DE689638C - High pressure lubricant - Google Patents

Description

In well-lubricated shaft bearings, the bearing pressures usually do not exceed ι j4 kg / mm ² , and under such conditions one can expect that a heavy oil film between the rubbing surfaces is .vorhanden. In the case of gearboxes, however, the bearing pressure often reaches 1.7 to 18 kg / mm ² . At such high pressures, an ordinary lubricating oil is not viscous enough to prevent metallic contact, which leads to abrasion of the gears.

It is known to use sulfur, chlorine, sulfur, Adding sulfurized oil, heavy metal soaps, castor oil and organic halogen compounds, however, is the effect these means unsatisfactory because they give rise to hydrolysis or oxidation

ao formation of corrosive substances. The presence of a small amount of water makes the corrosion significant increased. Lubricants are also known which contain tricresyl phosphate or of phosphoric acid esters of secondary alcohols, but the lubricating effect of an oil is enhanced by the addition such esters are not significantly improved, especially at high pressures.

According to the invention, the following are used as _: high-pressure lubricants, lubricating oils which contain esters of phosphoric acid with primary alcohols. The alkyl esters mainly considered are those which contain a carbon chain with at least 8 atoms, in particular mixtures of such esters, since these are generally liquid, stable and easily soluble in the lubricant.

These organic esters, when dissolved in lubricating oil, are capable of interacting with the metal of the bearing surface, with which they come into contact, a non-corrosive lubricating film to form the "wear and tear" by preventing metallic contact with the bearing surfaces holds back and withstands high bearing pressures. These films have unusually good lubricating properties all prints, but are particularly valuable with high stock pressures and with high all-around running speeds. They are caused by water, oil or organic solvents not washed away from the bearing surfaces, nor do they flow from vertical ones Bearing surfaces from, but rather remain on them and continue to exert their effect until they are consumed the end. Phosphoric acid esters of the primary alcohols are also more stable than that of the secondary alcohols.

The formation of the desired lubricating film depends on the nature of the one used Esters, from the lubricating oil in which it is distributed, as well as from the temperature

the temperatures and pressures to which it is exposed. Lubricating oil mixtures with acidic esters easily form the desired film at ordinary pressures and temperatures. Lubricating oil mixtures with neutral esters, on the other hand, must have high pressures and resp. or exposed to temperatures if the desired effect is to occur.

These esters are used together with a

to lubricating oil, preferably of mineral or vegetable origin, in which the organic esters are soluble, dispersible or emulsifiable.

The organic esters can either be in the form of the free esters or in the form of Salts such as B. of sodium, potassium, ammonium and organic amine salts,

medium Ester Movie
resistance
in kg / mm ² Turn
moment
in kg / cm Paraffin oil o, 5 ° / ₀ Düaurylphosphat
ι% dicetyl phosphate
ι ° / ₀ dioleyl phosphate
ι ° / ₀ dilauryl phosphate 2.1 to 3.5 containing oil S 14.1
38.67
38.67
31.5
36.56 over 55.3
26.7 to 29.4
26.7
26.7
29.4 Mineral oil SAE 30
Mineral oil SAE 30
Mineral oil SAE 30
Mineral oil 600 W ...........

Mineral oil SAE 30 is a medium oil

Viscosity, mineral oil 600 W is a heavy oil.

Other compounds of this type found to be effective are: diethyl phosphate, triethyl phosphate, the monophosphate of the diglyceride obtained by partial hydrolysis of linseed oil, mono- and dibutyl phosphate mixtures.

be turned. An addition of such a small amount as 0.05 o / _o to an oil has a remarkable effect already, but it is usually necessary for practical purposes, of which to use at least 0.20 / 0th

For the table below, the effect of the invention was illustrated that of J. O. AlImen (Oil and Gas Journal 30, 109, 1931.) described test method applied. The values given in the following examples represent those calculated actual stock pressures achieved without the film disappearing. These Values indicate the film thickness. The developed friction or torque are also indicated.

Claims (1)

Claim: High pressure lubricant, characterized in that the same next to a Lubricating oil in small quantities with one or more alkyl esters of phosphoric acid contains primary alcohols.