259results about How to "Reduce damping force" patented technology

A micromechanical resonator device and a method of making the micromechanical resonator device, as well as other extensional mode devices are provided wherein anchor losses are minimized by anchoring at one or more side nodal points of the resonator device. Lower damping forces are experienced by the resonator device when operated in air.

The invention involving a magnetorheological fluid damping device for automobile suspension system.The magnetic field generator of this damping device consists of permanent magnet and electromagnetic coil.On the top of the damping device,there are guide apparatus and damping regulator,the function of which is that to ensure the damping channel is uniform annular duct and to meet the high-damp requirement in the restoration process and low-damp requirement in the compression process of damper seperately.The current in the electromagnetic coil designs of bi-directional and this controls the magnetic field intersity of the damping channel,decreases the excitation current of the electromagnetic coil,reduces energy consumption and decreases damper fever.On the non-controlling conditions,this damping device has the equivalent characteristics of the traditional shock absorber and can instead the passive shock absorber,after equiping corresponding current controller,this device can regulate the damping characteristics of suspension system,which improves the automobile driving safety and ride comfort.

A vibration damper includes a cylinder in which a piston rod is guided so as to be axially movable. A first piston is mounted stationary on the piston rod and a second piston is mounted so as to be displaceable axially on the rod against a spring force. The cylinder has a work space at the piston rod side, a work space remote of the piston rod, and a work space between the two pistons. Through-openings which are outfitted with valves control a connection between the work spaces. The second piston has at least one return spring on both sides, and the piston is mounted so as to be displaceable axially in two directions against the return springs.

A shock absorbing device includes a cylinder. A partition wall member is inserted into the cylinder to be free to slide and partitions an interior of the cylinder into two operating chambers. A passage connects the two operating chambers. A free piston is inserted into a pressure chamber to be free to slide and partitions the pressure chamber into one chamber that communicates with one operating chamber via a one side flow passage and another chamber that communicates with the other operating chamber via another side flow passage. A spring element generates a biasing force for suppressing displacement of the free piston relative to the pressure chamber. One or both of a bypass flow passage that connects the other chamber and the one operating chamber and a bypass flow passage that connects the one chamber and the other operating chamber is provided. A relief valve is provided in the bypass flow passage.

Disclosed herein is a shock absorber for damping vibration transmitted to a vehicle according to a road state. The shock absorber includes a cylinder and a piston valve disposed within the cylinder and connected to a piston rod to divide the cylinder into a first chamber and a second chamber. The piston rod includes a hollow chamber formed within the piston rod, first and second orifices formed in upper and lower ends of the hollow chamber and connected to the first and second chambers, respectively, a floating piston disposed within the hollow chamber to move up and down and to divide the hollow chamber into upper and lower chambers, and a moving mechanism formed in the hollow chamber to move an operating fluid to upper and lower portions of the floating piston. The shock absorber can change a damping force according to a displacement of the piston rod, thereby improving driving comfort and stability of the vehicle.

A control mode for a damping force characteristic is set to be a variable control when a product of the sum x_b′ of sprung member speeds and a sprung-member-unsprung-member-relative-speed x_s″ is positive. Accordingly, when the vibration in a middle/high frequency range is not being input to a suspension apparatus, an operation of a variable throttle mechanism is controlled so that a step number representing the damping force characteristic of a damper varies with a vibration state of a sprung member HA based on a Nonlinear H_∞ control theory. When the product of x_b′ and x_s′ is negative, the control mode is set to be an operation prohibiting control. When the vibration in the middle/high frequency range is input to the suspension apparatus, operation of the variable throttle mechanism is prohibited, and suppresses an increase in the operation frequency or in the operation amount of the variable throttle mechanism.

The invention relates to a damper of a washing machine which produces a large damping force for low-frequency vibration while small damping force for high-frequency vibration. A piston (3) coupled with a piston rod (4) is embedded inside a cylinder which is filled with mixed oil liquid and gas, and the piston (3) is infused in the oil liquid. No free piston and other isolators are arranged at the borderline of the oil liquid and gas inside the cylinder (2). The piston (3) is provided with a throttle path (7) communicated with two chambers (2A and 2B). The cylinder (2) is connected with one side of a water tank holding the cylinder, while the piston rod (4) is connected with one side of the shell. For low-frequency vibration during the washing and rinsing process, a large damping force is generated through the resistance of the oil liquid flowing through the throttle path (7) so as to restrain the shaking of the cylinder; while for the high-frequency vibration during the dehydrating process, inflated air is generated actively to reduce the damping force and to absorb the vibration of the cylinder so as to reduce the vibration and noise.

