Lithium soap grease containing methacrylate ester polymer for bearing noise suppression

Claim 1

A LUBRICATING GREASE FOR ANTI-FRICTION BEARINGS COMPRISING ESSENTIALLY A LUBRICATING BASE CONSISTING OF AT LEAST A MAJOR PROPORTION OF AN OILSOLUBLE HIGH MOLECULAR WEIGHT HIGH BOILING LIQUID ALIPHATIC DICARBOXYLIC ACID ESTER WITHIN THE LUBRICATING OIL VISCOSITY RANGE AND POSSESSING LUBRICATING PROPERTIES, ABOUT 10-25% BY WEIGHT BASED ON THE GREASE OF A LITHIUM SOAP OF SOAPFORMING FATTY MATERIAL CONTAINING AT LEAST 50% BY WEIGHT ON THE BASIS OF THE FATTY MATERIAL OF A HYDROXY SOAP-FORMING MATERIAL SELECTED FROM THE GROUP CONSISTING OF 12-HYDROXY STEARIC ACID AND HYDROGENATED CASTOR OIL, SAID SOAP THICKENING SAID LUBRICANT BASE TO A GREASE-LIKE CONSISTENCY SUITABLE FOR BALL AND ROLLER BEARING LUBRICATION, SAID GREASE BEING NORMALLY SUBJECT TO PRODUCING A HIGH PITCHED OBJECTIONABLE NOISE WHEN EMPLOYED FOR THE LUBRICATION OF A BALL BEARING ROTATED AT HIGH SPEED, AND ABOUT 0.3-5% BY WEIGHT BASED ON THE GRASE OF A POLYMERIZED N-ALKYL ESTER OF METHACRYLIC ACID WHEREIN THE SAID N-ALKYL GROUP CONTAINS FROM 8 TO 12 CARBON ATOMS, SAID POLYMERIZED ESTER IN 30% SOLUTION IN TOULENE HAVING A KINEMATIC VISCOSITY AT 100* F. WITHIN THE RANGE OF 80-2000 CENTISKOTES AND BEING INCORPORATED IN SAID GREASE BY STIRRING AT A TEMPERATURE IN EXCESS OF ABOUT 290* F. FOR A PERIOD OF TIME EFFECTIVE TO REDUCE SAID NOISE TO A SATISFACTORY INTENSITY.