deva.bm technical handbook
24Pages

World Class Bearing Technology deva.bm® sliding bearings Maintenance-free, self-lubricating

deva.bm ® Self-lubricating composite bearing material Contemporary designs represent an enormous challenge to modern-day bearing materials because, frequently, zero maintenance is expected under severe to extreme conditions as well as under maximum loads. The constant pressure on costs additionally calls for increasing uptime of machinery and equipment and uncompromising standards of operational reliability. The maintenance-free, permanently self-lubricating heavy-duty bearing materials from the DEVA® product range offer bearing solutions guaranteed to operate reliably and safely over a...

Profit from more than 60 years of experience in self- lubricating sliding bearings. Make use of our extensive material and application expertise spanning a very wide range of industries. Let our application engineering team assist you in ■ selection of the bearing materials, ■ design, purpose-built to your requirements, ■ calculation of estimated life time. Benefit from the latest material developments, tested using state of the art facilities. Ask for a simulation of your bearing application on Expect the highest quality standards, certified to One of eight of our test benches Data...

1 Material properties deva.bm ® is a self-lubricating composite bearing material, comprising a steel backing with a sliding layer of deva.metal ®. deva.bm is produced using a special sintering process to get the following advantages: deva.bm does not absorb water and guarantees maximum dimensional accuracy. is utilisable in seawater. is utilisable in radioactive environments. is electrically conductive. No electrostatic charging effects occur. is suitable for rotational, oscillating and linear movements. is suitable for micro movements. is suitable even for applications involving high edge...

deva.bm ® maintenance-free Layer structure and microstructure of deva.bm The distinguishing features of deva.bm are its highly durable steel backing and the bronze matrix with homogeneous solid lubricant indentations that ensure low friction coefficients. The latter is either graphite of varying particle form and size, or PTFE. Microstructure of deva.bm Figure 2.1 1 1 Sliding surface, optionally with initial, running-in film 2 Sliding layer (bronze) 3 Solid lubricant deva.bm : graphite deva.bm/9P : PTFE 4 Steel backing 2 3 4 © Federal-Mogul DEVA GmbH – The current version of this handbook...

3 Materials 3.1 Material properties Properties of steel backing and physical properties of deva.bm ® 1) Materials Table 3.1.A Properties of steel backing 0.2 % Yield min. Alloys 5) Physical properties Tensile strength Linear coefficient of thermal expansion 20 - 100 °C Mechanical properties Density Compressive strength Hardness Symbol Rp02 Rm α1 ρ Unit MPa MPa 10 -6/K g/cm³ HBmin MPa 320 σdB Bronze alloys deva.bm 302 stainless 4) 210 500 - 700 16.0 6.5 40 deva.bm 372 stainless 4) 210 500 - 700 16.0 6.3 40 320 deva.bm 382 unalloyed 3) 140 270 - 350 12.0 6.0 40 300 deva.bm 388 2) unalloyed 3)...

deva.bm ® maintenance-free 3.2 Chemical resistance The following decision chart provides guidance on the selection of the appropriate deva.bm alloy according to the environmental conditions of the application. Definitions – Resistant Resistant depending on construction, oxygen content, temperature, etc. Not recommended No data available Chemical resistance of deva.bm Medium / chemical substance Concentration in % Table 3.2.1 Temperature in °C Alloys deva.bm 302 / 372 / 392 / 362/9P 382 / 388 Strong acids 5 Hydrochloric acid 5 20 Hydroflouric acid 5 20 Nitric acid 5 20 Sulphuric acid 5 20...

4 Mating material The deva.bm® bearing materials can be used only with mating materials demonstrating a hardness of at least 180 HB. Where lubricant is addition­ lly introduced into a the sliding contact, hardness values of >130HB are also permissible. In abrasive environments, a surface hardened to 35 HRC / 45 HRC should be used. The ideal mating surface roughness for deva.bm is Ra = 0.2 to 0.8 µm, produced by grinding. Rougher surfaces are also acceptable, depending on the operating conditions. To obtain the right surface roughness, it is equally possible to use bushings of a suitable...

deva.bm ® maintenance-free 5 Fits deva.bm is pressed into the housing with an interference fit (using a screw press, hydraulic press or press-fit mandrel). Tapping or driving into place is not permissible. The standard housing bore is H7. Mean roughness of housing: Ra = 3.2 µm The housing has a chamfer of 20° - 40° for easier mounting. To achieve minimum clearances after mounting (IT7 or higher), finishing should take place in the mounted state. For this purpose, deva.bm can be provided with a machining allowance, in which case the running-in film has to be applied after finishing....

6.2 Special design solutions deva.bm ® radial segment including mounting and screw joint deva.bm axial segment with cleaning grooves Figure 6.2.2 deva.bm spherical sliding bearing Figure 6.2.3 deva.bm spherical sliding bearing 10 Figure 6.2.1 Figure 6.2.4 The current version of this handbook can be found on our website. – © Federal-Mogul DEVA GmbH

deva.bm ® maintenance-free 6.3 Description what values to be considered for design DEVA® differentiates load cases (0 to 3) regarding the character of load stressing a bearing. This is to consider fatigue influences in case of dynamic pressure. The percentage values are refering to the limit values described in the material data sheet or technical handbooks. This worksheet is related to DEVA work instruction A 616 (see also “Qualitäts-, Umwelt- und ArbeitsschutzManagement Handbuch, Verfahrensanweisungen + Arbeitsanweisung”). Load cases 0-3 Figure 6.3.1 Load case 0 σ σS 100 % of static load...

7.1 Installation of deva.bm cylindrical bearings Installation of deva.bm cylindrical bearings with D1 < 550 mm by press-fitting Installation of precision bearings (HS) Installation of a) Standard bearing (H9) b) Precision bearing with D1 > 180 mm c) Bearing with machining allowance Press-fit mandrel Press-fit mandrel machining allowance Auxiliary bush nner diameter with machining allowance nner diameter Outer diameter Bearing width measured wall thickness Housing bore diameter for long bearings only Guide bush Guide bush Material: grey cast iron, large quantities Spacer ring Slight oiling...