摘要:
A method for increasing and/or modulating the yield shear stress of an electrorheological fluid includes applying a sufficient electric field to the fluid to cause the formation of chains of particles, and then applying a sufficient pressure to the fluid to cause thickening or aggregation of the chains. An apparatus for increasing and/or modulating the transfer or force or torque between two working structures includes an electrorheological fluid and electrodes through which an electric field is applied to the fluid such that particles chains of particles are formed in the fluid and, upon application of pressure to the fluid, the chains thicken or aggregate and improve the force or torque transmission.
摘要:
An electro-rheological (ER) fluid damper control system employs fuzzy logic to attain real time control in a highly responsive manner. The ER fluid damper is interposed in a vehicle between its sprung mass (vehicle body) and unsprung mass (suspension). Signals corresponding to the velocity of the sprung mass and the relative velocity between the sprung and unsprung masses are generated by pairs of accelerometers and electronic integrators. A fuzzy rule, taking into account weighted values of these input signals, is applied to the signals to determine an output value which, in turn, establishes a control signal for application to the electrodes of the ER fluid damper. As the velocity signals change, the voltage applied to the electrodes also changes, thus adjusting the fluid viscosity and mechanical responsiveness of the ER fluid damper.
摘要:
The disclosure relates to a viscous damper of the labyrinth ring type for incorporation in a mounting for a TV or video camera for damping pan or tilt movement of the camera. The damper has a stator (10) having a multiplicity of upstanding concentric annular fins (12) and a rotor (17) having a corresponding multiplicity of concentric annular fins (32) projecting downwardly which interleaf with clearance with the upstanding flanges of the stator, the space between the fins being filled with a viscous fluid to provide a resistance to relative movement between the rotor and stator. The rotor is adjusted with respect to the stator by a motor driven lead screw. A speed sensor measures speed of the rotor with respect to the stator and torque applied to the camera by the hand control to pan or tilt the camera is measured by a strain gauge associated with the hand control. A control system is provided for the motor embodying a microprocessor preprogrammed with one or more algorithms coordinating torque and speed. Thus the viscous damper may be controlled to provide a resistance torque to movement which rises generally linearly with speed as detected by the speed sensor to a certain level whereafter the resistance is maintained constant.
摘要:
This invention relates to laminated composite structure elements containing electrodes, flexible laminae which may also serve as electrodes, and an electrorheological fluid located between the flexible laminae. The rheological properties of the electrorheological fluid and its cohesive force with solid surfaces may be changed by applying an electric field, and the mechanical properties of the whole laminated composite structure may thereby be varied.
摘要:
A vibration damping device comprises two cylindrical and flexible membrane members liquid-tightly connected at its end portion to respective end portion of a piston member and at its other end portions to respective face plates, a connecting member connecting the face plates to each other to form a closed chamber, a liquid filled in the closed chamber, and fastening members arranged onto the piston member and face plate, respectively. Moreover, at least one restricted passage is formed in the piston member or the connecting member. When an electrorheological fluid is used as a liquid, electrodes are arranged on opposed walls of the restricted passage.
摘要:
A vibration damping device comprises two cylindrical and flexible membrane members, a restricted passage constituting member connected at both end portions to these membrane members, two face plates connected at their end portion to the membrane members, a closed chamber defined by these members and face plates, a rigid member connecting both the face plates to each other at inside or outside of the closed chamber, a fluid filled in the closed chamber, and a fastening member disposed at each side of the restricted passage constituting member and the face plate.
摘要:
Adjustable dampers using electrorheological (ER) fluids comprise one or more annular ER fluid transfer ducts in fluid communication with fluid chambers on opposite sides of the damper pistons. Each duct has one or more contoured surfaces or bands along a portion of the length of one or both walls of the ducts providing one or more annular constricted working areas through which the ER fluid is forced when displaced by movement of the pistons. By selectively applying a voltage/electric field across the primary working areas, the flow resistance of the ER fluid passing through the primary working area is increased which increases the damping force of the dampers.
摘要:
A piezo-actuator's displacement magnifying mechanism includes a first cylinder and a second cylinder which is smaller in diameter than the first cylinder and communicates with the same. A plunger is slidably mounted in the first cylinder. The plunger is moved by a piezo-actuator in the first cylinder when a predetermined voltage is applied to the piezo-actuator to cause the same to expand and contract. A piston is slidably mounted in the second cylinder. A reservoir is communicating with the first cylinder. A hydraulic fluid is received in the first and the second cylinder and the reservoir. The hydraulic fluid is variable in viscosity in response to electric fields to which the fluid is subjected. A fluid passage is provided between the first cylinder and the reservoir for compensating for thermal expansion/contraction of the fluid. An electrode is provided for subjecting the hydraulic fluid to electric fields in the passage according to an instruction for applying the voltage to the piezo-actuator.
摘要:
A general electro-rheological valve is disclosed used in controlling the flow of fluids in a variety of applications. The valve comprises an inlet in communication with a fluid source, an outlet for transporting the fluid out of said valve, and an oscillating valve member for opening and closing off said inlet. The valve member has a cavity containing an electro-rheological fluid, a perforated electrode member emersed in the electro-rheological fluid within the cavity, and means for electrifying the perforated electrode member such that the electro-rheological fluid within the electrode solidifies, thereby locking the position of the valve member relative to the electrode. In this manner, the valve member, which oscillates with respect to the perforated electrode member, can be frozen in an open, closed, or intermediate position with respect to the inlet. The valve member thereby controls the level of fluid flow through the valve.
摘要:
An apparatus and method for control of stiffness and damping in a flexible composite structure by the application of an electric field to an electrophoretic fluid forming part of the structure. The structure includes spaced, parallel, flexible layers of material which include confronting electrodes. The electrophoretic fluid is capable of separating into particle-rich and particle-deficient phases by electrophoresis and operates in surface contact with the layers. An electrically nonconductive material having raised surface areas and spaces between the surface areas is associated with one or more of the layers. When a voltage is applied between the layers in a first direction, the particle-rich phase of the fluid collects on one of the layers and also makes contact with the spaces and the raised surface areas of the material associated with the other layer thereby engaging or locking the layers together to increase the shear strength of the layers and thus the complex stiffness of the structure. When the voltage potential is applied in the opposite direction, the particle-rich phase migrates to the other layer and collects in the spaces between the raised surfaces of the material, thereby disengaging the layers to decrease their shear strength and thus the stiffness of the structure. The structure may be configured as a panel, plate, or beam, in association with a variety of mechanical systems.