Use of Lubricants on the Basis of Water-Soluble, High Viscosity Polyglycols

Abstract

The present invention relates to the use of lubricants on the basis of water-soluble, high-viscosity polyethylene glycols for lubricating open gearing, which is for example used in rotary kilns and mills.

Claims

1. The use of a lubricant comprising: providing a lubricant comprising; 90% to 99% by weight of a high-viscosity, water-soluble polyalkylene copolymer selected from the group consisting of (a) polyethylene oxide/polypropylene oxide in a ratio of 1:1 having a viscosity of 5 to 1500 cSt at 40 C. and a molecular weight of 90 to 4000, and (b) polyethylene oxide/polypropylene oxide in a ratio of 3:1 having a viscosity in the range from 90 to 54,000 cSt at 40 C. and a molecular weight in the range from 980 to 20,000, and 10% to 1% by weight of one or more additives; and introducing the lubricant into an open gear transmission system for rotary furnaces and mills used in one or more of the obtaining of minerals and ores, in the production of fertilizers, in waste processing, in cement production and in papermaking.

2. The use as claimed in claim 1, wherein the one or more additives are selected from the group consisting of antioxidants, anticorrosives, antiwear agents, pour point improvers, viscosity improvers, and UV stabilizers.

3. The use as claimed in claim 1 wherein the one or more additives are selected from the group consisting of boron nitride, compounds based on phosphates, carbonates, carboxylates, and alkali metal and alkaline earth metal salts of mono- and dicarboxylic acids.

4. The use as claimed in claim 1, wherein the lubricant further comprises one or more selected from the group consisting of esters, mineral oils, synthetic hydrocarbons, water-insoluble polyglycols.

5. The use as claimed in claim 1, wherein the lubricant contains: 98.7% by weight of polyethylene glycol/poly-propylene glycol 3:1 having a viscosity of 17,850 cSt at 40 C. and a molecular weight of 15,000 and a pour point of 4 C.; 1% by weight of phenolic antioxidant; and 0.3% by weight of succinic monoester as anticorrosive.

6. The use as claimed in claim 1, wherein the polyethylene oxide/polypropylene oxide has a viscosity in the range from 1000 to 18,000 cSt at 40 C. and a molecular weight in the range from 980 to 20,000.

7. A lubricant comprising: 90% to 99% by weight of a high-viscosity, water-soluble polyalkylene copolymer selected from the group consisting of polyethylene oxide/polypropylene oxide in a ratio of 1:1 having a viscosity of 5 to 1500 cSt at 40 C. and a molecular weight of 90 to 4000, and polyethylene oxide/polypropylene oxide in a ratio of 3:1 having a viscosity in the range from 90 to 54,000 cSt at 40 C. and a molecular weight in the range from 980 to 20,000; and 10% to 1% by weight of one or more additives.

8. The lubricant of claim 7, wherein the one or more additives are selected from the group consisting of antioxidants, anticorrosives, antiwear agents, pour point improvers viscosity improvers, and UV stabilizers.

9. The lubricant of claim 7, wherein the one or more additives are selected from the group consisting of boron nitride, compounds based on phosphates, carbonates, carboxylates, and alkali metal and alkaline earth metal salts of mono- and dicarboxylic acids.

10. The lubricant of claim 7, further comprising one or more base oils selected from the group consisting of esters, mineral oils, synthetic hydrocarbons, water-insoluble polyglycols.

11. The lubricant of claim 7, wherein the lubricant contains: 98.7% by weight of polyethylene glycol/poly-propylene glycol 3:1 having a viscosity of 17,850 cSt at 40 C. and a molecular weight of 15,000 and a pour point of 4 C.; 1% by weight of phenolic antioxidant; and 0.3% by weight of succinic monoester as anticorrosive.

12. The lubricant of claim 7, wherein the polyethylene oxide/polypropylene oxide has a viscosity in the range from 1000 to 18,000 cSt at 40 C. and a molecular weight in the range from 980 to 20,000.

