Lubricant compositions

1. A wind turbine gear additive concentrate, comprising:

a) about 20 to about 60 wt. % of an extreme pressure compound comprising a sulfur-containing compound;

b) load carrying capacity enhancing combination comprising

(i) about 10 to about 30 wt. % of a hydrocarbylamine compound selected from the group consisting of N-oleyl-trimethylene diamine, N-tallow-trimethylene diamine, N-coco-trimethylene diamine, and combinations thereof, and

(ii) about 10 to about 30 wt. % of an alkylphosphoro(mono)thioate compound represented by the formula:

 where each of R 1 , R 2 , and R 3 is, independently, an unsubstituted alkyl group or a hydrogen atom, and where at least one of R 1 , R 2 , and R 3 is an unsubstituted alkyl group, and where each of X 1 , X 2 , and X 3 represents an oxygen atom;

c) about 10 to about 30 wt. % of a long chain alkyl phosphonate friction modifying compound represented by the formula:

 wherein R a is an alkyl group having from 12 to 18 carbon atoms and R b and R c each independently comprise from about 1 to about 4 carbon atoms; and

d) a diluent oil,

wherein any of compounds a), b)(i), b)(ii), and c) can be the same or different compounds.

2. The additive concentrate according to claim 1 , wherein at least one of R 1 , R 2 , and R 3 is an unsubstituted aliphatic alkyl group of 3 to 20 carbon atoms.

3. The additive concentrate according to claim 1 , wherein the extreme-pressure agent comprises a metal-free sulfur-containing extreme-pressure agent selected from the group consisting of sulfurized olefin and polysulfide composed of one or more groups represented by the formula R a —S x —R b where R a and R b are hydrocarbyl groups each of which contains 3 to 18 carbon atoms and x is in the range of from 2 to 8.

4. A wind turbine gear composition, comprising:

a) about 0.5 to about 2.5 wt. % of an extreme pressure compound comprising a sulfur-containing compound;

b) load carrying capacity enhancing combination comprising

(i) about 0.1 to about 1.0 wt. % of a hydrocarbylamine compound selected from the group consisting of N-oleyl-trimethylene diamine, N-tallow-trimethylene diamine, N-coco-trimethylene diamine, and combinations thereof, and

(ii) about 0.1 to about 1.0 wt. % of an alkylphosphoro(mono)thioate compound represented by the formula:

 where each of R 1 , R 2 , and R 3 is, independently, an unsubstituted alkyl group or a hydrogen atom, and where at least one of R 1 , R 2 , and R 3 is an unsubstituted alkyl group, and where each of X 1 , X 2 , and X 3 represents an oxygen atom;

c) about 0.1 to about 1.0 wt. % friction modifying compound of a long chain alkyl phosphonate friction modifying compound represented by the formula:

 wherein R a is an alkyl group having from 12 to 18 carbon atoms and R b and R c each independently comprise from about 1 to about 4 carbon atoms; and

d) about 90 to about 99 wt. % of base oil,

wherein any of compounds a), b)(i), b)(ii), and c) can be the same or different compounds with the proviso that b)(i) and b)(ii) are different.

5. The composition according to claim 4 , wherein at least one of R 1 , R 2 , and R 3 is an unsubstituted aliphatic alkyl group of 3 to 20 carbon atoms.

6. The composition according to claim 4 , wherein the extreme-pressure agent comprises a metal-free sulfur-containing extreme-pressure agent selected from the group consisting of sulfurized olefin and polysulfide composed of one or more groups represented by the formula R a —S x —R b where R a and R b are hydrocarbyl groups each of which contains 3 to 18 carbon atoms and x is in the range of from 2 to 8.

7. The composition according to claim 4 , wherein the composition has a kinematic viscosity of at least 12 cSt at 100° C.

8. The composition according to claim 4 , wherein the base oil has a viscosity in the range of SAE 50 to SAE 250.

9. The composition according to claim 4 , wherein the base oil has a viscosity in the range of SAE 70W to SAE 140.

10. A method of manufacturing a composition suitable for use in a wind turbine gear assembly comprising blending a base oil; about 0.5 to about 2.5 wt. % of an extreme pressure compound comprising a sulfur-containing compound; about 0.1 to about 1.0 wt. % of a hydrocarbylamine compound selected from the group consisting of N-oleyl-trimethylene diamine, N-tallow-trimethylene diamine, N-coco-trimethylene diamine, and combinations thereof; about 0.1 to about 1.0 wt. % of an alkylphosphoro(mono)thioate compound represented by the formula:

where each of R 1 , R 2 , and R 3 is, independently, an unsubstituted alkyl group or a hydrogen atom, and where at least one of R 1 , R 2 , and R 3 is an unsubstituted alkyl group, and where each of X 1 , X 2 , and X 3 represents an oxygen atom; and about 0.1 to about 1.0 wt. % friction modifying compound of a long chain alkyl phosphonate friction modifying compound represented by the formula:

wherein R a is an alkyl group having from 12 to 18 carbon atoms and R b and R c each independently comprise from about 1 to about 4 carbon atoms, and wherein the composition demonstrates improved load carrying capacity as compared to a composition devoid of the hydrocarbylamine compound and alkylphosphoro(mono)thioate compound.

11. A method of lubricating a gear comprising using as the lubricant for said gear a gear oil composition according to claim 4 .

12. A lubed gear-box comprising a gear within the gear box, in which the gear is lubricated according to the method of claim 11 .

13. A method of lubricating a wind turbine gear assembly comprising using as the lubricant for said gear assembly a composition according to claim 4 .

14. A wind turbine gear assembly lubricated with a composition according to claim 4 .