Fig. 32
Fig. 33
Fig. 34
Fig. 35
Accuracy Classes
(Fig. 32) The four accuracy classes allow the user to select both the guiderails and the carriages in line with specific application and design requirements. Accuracy classes define the running accuracy of the rails and determine the dimensional tolerances of the carriages.
| Icon | Code | Name |
|---|---|---|
 | G0 | Highly accurate |
 | G1 | Very accurate |
 | G2 | Accurate |
 | G3 | Standard |
The tolerance values for each class are given in the next section, Dimensional Tolerances.
Dimensional Tolerances
(Fig. 33) MONORAIL carriages and rails are manufactured independently to very strict tolerances and are therefore fully interchangeable. This means any carriage can be used on any rail of the same size without affecting preload, as preload is determined by the rolling elements of the carriage. For dimensional differences between any carriage on any rail, the values in the first column of the table below apply.
| Accuracy class | Tolerances between carriages and rails | Max. difference in measurement between the carriage on a rail when products are delivered as a system (rails with carriages) | Max. dimensional difference of the carriages between 2 or more rails, standard |
|---|---|---|---|
| A/B2 | ΔA/ΔB2 | ΔA Standard | |
| G0 | ± 5 µm | 3 µm | 10 µm |
| G1 | ± 10 µm | 5 µm | 20 µm |
| G2 | ± 20 µm | 7 µm | 40 µm |
| G3 | ± 30 µm | 25 µm | 60 µm |
| Measured at the middle of the carriage and in any rail position Values only valid up to 1 m rail length | Measured at the middle of the carriage and at the same rail position The parameters are doubled for ball products and products delivered individually | Measured at the middle of the carriage and at the same rail position |
Matched Carriages
(Fig. 34, 35) All carriages in a set are installed sequentially under production specifications, with their top and side mating surfaces ground smooth. The main dimensions A and B2 are then measured on a test rail, and the carriages can be matched. Matched carriages are available in two quality grades.
| Matched carriages | Max. dimensional difference between matched carriages (ΔA/ΔB2) |
|---|---|
| SLWGP0 | 3 µm |
| SLWGP1 | 5 µm |
Matched Rails
Using "matched rails", we search the data to find rails with similar characteristics. The criterion of the selection process is the maximum deviation over the entire rail length, the so-called matching tolerance. The deviation reports of all matched rails are within this tolerance range. Matched rails are available in four quality grades.
| Matched rails | Matching tolerance |
|---|---|
| SLSGP0 | 5 µm |
| SLSGP1 | 10 µm |
| SLSGP2 | 15 µm |
| SLSGP3 | 20 µm |
Running Accuracy
The running accuracy of the carriage can be linear (along a line) or fluctuating in shape (within the tolerance range). The maximum permissible deviation is determined as a function of the accuracy class and the rail length in the diagram below.
Example: With L3 = 2000 mm and G2 accuracy class, the deviation is 0.015 mm.
Straightness
For effective installation of profiled rail guideway sections, it is important to understand the straightness of the rail and the curvature of the rail side surfaces. Since the side sections are flexible elements, they may deform under their own weight. Deformation may also be caused by the manufacturing process. To meet customer installation requirements, rail straightness is optimised during manufacturing.
Fig. 36 - T2: Rail top surface straightness / T3: Rail side surface straightness
In addition to the standard rail straightness, SCHNEEBERGER also offers special tolerances and/or inspection reports to meet specific customer requirements.
Preload Classes
Roller guideways are preloaded so that they can operate without clearance under different load conditions. Basically, preload increases the rigidity of the system, but also increases the thrust. SCHNEEBERGER guideways are available in four preload classes to meet specific application requirements. The preload class depends on the dynamic load capacity.
| Code | Preload class | Preload (× C₁₀₀) | Operating conditions | Characteristics |
|---|---|---|---|---|
| V0 | Very light preload | 0 – 0.02 | Low friction guideway, suitable for uniform loads, minimal vibration | Low rigidity |
| V1 | Light preload | 0.03 | Low friction guideway, suitable for uniform loads, slight vibration | Long service life |
| V2 | Medium preload | 0.08 | High rigidity, moderately varying loads and vibration | High rigidity and vibration resistance |
| V3 | High preload | 0.13 | Maximum rigidity, impact loads, drastically varying loads | High load and high friction |
Reference Sides
Depending on the installation conditions of the product, the reference sides of the carriages and the profiled rails must be specified when ordering.
| Code | Position | Description |
|---|---|---|
| R1 | Reference at bottom | Reference at bottom - standard configuration |
| R2 | Reference on top | Reference on top |
Lubrication Connections
All carriages have extensive lubrication connection options on the front plate and on top. Connections can therefore be made in the optimal way for the lubricant supply, in line with customer specifications. As standard, all four raceways are lubricated through one connection.
| Code | Position | Description |
|---|---|---|
| S10 | Left center | Left center |
| S20 | Right center | Right center |
| S11 | Top left | Top left |
| S21 | Top right | Top right |
| S12 | Lower left side | Lower left side |
| S22 | Lower right side | Lower right side |
| S13 | Upper left side | Upper left side |
| S23 | Upper right side | Upper right side |
| S32 | Left side | Left side |
| S42 | Right side | Right side |
Separate Carriage Lubrication Connections
As a special feature, SCHNEEBERGER systems can provide separate lubrication on both sides of the carriage (S32, S42) for certain installation positions. This enhances lubrication of the guideway and extends the service life of the machine.
Separate lubrication combination codes
- S99: S10+S12+S13+S20+S22+S23 locked with threaded nipples
- S98: S32+S33+S42+S43 locked with threaded nipples (MR only)
- S49: For AMS with housing position P1: S10+S12+S13 locked with threaded nipples
- S49: For AMS with housing position P3: S20+S22+S23 locked with threaded nipples
Lubrication as Delivered
Carriages can be equipped with various lubricants according to the requirements of the application. For applications that provide continuous lubrication during the installation and operating phases, light oiling or a thin layer of grease is sufficient. For manually lubricated applications, a full grease filling is recommended.
| Code | Type | Description | Suitable applications |
|---|---|---|---|
| LN | Oil protect | Oil protect - light oiling | Applications with continuous oil supply after installation |
| LG | Grease protect | Grease protect - thin layer of grease | Applications with continuous grease supply after installation |
| LV | Full greasing | Full greasing - complete grease filling | Manually lubricated applications |
Friction
Thrust is an important value in the characteristics of a guideway system. In the case of profiled rail guideways, this largely depends on the friction of the sealing system. There are also other contributions from sliding contacts and from friction when changing direction.
Application-specific factors, such as the type of lubricant, the amount of external load and the speed, also have an influence. To adjust the friction of the seal type, special plastics can be used to adapt to the requirements of the application.
Coating
For applications requiring special corrosion protection, for example in cleanroom applications or due to high humidity environments, or when increased surface wear resistance is required, MONORAIL carriages and rails are available in hard chromium plated versions.
| Code | Type | Features |
|---|---|---|
| CN | None | Standard steel surface |
| CH | Hard chromium |
|
Note
Holes, threads and rolling elements are not chromium plated.