Development of fast response MR-fluid actuator

Takesue, Naoyuki; Kiyota, Y.; Furusho, Junji

doi:10.1109/sice.2002.1195294

Cited by 5 publications

(4 citation statements)

References 5 publications

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“…MR fluids are now being developed and applied to many actuators such as automobile shock absorbers, dampers, clutches, brakes, air valve, hydraulic valve, prosthetic limbs (leg and hand in medicine), exercise devices, surface polishing of processed machine parts, and others [4][5][6][7][8][9][10][11][12][13][14][15]. These reports solved some of the problems of the MR fluid devices such as controllability, a high damping force, simple construction of devices, low power requirements for control and fast response.…”

Section: Introductionmentioning

confidence: 99%

A new structure of a magnetorheological brake with the waveform boundary of a rotary disk

Nam¹,

Ahn²

2009

Smart Mater. Struct.

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This paper presents a novel magnetorheological (MR) brake design incorporating a rotary disk with a waveform boundary that generates a resistance force based on the effects of a material deformation process. This force is transmitted from an external agent and creates the necessary energy for breaking the structure of the hardened MR fluid. Its minimum destructive ability is proportional to the variable stiffness of an MR fluid in a magnetic field. In this design, the waveform wall of a rotary disk crushes the particles chains (fibrils) of the MR fluid together instead of breaking them via strain in a conventional MR brake. The resistance forces and braking torques generated by this crush action are stronger than those produced by strain action. To verify our proposed MR brake, the proposed and conventional MR brakes are designed using similar magnetic circuits and material parameters. We compared the performance of our novel MR brake to the performance of a conventional MR brake, and demonstrated that the measured resistance torque of the proposed MR brake is approximately 600% greater than resistance torques generated by conventional brakes.

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Section: Introductionmentioning

confidence: 99%

A new structure of a magnetorheological brake with the waveform boundary of a rotary disk

Nam¹,

Ahn²

2009

Smart Mater. Struct.

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“…However, the response time of damper is strongly dependent on the magnitude of the applied electric current and the piston velocity. Takesue et al [26] presented the design of the MR clutch where they improved the dynamic behavior of this actuator by reduction of eddy current in the magnetic circuit. The same aim had Strecker [27] and Kubík [16] who published the design of MR damper with a short response time where the ferrite material of the magnetic circuit was used.…”

Section: Introductionmentioning

confidence: 99%

Insight into the response time of fail-safe magnetorheological damper

Jeniš¹,

Kubík²,

Macháček³

et al. 2020

Smart Mater. Struct.

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The significant problem of magnetorheological (MR) dampers is their poor fail-safe ability. In the case of power supply failure, the damper remains in a low damping state which is dangerous for several technical applications. This can be solved by accommodating a permanent magnet to the magnetic circuit of the damper. Currently, the MR dampers are used in progressive semiactive (S/A) control of suspension systems. The dynamics (force response time) of the damper is an important parameter that affects the performance of semiactive control. The main goal of this paper is to introduce the dynamic behavior of MR damper with a permanent magnet. The damper design with the permanent magnet in the magnetic circuit, transient magnetic simulation including magnetic hysteresis and eddy currents, and experiments are presented. The magnetic field response time and MR damper force response time are measured and also determined from magnetic simulation. The permanent magnet significantly influences the MR damper dynamics. The decrease of the damping force from a fail-safe state -medium damping to off-state -low damping is significantly faster (2 ms, -1A) than the increase to on-state -high damping (12 ms, 1A). The exact value is depending on the electric current magnitude and piston velocity. The damper achieved fail-safe damping force approximately 1/3 of the maximum damping force. The exact value of the fail-safe force is magnetization history-dependent. The maximum dynamic force range is 8.5 which is comparable with the common design of MR damper.

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“…The MR fluids can be widely used in designing damping devices such as shock absorbers, clutches, surface polishing machine parts and vibration dampers [18][19][20][21][22][23][24][25][26][27][28][29]. Soft ferro magnetic materials like magnetite and iron are adopted as the MR materials [30][31].…”

Section: Introductionmentioning

confidence: 99%

Magneto Mechanical Properties of Iron Based MR Fluids

Premalatha¹,

Chokkalingam²,

Mahendran³

2012

AJPS

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The main aim of this article is to prepare MR fluids, composed of iron particles and analyse their flow behaviour in terms of the internal structure, stability and magneto rheological properties. MR fluids are prepared using silicone oil (OKs) mixed with iron powder. To reduce sedimentation, grease is added as stabilizers. The size of the particles is observed by Optical microscope and flow properties are examined by rheometer. Sedimentation is measured by simple observation of changes in boundary position between clear and turbid part of MR fluid placed into glass tube. The various additive percentages can also influence the MR fluid's performances.

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Development of fast response MR-fluid actuator

Cited by 5 publications

References 5 publications

A new structure of a magnetorheological brake with the waveform boundary of a rotary disk

A new structure of a magnetorheological brake with the waveform boundary of a rotary disk

Insight into the response time of fail-safe magnetorheological damper

Magneto Mechanical Properties of Iron Based MR Fluids

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