Specialists of the Company "LEG" Ltd. have developed and put into production new carbon brush materials - EF-68 and FE6X.
Carbon brushes from the new graphite-polymeric materials EF-68 and FE6X have improved physico-mechanical and collector characteristics. The materials passed a full cycle of bench tests at the certified center of the SE Plant Electrotyazhmash. The above-mentioned materials are characterized by: low wear, reduced coefficient of friction (0.13-0.16) when the total voltage on a pair of brushes drops to 1.6-3.2 V and a uniform brush film, which is fast formed.
A key feature of these materials is that they work instead of several completely different classes of brush materials: EG61A, G-27, MGS8. This list is by no means exhaustive. Thus, the carbon brushes of grades EF-68 and FE6X can be installed on electric machines for a variety of applications (electric transport, traction motors, electric drives and on-board system alternators, etc.).
Technical characteristics of carbon brushes made of EF-68 and FE6X material grades:
| Brush grade | Resistivity of brush material, (µΩ-m) | Contact voltage drop (sum of both polarities), В | Friction coefficients, no more | Wearing rate, mm, no more | Surface Speed, m/s | Normal Current Density, A/cm² | Spring pressure, kPa |
| FE6X | from 55 to 100 | from 1,6 to 3,6 | 0,22 | 0,25 | 55 | 30 | from 25 to 60 |
| EF-68 | from 38 to 78 | from 1,6 to 3,8 | 0,22 | 0,25 | 20 | 30 | from 25 to 60 |
| 50 | 15 |
Nowadays brushes of the EF-68 grade pass operational tests at transport enterprises in Ukraine and Mongolia. This kind of tests covers various types of electric machines including but not limited to: traction and auxiliary engines of diesel locomotives, freight and passenger AC and DC current electric locomotives, electric trains. The measured specific wear of traction motor brushes is less than 1.5 mm / 10,000 km., which provodes a mileage of more than 150,000 km.
A well-organized production cycle of these materials enables LEG Ltd. to produce graphite-polymeric electric brushes of EF-68 and FE6X grades in any models (in more detail) and quantity.
LEG Ltd. recommends to use brushes grades EF-68 and FE6X complete with our own brush holders.
