Aqueous magnetorheological materials

• US 5,670,077 A
• Filed: 10/18/1995
• Issued: 09/23/1997
• Est. Priority Date: 10/18/1995
• Status: Expired due to Fees

• Current Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Original Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Inventors: JonesGuion, Jeannine C., Carlson, J. David
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US08/544,689
• Time in Patent Office: 706 Days
• Field of Search: 252/62.53, 252/62.54, 252/62.52
• US Class Current: 252/62.52
• CPC Class Codes: H01F 1/447 characterised by magnetoviscosity, e.g. magnetorheological, magnetothixotropic, magnetodilatant liquids electrorheological fluids C10M171/001

Abstract

A magnetorheological material that includes magnetic particles; at least one water-soluble suspending agent selected from the group consisting of cellulose ether and biosynthetic gum; and water. The material can have a high particle loading, minimizes waste disposal problems, and can be produced at a lower cost relative to magnetorheological materials that include hydrophobic-oil type fluids as a carrier fluid.

Claims

1. A magnetorheological fluid comprising magnetic particles;

at least one biosynthetic gum; and

water.

2. A magnetorheological fluid according to claim 1 wherein the biosynthetic gum is selected from the group consisting of xanthan gum, rhamsan gum and welan gum.

3. A magnetorheological fluid according to claim 2 wherein the biosynthetic gum is xanthan gum.

4. A magnetorheological fluid according to claim 2 further comprising an additional material selected from the group consisting of locust bean gum and polyethylene oxide.

5. A magnetorheological fluid according to claim 1 wherein the biosynthetic gum is present in an amount of 0.1 to 5 weight percent, based on the total weight of the water.

6. A magnetorheological fluid according to claim 1 wherein the magnetic particles have an average diameter of 1 to 1000 μ

m.

7. A magnetorheological fluid according to claim 1 wherein the magnetic particles comprise a carbonyl iron powder.

8. A magnetorheological fluid according to claim 1 further comprising at least one rust inhibitor selected from the group consisting of a nitrite compound, a nitrate compound, sodium benzoate, borax and ethanolamine phosphate.

9. A magnetorheological fluid according to claim 8 wherein the rust inhibitor is selected from the group consisting of sodium nitrite and sodium nitrate.

10. A magnetorheological fluid according to claim 1 wherein the water is present in an amount of 50 to 95 percent by volume of the total magnetorheological material.

11. A magnetorheological fluid according to claim 1 wherein the biosynthetic gum is xanthan gum, the magnetic particles comprise carbonyl iron powder having an average diameter of 1 to 1000 μ

m, and the water is present in an amount of 50 to 95 percent by volume of the total magnetorheological material.

12. A magnetorheological fluid comprising magnetic particles;

a carrier component for the magnetic particles comprising water; and

0.1 to 2 weight percent (based on the total weight of the water) of at least one cellulose ether.

13. A magnetorheological fluid according to claim 12 wherein the the cellulose ether is sodium carboxymethylcellulose.

14. A magnetorheological fluid according to claim 12 wherein the cellulose ether is selected from the group consisting of sodium carboxymethylcellulose and methyl hydroxyethylcellulose.

15. A magnetorheological fluid according to claim 12 further comprising an additional material selected from the group consisting of locust bean gum and polyethylene oxide.

16. A magnetorheological fluid according to claim 12 wherein the magnetic particles have an average diameter of 1 to 1000 μ

m.

17. A magnetorheological fluid according to claim 12 wherein the magnetic particles comprise a carbonyl iron powder.

18. A magnetorheological fluid according to claim 12 further comprising at least one rust inhibitor selected from the group consisting of nitrite compound, a nitrate compound, sodium benzoate, borax and ethanolamine phosphate.

21. A magnetorheological fluid according to claim 12 wherein the water is present in an amount of 50 to 95 percent by volume of the total magnetorheological material.

22. A magnetorheological fluid according to claim 12 wherein the cellulose ether is sodium carboxymethylcellulose, the magnetic particles comprise carbonyl iron powder having an average diameter of 1 to 1000 μ

m, and the water is present in an amount of 50 to 95 percent by volume of the total magnetorheological material.

23. A magnetorheological fluid according to claim 12 wherein the cellulose ether is present in an amount of 0.5 to 2 weight percent, based on the total weight of the water.

24. A magnetorheological fluid according to claim 12 wherein the magnetic particles are present in an amount of 29 to 89 weight percent, based on the total weight of the fluid.

19. A magnetorheological fluid according to claim 19 wherein the rust inhibitor is selected from the group consisting of sodium nitrite and sodium nitrate.

20. A magnetorheological fluid according to claim 20 further comprising a glycol compound.

25. A magnetorheological fluid comprising magnetic particles;

at least one water-soluble suspending agent selected from the group consisting of cellulose ether and biosynthetic gum;

water; and

a glycol compound.