use for space applications such as vibration isolators, vibration dampeners, and latch mechanisms.

Abstract: The hydraulic antivibration support comprises two strength members interconnected by an elastomer body defining part of a liquid-filled working chamber which communicates via a constricted passage with a compensation chamber that is separated from said working chamber by a rigid partition. The compensation chamber is defined by an annular bellows presenting an annular fold which projects into the compensation chamber and which is of a shape that does not present circular symmetry.

Abstract: A switchable liquid-filled vibration absorbing mount has a stopper device interposed between a first diaphragm and a bottom portion for regulating downward movement of pushing member when a vacuum is introduced into a switching chamber, so that a protrusion of a valve member does not come out of an inner orifice when a vacuum is applied to the switching chamber to move the first diaphragm to a first position opening the orifice.

Abstract: A spacecraft isolator including shape memory alloy components that are electronically heated to unlock the isolator. The isolator can be manually unlocked with an adjustment bolt.

Abstract: An adaptive isolator with a passive mount and an electromagnetic actuator is provided. The adaptive isolator is useful for vibrational mounts for equipment.

Abstract: A fluid-filled active vibration damping device comprising an elastic body elastically connecting a first and a second mounting member and partially defining a fluid chamber filled with a non-compressible fluid, an oscillating member partially defining the fluid chamber and being reciprocatory movable in order to control a pressure of the fluid in the fluid chamber. The above vibration damping device further includes an independently formed electromagnetic actuator for applying driving force to oscillate the oscillating member and having an oscillating sleeve member fixedly connected to the oscillating member, and a retainer adapted to support the electromagnetic actuator with respect to the second mounting member such that the retainer fixed to the second mounting member while housing the electromagnetic actuator, while a yoke member of the electromagnetic actuator is fixed to a bottom wall portion of the retainer so as to extend through the bottom wall portion.

Abstract: A damping actuator includes: an inner shaft member; an outer sleeve member disposed in a coaxial relationship with each other with a radial spacing therebetween such that the outer sleeve member being movable relative to the inner shaft member; a coil and an inner yoke disposed coaxially with and fixedly mounted to the inner shaft member so as to give inner magnetic pole portions; and a permanent magnet and an outer yoke fixedly mounted to the outer sleeve member so as to give outer magnetic pole portions. The outer magnetic pole portions are opposed to the inner magnetic poles in a radial direction perpendicular to an axial direction of the inner shaft member with a radial gap therebetween, and are offset from the plurality of inner magnetic poles in the axial direction. The coil is energized for generating magnetic axial driving force acting between said inner and outer magnetic poles so that the inner and outer magnetic poles are moved relative to each other in the axial direction.

Abstract: Disclosed is a fluid-filled active vibration damping device including: an elastic body; a primary fluid chamber partially defined by the elastic body; a movable member partially defining the primary fluid chamber on one side and a working air chamber on the other side; and a vacuum pump including an air intake port and an exhaust port, which are connectable to the working chamber via a valve mechanism. A fluid pressure variation in the primary fluid chamber can be actively controlled by transmitting an air pressure variation in the working air chamber to the primary fluid chamber via the movable member. A switching operation of the valve mechanism selectively applies a negative pressure generated in the air intake port and a positive pressure generated in the exhaust port to the working air chamber in order to generate the air pressure variation in the working air chamber.

Abstract: A vibration absorber for absorbing a vibration between first and second members each of which is connected to the vibration absorber, includes a movable member adapted to contact with a fluid, and including a portion connected mechanically to one of the first and second members so that a movement of the fluid and a movement of the portion of the movable member correspond to each other, and a fluid moving member for flowing the fluid in either of an extension direction in which the portion of the movable member moves to increase a distance between the first and second members and a contraction direction in which the portion of the movable member moves to decrease the distance between the first and second members in such a manner that the vibration is restrained by a change of the distance between the first and second members from being transmitted between the first and second member.

Abstract: A fluid-filled elastic engine mount including an elastic body elastically connecting two mutually spaced-apart first and second mounting members and partially defining a pressure-receiving chamber filled with a non-compressible fluid, a flexible diaphragm partially defining an equilibrium chamber whose volume is variable, a movable oscillating plate partially defining the pressure-receiving chamber, an oscillating device for oscillating the movable oscillating plate for controlling pressure of the fluid in the pressure-receiving chamber, a first and a second orifice passage for effecting fluid communication between the pressure-receiving and equilibrium chambers. The first and second orifice passages are tuned to a low frequency band corresponding to an engine shake vibration and a medium-frequency range corresponding to an engine idling vibration, while the first and second orifice passages are disposed parallel to each other.

Abstract: The liquid-sealing type vibration isolating apparatus of the present invention includes a coupler configured to be attached to a vibrating body, a holder, an insulator for absorbing and isolating vibration from the vibrating body at a position between the coupler and the holder, and a vibration isolating mechanism directly following the insulator and including liquid chambers sealing an incompressible fluid. This vibration isolating mechanism has a main chamber sealing a liquid, having a part of a wall thereof formed by the insulator, an auxiliary chamber communicating with the main chamber via an orifice, and an equilibrium chamber provided in a portion of the main chamber via a diaphragm and having a varying volume in the chamber. The vibration isolating apparatus further includes a switching mechanism for introducing a negative pressure and the atmospheric pressure continuously or in synchronization with vibration of the vibrating body, and a control mechanism for controlling this switching operation.

Abstract: Active hydraulic anti-vibration mount comprising two support elements connected by an elastomer body partially delimiting a working chamber filled with liquid, this working chamber communicating by a throttled passage with a compensation chamber separated from said working chamber by a rigid partition. The rigid partition is penetrated by a first regulating nozzle closed by a movable exciting device, and a second regulating nozzle closed by a valve the movements of which are limited to correspond to an amplitude of variation in the volume of the working chamber which is less than 20% of the amplitude of the variations in volume generated by the exciting device.

Abstract: A vibration absorber for absorbing a vibration between first and second members each of which is connected to the vibration absorber, includes a movable member adapted to contact with a fluid, and including a portion connected mechanically to one of the first and second members so that a movement of the fluid and a movement of the portion of the movable member correspond to each other, and a fluid moving member for flowing the fluid in either of an extension direction in which the portion of the movable member moves to increase a distance between the first and second members and a contraction direction in which the portion of the movable member moves to decrease the distance between the first and second members in such a manner that the vibration is restrained by a change of the distance between the first and second members from being transmitted between the first and second member.