EL 44 075.0 traction gearbox: the teeth gained metal, the control one kept wearing

Gear teeth of the treated gearbox regained thickness, the untreated one kept wearing. EL 44 electric locomotive No. 075.0, ZhP Traktsia Lokomotivi, BDZ EAD.

ZhP Traktsia Lokomotivi — Sofia, BDZ EAD · signed by: Eng. V. Todorov, Eng. R. Lukanov, Eng. S. Nikolova · treatment by XADO technology carried out by MAY OOD — A. Iliev, V. Dzhondzhorova

Sofia, Bulgaria · treatment 24.01.2003 · control measurements 01.07.2003

PRODUCTTreatment
by XADO technologyone traction motor gearbox was treated, the second gearbox of the same locomotive was left as the control

TEST OBJECTEL 44 electric locomotive No. 075.0BDZ EAD · traction motor gearboxes, wheelsets 20958 X 76 951 and 34051 XI 79 1237

DOCUMENT TYPECommission report
with five signatures

Key results

↑0.47mm

small gear tooth thickness, average; deviation from nominal 0.50-0.57 → 0.00-0.03 mm

↑0.20mm

large gear tooth thickness, average; deviation from nominal 0.70-1.11 → 0.60-0.95 mm

↓0.20mm

small gear of the untreated gearbox over the same 63 314 km, deviation 0.25-0.32 → 0.40-0.55 mm

MACHINE AND UNIT	SERVICE DURING THE TEST	WHAT WAS MEASURED
EL 44 electric locomotive No. 075.0, traction motor gearbox — experimental, wheelset 20958 X 76 951	63 314 km · 158 days	Thickness of five marked teeth of the large gear at three points, with two tooth calipers; thickness of five teeth of the small gear
Same locomotive, traction motor gearbox — control, wheelset 34051 XI 79 1237, not treated	63 314 km · 158 days	Thickness of the small gear teeth, the same measuring points

Treated gearbox — large gear wheel, tangential tooth caliper

TOOTH	READING AT 30 MM	READING AT 60 MM	READING AT 80 MM
1	−1.0 → −0.70	−1.03 → −0.90	−1.06 → −0.80
2	−1.01 → −0.95	−1.05 → −0.90	−1.10 → −0.91
3	−1.0 → −0.82	−0.99 → −0.80	−0.95 → −0.80
4	−0.70 → −0.65	−1.06 → −0.80	−0.90 → −0.60
5	−1.11 → −0.80	−1.10 → −0.92	−1.05 → −0.90

Deviation of tooth thickness from nominal, in millimetres: before treatment → after 63 314 km of running. Five pre-marked teeth were measured, each at three points; the control readings were taken on the same teeth. Thickness increased at all fifteen points, growth 0.05-0.31 mm.

The same gear wheel, second caliper — standard type

TOOTH	READING AT 30 MM	READING AT 60 MM	READING AT 80 MM
1	16.60 → 16.90	16.50 → 16.66	16.48 → 16.72
2	16.50 → 16.68	16.52 → 16.62	16.52 → 16.70
3	16.42 → 16.60	16.55 → 16.70	16.55 → 16.69
4	16.48 → 16.60	16.60 → 16.65	16.55 → 16.72
5	16.55 → 16.65	16.55 → 16.68	16.55 → 16.64

Tooth thickness in millimetres. The same teeth and the same points were measured with a second caliper: growth 0.05-0.30 mm, an increase at all fifteen points. Two different instruments give one and the same result for the treated gearbox.

Treated gearbox — small gear wheel

TOOTH	DEVIATION BEFORE TREATMENT	DEVIATION AFTER 63 314 KM	THICKNESS CHANGE
1	−0.57 mm	0.00 mm	+0.57 mm
2	−0.53 mm	+0.03 mm	+0.56 mm
3	−0.50 mm	+0.03 mm	+0.53 mm
4	−0.50 mm	+0.03 mm	+0.53 mm
5	−0.50 mm	+0.03 mm	+0.53 mm

Measured at mid-tooth, deviation from nominal. All five teeth reached nominal thickness: four exceeded it by 0.03 mm, the fifth came out exactly at nominal.

Control gearbox of the same locomotive — small gear wheel

TOOTH	DEVIATION AT THE START	DEVIATION AFTER 63 314 KM	THICKNESS CHANGE
1	−0.30 mm	−0.40 mm	−0.10 mm
2	−0.25 mm	−0.50 mm	−0.25 mm
3	−0.32 mm	−0.55 mm	−0.23 mm
4	−0.32 mm	−0.55 mm	−0.23 mm

This gearbox was not treated and covered the same 63 314 km on the same locomotive, under the same conditions. Before the test it was less worn than the treated one, therefore the absolute thicknesses of the two gearboxes are not compared with each other: every tooth is compared with itself.

Conclusions of the report

Both gearboxes ran the same 63 314 km on one locomotive and under identical conditions; the oil of the treated gearbox was neither changed nor topped up over the whole run. The commission of ZhP Traktsia Lokomotivi — Sofia recorded in the section "Izvodi" (Conclusions): 1. The teeth of the large gear of the experimental gearbox grew on average by 0.20 mm. 2. The teeth of the small gear of the experimental gearbox grew on average by 0.47 mm. 3. On the teeth of the large gear of the control gearbox slight wear was noted — up to 0.02 mm. 4. On the teeth of the small gear of the control gearbox wear of up to 0.2 mm was noted. 5. On the teeth of the large gear of the experimental gearbox the healing of existing pittings is observed, except for those outside the contact zone.

The results refer to the traction motor gearbox of EL 44 electric locomotive No. 075.0 at a run of 63 314 km; on other units and under other operating modes the figures may differ. The treatment was carried out by MAY OOD — a XADO distributor; the measurements and their certification — by the commission of ZhP Traktsia Lokomotivi, Sofia. The report is published in full and available for download.

Current equivalent

Revitalizant gel for gearboxes →

Industrial gearboxes, final and central drives, truck and tractor gearboxes, open gear and chain drives.

How such units are treated: Reduction gearbox Gear drive

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