Trends in machine tool development indicate faster cutting speeds are required, as well as increased machining accuracies and the ability to machine new materials. Designers of machine tools and other high precision production machinery therefore require components, assemblies and systems that provide suitable levels of stability, precision and dynamics. Energy consumption and resources must also be minimised.
At the same time, high precision motion control of machine tools increasingly requires ready-to-fit, complete linear motion systems with integrated features such as sealing and lubrication, specifically matched to the application.
In response, Schaeffler has extended its RUE-E range of linear recirculating roller bearings and guideway assemblies to include a new size, the RUE25-E, which also offers a range of new integrated features and technical benefits.
For the main axis of machine tools, monorail guidance systems based on recirculating balls and rollers are well proven alongside flat cage units and linear recirculating roller bearings. These systems are ready-to-fit, preloaded and can support loads and forces from all directions. Linear recirculating roller bearing and guideway assemblies of series RUE are primarily used in these applications due to increasingly heavy workpieces, new machining materials and high cutting forces. These units offer very high load carrying capacities, greater flexibility and integrated functions.
Schaeffler's RUE25-E maintains numerous proven features from its predecessor, the RUE-D series, but also provides more integrated functions. These include, for example, a lubricator that distributes the minimum volume of lubricant. This enables lubrication with oil (rather than grease), regardless of the mounting position and without additional precautions needing to be taken such as extra lubricant connectors on both sides of the carriage.
By optimising the design, materials and manufacturing process for the RUE25-E, Schaeffler has also reduced friction and displacement resistance by approximately 40%. This results in improved performance in terms of the running characteristics and dynamics of the guides, as well as an increased maximum travel speed of up to 3 m/s. The power density of the unit is therefore higher, while the size and dimensions remain similar. The new optimised sealing concept for the RUE-E series is also fully maintained. Even the standard design incorporates double lip end wipers. These keep the lubricant inside the carriage and prevent the ingress of contaminants. The rolling element recirculating systems are therefore sealed in the best possible way for every conceivable application.
The RUE25-E can be retrofitted as a one-for-one replacement of its predecessor, the RUE D series. The guideways remain unchanged, but the carriages and guideways can now be combined in any way desired. The units can be specified in accuracy classes G2 or G3 and stored separately, which reduces procurement and stockholding costs for the customer, while ensuring high availability. The RUE25-E is available as a standard flange mounted unit, with either a long flange carriage or a high, long carriage. Mounting options include standard screw mounting from above, screw mounting from below (‘U’ version) and a clamped covering strip (‘ADK/ADB’ version).