RU2238304C1 - Friction modifier - Google Patents

Abstract

FIELD: lubricants, in particular lubricants for railway machines.

SUBSTANCE: invention relates to lubricants for high-loaded friction assembly of various mechanisms, in particular friction pair of side and functional top of rail surfaces. Claimed friction modifier contains (%): glass 2-30; cement 3-25; bitumen 0.5-50; graphite 0-30; sand 0-75 %; potassium permanganate 1-20; glycerol 0.5-23; antiscratch additive (e.g. molybdenum disulphide) 0.5-30; antifriction additive (e.g. polyethylene) 0.5-30; plate additive (e.g. copper powder) 0.5-30; and balance: hydrocarbon solvent.

EFFECT: enhancement of functional temperature range, improvement of plating and antiscratch lubricant characteristics, etc.

1 tbl, 2 dwg

Description

The invention relates to lubricants and can be used to lubricate heavily loaded friction units of various mechanisms, in particular friction pairs of the side and working (traction) surfaces of the rail head - flange, the rolling surface of a railway wheel.

Known lubricant for lubrication of railway rails consisting of graphite, bitumen, silicate glue (1. RF patent No. 2065484 C1, C 10 M 169/04, publ. 08/20/96).

The disadvantage of this lubricant is a narrow scope, for example, the inability to apply wheel pairs of locomotives and rails to the working surface due to the low level of adhesion coefficient, insufficient for the locomotive to realize high traction forces.

Closest to the described solution is the "Rail friction modifier" (2. RF patent No. 2170756 C1, C 10 M 169/04, 07.20.2001)

The lubricant composition of the prototype is as follows, wt.%:

Bitumen 0.5-50

Graphite 0-30

Sand 0-75

Glass 2-20

Cement 5-25

Boric acid 1-10

Silicone composition 3-40

Hydrocarbon solvent

The disadvantage of the prototype lubricant is a narrow operating temperature range due to the increase in the viscosity of the rail friction modifier at temperatures below -11 ° C, the low speed of the friction pair wheel-rail entry into the established friction mode when the modifier is fed into the friction contact zone, the absence of cladding and extreme pressure additives .

The technical task of the proposed solution is to expand the operating temperature range, accelerate the process of entry of the friction wheel – rail pair into the steady state of friction when the modifier is fed into the friction contact zone, and increase the cladding and extreme pressure properties of the lubricant.

The object is achieved in that the lubricant for lubrication of railway rails, containing glass, a hydrocarbon solvent, cement, bitumen and optionally graphite and sand, according to the invention further comprises: potassium permanganate, glycerin, extreme pressure (for example, molybdenum disulfide), anti-friction (for example, polyethylene ) and cladding (for example, copper powder) additives in the following ratio of components, wt.%:

Bitumen 0.5-50

Graphite 0-30

Sand 0-75

Glass 2-30

Cement 3-25

Potassium Permanganate 1-20

Molybdenum disulfide 0.5-30

Copper Powder 0.5-30

Polyethylene 0.5-30

Glycerin 0.5-23

Hydrocarbon solvent

A lubricant is prepared by mixing glass (for example, GOST 13078-81 glass), heated bitumen (for example, GOST 6617-76 bitumen) with a hydrocarbon solvent (for example, A-76 gasoline GOST 2084-77), then glycerin (for example, GOST glycerin is introduced) 6824-96), a cladding additive consisting of a metal powder having a lower hardness on the Maos scale than metal of working bodies (for example, TU 48-0318-054-91 copper powder), potassium permanganate (for example, KMnO ₄ ), graphite ( for example, graphite C - 1 TU 13-08-48-63-9), sand (for example, sand GOST 8736-93), cement (for example, cement 500 GOST 969-91), anti-friction an additive (for example, polyethylene TU 2211-06-05796653-98), an extreme pressure additive (for example, molybdenum disulfide GOST 16539-79) are mixed for 20-25 minutes until the components are evenly distributed and the grease acquires a uniform color.

Introduction to the composition of the lubricant glycerol allows to reduce the evaporation of the base with increasing temperature and prevents it from hardening at low temperatures.

The introduction of potassium permanganate into the lubricant makes it possible to increase the speed of the entry of the friction wheel – rail pair into the steady friction mode when the modifier is fed into the friction contact zone, and the cladding and extreme pressure properties of the lubricant are increased.

The introduction of molybdenum disulfide and “soft metals” powders into the grease makes it possible to enhance the extreme pressure and clad properties of the grease.

The introduction of polyethylene into the lubricant makes it possible to enhance the antifriction properties of the lubricant.

To evaluate the lubricating ability of the “friction modifier” when operating in the rolling friction mode with slippage, the upgraded friction machine 2070 SMT-1 of the Amsler type was used.

The parameters of the samples were set so as to satisfy the scale of the simulation, in particular, the specific pressure in the contact and the sliding velocity in nature and the model were kept the same.

Rollers are made of steel with a chemical composition close to bandage and rail steel: a wheel roller is made of 60 G steel, GOST 1050-74;

lower (rail) - from steel 70 G, GOS T 1050-74.

Test modes.

The tests were carried out under the regimes corresponding to the real wheel crest - rail friction unit and the brace working surface - rail, specific contact pressure 3500 MPa and 850 MPa, respectively, sliding speed 0.05 m / s. During testing at room temperature, these factors remained constant. Continuously recorded the moment of friction (see figure 1).

To determine the viscosity of the base when glycerol was added, a thermostat and a viscometer with a capillary diameter of 0.62 mm were used (GOST 10028-67).

Determination of the extreme pressure properties of the lubricant was carried out by visual analysis of the friction surfaces of the samples using a MIM - 7 microscope at a hundredfold increase. The analysis shows that the introduction of molybdenum disulfide into the lubricant helps to reduce the concentration and size of the grooves on the friction surface in the sliding direction, which are the hallmark of scoring according to GOST 16429-70.

The test results are presented in the table. The results of changing the viscosity of the base are presented in figure 2.

The test results show that the proposed composition is superior to the prototype lubricant in terms of the speed of the friction pair entering the steady state friction when applying the modifier to the friction contact zone.

The lubricant improves the conditions for the interaction of the working surfaces of the bandages of wheelsets of locomotives and rails.

When applying lubricant to the surface of the bandage, a uniform contact (0.001-0.005 mm) strong lubricant layer is formed, which is well perceptible to dynamic loads, is kept under the influence of atmospheric precipitation, changes in ambient temperature, has a high bearing capacity, lubrication of the working (traction) surface of the rail head and bandages of locomotive wheelsets with a certain percentage of components allows to increase the coefficient of adhesion of the wheel to the rail, which leads to the possibility of realizing more e high tractive effort.

Claims (1)

A friction modifier comprising glass, a hydrocarbon solvent, cement, bitumen, and optionally graphite and sand, characterized in that it further comprises potassium permanganate, glycerin, extreme pressure, such as molybdenum disulfide, anti-friction, such as polyethylene, and cladding, such as copper powder, additives in the following ratio of components, wt.%: Bitumen 0.5-50 Graphite 0-30 Sand 0-75 Glass 2-30 Cement 3-25 Potassium Permanganate 1-20 Molybdenum disulfide 0.5-30 Copper Powder 0.5-30 Polyethylene 0.5-30 Glycerin 0.5-23 Hydrocarbon solvent

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