RU2414504C1 - Grease - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to grease for lubricating rolling bearings working under heavy loads at low and average rational speeds at temperature between minus 40 and 120°C. The grease contains a base in form of Litol-24, and highly dispersed powder of metallic filler. The metallic filler used is quasi-crystalline Al-Cu-Fe powder with particle size of not more than 1 mcm with the following ratio of components, wt %: quasi-crystalline powder 4-6, Litol-24 grease - the rest.

EFFECT: longer service life of friction couples in a wide temperature range.

2 tbl, 1 dwg

Description

The invention relates to plastic antifriction greases intended for the lubrication of rolling bearings operating under high loads at low and medium speeds in the temperature range from minus 40 to 120 ° C. The composition of plastic antifriction multi-purpose grease obtained by thickening petroleum oils with lithium 12-oxystearate and containing antioxidant additive (Chemical Encyclopedic Dictionary edited by I.N. Knunyants. M: Soviet Encyclopedia, 1983, p. 304). Known grease is produced on an industrial scale under the brand name "Litol-24" - GOST 21150-87.

Known lubricant has good water resistance, mechanical stability and performance in a wide temperature range. However, its use in friction units, in particular in rolling units, does not prevent their wear and provide indicators that increase the service life.

Greases based on Litola-24 are known, in which a powdery antifriction filler, for example graphite, is added to increase the service life of friction pairs (sealed rolling bearings). (USSR AS No. 1705333, IPC S10M 141/04, op. 15.01.92). The service life of bearings is 2700 hours.

Closest to the patented is a grease, including a base, which is used as Litol-24, and a fine powder of a metal filler of non-ferrous metals or their alloys with a particle size of not more than 20 microns, in the following ratio of components, wt.%: Fine powder of metal filler from non-ferrous metals or their alloys - 0.05-0.1; Litol-24 - the rest. (see RU 2267520, C10M 125/04, 2005). As a metal filler powder, soft metals are used - zinc, bronze, lead. The claimed amount of metal powder provides a lubricant with improved protective properties that helps to prevent wear during operation of high-speed friction pairs in a wide temperature range from -50 to + 150 ° C. The disadvantage of this lubrication is the limited service life of 5700 hours for the best sample.

The objective of the patented invention is to increase the service life of friction pairs in a wide temperature range.

The problem is solved by grease, including a base, which is used as Litol-24, and highly dispersed metal filler powder, while Al-Cu-Fe quasicrystalline powder with a particle size of not more than 1 μm is used as a metal filler in the following ratio of components, wt .%: quasicrystalline powder - 4-6; Litol-24 - the rest.

Preparation of the lubricant described in the application materials.

Powder of quasicrystals of Al, Fe, Cu with a particle size of not more than 1 μm in a ratio of 45.23-18.72-36.05 wt.% Is preliminarily prepared

The required amount of Litol-24 grease is weighed on a technical balance with an accuracy of 0.1 g and transferred to a mixer glass. The amount of lubricant in the mixer should not exceed 2/3 of the volume of the mixer.

The quasicrystal powder is weighed in a special container on a technical balance with an accuracy of 0.1 g. Then, carefully, without dusting, the powder is introduced into the cylinder with lubricant, and the mixer lid is closed. Turn on the stirrer for stirring.

As a mixing device, a perforated disk or a Z-shaped mixer is used.

The mixing time for the disk mixer is 60 single strokes, for the Z-shaped one - no more than 10 minutes in each direction (depending on the capacity of the mixer) is established experimentally, while reducing the tensile strength is not allowed (see table 1).

The lubricant quality assessment was carried out according to the laboratory bench test methodology adopted in the bearing industry, and included the determination of physicochemical parameters and comparative bench tests.

Table 1 shows the compositions of the studied lubricants and their physico-chemical parameters, which were determined in accordance with existing regulatory documents (GOST 7141-73 method B, GOST 7141-74).

Bench tests were carried out in the standard test mode (n = 8000 min ^-1 , F _r = 1500 H, the temperature of the outer ring of the bearing t is steady state). The criterion for terminating the tests was an increase in the temperature of the outer ring by 20 ° C compared with the steady-state temperature.

The drawing shows graphs of the temperature of self-heating bearings with lubricants of compositions 1 and 6 (No. of samples in table 1 - pure Litol-24 and Litol-24 + 5% quasicrystal powder). The temperature of the outer ring of the bearing with a modified lubricant is significantly lower than in the case of pure Litol-24, which helps to reduce the rate of development of destructive processes in the lubricant.

Bench test data are given in table 2.

From table 2 it follows that the performance of radial ball bearings with standard grease Litol-24 is 5300 hours. The performance of Litol-24 grease with 5% quasicrystals is more than 8500 hours. Thus, the results of bench tests showed that the lubricant of the proposed composition for bearings of the closed type of general purpose with permanently embedded grease can increase the service life of these bearings.

Table 1 Sample Number Compositions, wt.% one 2 3 four 5 6 7 8 9 10 eleven Al-Cu-Fe quasicrystals 0 1,0 2.0 3.0 4.0 5,0 6.0 7.0 8.0 9.0 10.0 Litol-24 100.0 99.0 98.0 97.0 96.0 95.0 94.0 93.0 92.0 91.0 90.0 Tensile strength, Pa at 20 ° C 500-1000 780 820 840 860 860 880 880 900 920 1100 50 ° C 700 700 710 720 720 740 740 760 780 780 800 Colloidal stability,% extracted oil ≤12 10.7 10.5 10.5 10.0 9.6 9,4 9.2 8.6 8.0 7.8

table 2
The results of comparative bench tests of Litol-24 grease and its derivatives in sealed ball bearings. Grease Compositions Litol-24 + quasicrystal powder one 2 3 four 5 6 7 8 8 10 eleven Average working hours 5300 5300 5300 7500 8300 8500 * 8500 5500 2500 1200 500 ^* - tests are terminated due to high operating time.

Thus, the proposed lubricant will increase the service life of friction pairs, in particular rolling bearings operating under high loads at low and medium speeds in the temperature range from minus 40 to 120 ° C.

Claims (1)

A grease comprising a base, which is used as Litol-24, and a finely dispersed metal filler powder, characterized in that Al-Cu-Fe quasicrystalline powder with a particle size of not more than 1 μm is used as a metal filler in the following ratio of components, wt. %: quasicrystalline powder - 4-6, grease Litol-24 - the rest.

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