The invention discloses an energy feedback type damper which can combine piezoelectric ceramic and magnetorheological fluid, wherein the energy feedback type damper can supply electric energy which is generated by piezoelectric electricity generation units due to vibration to the magnetorheological fluid for shock absorption. The energy feedback type damper comprises a cylinder body, a piston rod, the upper piezoelectric electricity generation unit, the lower piezoelectric electricity generation unit, an electric energy extraction and storage unit, a pressure sensor and a controller. The upper piezoelectric electricity generation unit is installed outside a rod body in a sleeved mode. An upper partition plate is arranged below the upper piezoelectric electricity generation unit in an overlapping mode. The lower piezoelectric electricity generation unit is arranged on the inner bottom surface of the cylinder body. A lower partition plate is arranged on the lower piezoelectric electricity generation unit in an overlapping mode. An upper magnetorheological fluid chamber containing magnetorheological fluid is formed between the upper partition plate and a piston body. A lower magnetorheological fluid chamber containing magnetorheological fluid is formed between the piston body and the lower partition plate. The piston body is provided with a plurality of throttling holes. An excitation coil mechanism is installed in the piston body. The upper piezoelectric electricity generation unit and the lower piezoelectric electricity generation unit are connected with the electric energy extraction and storage unit. The pressure sensor is connected with the controller. The electric energy extraction and storage unit is connected with the excitation coil mechanism through the controller. The pressure sensor is installed on the upper partition plate.

A chain tensioner includes a cylindrical cylinder having a closed end, a plunger slidably mounted in the cylinder, and a return spring biasing the plunger. The cylinder is formed with an oil supply passage through which hydraulic oil is introduced into a pressure chamber defined by the plunger and the cylinder. The oil supply passage has an orifice at its end portion facing the pressure chamber. A leak gap is defined between sliding surfaces of the plunger and the cylinder. A damper force is produced by viscous resistance of hydraulic oil flowing from the pressure chamber through the leak gap, and by viscous resistance of hydraulic oil flowing from the pressure chamber into the oil supply passage through the orifice.

A suspension ECU 13 computes an actual roll angle φ and an actual pitch angle θ of a vehicle, and computes a difference Δθ between a target pitch angle θa and the actual pitch angle θ. The ECU then computes a total demanded damping force F which must be cooperatively generated by shock absorbers 11a, 11b, 11c, and 11d so as to decrease the computed Δθ to zero, and distributes the total demanded damping force F in proportion to the magnitude of a lateral acceleration Gl such that a demanded damping force Fi on the turn-locus inner side becomes greater than a demanded damping force Fo on the turn-locus outer side. Further, the ECU 13 determines whether or not the vehicle body is vibrating in the vertical direction as a result of input of a road surface disturbance, calculates a vibration-suppressing damping force Fd needed for damping the vibration, and determines the demanded damping forces Fi and Fo by use of the vibration-suppressing damping force Fd. Thus, unnecessary vibration in a turning state is quickly converged.

Included are an elastic support mechanism (10) and a shock absorber (11) in a suspension (3) interposed between an in-wheel motor device (1) and a vehicle body structure (2). The elastic support mechanism (10) can change a modulus of elasticity and the shock absorber (11) can change a damping force. The provision is made of a resonance monitoring unit (21) to monitor whether or not a rotational speed of a motor (7) falls within a predetermined resonance frequency range. When the rotational speed of the motor (7) is determined as falling within the resonance frequency range, an elastic modulus control unit (22) changes the modulus of elasticity, and a damping force control unit (23) changes the damping force of the shock absorber (11).

A method of launching a catapult, a catapult and a locking device for a catapult. The catapult comprises a carriage (4) for fastening an aircraft (5). The carriage (4) can be provided with a high acceleration by directing a launching force (F₁) generated by a launching device thereto. The carriage (4) can be held at a launching position (6) by means of the locking device (9). The catapult further comprises a takeoff damper (34) that generates a damping force (F₂) having a direction opposite relative to the launching force. Accordingly, the takeoff damper (34) restricts the acceleration of the carriage (4) at the initial launching moments.

