Gear oil lubricants of enhanced friction properties
AssigneeEthyl Petroleum Additives, Inc.
InventorsGraeme M. Wallace, Julia C. Poat
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Abstract
The frictional properties of gear oils are improved by including at least one overbased alkali or alkaline earth metal carboxylate, sulphonate or sulphurized phenate having a TBN of at least 200 in a gear oil which comprises: oil of lubricating viscosity at least 80% by volume of which is mineral oil, synthetic ester oil or a mixture thereof; Mannich base ashless dispersant; metal-free, sulphur-containing antiwear and/or extreme pressure agent; and metal-free, phosphorus-containing and nitrogen-containing antiwear and/or extreme pressure agent. The resultant gear oils exhibit excellent performance when used in synchromesh-based transmissions.
Claims8
A method of improving the gear shift performance in a synchromesh transmission which comprises contacting the gears of the synchromesh transmission with a gear oil which comprises at least the following components:
- a) oil of lubricating viscosity at ].east 80% by volume of which is mineral oil or synthetic ester oil or a blend thereof;
- b) at least one Mannich base ashless dispersant;
- c) at least one metal-free, sulphur-containing antiwear and/or extreme pressure agent;
- d) at least one metal-free, phosphorus-containing and nitrogen-containing antiwear and/or extreme pressure agent;
- and
- e) at least one overbased alkali or alkaline earth metal carboxylate, sulphonate or sulphurized phenate having a TBN of at least 200;
- in proportions sufficient to improve the gear shift performance of the synchromesh transmission, said lubricant containing at most, if any, 100 ppm of metal as one or more metal-containing additive components other than said component e).
In a method of increasing the frictional properties of a gear oil lubricant comprising components (i) at least one Mannich base ashless dispersant;
- (ii) at least one metal-free, sulphur-containing antiwear and/or extreme pressure agent;
- (iii) at least one metal-free, phosphorus-containing and nitrogen-containing antiwear and/or extreme pressure agent;
- the improvement comprising the addition to said gear oil lubricant for use in a synchromesh transmission of (iv) at least one overbased alkali or alkaline earth metal carboxylate, sulphonate or sulphurized phenate having a TBN of at least 200 in proportions sufficient to thereby improve the frictional properties of said lubricant in a synchromesh transmission;
- said lubricant containing at most 100 ppm of metal as one or more metal-containing additive components other than said component (iv).
A method of operating a motor vehicle having a manual sychromesh transmission equipped with at least one cone-type synchronizer, which method comprises employing in said transmission a gear oil which comprises:
- a) oil of lubricating viscosity at least 80% by volume of which is mineral oil or synthetic ester oil or a blend thereof;
- b) at least one Mannich base ashless dispersant;
- c) at least one metal-free, sulphur-containing antiwear and/or extreme pressure agent;
- d) at least one metal-free, phosphorus-containing and nitrogen-containing antiwear and/or extreme pressure agent;
- and
- e) at least one overbased alkali or alkaline earth metal carboxylate, sulphonate or sulphurized phenate having a TBN of at least 200 in an amount sufficient to raise the coefficient of friction between the synchronizer cones to greater than or equal to 0.065;
- in proportions sufficient to improve the gear shift performance of the synchromesh transmission, said gear oil containing at most, if any, 100 ppm of metal as one or more metal-containing additive components other than said component e).
Dependencies are inferred from the claim text.