BK, EK, and FK Ball Screw Support Brackets
The BK, EK, and FK Ball Screw Support Brackets represent the three main standardized series of fixed-side bearing units specifically designed to support the ends of ball screws.
These fixed-side units are crucial for anchoring the ball screw shaft against high axial thrust loads. The fundamental differences between the BK, EK, and FK series lie in their mounting geometry, size range, and inherent stiffness capability. This variety allows design engineers to precisely select the bracket that provides the best mechanical fit for the machine frame and meets the required load-bearing and rigidity specifications for the application.
The three main standardized series of ball screw fixed-side support brackets-BK, EK, and FK-are differentiated primarily by their design geometry, which dictates their application:
1. BK Support Brackets (The Standard Workhorse)
Design: A solid, rectangular block that mounts directly onto a flat base plate. The shaft's mounting hole is centered within the block.
Advantage: Highest Rigidity (Typical): The large, stable footprint provides excellent stability, making it the most common choice for medium-to-heavy-duty industrial stages and machine tool tables where maximum axial and radial stiffness is a requirement.
Use Case: The most common fixed-end support for standard ball screw axes (X, Y, and Z).
2. EK Support Brackets (The Miniature/Compact Choice)
Design: A significantly smaller, more cube-like block, engineered specifically to minimize its footprint.
Advantage: Space Saving: It is essential for compact machine designs, miniature stages, and applications where the ball screw shaft itself is small in
diameter (≤15 mm). It allows the support unit to fit into very tight machine envelopes.
Use Case: Small robotic arms, miniature positioning stages, and laboratory automation equipment.
3. FK Support Brackets (The Flange Mount Solution)
Design: Features a prominent flange or square mounting face, where the bolt holes are drilled parallel to the shaft's axis (on the front face).
Advantage: Easy Flange Mounting: It is uniquely designed to bolt directly to the vertical end face of an aluminum extrusion or a machine's bulkhead. This design saves vertical space (height) in the machine structure and simplifies installation when mounting to a specific end plate.
Use Case: Common in modular linear actuators and stages where the support block needs to fit flush with the end of the module or machine frame.