High efficiency hydraulic oils

Abstract

Methods for achieving favorable efficiency properties are disclosed including methods for blending a lubricant composition and lubricant compositions. In one embodiment, the method comprises the steps of obtaining at least one base stock and at obtaining at least one base stock chosen to have a favorable air release properties, obtaining at least one additive, blending at least one base stock and at least one additive to achieve a favorable effective bulk modulus through air release property, bulk modulus, and using a relationship between density and bulk modulus.

1 . A hydraulic lubricating oil, comprising
 a) at least one base stock;   b) at least one additive;   c) wherein the base stock has a density at 15.6° C. of greater than 0.9 and a ASTM D-3427 air release of less than 1.25 percent air at 1 minute.   
     
     
         2 . The lubricating oil of  claim 1  wherein the base stock has an ASTM D-3427 air release of less than 1 percent air at 1 minute. 
     
     
         3 . The lubricating oil of  claim 1  wherein the base stock has an ASTM D-3427 air release of less than 0.6 percent air at 1 minute. 
     
     
         4 . The lubricating oil of  claim 1  wherein the base stock has a bulk modulus of greater than 215,000 at 34.47 MPa (5,000 PSI). 
     
     
         5 . The lubricating oil of  claim 1  wherein at least one base stock is chosen from the group consisting of PAOs, Group III, GTL, aromatic esters, polyol esters, alkylated aromatics, phosphate esters, and any combinations thereof. 
     
     
         6 . The lubricating oil of  claim 1  wherein the lubricating oil has an ASTM D-3427 air release of less than 2 percent air at 1 minute. 
     
     
         7 . The lubricating oil of  claim 1  wherein the lubricating oil has an ASTM D-3427 air release of less than 1 percent air at 1 minute. 
     
     
         8 . The lubricating oil of  claim 1  wherein the lubricating oil has a Bulk Modulus greater than 195,000 at 34.47 MPa (5,000 PSI). 
     
     
         9 . The lubricating oil of  claim 1  wherein the lubricating oil has a density greater than 0.9. 
     
     
         10 . The lubricating oil of  claim 1  wherein at least one base stock is an ester and the ester comprises at least 20 percent of the hydraulic oil. 
     
     
         11 . The lubricating oil of  claim 1  wherein the base stock has air release properties better than equation:
     Y= 0.025 X− 0.55   Wherein:   Y=Percent air at 1 minute using ASTM D-3427 at 50° C.   X=Kinematic Viscosity at 40° C. in cST.   
     
     
         12 . A method of improving hydraulic efficiency in a system comprising
 a) determining a favorable hydraulic efficiency requirement of the system.   b) obtaining a hydraulic oil to achieve a favorable hydraulic efficiency property using a relationship between the hydraulic oil's density, and bulk modulus to obtain a high bulk modulus hydraulic oil.   c) lubricating the system with the lubricant.   
     
     
         13 . The method of  claim 12  further comprising choosing a hydraulic oil with favorable air release properties wherein the base stock has air release properties greater than equation:
     Y= 0.025 X− 0.27   Wherein:   Y=Percent air at 1 minute using ASTM D-3427 at 50° C.   X=Kinematic Viscosity at 40° C. in cST   
     
     
         14 . The method of  claim 12  wherein the density is chosen to be greater than 0.8 at 15.6° C. and the ASTM D-3427 air release is chosen to be less than 1.25 percent air at 1 minute. 
     
     
         15 . The method of  claim 12  further comprising choosing a hydraulic oil with at least one base stock from the group consisting of consisting of PAOs, Group III, GTL, aromatic esters, polyol esters, alkylated aromatics, phosphate esters, and any combinations thereof with favorable air release properties. 
     
     
         16 . The method of  claim 12  wherein at least one base stock is an ester and the ester comprises at least 20 percent of the hydraulic oil. 
     
     
         17 . A method of formulating a lubricating oil with favorable hydraulic efficiency comprising:
 a) obtaining at least one base stock chosen to have a favorable air release properties;   b) obtaining at least one additive;   c) blending at least one base stock and at least one additive to achieve a favorable bulk modulus and air release property using a relationship between density and bulk modulus.   
     
     
         18 . The lubricating oil of  claim 17  wherein the base stock has an ASTM D-3427 air release of less than 0.6 percent air at 1 minute. 
     
     
         19 . The lubricating oil of  claim 17  wherein the base stock has a bulk modulus of greater than 215,000 at 34.47 MPa (5,000 PSI). 
     
     
         20 . The lubricating oil of  claim 17  wherein at least one base stock is chosen form the group consisting of PAOs, Group III, GTL, aromatic esters, polyol esters, alkylated aromatics, phosphate esters, and any combinations thereof. 
     
     
         21 . The lubricating oil of  claim 17  wherein the lubricating oil has an ASTM D-3427 air release of less than 2 percent air at 1 minute. 
     
     
         22 . The lubricating oil of  claim 17  wherein the lubricating oil has an ASTM D-3427 air release of less than 1 percent air at 1 minute. 
     
     
         23 . The lubricating oil of  claim 17  wherein the lubricating oil has a bulk modulus greater than 195,000 at 34.47 MPa (5,000 PSI). 
     
     
         24 . The lubricating oil of  claim 17  wherein the base stock has air release properties better than equation:
     Y= 0.025 X− 0.55   Wherein:   Y=Percent air at 1 minute using ASTM D-3427 at 50° C.   X=Kinematic Viscosity at 40° C. in cST.   
     
     
         25 . The lubricating oil of  claim 17  wherein the base stock has air release properties better than equation:
     Y= 0.025 X− 0.27   Wherein:   Y=Percent air at 1 minute using ASTM D-3427 at 50° C.   X=Kinematic Viscosity at 40° C. in cST