The installation of TBR supported linear guides (supported round shafts with open ball bushings) is simpler than that of profile rails, but certain considerations are critical to prevent binding, premature wear, and loss of accuracy.
Here are the key factors and procedures to consider when installing TBR linear guides:
I. Preparation of the Mounting Surface (Flatness)
The support rail's performance relies heavily on the surface it is mounted to.
1.Mounting Surface Flatness: The base plate must be flat and rigid. Although the aluminum support rail (the "TBR" base) is rigid, it is not perfectly straight. It will conform to the flatness of the mounting base. Any bows or twists in the base will be directly transferred to the linear shaft, causing the ball bushings to bind and fail quickly.
2.Cleanliness: Thoroughly clean the mounting base and the bottom of the TBR support rail. Even tiny metal chips or particles under the rail can create bumps that directly cause misalignment and binding.
3.Fastener Clearance: Ensure the mounting bolts and screw holes are completely free of burrs and debris.
II. Rail Alignment and Parallelism (The Main Challenge)
Unlike profile rails, TBR systems are often used in pairs, which means the two rails must be parallel to each other.
1.Reference Rail First: Install the first TBR rail (the "Reference Rail") and secure it firmly. Ensure the rail is seated flat against the base.
2.Align the Secondary Rail:
Parallelism Check: The most crucial step is ensuring the second TBR rail is parallel to the first. Use a precision tool (like a dial indicator or caliper) to measure the distance between the two shafts/rails at both ends and the center.
Self-Alignment (Practical Method): Attach the moving carriage/plate to the blocks on both rails, then hand-tighten the secondary rail mounting bolts loosely. Move the entire plate back and forth across the full stroke. Allow the connecting plate to "float" the secondary rail into its parallel position before final tightening.
3.Tightening: Secure the mounting bolts for both rails firmly (using a torque wrench if specifications are provided).
III. Ball Bushing and Shaft Integrity
These elements must be protected during installation and commissioning.
1.Handle the Shaft Carefully: The chrome-plated surface of the shaft is very hard but can be damaged by impact. Do not strike the shaft or drop the TBR assembly. Any nicks or scratches on the shaft will translate directly to rapid wear on the ball bushings.
2.No Twisting: When securing the blocks or the load to the carriage, ensure there is no twisting or excessive force that could warp the block's housing.
3.No Cantilevering the Load: While the TBR system supports the shaft, the load plate must be designed to distribute the load evenly across both linear blocks. Avoid excessive cantilevering (overhanging) the load, as it creates high moment loads that can exceed the bearing's capacity.
IV. Lubrication and Commissioning
Proper lubrication is non-negotiable for TBR systems.
1.Immediate Lubrication: TBR bearings are highly susceptible to running dry. Always lubricate the shaft immediately after installation. Apply a thin, even film of the specified oil or grease to the exposed shaft.
2.Run-In: Run the carriage block back and forth across the full stroke several times at low speed. This distributes the lubricant evenly and helps the blocks settle into their final, aligned position.
3.Check for Binding: After final tightening, manually move the carriage. The motion should be smooth and consistent across the entire length. Any excessive friction or "tight spots" indicates a misalignment that must be corrected by re-aligning the secondary rail.