INDUSTRIAL CASE|METALLURGY|METAL-CUTTING MACHINE TOOLS
TEST REPORT · MACHINE SHOP, ZAPOROZHSTAL OJSC
16K20 lathe: accuracy and surface finish restored without disassembly
PRODUCTXADO revitalizant gelfor compressors and bearings · lubrication system of the machine treated without stopping production
TEST OBJECT16K20 screw-cutting latheinv. No. 10512471 · spindle unit, gearbox, lubrication system, drive
DOCUMENT TYPETest report,
Zaporozhstal OJSCsigned by the plant commission and the lead engineer of XADO LLC
Zaporozhstal OJSCsigned by the plant commission and the lead engineer of XADO LLC
Key results
↑0.05-0.15mm
gearbox tooth thickness, 5.8 → 5.9 and 6.0 → 6.15 mm
↓7.6%
power draw under load, 3.48-3.74 → 3.2-3.45 kW
↓59-89%
vibration velocity at control points, 1.23-1.71 → 0.10-0.70 mm/s
↓3.3-3.8×
roughness of the turned surface Ra, 7.98 → 2.1-2.4 µm
| MACHINE UNIT | CONDITION BEFORE TREATMENT | WHAT WAS MEASURED |
|---|---|---|
| Spindle unit | Increased radial clearance and axial play of the spindle bearings | Bearing play, radial and face runout of the spindle seat |
| Gearbox | Micro-damage on the contact patches of the loaded gear wheels | Tooth thickness of the gearbox pinion and the spindle gear at the constant-chord height |
| Drive, electric motor | Machine in service in the machine shop | Current, voltage and power on three phases at idle and under load |
| Machine as a whole | Ovality of the turned surface 0.03 mm, roughness Ra 7.98 µm — class 4 | Vibration at seven control points, ovality and Ra of the test workpiece |
Spindle accuracy and gearbox tooth geometry
| PARAMETER | BEFORE TREATMENT | AFTER 1280 H | CHANGE |
|---|---|---|---|
| Axial play of the spindle bearings | 0.05 mm | 0.02 mm | −0.03 mm |
| Radial play of the spindle bearings | 0.03 mm | 0.015 mm | −0.015 mm |
| Radial runout of the spindle seat | 0.03 mm | 0.01 mm | −0.02 mm |
| Face runout of the spindle seat | 0.01 mm | 0.005 mm | −0.005 mm |
| Tooth thickness of the gearbox pinion, 3 teeth | 5.8 mm | 5.9 mm | +0.1 mm |
| Tooth thickness of the spindle gear, 3 teeth | 6.0 mm | 6.15 mm | +0.15 mm |
Play and runout — ICh-10 dial indicator; tooth thickness at a constant-chord height of 3.0 mm with m = 3.5 — ShZN-18 gear tooth vernier caliper.
Power consumption of the machine drive on three phases
| MODE AND PARAMETER | PHASE A | PHASE B | PHASE C |
|---|---|---|---|
| Current under load | 9.81 → 8.9 A | 10.1 → 9.2 A | 9.95 → 9.0 A |
| Power under load | 3.48 → 3.2 kW | 3.74 → 3.45 kW | 3.52 → 3.22 kW |
| Current at idle | 7.83 → 7.05 A | 7.65 → 7.1 A | 7.76 → 6.98 A |
| Power at idle | 2.92 → 2.6 kW | 2.89 → 2.53 kW | 3.01 → 2.67 kW |
ATK2200 clamp meter. According to the conclusions of the report, in the loaded turning cycle the current fell by 9.6 % and the power by 7.6 %; at idle, by 9 % and 11 %.
Vibration at the control points of the headstock and the bed
| MEASUREMENT POINT | VIBRATION ACCELERATION, m/s² | VIBRATION VELOCITY, mm/s | VIBRATION DISPLACEMENT, µm |
|---|---|---|---|
| Front bearing, vertical | 3.56 → 3.49 | 1.28 → 0.19 | 4.84 → 1.62 |
| Front bearing, horizontal | 8.8 → 3.69 | 1.53 → 0.7 | 4.25 → 3.22 |
| Rear bearing, vertical | 5.59 → 2.44 | 1.39 → 0.21 | 3.99 → 2.12 |
| Bed at the rear bearing, horizontal | 9.93 → 5.24 | 1.71 → 0.7 | 18.9 → 4.0 |
| Bed at the rear bearing, axial | 7.46 → 4.8 | 1.32 → 0.17 | 4.18 → 1.72 |
| Bed, left support, horizontal | 4.08 → 2.12 | 1.26 → 0.1 | 4.4 → 1.54 |
| Bed, right support, horizontal | 3.49 → 2.33 | 1.23 → 0.14 | 3.99 → 2.48 |
SENDIG 911 vibration meter, seven control points; the reduction was recorded at every point and for all three vibration quantities.
Test workpiece turned on the machine
| PARAMETER OF THE TURNED SURFACE | BEFORE TREATMENT | AFTER 1280 H |
|---|---|---|
| Ovality of the turned surface | 0.03 mm | 0.01 mm |
| Surface roughness Ra | 7.98 µm — class 4 | 2.1-2.4 µm — class 6 |
The workpiece was turned under identical conditions each time: 800 rpm, feed 0.15 mm/rev, depth of cut 1.0 mm.
Conclusions of the plant commission
The commission of specialists of Zaporozhstal OJSC, by final measurements after a total run of 1280 h, established that: in the loaded turning cycle at fixed cutting conditions the current draw decreased by 9.6 % and the power draw by 7.6 %; the radial runout of the spindle decreased from 0.03 mm to 0.01 mm, and the axial play of the bearings from 0.05 mm to 0.02 mm; the vibration level "decreased at all control points by at least 56 %, and at individual points of the spindle bearings the vibration parameters decreased by more than 2×"; the thickness of the control teeth on the gearbox gears increased by 0.05-0.15 mm, and the contact patches of the loaded gear wheels "visually became smoother, without the micro-damage that was visible before the start of the treatment"; the roughness of the turned surface improved by 2 classes — from Ra 7.98 µm to Ra 2.1-2.4 µm. The treatment of the lubrication system with XADO revitalizant compounds was carried out without stopping the machine and without disassembling its units; in the assessment of the commission, the geometric parameters of the machine and the vibration level of the spindle bearings correspond to the accuracy parameters of a machine after a major overhaul.
The results apply to the 16K20 screw-cutting lathe (inv. No. 10512471) of the machine shop of Zaporozhstal OJSC under the stated measurement conditions; on other equipment and under other conditions the figures may differ. The original report dated 08.08.2013 is published in full and available for download.
Current equivalent
- Revitalizant gel for compressors and bearingsCompressors · bearings · spindles
- Revitalizant gel for gearboxesGearboxes · transmissions · gear drives
How such units are treated: