Trw Limited

Northrop Grumman Systems Corporation

Emil M Shtarkman

John A Starkovich

A Dale Parker

Kathleen M Doherty

Andrew Frank Pinkos

Jim L Rau

Hsiao-Hu Peng

Louis A Rosales

John B Colletti

James L Graves

Thomas J Fitzgerald

William W Davison

David S Haber

A method and apparatus for controlling the tension in a bobbin assembly having a supply bobbin with yarn thereon. As the yarn is fed to a drive bobbin, a magnetic field is variably applied to magnetorheological fluid to apply resistance to the supply bobbin as it rotates thereby controlling the tension on the yarn.

Magnetorheological fluid actively controlled bobbin tensioning apparatus

A magnetorheological fluid ( ) having controlled-shaped particles ( ), such as rod, prism, tetrahedral, and other regularly shaped particles. The regularly shaped particles ( ) 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.

High yield stress magnetorheological material for spacecraft applications

A composite structure element ( ) with built-in damping is formed with a non-metallic matrix ( ) reinforced by a plurality of filaments ( ) within the matrix. A lightweight metal ( ) having a specific damping capability of at least 1% is provided on at least one of the matrix and the filaments of the composite structure element for attenuating vibrations of the element. The lightweight metal is preferably a magnesium alloy or an aluminum alloy which is coated on the filaments ( ) and/or the pores ( ) of a porous matrix ( ). A metal structural member, such as a satellite antennae ( ), subject to disturbance when used for its intended purpose can also be provided with built-in damping by providing a lightweight metal ( ) having a specific damping capability of at least 1% on the structural member on the wire mesh ( ) of the deployable antennae for damping disturbances.

Composite structure element with built-in damping

A deployable antenna reflector structure (,) that provides a reduced number of components without compromising mechanical stability or deployment reliability. The structure (,) uses a truss hoop (,) with identical elements (,) and parallel pivot axes (,) to transition from a stowed position (,) to a deployed position (,). The use of identical elements (,) provides reduced manufacturing and assembly costs due to the reduction in components and added simplicity of the design. The truss hoop (,) achieves mechanical stability by making use of a two-dimensional element design having vertical portions (,) and horizontal portions (,) located in the same plane. Each parallel pivot axis (,) is defined by two pivot points. The first pivot point (,) connects horizontal portions (,) of adjacent identical elements (,) and the second pivot point (,) connects vertical portions (,) of adjacent identical elements (,). The structure (,) also provides a reflector (,) and a deployment control mechanism. The reflector (,) guides antenna signals when the structure (,) is in the deployed position (,). The deployment control mechanism determines when the parallel pivot axes (,) transition the structure from the stowed position (,) to the deployed position (,).

Deployable large antenna reflector structure

A vibration control system is provided for an appendage such as an antenna,coupled to a platform such as a spacecraft,The antenna,is coupled at a base,so as to extend from the spacecraft,A plurality of guidelines,extend between remote portions,of the antenna,and the antenna base,A plurality of motion control elements,are provided within the antenna structure for reducing oscillation settling time of the antenna,relative to the spacecraft,The motion control elements,include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.

Spacecraft antenna vibration control damper

A motion control apparatus is provided for controlling oscillations of an appendage 10 coupled to a spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the appendage 10 and the appendage base 14. A plurality of motion control elements 28 are interposed between the appendage base 14 and the spacecraft 12 and/or along the guidelines 20 between the appendage base 14 and the remote portions 22 of the appendage 10 or both. The motion control elements 28 include visco-elastic fluid, electro-rheological fluid, magnetic-rheological fluid, or a piezo-electric stack so that a motion control property of the motion control elements 28 may be varied according to the magnitude of an electric or magnetic field source 30 coupled thereto.

Spacecraft antenna slew control systems

A vibration control system is provided for an appendage such as an antenna 10 coupled to a platform such as a spacecraft 12. The antenna 10 is coupled at a base 14 so as to extend from the spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the antenna 10 and the antenna base 14. A plurality of motion control elements 36 are provided within the antenna structure for reducing oscillation settling time of the antenna 10 relative to the spacecraft 12. The motion control elements 36 include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.

A controllable strut (10) includes a helical spring (22) which extends between first and second end portions (12 and 14) of the strut (10). A field responsive fluid (30) is disposed about the spring. A source of electromagnetic energy (40) provides a magnetic field through at least a portion of the fluid (30) and the spring (22). The fluid viscosity changes with changes in the intensity of the magnetic field.

