Magneto-rheological fluid composition

Patent metadata

Field	Value
Publication number	US-9449744-B2
Application number	US-201414569692-A
Country	US
Kind code	B2
Filing date	Dec 13, 2014
Priority date	Feb 11, 2014
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

Disclosed is a magneto-rheological fluid composition which comprises magnetic particles, a fluid, a dispersant, a structure stabilizer and an anti-friction additive. Particularly, the magnetic particles include non-coated magnetic particles and polyvinyl butyral-coated magnetic particles at the weight ratio of about 1:1 to 4:1. Accordingly, dispersion stability and yield stress are improved substantially when magnetic field is applied to the magneto-rheological fluid.

First claim

What is claimed is:

1. A magneto-rheological fluid composition, comprising:
magnetic particles;
a fluid;
a dispersant;
a structure stabilizer; and
an anti-friction additive,
wherein the magnetic particles include non-coated magnetic particles and polyvinyl butyral-coated magnetic particles at the weight ratio of about 1:1 to 4:1.

2. The magneto-rheological fluid composition of claim 1 , comprising:
the magnetic particles including the non-coated magnetic particles and the polyvinyl butyral-coated magnetic particles at the weight ratio of 1:1 to 4:1 in an amount of about 55 to 85 wt % based on the total weight of the magneto-rheological fluid composition;
the fluid in an amount of about 10 to 40 wt % based on the total weight of the magneto-rheological fluid composition;
the dispersant in an amount of about 0.1 to 2.0 wt % based on the total weight of the magneto-rheological fluid composition;
the structure stabilizer in an amount of about 0.1 to 2.0 wt % based on the total weight of the magneto-rheological fluid composition; and
the anti-friction additive in an amount of about 1 to 5.0 wt %, based on the total weight of the magneto-rheological fluid composition.

3. The magneto-rheological fluid composition of claim 1 , wherein an average particles size of the magnetic particles is of about 1 to 10 μm.

4. The magneto-rheological fluid composition of claim 1 , wherein the magnetic particles contain iron (Fe) in an amount of about 97 wt % or greater based on the total weight of the magnetic particles.

5. The magneto-rheological fluid composition of claim 1 , wherein the fluid is at least one selected from the group consisting of ester oil, mineral oil, synthetic hydrocarbon oil and silicon oil.

6. The magneto-rheological fluid composition of claim 1 , wherein the fluid has kinematic viscosity of about 5 to 50 m 2 /s at a temperature of about 40° C.

7. The magneto-rheological fluid composition of claim 1 , wherein the dispersant is alkyl ammonium salt.

8. The magneto-rheological fluid composition of claim 1 , wherein the structure stabilizer is modified urea.

9. The magneto-rheological fluid composition of claim 1 , wherein the anti-friction additive is at least one selected from the group consisting of molybdenum disulfide, zinc phosphate, triaryl phosphate, triphenyl phosphorothionate and amine phosphate.

10. The magneto-rheological fluid composition of claim 1 , further comprising an antioxidant, an anticorrosive agent, an antirust agent or combinations thereof.

Assignees

• Hyundai Motor Co Ltd
• Klueber Lubrication Korea Ltd

Inventors

• Lee Sung Uk
• Park Jong Min
• Bae Dae Yun
• Lee Jin Young

Classifications

• H01F1/447 Primary

  characterised by magnetoviscosity, e.g. magnetorheological, magnetothixotropic, magnetodilatant liquids (electrorheological fluids C10M171/001) · CPC title