Magnetorheological fluid and braking device

By employing metal magnetic particles with ionic liquid modification and matching cation/anion groups in the dispersion medium, the fluid maintains stable dispersion and high excitation stress across extreme temperatures, addressing aggregation and sedimentation issues in magnetorheological fluids.

JP2026059921APending Publication Date: 2026-04-08SEIKO EPSON CORP
1 Cites 0 Cited by

Patent Information

Application Number
JP2024168152
Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-09-27
Publication Date
2026-04-08

AI Technical Summary

Technical Problem

Existing magnetorheological fluids face challenges in maintaining dispersion and high excitation stress at low and high temperatures, leading to aggregation and sedimentation of magnetic particles, which affects their reliability and performance in various applications.

Method used

The use of metal magnetic particles with ionic liquid modification sites and an ionic liquid dispersion medium having matching cation and anion groups, such as quaternary ammonium, imidazolium, or phosphonium ions, and anions like tetrafluoroborate or hexafluorophosphate, ensures strong affinity and stability across temperature extremes, preventing particle sedimentation and maintaining high excitation stress.

Benefits of technology

This configuration results in a magnetorheological fluid that maintains a stable dispersion and high excitation stress across a wide temperature range, from low temperatures below 0°C to high temperatures above 250°C, enhancing reliability and performance in devices like brakes and clutches.

✦ Generated by Eureka AI based on patent content.
Patent Text Reader

Abstract

To provide a magnetic viscous fluid capable of achieving both high reliability and high excitation stress even when used under low temperature or high temperature, and a braking device including the magnetic viscous fluid.SOLUTION: A magnetic viscous fluid comprising: metal magnetic particles modified with an ionic liquid modifying site containing a first cationic group and a first anionic group; and an ionic liquid dispersion medium containing a second cationic group and a second anionic group, wherein the first cationic group and the second cationic group are the same kind of cations, and are selected from the group consisting of a quaternary ammonium ion, an imidazolium ion, a pyridinium ion, and a phosphonium ion, and wherein the first anionic group and the second anionic group are selected from the group consisting of a tetrafluoroborate ion, a hexafluorophosphate ion, a trispentafluoroethyltrifluorophosphate ion, a bis(trifluoromethanesulfonyl)amide ion, a hydrogen phthalate ion, and a bissulfuryl fluoride imide ion.SELECTED DRAWING: Figure 1
Need to check novelty before this filing date? Find Prior Art