Controllable vehicle strut

An electric steering system (10) includes a power source (34) and an electric motor (28) which provides an auxiliary steering force in response to a large capacity capacitor (C1) being selectively connected to the power source (34), for charging the large capacity capacitor (C1), and to the motor (28), for discharging the large capacity capacitor (C1) to drive the electric motor (28) for providing the auxiliary steering force.

Electric steering system

The present invention provides an electrorheological magnetic (ERM) fluid-based rotary motion damper (12). According to the invention, the ERM fluid-based rotary motion damper (12) generally includes an input shaft (18) coupled to a first damping member (16) and rotatably supporting a second damping member (20). A cylinder (28) coupled about the first damping member (16) rotatably engages a housing (36) circumferentially coupled about the second damping member (20). As such, the cylinder (28) is configured for rotary movement relative to the housing (36). ERM fluid (56) disposed in the housing (36) surrounds the cylinder (28) such that it coacts with the housing (36) and cylinder (28). In the presence of a magnetic field, the ERM fluid (56), cylinder (28) and housing (36) frictionally control the rotary movement of the first damping member (16) relative to the second damping member (20).

Spacecraft deployment mechanism damper

An apparatus (10) includes a vehicle drive shaft (12), a roller bearing (16) supporting the drive shaft (12) for rotation, and a housing (18) which contains and supports the roller bearing (16) in a vehicle. The roller bearing (16) includes an inner race (34) rotatable within an outer race (36). The apparatus (10) further includes a damper assembly (20) which damps vibrations radially between the roller bearing (16) and the housing (18). The damper assembly (20) defines a closed chamber (150) containing rheological fluid (152), and has a flow-inducing part (80) projecting into the fluid (152). The flow-inducing part (80) of the damper assembly (20) is movable radially within the fluid (152) in response to radial vibrations of the outer bearing race (36).

Center bearing assembly with rheological fluid for damping vibrations

An apparatus (40) is connectable between relatively movable parts (12, 14) to resist relative vibration of the parts. The apparatus comprises a first ring-shaped member (50) having a first platform surface (54) engageable with one part (12). A second ring-shaped member (60) has a second platform surface (64) engageable with another part (14). One of the first and second ring-shaped members (50, 60) defines a series of sealed fluid chambers (48) located between the first and second members (50, 60) and spaced apart from each other around the first and second members. Each chamber (48) contains a fluid having a resistance to shear which varies in response to an energy field acting on the fluid. Each chamber (48) has its own respective blade member (42) connected to one of the first and second members (50, 60). The blade member (42) extends into the associated chamber (48). Each chamber (48) has its own respective pair of electromagnets (90, 92) for applying an energy field to the fluid in the chamber to vary the resistance to shear of the fluid as a function of the energy field acting thereon. The movement of the blade member (42) in the chamber (48) is resisted by the fluid.

Actively controlled damper

A power steering system includes a housing and a first member supported by the housing for movement relative to the housing. A second member is supported by the housing for movement relative to the housing and the first member. Steerable vehicle wheels are moved in response to relative movement between the first and second members. A power steering resistance control system resists relative movement between the first and second members with a force which varies as a function of variations in vehicle speed. Material is located in a chamber circumscribing the first member. The material has a viscosity which varies as a function of the magnitude of an energy field acting thereon to vary the resistance to relative movement between the first and second members. The energy field is applied to act on the material with a magnitude that varies as a function of the vehicle speed.

Power steering system

An apparatus controls a damper connectable between a vehicle body and a vehicle wheel. A position sensor senses the amount of angular displacement between the vehicle body and the vehicle wheel and provides a position signal indicative thereof. An acceleration sensor senses the amount of vertical acceleration of the vehicle body relative to ground and provides a vertical acceleration signal indicative thereof. Another acceleration sensor senses the amount of lateral acceleration of the vehicle body and provides a lateral acceleration signal indicative thereof. A processor processes the position signal, the vertical acceleration signal, and the lateral acceleration signal to provide a control signal which continuously varies as a function of (i) a summation of the position signal and the vertical acceleration signal, and (ii) a summation of the position signal and the lateral acceleration signal. Preferably, the processor is a digital signal processor. A drive circuit applies the control signal from the processor to the damper to control the damping rate of the damper.

Growing community of inventors

Marina Del Rey, CA, United States of America

Emil M Shtarkman