DE2031381A1 - Lubricating greases - Google Patents

Description

PAfENTANWJUTt

DR.-1NG. BY KREISLER DR.-ING. SCHÖNWALD DR.-ING. TH. MEYER DR.FUES DlPL-CHEM. ALKK BY KREISLER DIPL-CHEM. CAROLA KELLER DR ₁ -INCKLoPSCH Onqi

COLOGNE 1, DEICHMANNHAUS

Cologne, June 22nd, 1970

Fu / Ax

The British Petroleum Company Limited, Britannic House, Moor Lane, London, E.G.2 (England) »

Lubricating greases

The invention "relates to lubricating greases that are used to lubricate of gear wheels, in particular worm gears, consisting of a steel worm and a Worm gear made of bronze are suitable.

Certain sealed gears, such as those in gear boxes and automobile rear axles, which are lubricated with Sehmier oils, have been found to leak from the case. This leakage can lead to loss of lubrication and, consequently, excessive wear. «Furthermore, the surroundings become contaminated with oil. In order to reduce the leakage of the lubricant oil has been replaced by a fat _o In the previously used fats however arise during operation high temperatures, especially in environments where high shear and thrust forces. The high temperatures can lead to a loss of lubricity of the grease and to warping and wear of the gears. In order to avoid these difficulties, the output power must be reduced considerably.

It has now been found that soft greases, d _o h Schmierfetce with a high penetration value resulting from

1Q9813 / 14S0

certain synthetic lubricants thickened with a surface treated clay as a thickener are manufactured, good lubrication under high loads even in the difficult environment of worm gears result,.

The invention accordingly greases ₉ have a penetration value of more than 420 mm / 10 and contained a polyoxyalkylene compound of the type described below having a viscosity of 5 to 500 cS at 37.8 ⁰ C, with 2 to 8 wt _o - $ an oleophilic clay as a thickener is thickened to the consistency of grease.

The penetration value of the fat can be _s in ASTM D 217-58, is / / described IP5O 69 or IP167 59, determined with the aid of the test "

Polyoxyalkylene compounds include polyoxyalkylene glycol ethers the formula

see below »In this formula IL and R ^ each stand for a hydrogen atom, a non-aromatic hydrocarbon radical or an acyl radical _s R ₂ for an alkylene radical and η for an integer, preferably 1 Ms 15 =

In the polyoxyalkylene chain = 2Χ) θ7η * - ~, Rg can be an alkyleni ⁵ est, preferably an alkylene radical having 2 to 8 carbon atoms. RJ is preferably a ¥ asserstoffatom ₉ and R ^ is an alkyl radical, z ', B _e, a propyl ~ _{s s} butyl pentyl or decyl radical "

Me Polyoxyalkylenglykoläther preferably have a viscosity of from 5 Yis = Ms 300 cS at 38 ⁰ G ₀ Preferably, the alkylene component an ethylene-propylene or tetramethyl ^ = thylendiraäikalo In any given molecule can 2 or more different Alkylenkosponenten be present _o. The components can be made from any genius of 2 or 3 '

1011137 148 0

_ 3 -

Ethylene, isopropylene or tetramethylene residues exist. The tetramethylene radical can be derived from tetrahydrofuran be.

These types of polyoxyalkylene glycol ethers are among the Names Oxilube, Polyran, Ucon, Napter, Bisolube and ethylan are commercially available.

Oleophilic clays are known thickeners for Lubricating greases. The preferred clay is a montmorillonite, e.g. a bentonite which has been treated by reaction with a quaternary ammonium salt is used. The quaternary ammonium salt preferably contains an aromatic radical bonded to the nitrogen atom. Suitable clays are available under the trade name "Baragel" in trade.

The greases preferably have a penetration of 4-60 to 560 mm / 10, preferably from 480 to 560 mm / 10. The clay is preferably present in the grease in an amount from 2 to 6.5% by weight.

The greases can be made by conventional methods of making clay thickened greases will.

The lubricating greases according to the invention are particularly advantageous for the lubrication of worm gears, e.g. of sine corner gears in industry as well as in the Rear axles of certain automobiles. With this type of When driven, high shear and shear forces as well as high temperatures are generated. The preferred greases according to of the invention are semi-liquid and have lubricating properties approximately those of a good liquid lubricant while they do not drip and leak like normal greases. The lubricants according to the invention lubricate better than the harder ones Greases that have the same lubricating oil and one

1 0 9 8 1 3 / U 6 0

contain larger amount of thickener, and they also lubricate "better than greases of the same hardness made from the same base oil that are used with common High temperature soap thickeners such as lithium hydroxystearate The greases according to the invention are also soap-thickened Lubricating greases. Superior because they practically do not melt and from rotating mechanisms even at elevated levels Temperatures are not thrown away.

In certain cases the greases lubricate according to the Invention at least as good as the non-thickened lubricating oil.

In order to improve the antioxidant and anticorrosion properties of the lubricating greases, conventional additives can be added to them. Preferred as additives are anti-corrosion additives such as benzotriazole preferably in an amount of 0.05 to 5 percent by O ₉ "- $ Polytrialkylaihydrochinoline and preferably in an amount of 1 to 3 #.

The invention is illustrated by the following examples. Examples 2 to 4 describe comparative experiments. other lubricating greases "

example 1

Four greases were prepared by using a bentonite clay, the surface of which had been treated with 2 methyl groups, 1 phenyl group and a long chain alkyl group on the nitrogen atom-containing quaternary ammonium chloride, was in a heated Polyoxyalkylenglykoläther ₃ of a viscosity from 220 to 240 cS hei 37 ₉ 8 ° C »Was stirred in» The alkylene residues ■ of the polyoxyalkylene glycol were ethylene and propylene diradicals »

The four greases were in a worm gear that is used in practice in rear axles »at

10981 3 / U60

BATH ORIGINAL

a worm wheel torque of 138.3 mkg (1000 lbs.ft.) ($ 20 overload). The exam included Trials of 4 χ 10 hours. The results are after- j listed in Table 1. The basic liquid is included for comparison. I.

