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US 6,547,983 B2Granted
Durable magnetorheological fluid compositions
AssigneeDelphi Technologies, Inc.
InventorVardarajan R. Iyengar
Life of this patent
Estimating the term…
Abstract
A durable MR fluid formulation is described which includes mechanically hard magnetizable particles, a carrier fluid derived from a polyalphaolefin and a plasticizer, and at least one colloidal additive such as colloidal polytetrafluoroethylene or colloidal graphite. The use of these colloidal additives inhibits surface-to-surface contact and scuffing while providing reliable lubrication under boundary lubrication conditions.
Claims12
A durable magnetorheological fluid comprising:
- a. mechanically hard magnetizable particles having a hardness greater than B50 on the Rockwell scale and a particle size less than about 10 microns that is selected from the group consisting of unreduced carbonyl iron particles, cobalt iron alloy particles, and mixtures thereof;
- b. a carrier fluid consisting essentially of a mixture of a dimer of dodecene and dioctyl sebacate;
- c. untreated fumed silica having a surface area of between about 300 m2/g to about 350 m2/g;
- and
- d. a colloidal additive selected from colloidal polytetrafluoroethylene, colloidal graphite or mixtures thereof.
2 more elements
A magnetorheological fluid comprising:
- a. mechanically hard magnetizable particles of unreduced carbonyl iron having a hardness of about C65 on the Rockwell Scale and an average particle size of about 1 to 2 microns;
- b. a carrier fluid consisting essentially of a mixture of a dimer of 1-dodecene and dioctyl sebacate in a volume ratio of about 4;
- c. untreated fumed silica having a surface area of about 350 m2/g;
- d. a colloidal additive selected from colloidal polytetrafluoroethylene, colloidal graphite or mixtures thereof;
- and
- e. an ethoxylated amine.
3 more elements
Dependencies are inferred from the claim text.