Description

[0032] FIG. 1 shows the FZG* test rig (* Gear Research Center, Technical University of Munich).

[0033] The test was conducted under the following test conditions:

Circumferential speed: 2.8 m/s
Sprocket speed: 500 rpm
Run time per load stage: 45 minutes
Driving test wheel: sprocket
Total motor revolutions per load stage: 21 700
Dip lubrication: oil sump temperature from load stage 4 (LS 4): 50 C.
Amount of test oil: about 1.25 L
Test result: scuffing load stage DIN ISO 14635-3-A/2.8/40-M: ><12
Pitting load torque M.sub.test 534.5 Nm
Change in weight based on work performed M.sub.s 0.0186 mg/kWh

[0034] Table 1 shows the results.

TABLE-US-00001 TABLE 1 Mass of sprocket Mass of the sprocket Mass of the wheel and wheel Change Change Change in Load Work After LS in ms After LS in mw ms + w stage W ms [mg] mw [mg] [mg] LS [kWh] [g] [g] New 0.19 730.021 1260.370 4 6.43 730.021 0 0 1260.370 0 0 0 0 5 11.80 730.021 0 0 1260.370 0 0 0 0 6 19.50 730.021 0 0 1260.370 0 0 0 0 7 29.90 730.021 0 0 1260.370 0 0 0 0 8 43.50 730.021 0 0 1260.370 0 0 0 0 9 60.80 730.021 0 0 1260.370 0 0 0 0 10 82.00 730.021 0 0 1260.370 0 0 0 0 11 107.70 730.021 0 0 1260.370 0 0 0 0 12 138.10 730.021 3 3 1260.370 3 3 6 6

[0035] It becomes clear from the results shown in table 1 that the wear/attrition on combination of the values for sprocket and wheel is 6 mg after load stage 12.

[0036] In order to show the advantages with regard to the low wear or relatively low attrition, the FZG test was conducted with a conventional lubricant composition. The lubricant contained a mineral oil and polyisobutylene and had a viscosity of 10 000 cSt at 40 C. The abovementioned parameters are also the basis of this FZG test.

[0037] The results are shown Table 2.

TABLE-US-00002 TABLE 2 Mass of sprocket Mass of the sprocket Mass of the wheel and wheel Change Change Change in Load Work After LS in ms After LS in mw ms + w stage W ms [mg] mw [mg] [mg] LS [kWh] [g] [g] New 0.19 728.362 1267.747 4 6.43 728.362 0 0 1267.747 0 0 0 0 5 11.80 728.362 0 0 1267.747 0 0 0 0 6 19.50 728.362 0 0 1267.747 0 0 0 0 7 29.90 728.362 0 0 1267.747 0 0 0 0 8 43.50 728.362 0 0 1267.747 0 0 0 0 9 60.80 728.362 0 0 1267.747 0 0 0 0 10 82.00 728.362 0 0 1267.747 0 0 0 0 11 107.70 728.362 0 0 1267.747 0 0 0 0 12 138.10 728.362 17 17 1267.747 14 14 31 31

[0038] By contrast with the lubricant composition of the invention, the friction/wear loss was 31 mg at load stage 12.

[0039] As already mentioned, open gear transmission devices are mainly lubricated by means of spray devices. Therefore, the lubricant has to have excellent sprayability. The excellent sprayability of the abovementioned lubricant composition of the invention was conducted at various temperatures and pump pressures. Table 3 shows the results.

TABLE-US-00003 TABLE 3 Temperature Spray Spray method ( C.) Pump pressure (bar) pattern* fixed 10 3 fixed 10 5 fixed 10 7 OK fixed 25 3 fixed 25 5 not determinable fixed 25 7 good fixed 40 3 not determinable fixed 40 5 good fixed 40 7 good *The spray pattern was determined visually.

[0040] It was thus shown that the lubricant composition of the invention has good sprayability.

[0041] The lubricant composition of the invention is used in open gear transmission systems for rotary furnaces and mills that are used in the obtaining of minerals and ores, in the production of fertilizers, in waste processing, in cement production or in papermaking.