Table 1

Concentration of the penetration Test result thickener mm / 10. .

1. 8.2 382 failure before application

the full load

2. 7.4 415 dto.

3. 6.0 457 Very little wear,

pass an exam

4.1479

The condition of the worm gear was at the test. 3 and 4 at least as good as in attempt 5

The properties of the grease 4 of Table 1 are given in Table 2 below.

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-30 -20 0 2031381 90 +75 76 Table 2 310 330 0 +25 +50 515 Temperature, ° C -40 - kg / cm penetration 385 460 498 Rest penetration mm / 10 275 480 Ijialkpe netrat ion,
60 shocks 640 190 510 Walk penetration j
105 shocks 485 140 Torque "at
low temperature
(IP) Starting torque,
according to 2200 O ₈ 28 Torque "at
Run, gladly -1407 0.7 Resistance to oxidation
age Pressure drop in
100 hours Pressure drop in
500 hours Steel corrosion
(24 hours, 25 ⁰ C ₃
$ 100 relative
Humidity) Pafnir fretting corrosion
Testing machine

load
Oscillation arc oscillation frequencies E.
¥ duration of the request

Mean weight loss of the tread

FZ-Gh gear testing machine

vjo'lf! t Uf en loading

est A / H ₃ -S / SO · "-

499 kg

12 °
1400 / minute 25 hours

O ₀ 3 mg

SssasirsTrsrsohlel ,? the tooth"

18 rag

BATH ORIGINAL

* Α: tooth profile of the gears (drive pinion: 16 teeth;

Gear: 24 teeth)
2.8: Circumferential speed in the pitch circle in m / sec.

80 ι Starting temperature of the grease in G

Example 2

Two greases were put through a worm gear Gradual increase of the loads - to 180 mgk (1300 lbs. ft.) and recording of the engine power in Ampe're Forward run and reverse run checked. The center-to-center spacing of the gears was 10.2 cm and the reduction ratio 60: 1. The power consumption was 7 HP at 1400 rpm. The gears were completely in the Embedded in lubricating greases. A current of less than 16 A was considered satisfactory.

Both fats had a penetration between 420 and 480mm / 10 (ranges about 00 and 000) and were made from similar polyoxylalkylene glycols as the base fluid been. The fat A was thickened by the clay described in Example 1, and the fat 4 and B were thickened with lithium hydroxystearate.

The results are given in Table 3 below. The results for Grease A are the mean of four tests. The results for grease B are the mean values of two experiments.

109813 / U-6 0 BADORIGINAU

372 Table 3 current
- backwards
run, A Grease B 5.1 744 Grease A 5.4 Electricity electricity
Forward backward
run, A run, A 6.0 load
kg / m 1116 current
Forward
run, A - 5.1 7.9 O 1488 5.4 8.3 5.9 - 1637 - 9.8 7.9 13.7 1935 7.6 12.25 - 9.6 13.0 14.7 21.2 11.4 15.4 - 12.4 19.2 14.0

After completing the tests, the condition of the worm shaft was determined. The worm shafts were After all tests with lubricating grease A, it is flawless, but after testing with lubricating grease B due to overheating turned blue.

Example 3

A number of lubricating greases were tested in a bevel gear box with drive pinion and ring, whereby the ring ran at 6500 rpm and the drive pinion ran at 16000 rpm for 200 hours. The greases used and the Results are given below, “Greases

Mineral oil thickened with lithium soap

Mineral oil thickened with sodium soap

Mineral oil thickened with aluminum soap

Mineral oil thickened with sodium soap

* Thickened with clay. Polyoxyalkylene glycol

109813 / U 6 0

Penetra
tion
mm / 10 Result 330 insufficient 330 Il 330 It 380 Il 420 perfect · BATH ORlGMAL

- 9 - 2031

* Grease 4 from example 1.

If the lubricating grease was insufficient, the gearbox failed because the oil was separated out by centrifugation, as a result of which the lubrication failed and the bearing would press

These results show that with the according to the invention from the special thickener and the special Oil produced soft Sehmierfett a better lubrication than is achieved with the systems tried so far. This improvement in lubrication was completely unexpected.

Example 4

A number of lubricating greases have been used on the load-bearing capacity in a worm gear with a reduction ratio checked by 30: 1 “The maximum temperature above the ambient temperature, depending on the load in ft.lbs. graphically represented. the Results can be seen from the graph,

The grease A was prepared by thickening one serving as a base oil polyoxyalkylene glycol ether with a Lithium hydroxystearate soap, a grease being des Type 00 was obtained. Grease B was obtained by thickening a polyoxyalkylene glycol ether of 8.2% by weight of an oleophilic clay to a grease of type 000 ". The grease C corresponded to the grease 4 according to FIG Example 1.

ORIGfNAL

Claims

Sehmier fat based on a base oil which is thickened to a lubricating fat consistency by adding clay as a thickener, characterized in that the base oil is polyoxyalkylene glycol ether with a viscosity of 5 to 500 cS at 38 ° C and the thickener in amounts of 3 to 6.5 wt. -% are present and that the grease has a penetration value of more than 420 mm / 10 »

Lubricating grease according to claim 1, characterized in that up to 2 wt »0.05 - $ benzotriazole and / or 1 to 5 wt -.% Polytrialkyldihydrochinolin contains"