Consolidated register of the evidence base
Industrial test reports collated by defect type and equipment component: median and range from direct measurements, instruments and modes taken from the text of the original document; the document type is stated on the case card.
239
cases with a published report and the scanned original
348
industrial test reports with the signatures of responsible persons
18
countries where the tests were carried out
24
industries
35
equipment types: from compressors and machine tools to locomotives
17
components: bearings, gearboxes, cylinder-piston group and others
Methodology of sample formation
- Assignment to categories: a report is counted in a parameter's row if the protocol contains a direct instrumental measurement of that quantity. One document may relate to several defects and components.
- Statistical processing: median values and spread intervals are calculated exclusively for relative quantities (in per cent) to avoid distortion from mixing heterogeneous physical units.
- Absolute values: protocols with measurements only in absolute units (bar, mm, °C, etc.) are included in the overall quantitative register of reports but excluded from the median calculation.
By sign
| Sign | Cases | With direct measurement | Values, % | Median | Range | Years |
|---|---|---|---|---|---|---|
| Increased electric power consumption | 70 | 67 | 108 | ↓ 10 % | 2.2–59.7 % | 1998–2019 |
| Loss of compression | 68 | 66 | 115 | ↑ 13 % | 0.7–72.0 % | 1999–2021 |
| Elevated vibration | 66 | 41 | 42 | ↓ 46 % | 7.0–89.0 % | 1998–2021 |
| Increased fuel consumption | 30 | 19 | 20 | ↓ 12 % | 3.0–25.0 % | 1999–2018 |
| Increased clearances and backlash | 57 | 48 | 27 | — | — | 2000–2015 |
| Elevated operating temperature | 28 | 21 | 18 | ↓ 15 % | 1.2–40.0 % | 1998–2020 |
| Oil pressure drop | 30 | 25 | 9 | ↑ 30 % | 11.0–75.0 % | 1999–2009 |
By component
| Component | Cases | Reports | Years | Countries |
|---|---|---|---|---|
| Cylinder-piston group | 84 | 152 | 1999–2021 | 12 |
| Bearings | 74 | 102 | 1999–2018 | 8 |
| Compressor | 65 | 97 | 1998–2021 | 9 |
| Reduction gearbox | 55 | 85 | 1999–2018 | 8 |
| Diesel engine | 52 | 88 | 1999–2021 | 7 |
| Gear drive | 46 | 77 | 1999–2013 | 6 |
| Electric motor | 46 | 66 | 1999–2019 | 7 |
| Petrol engine | 33 | 61 | 2000–2018 | 7 |
| Pump | 16 | 17 | 1999–2008 | 5 |
| Gearbox | 14 | 18 | 2001–2013 | 5 |
| Friction pair | 9 | 11 | 2000–2005 | 3 |
| Hydraulic system | 7 | 9 | 2000–2008 | 5 |
| Turbocompressor | 6 | 9 | 1999–2011 | 2 |
| Joints & linkages | 5 | 12 | 2000–2009 | 2 |
| Internal combustion engine | 3 | 3 | 2002–2020 | 2 |
| Driveshaft | 3 | 4 | 2000–2009 | 1 |
| Slideways | 2 | 13 | 2002–2005 | 1 |
Limits of data applicability
- Applicability. The figures relate to the equipment and operating conditions of the enterprises named in the reports; on a different unit the result depends on initial wear, load and oil.
- Source document. A scan of the original report is published under every case; if the card and the scan disagree, the scan is authoritative.