Profile Rail Guideways
Profile rail guideways are among the linear guides used in mechanical engineering. These rail guides generally have one or more carriages on a guide rail, which has one or more raceways for rolling elements and revolves to the right or left of the rail in the carriage. They belong to the further development of shaft guidance systems, in which a corresponding ball recirculation is implemented in the linear ball bearing.
Profile rail guideways have the characteristic that the rolling elements roll on hardened raceways between the guideway and the carriage. The rolling elements are guided in a recirculating motion in the carriage, deflected and returned to the raceway by the return motion. This circulation ensures that endless guidance with unlimited stroke is possible.
Structure & Function
The rolling elements used in profiled rail guideways are balls or rollers. Profile rail guides with ball bearings (recirculating ball units) are suitable for applications characterized by higher speeds and higher accelerations.
Profile rail guideways with rollers, on the other hand, are used when longitudinal guides have to support high loads, when rigidity is required above all, and when a very precise approach is important.
As a rule, two, four or six rows of rolling elements are used. As the number of rows of rolling elements increases, the load carrying capacity and rigidity of the profiled rail guide increase, since loads are carried by more rolling elements. However, this also increases friction.
Depending on the course of the force lines of action through the contact points, we speak of either an X or O arrangement of the raceways. Profile rail guides with an X arrangement have a shorter lever arm due to the smaller distance between the raceways. This facilitates misalignment in multi-axis systems (self-alignment). Profile rail guides with an O arrangement, on the other hand, have significantly higher rigidity and greater moment load capacity in the Mx direction and offer advantages in the case of lifting forces.
Recirculating Ball Guides
In general, the recirculating ball bearing guides are characterized by a high load capacity with maximum precision. The design is very compact. The linear recirculating ball bearing and guideway assemblies can support multiaxial loads and are very rigid due to the steel rails mounted on the guideway profile.The linear recirculating ball bearing and guideway assembly consists of a guideway and the carriage with four internal rows of balls that are returned in closed channels with plastic deflectors. The carriage of the linear recirculating ball bearing and guideway assembly is made of hardened and ground steel and can be slid directly from the guard rail onto the guide rail. The carriages offered as standard are lightly preloaded and therefore predestined for the most common applications. Depending on requirements, no preload or very high preload is recommended. The carriages are individually adapted to the conditions.
- High speeds up to max. 10 m/s
- High accelerations up to max. 500 m/s²
- High static and dynamic moment loads possible
- Same basic load ratings for all load directions
- Long-term lubrication through lubrication pads integrated in the carriages, advantageous for short-stroke applications
- Relubrication possible from all sides, lubrication nipples are included in the scope of delivery
- Reinforced stainless steel end plates increase rigidity in the direction of the X-axis, enable higher travel speeds and accelerations, and extend service life
- Carriage with double lip seal as standard
- Suitable for fast linear movements with high precision
- Absorption of high torques (off-center loads)
- Absorption of high forces
- Automation technology, handling systems, packaging systems, automatic assembly machines
- Machine tool building, woodworking
- Punching and injection molding machines
Linear recirculating roller bearing unit
A special type of linear recirculating roller bearing and guideway assembly is the linear recirculating roller bearing and guideway assembly. In linear recirculating roller bearing and guideway assemblies, rollers arranged in rows on both sides run around a precision-ground, rigid supporting body. A cage guides and secures the rollers. Furthermore, a linear roller bearing and guideway assembly should reliably prevent skewing of the rollers and guarantee uniform rolling motion. Recirculating roller bearings are used, for example, in XYZ guide axes of NC machine tools, guides for precision presses, changing devices for precision molding presses and for transporting heavy loads.
Cross Roller Guides
Crossed roller guides are characterized by exceptionally smooth running, an extremely compact design and maximum precision. In addition, there are high rigidity and low friction values of the cross roller guides. These properties make this type of cage rail guide particularly suitable for use in medical technology, biotechnology and semiconductor products as well as in the optical industry. Cross roller guides can be installed either horizontally or vertically. If two pairs of rails are arranged in parallel, these linear guides can guide a linear slide. This results in new approaches to solutions, which are primarily used for linear technology applications in confined spaces.
Miniature Rail Guides
Miniature Rail Guides have a similar design to the profiled rail guideways. Due to their low overall height, these guideways have a double-row design and are produced from rust-resistant material as standard. Miniature rail guides operate on the principle of rotating balls. Due to this, travels of any length are possible. With regard to miniature tables, the balls are held in a cage. As a result, the travels there are limited to a specific length. However, both designs have in common that they are characterized by an above-average running smoothness.
Profile rail guides in miniature design have been specially developed for use in very confined spaces. With their precision and compactness, they achieve maximum productivity. They are also ideal for all applications where rapid, repeatable positioning is required. These include applications in solar, chip, medical, measuring and sorting technology.
PACH Systems offers you a wide product range of different profile rail guides. For this purpose, we cooperate with our long-term partners. Please let us know your requirements via our contact form. We will be happy to provide you with a non-binding offer or contact you to discuss the details.