PRODUCTION CASE STUDY|MECHANICAL ENGINEERING · BEARING MANUFACTURING|METAL-CUTTING MACHINE TOOLS

TECHNICAL REPORT OF 28.09.2006

Grinding machine 3A487: precision restored without teardown or repair

OJSC “Moskovskiy Podshipnik” · commission: Deputy Technical Director A. V. Pchelintsev, Head of the Engineering and Design Department S. A. Volchkov, representatives of LLC “XADO”

Russia · measurements 28.06.2006, after 110 h of machine operation following treatment · report approved 28.09.2006

PRODUCTXADO revitalizant compoundstreatment of the machine oil system without disassembling the units

TEST OBJECTGrinding machine 3A487 N58serial no. 55316/83, inventory no. 112010011 · plain bearings of the wheelhead and the workhead

DOCUMENT TYPETechnical report
of OJSC “Moskovskiy Podshipnik”approved by the Deputy Technical Director of the plant

Key result

↓26-78%

vibration displacement in the plain bearings, 2.27-42.30 → 1.68-9.37 µm

EQUIPMENT	CONDITION AT THE START OF THE TESTS	WHAT WAS MEASURED
Grinding machine 3A487 N58, serial no. 55316/83, in service since 1974	Finishing operations impossible: severe surface waviness (chatter), unstable dimensions, excessive ovality of parts (0.03 mm). Repair and adjustment of the machine failed to remove it	Vibration at 8 control points of the wheelhead and workhead bearings; ovality of the ground ring; drive current and voltage

Wheelhead — plain bearing vibration

MEASUREMENT POINT	VIBRATION DISPLACEMENT, µm	VIBRATION VELOCITY, mm/s	VIBRATION ACCELERATION, m/s²
Pt. 1 — front bearing, vertical	9.50 → 5.12	0.437 → 0.316	0.487 → 0.305
Pt. 2 — front bearing, horizontal	42.30 → 9.37	1.210 → 0.437	0.697 → 0.420
Pt. 3 — rear bearing, vertical	7.14 → 3.47	0.396 → 0.333	0.643 → 0.464
Pt. 4 — rear bearing, horizontal	38.20 → 6.72	1.230 → 0.424	0.932 → 0.516

The report names points Pt. 2 and Pt. 4 as the most critical for machining accuracy: there vibration velocity fell by 64-66% and vibration displacement by 78-82%.

Workhead — plain bearing vibration

MEASUREMENT POINT	VIBRATION DISPLACEMENT, µm	VIBRATION VELOCITY, mm/s	VIBRATION ACCELERATION, m/s²
Pt. 5 — front bearing, vertical	9.48 → 3.08	0.408 → 0.218	0.211 → 0.203
Pt. 6 — front bearing, horizontal	4.13 → 3.57	0.261 → 0.260	0.513 → 0.221
Pt. 7 — rear bearing, vertical	2.27 → 1.68	0.234 → 0.211	0.381 → 0.298
Pt. 8 — rear bearing, horizontal	4.19 → 3.88	0.233 → 0.233	0.537 → 0.232

SENDIG 911 vibration meter, 8 control points; vibration displacement decreased at all eight. The repeat measurements were taken with the same grinding wheel as the initial ones.

Conclusions of the plant commission

The commission of OJSC “Moskovskiy Podshipnik” recorded in the report: 1. The vibration level at all control points decreased substantially, and at points Pt. 2 and Pt. 4, the most critical ones for machining accuracy, vibration velocity fell by 64-66% and vibration displacement by 78-82%. 2. Waviness of the ground surface disappeared completely. 4. The machine became able to perform finishing operations without rejects. 5. Thus, XADO revitalizant compounds provided a perfect fit of the mating parts in the plain bearings of the wheelhead and the workhead, with optimal clearances formed, whereby the required accuracy of the machine was restored. Before the treatment the machine, built in 1974, had been withdrawn from finishing operations, and repair had failed to return it to service.

The results apply to grinding machine 3A487 N58 with plain bearings in the spindle units and to the production conditions of OJSC “Moskovskiy Podshipnik”; on other equipment and under other operating modes the figures may differ. The original technical report is published in full and available for download.

Current equivalent

Revitalizant gel for compressors and bearings →

Piston, screw and centrifugal compressors; rolling and sliding bearings running in an oil bath; machine-tool spindle units and slideways.

How such units are treated: Bearings

← Full catalogue