The invention discloses an auxiliary rehabilitation exercise device for realizing finger rehabilitation exercise. The device comprises a bracket and a finger support arranged on the bracket. One end of the bracket is provided with a first shaft, and one end of the first shaft is connected with a motor; the other end of the bracket is provided with a second shaft, one end of the second shaft is connected with a magnetorheological fluid damper, and the other end of the second shaft is connected with the other end of the first shaft by a spring; the finger support is fixed on the second shaft, the second shaft is also provided with an angular transducer for measuring angular displacement of the second shaft and a force transducer for measuring torque of the second shaft. Compared with the prior art, the device combines active and passive finger rehabilitation exercises, is especially suitable for the rehabilitation exercise of single wounded finger. Meanwhile, the device has simple and compact structure and low machining precision requirement.

The invention relates to an impeller-type energy feedback shock absorber, which is mainly used in the technical field of vehicles. The impeller-type energy feedback shock absorber comprises a shock absorbing pressure cylinder, an energy conversion device and an auxiliary device, wherein the shock absorbing pressure cylinder comprises a cylinder body and a hollow piston rod; the energy conversion device comprises an impeller device, an output shaft, a coupling, a transmission, a flywheel and a power generator; and the auxiliary device comprises a sealing ring, a one-way valve and a fluid treatment device. When a vehicle runs, an uneven pavement enables the cylinder body and the piston rod of the shock absorber to move relatively to stimulate fluid in the cylinder body to flow back and forth between an upper chamber and a lower chamber. The flowing of the fluid is converted into one-way rotary motion through the impeller device, so as to drive the power generator to generate power. The impeller-type energy feedback shock absorber has the advantages that the axial size is small and the structure is more compact; the output driving direction is constant, the impact is reduced and the service life and the efficiency are improved; and the flow of a working medium in the reciprocating travel is high, work is done fully, the energy feedback effect is better and the energy feedback can be reliably realized under working conditions of high-frequency small amplitude and low-frequency large amplitude.

The invention discloses a magneto-rheological damper with unidirectional damping property, and relates to the technical field of devices for adjusting damping property by changing fluid viscosity. The magneto-rheological damper comprises a damping cylinder, a unidirectional damping piston assembly, a coil assembly, a piston rod and magneto-rheological liquid, wherein the unidirectional damping piston assembly comprises a damping piston, a spring sheet and a gasket; a first annular through hole and a second annular through hole are formed in the damping piston; a magneto-rheological fluid passage is arranged on the coil assembly and is communicated with the first annular through hole, and the coil assembly does not cover the second annular through hole. The magneto-rheological damper has the advantages that when the damping piston moves up, the spring sheet seals the second annular through hole, the magneto-rheological fluid only passes through the magneto-rheological liquid passage under the action of a magnetic field, and the damping force can be adjusted by adjusting the intensity of the magnetic field; when the damping piston moves down, the second annular through hole is opened under the action of no magnetic field, and the produced damping force is little, so that the unidirectional damping property of the magneto-rheological damper is realized.

The invention provides a valve control type semi-active oscillating damper. The valve control type semi-active oscillating damper comprises an oil cylinder component and an extra-cylinder component which is positioned on the outer side of the oil cylinder component, wherein the oil cylinder component comprises a guide bearing, an oil cylinder and a bottom valve seat which are fixedly connected with one another in turn; an oil storage tank is arranged outside the oil cylinder, and a piston and a piston rod are arranged in the oil cylinder; the extra-cylinder component comprises a first switching valve, a second switching valve, a two-position three-way valve, a proportional overflow valve, a throttling valve, a throttling overflow valve, a body acceleration sensor and a controller; the body acceleration sensor is used for detecting the acceleration of a body, outputting a signal and transmitting the signal to the controller; and the controller is used for controlling the energization and de-energization states of the first switching valve, the second switching valve and the two-position three-way valve, and controlling the current intensity of the proportional overflow valve at the same time. The valve control type semi-active oscillating damper is simple in structure, can make real-time responses and provide a continuously adjustable damping force according to the state of a train during operation, and can be simply and reliably controlled.

