Locomotive traction gearbox: gear teeth gained metal with no teardown, in service

“MAY” OOD together with Locomotive Depot – Plovdiv · signed by: Deputy Director of Rail Traction D. Spasov, Head of Repairs N. Hristev, Chief Specialist for Safety and Inspection Yonchev, fitter N. Zhekov, Manager of “MAY” OOD A. Iliev

Plovdiv, Bulgaria · testing 22.06–10.10.2002 · report dated 16.10.2002

PRODUCTXADO revitalizant gel for gearboxesadded to the oil bath in 3 stages at 8-hour intervals, without dismantling the gearbox

TEST OBJECTTwo traction gearboxes of locomotive No. 44 099one gearbox treated, the other left as control · both ran under identical conditions

DOCUMENT TYPECommission report
signed and stamped by the depot

Key results

↑0.34-0.58mm

tooth thickness of the treated gear wheel, deviation from nominal 0.62-1.22 → 0.26-0.64 mm

↓0.30-0.32mm

tooth thickness of the untreated gear wheel over the same 35,000 km, deviation 0.68-0.70 → 1.00 mm

EQUIPMENT	MILEAGE DURING TEST	WHAT WAS MEASURED
Locomotive No. 44 099, traction gearbox — experimental	35,000 km	Tooth thickness of the large gear wheel at the constant chord height
Locomotive No. 44 099, traction gearbox — control	35,000 km	Tooth thickness of the small gear wheel, same measuring points

Treated gearbox — tooth thickness of the large gear wheel

TOOTH	DEVIATION BEFORE TREATMENT	DEVIATION AFTER 35,000 KM	THICKNESS CHANGE
I	-0.62 mm	-0.28 mm	+0.34 mm
III	-0.61 mm	-0.27 mm	+0.34 mm
IV	-0.62 mm	-0.26 mm	+0.36 mm
V	-1.22 mm	-0.64 mm	+0.58 mm

The largest gain was on the most worn tooth V: the coating builds up where wear is greater and does not build up where there is none.

Control gearbox of the same locomotive — tooth thickness of the small gear wheel

TOOTH	DEVIATION AT START	DEVIATION AFTER 35,000 KM	THICKNESS CHANGE
I	-0.68 mm	-1.00 mm	-0.32 mm
II	-0.70 mm	-1.00 mm	-0.30 mm
III	-0.69 mm	-1.00 mm	-0.31 mm
IV	-0.70 mm	-1.00 mm	-0.30 mm
V	-0.70 mm	-1.00 mm	-0.30 mm

The report notes: after the large gear wheel of the control gearbox failed, the small gear wheel of the experimental gearbox was fitted into it.

Commission conclusion

The commission of the Plovdiv locomotive depot recorded in the report: “Analysis of the data obtained shows that on the experimental gear wheel wear was stopped and an increase in tooth thickness occurred, while on the control gear wheel wear continued. A metal-ceramic protective layer of high hardness formed on the working surface of the teeth of the experimental gearbox gear wheels.” Visual inspection revealed a transparent layer on the working surfaces that had completely filled the pits and other wear marks. Before the test began, the teeth of both gear wheels were thinner than the norm — deviation up to 1.22 mm — and the gearbox was not dismantled for treatment: the gel was added to the oil bath, and the locomotive ran all 35,000 km in regular service.

The results refer to the traction gearbox of locomotive No. 44 099 at the Plovdiv depot over 35,000 km of running; on other units and operating modes the figures may differ. The treatment was carried out by “MAY” OOD, a XADO distributor; the measurements and certification were made by the commission of the Plovdiv locomotive depot. 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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