SCHNEEBERGER MONORAIL offers a range of special versions for particular application environments. This chapter covers the coatings and the stainless steel models, for applications needing higher corrosion resistance or special environmental conditions.
4.15.1 Coatings
SCHNEEBERGER offers a variety of surface coatings with anti-corrosive properties for its MONORAIL MR, BM and AMS products. For information about the availability of individual products, please contact SCHNEEBERGER.
Coating options
| Icon | Code | Description |
|---|---|---|
 | CN | No CN coating |
 | CH | CH coating |
 | CL | CL coating, on request |
CH coating
The CH coating is an electroplated hard chromium thin film. Due to the special processing technology a micro pearl structure with excellent adhesion and good sliding properties is created. The pure chromium layer, in a molecular bond with the substrate, has a high level of hardness, high resistance to wear and excellent corrosion protection characteristics. No structural changes in the base material occur due to the low process temperature of below 70 °C. The matt grey chromium layer is in part able to store lubricant thanks to its pearl-like surface structure and thus has advantages in terms of mixed friction behaviour compared to non-coated products. The coating does not contain any levels of chromium-VI and is licensed for use in the food industry, where stringent requirements in respect of resistance to corrosion and wear are stipulated.
- High surface hardness (1200–1400 HV)
- High corrosion-resistance
- Coating thickness 2–5 μm
- Emergency running characteristics in case of mixed friction
- No effect on load carrying capacity
- Low influence on friction values
- Edge processing
- Fixing holes / undercuts uncoated
- Colour: matt, light grey
CL coating
CL coating is an electroplated thin-film hard chrome plating. It also has a surface with a fine pearl structure and excellent adhesion as well as very good sliding properties. The pearl structure is covered with a mixed oxide layer as part of an additional process and the cavities are filled. This enhanced chrome coating has an even higher wear resistance, very high corrosion resistance and extremely low friction values. Due to the low process temperature no loss of hardness or distortion in the coated base material occurs. The black gloss chrome coating has advantages over and above its fine decorative appearance in case of inadequate lubrication and as a result achieves significantly higher running performance compared with CH coating. The coating does not contain any levels of chromium-VI.
- High surface hardness (1200–1400 HV)
- High corrosion-resistance
- Coating thickness 4–6 μm
- Emergency running characteristics in case of mixed friction
- No effect on load carrying capacity
- Low influence on friction values
- Edge processing
- Fixing holes / undercuts uncoated
- Colour: black, gloss
Overview of coating types
| Coating | CH | CL |
|---|---|---|
| Colour | matt, light grey | black, glossy |
| Film thickness | 2–5 μm | 4–6 μm |
| Film hardness | up to 1400 HV | up to 1400 HV |
| Process | Chromium separation electroplating | Chromium separation electroplating, chromium oxide layer |
| Maximum length | 4000 mm | 4000 mm |
| Chromium VI | no | no |
| Corrosion protection | excellent | excellent |
| Wear-protection | good for mixed friction | excellent for mixed friction |
| Edge processing | yes | yes |
| Corrosion-protection of fixing holes, undercuts | no | no |
| Applications | Mechanical engineering with stringent requirements, cleanroom technology, food industry, medical technology | Mechanical engineering with stringent requirements, decorative purposes, minimum quantities of lubrication |
4.15.2 MONORAIL BM in its stainless steel model (WR, SR)
SCHNEEBERGER MONORAIL BM WR/SR have been specially developed for requirements where the standard coatings reach their limits: where no particles may escape during the process, or where product performance would be affected by corrosion.
- Food industry machinery
- Medical technology
- Cleanroom or vacuum applications
- Chemical processes
- Outdoor applications
Construction of the MONORAIL BM WR carriage
The bodies of SCHNEEBERGER MONORAIL BM WR carriages are made out of austenitic steel containing chromium. Only hardened stainless steel is used for the balls. Front plates and accessories are fastened with stainless steel screws.
Construction of the MONORAIL BM SR guide rail
The guide rail consists of stainless steel with a high level of chromium and is hardened using the hardening process at Rockwell C 56–58. The tracks and the entire surface of the guide rail are hard. If longer axes are to be built, MONORAIL BM SR guide rails with specially manufactured butt joints can be supplied. Process optimisations are currently being undertaken on the maximum length of guide rails.
Restriction to other products
- The guide rails are delivered without corrosion protection.
- In the case of the BM WR products only the lubricating option S99 is offered, as assembly with stainless steel lube nipples leads to increased delivery times.
- The tapped fixing holes of the lube connections are closed with stainless steel grub screws.
- Preload classes greater than V3 are not available.
- The G0 accuracy class can only be offered on request.
- The loading capacity is reduced compared with the standard products.
Features
The external dimensions are exactly the same as the corresponding BM product; similarly all accessory components such as additional wipers, metal wipers or lubrication plates can be used.
Stainless steel fastening screws are used for all components. Plastic plugs are offered for closing the guide rail fixing holes.
The maximum single-piece guide rail length is limited to 3000 mm. Finishing the butt joint of the guide rails is possible. See the SCHNEEBERGER MONORAIL and AMS product catalogue for the order descriptions of the product model.
Delivered condition
The guide rails are delivered without corrosion protection on their surface. The carriages are supplied with lubricant to guarantee reliable installation. The accessories from the standard product range (additional wipers, metal wipers, lubrication plates) can be used for the sizes and model variants above.
For the guide rail types, carriage types and the specification values of each size, see the cell-by-cell verified product catalogue pages: MONORAIL BM WR / SR (sizes 15, 20, 25, 30, 35).