Guide Rail Joints

5.4.1 Butt Transition Joints

Due to the length limitation of single guide rails, BZ systems with a length > 6 m consist of multiple segments. By connecting multiple segments, theoretically any length can be achieved, with guide rail butt joints and rack butt joints installed offset as standard configuration.

5.4.2 Design

The guide rail ends in the BZ system are pre-prepared and completed at the factory for system joints, so that the carriage and wipers do not suffer reduced service life due to any gaps that form.

5.4.3 Alignment

Careful installation of the system joints together with the machine bed is critical. In general, joints should not be placed in areas of heavy loads and frequent movement where possible.

There are two key criteria for properly aligning the system at joints:

• Alignment of the guide rails
• Correct rack tooth spacing of adjacent systems

Correct alignment of the guide rails in the vertical and horizontal directions perpendicular to the system axis can be achieved using precise machine-side end stops and alignment with a dial indicator. See the MONORAIL and AMS installation instructions. The system must be aligned axially using the rack so that the pinion does not jam when rolling over the joint. For this purpose, the tooth spacing at the joint must be set to correspond to the spacing of the rest of the rack, thus moving within the permissible single pitch error of adjacent racks. For this, the BZM assembly fixture should be used during installation, which is a short rack segment with a reverse gear. After orthogonal alignment of the guide rails, the fixture is used to pull them into gear mesh, thereby aligning the systems axially with each other. For this, at least one of the segments must be capable of axial alignment.

Installing Multi-Segment Guide Rails

5.4.4 Replaceability

For replacement parts, multi-segment BZ guide rails can only be replaced as complete units. It is not possible to order individual parts subsequently.