3У131 and BUA-25/630 cylindrical grinding machines
Machine performance is judged not by the unit but by the part: the surface roughness and ovality of a workpiece machined with the same wheel at the same cutting settings.
3У131 (25 l bath) and BUA-25/630 (40 l bath) cylindrical grinding machines: spindle unit
The class norm is 0.6 ml per litre of hydraulic system working fluid. Here a different unit is involved — the spindle oil bath — and 1.8 ml/l is prescribed for it. Cylindrical grinding machines →
What is treated
- Serviceable machine units with no components at 100 % wear.
What is measured before and after
| Parameter | Instrument | How and when |
|---|---|---|
| Radial and axial run-out of the spindle | indicator stand, accuracy to 0.002 mm | Rotating by hand, indicator tip on the seating surface. |
| Surface roughness of the reference part | profilometer | The same part, the same wheel, the same cutting settings. |
| Ovality of the machined workpiece | micrometer, accuracy to 0.002 mm | — |
| Vibration level of the spindle bearing units | vibrometer | — |
Dosage rates
| Compound | Rate | How and when |
|---|---|---|
| Gel for compressors and bearings — 3У131 machine | 1.8 ml per 1 litre of standard oil per stage | 25 l bath: 45 ml per stage (5 tubes), 135 ml for three stages. |
| The same gel — BUA-25/630 machine | 1.8 ml per 1 litre of standard oil per stage | 40 l bath: 72 ml per stage (8 tubes), 216 ml for three stages. |
Treatment stages
- Dilute the gel in 0.5 l of standard oil (40–50 °C) and introduce it into the oil bath of the spindle unit lubrication system.Start of operating time count
- The second stage — the same as the first.After 8–12 hours of machine operating time
- The third stage — the same as the first.After a further 8–12 hours
After treatment
- The full cycle is not less than 550 hours from the first stage — the longest among the machines analysed.
Points to watch
- Carrier oil — 0.5 l, heated to 40–50 °C.
- Spindle run-out and workpiece ovality are measured to within 0.002 mm — an order of magnitude finer than in bearing procedures.
Where 3У131 and BUA-25/630 has already been treated
- AVIASTAR-SP JSC · 2008↓ 48–72% — vibration velocity at the spindle bearings and bed, 0.4–2.9 → 0.2–1.4 mm/s
Source: XADO applied procedure, lead engineer I. N. Sharaikin. Class norm — instruction IE-24.6-25612000-005-2008, procedure No. 15.