A suspension system for a vehicle, including: (a) a suspension spring; (b) a hydraulic damper; (c) a displacement force generator disposed in parallel with the suspension spring and the damper; and (d) a controller including a damping-force controlling portion for controlling a damping force of the damper and a displacement-force controlling portion for controlling a displacement force of the displacement force generator. The displacement-force controlling portion is configured to execute a sprung-portion vibration damping control for controlling the displacement force, such that the generated displacement force acts as a damping force against sprung-portion vibration. The damping-force controlling portion is configured, upon execution of the sprung-portion vibration damping control, to execute a damping force reducing control for reducing the damping force that is to be generated by the damper, depending on an intensity of unsprung-portion resonance frequency vibration which occurs in the vehicle and which has a resonance frequency of the unsprung portion.

The invention relates to a passive low-frequency vibration isolator, which comprises an enclosed cylindrical base, wherein the top of the enclosed cylindrical base is provided with a through hole, and the inner side wall of the enclosed cylindrical base is uniformly provided and movably connected with cylinder bodies of three dampers; a center connecting rod is inserted into the through hole in the base, and the lower end of the center connecting rod is moveably connected with piston rods of the three dampers; the top of the base is uniformly provided with three mounting fixtures; the upper part of the center connecting rod is provided with a hexagonal center clamping piece which is uniformly provided and connected with one ends of three flat springs; the other ends of the three flat springs are connected with the three mounting fixtures respectively; and the top of the center connecting rod is provided with a bearing table. The passive low-frequency vibration isolator has obvious high static stiffness and low dynamic stiffness, reduces initial isolation frequency, can realize low-frequency vibration isolation and ultralow-frequency vibration isolation, has high static bearing capacity and reduces deformation; meanwhile, by optimizing the damping structure, the vibration isolator can automatically adjust damp according to working conditions to achieve effects of inhibiting resonance and resisting impact.

An electronic control unit determines driving force that is generated on wheels and has an identical absolute value and opposite directions to each other in order to suppress pitch behavior and/or heave behavior occurring on a vehicle body in association with travelling of a vehicle. Then, the unit controls the drive of in-wheel motors through an inverter based on the driving force. On the other hand, electronic control unit changes the damping forces of shock absorbers constituting suspension mechanisms in response to the pitch behavior and/or the heave behavior occurring on the vehicle body. In this way, by controlling one of the pitch behavior and the heave behavior that may occur in combination, enhancing of the occurrence of the other one that is not intended can be prevented effectively, and the occurrence of intended behavior on the vehicle body can be controlled independently.

The invention discloses an exoskeleton finger rehabilitation training device and a using method thereof. The exoskeleton finger rehabilitation training device comprises an exoskeleton finger rehabilitation training mechanism, and the exoskeleton finger rehabilitation training mechanism comprises a support base, a finger sleeve actuation mechanism and knuckle finger sleeves connected with the poweroutput end of the finger sleeve actuation mechanism; the knuckle finger sleeves can sleeve the peripheries of the knuckles to be rehabilitated and drive the knuckles to be rehabilitated to be passively bent/stretched under the power actuation of the finger sleeve actuation mechanism; the support base comprises a profiled shell, the inner surface of the profiled shell is set according to the profile of a complete palm back surface or a part of the palm back surface, and the back surface of the profiled shell is provided with a power fixing base; the power part of the finger sleeve actuation mechanism is installed on the power fixing base; when the knuckles to be rehabilitated undergo rehabilitation exercise, the finger sleeve actuation mechanism is located at the outer side of the palm. Therefore, the exoskeleton finger rehabilitation training device does not influence the gripping action of a patient, and the complete activity space for the rehabilitation of the patient can be achieved.

The invention discloses a magnetic steel piston type magneto-rheological damper with double ejection rods, comprising a working cylinder, a piston and two piston rods; the working cylinder is filled with magneto-rheological fluid; the piston is made of magnetic steel, two piston rods are both made of non-magnetic materials, a magnet exciting coil and a magnetizing-demagnetizing coil are wound in the middle of the piston, and the magnetic steel piston can be magnetized and demagnetized by controlling a power source, therefore, the magnetic steel piston has certain magnetic field intensity and the magnetic steel piston type magneto-rheological damper with double ejection rods has certain output damping force, and the output damping force of the magnetic steel piston type magneto-rheological damper with double ejection rods is regulated by changing the size and the direction of current input to the magnet exciting coil of the magnetic steel piston.