IE A064PLANT REPORT DATED 12.12.2002 · 526 HOURS OF SERVICE AFTER TREATMENT
Ural-2M herringbone gearbox: worn teeth regained metal, motor current dropped
Worn teeth built up metal, motor current under load decreased, the gearbox was not disassembled. 0.4–0.6 mm — tooth thickness of stage 2 gear and pinion, on average over 526 h of operation; 12.5 % — drive motor current under load, 440 → 385 A (2002).
Tube Rolling Plantapproved by the chief mechanic · six signatures of the commission
Key results
| UNIT | CONDITION AT THE START OF TESTING | WHAT WAS MEASURED |
|---|---|---|
| Ural-2M gearbox, stage 2 — treated | Tooth wear over 30 % of thickness; scoring, chipping and pitting up to 4 mm deep | Tooth thickness of gear and pinion (m = 20 mm) before treatment and after service |
| Ural-2M gearbox, stage 1 — not treated | Standard lubricant, same gearbox, same operating hours | Tooth thickness of gear and pinion (m = 11.2 mm) — control group |
| Gearbox drive motor | Standard mill operation, tube drawing in 2 strands | Current draw at no load and under load |
Tooth thickness of the treated stage 2 — before treatment and after 526 hours of operation
| PART · RIM · SECTOR | BEFORE, mm | AFTER, mm | GAIN, mm |
|---|---|---|---|
| Gear, left rim · S1 | 31.6–31.9 | 31.9–32.1 | 0–0.4 |
| Gear, left rim · S2 | 31.4–31.6 | 31.8–32.3 | 0.3–0.9 |
| Gear, left rim · S3 | 31.6–31.85 | 31.9–32.1 | 0.05–0.4 |
| Gear, right rim · S1 | 31.35–31.8 | 31.8–31.9 | 0–0.45 |
| Gear, right rim · S2 | 31.1–31.3 | 31.6–31.8 | 0.45–0.6 |
| Gear, right rim · S3 | 31.05–31.25 | 31.6–31.9 | 0.55–0.7 |
| Pinion, left rim · S1 | 22.8–22.9 | 23.2–23.4 | 0.4–0.5 |
| Pinion, right rim · S1 | 23.15–23.4 | 23.7–24.0 | 0.45–0.8 |
ShZN-40 gear tooth caliper; the same marked teeth were measured before treatment and after 526 h. The table gives the mean tooth section at height h = 25 mm.
Control: stage 1 of the same gearbox, untreated
| PART · RIM | BEFORE, mm | AFTER, mm | CHANGE ON THREE TEETH, mm |
|---|---|---|---|
| Stage 1 gear, right rim | 19.0–19.1 | 18.6–18.7 | −0.4 · −0.4 · −0.35 |
| Stage 1 gear, left rim | 18.7–18.8 | 18.75–18.9 | +0.05 · +0.1 · +0.05 |
| Stage 1 pinion | 17.0–17.1 | 16.95–17.05 | +0.05 · −0.05 · −0.15 |
Stage 1 (m = 11.2 mm) stayed on the standard lubricant and was not treated: same gearbox, same duty, same 526 h.
Drive motor current draw
| OPERATING MODE | BEFORE TREATMENT | AFTER 526 H | CHANGE |
|---|---|---|---|
| Under load — tube drawing in 2 strands | 440 A | 385 A | −12.5 % |
| No load | 30 A | 22 A | −26.6 % |
Measurements by the plant electrical laboratory: protocol No. 272 — before treatment, protocol No. 44 — after 526 h of operation.
Working surface of stage 2 teeth: inspection before and after
| BEFORE TREATMENT | AFTER 526 HOURS OF OPERATION |
|---|---|
| Transverse scoring, chipping and pitting up to 4 mm deep over the entire working surface of the gear and pinion teeth; tooth thickness wear over 30 % | Damage depth decreased, ridges smoothed out, minor damage on the contact patches disappeared; the working surface levelled out and became smoother |
Inspection by specialists of the plant technical services and representatives of XADO LLC during a scheduled gearbox shutdown.
Findings of the plant commission
Current equivalent
- Revitalizant gel for gearboxesGearboxes · transmissions · gear drives
- Revitalizant gel for compressors and bearingsCompressors · bearings · spindles
How such units are treated:
About this result:
Limits of this report: The results relate to the two-stage Ural-2M herringbone gearbox of a rolling mill and to its normal operating duty; on other units and duties the figures may differ. Geometry and current measurements were made by the plant services; the treatment was carried out by XADO LLC and Agrotekhkomplekt LLC, whose representatives were part of the commission.