Union Spindeln – Saxon engineering excellence for the heaviest loads
Union Spindeln – 170 Years of German Engineering Excellence
Based in the historic industrial city of Chemnitz, the Union brand looks back on more than 170 years of history and is considered Germany’s oldest machine tool manufacturer. Today, Union is managed as a quality brand within the internationally active HerkulesGroup under the leadership of WaldrichSiegen and is synonymous with excellence in the manufacture of horizontal boring mills.
These massive machines are designed to machine workpieces up to 40 meters in length. At the technological heart of the system is the extendable drilling spindle, which is what makes precision and stability on this scale possible in the first place. In its public image, the long-established Saxon manufacturer deliberately maintains a down-to-earth approach, preferring to let the dimensions and results of the machined workpieces speak for themselves. The company is reticent about the design details of the spindle systems, even though they set technological standards.
Stability and durability are deeply rooted in Union’s DNA. Industry experts know that the spindles maintain micrometer-level precision even with a W-axis travel of up to 1,500 mm. They prove their worth in both heavy-duty roughing and high-precision finishing of gear housings or turbine components weighing several tons.
As a global manufacturer, Union combines exceptional mechanical strength with precision engineering in its spindle components, thereby ensuring long-term reliability in heavy machinery manufacturing.
Union Spindeln's Technological Strengths
What sets Union spindles apart is their ingenious combination of a support journal (RAM) and an extendable drilling spindle. This system enables machining deep inside complex workpieces without compromising rigidity or precision. The precise guidance of the W-axis is one of the core strengths of Union drilling machines.
Another key factor is hydrostatic bearing support. In large product lines such as the PR series, hydrostatic guides and bearings are used, ensuring virtually wear-free operation and effectively damping vibrations. This ensures that long-term geometric accuracy is maintained for decades, which significantly improves manufacturing efficiency over the long term.
Despite their massive dimensions, Union spindles are designed with serviceability in mind. Areas requiring maintenance remain accessible, and high-quality details such as hand-finished spindle bearing housings underscore the quality of the workmanship. In the event of servicing, this design allows for targeted and professional overhauls, thereby reducing downtime on demanding large-scale projects.
This is what Union spindles look like on the inside
In their design, Union spindles reflect the robustness of heavy-duty Saxon mechanical engineering:
- Extendable drilling spindle (W-axis): Travel ranges of up to 1,500 mm with maximum rigidity.
- Heavy-duty bearings: Large-diameter precision bearings designed for maximum axial cutting forces.
- Hand-finished mounting surfaces: For perfect alignment and minimal vibration.
- Cooling system: Integrated temperature control to prevent thermal expansion during extended periods of operation.
Spindle Repair for Your Union Bohrwerk Spindles
Since Union spindles are often used in highly critical large-scale projects—such as wind energy or mining—professional service when the wear limit is reached is absolutely essential to ensuring your ability to meet deadlines. At KERN GmbH, we specialize in the repair of these massive and high-precision systems. We not only have a deep understanding of the mechanical hardware but also grasp the sensitive requirements for W-axis alignment. Our goal is to ensure that your Union spindle operates with its customary Saxon reliability after the overhaul.
Are you looking for a reliable service partner for your Union units? We recommend contacting our team of experts directly. As an experienced partner, KERN GmbH is here to assist you with all questions regarding the maintenance and repair of your Union spindles as well as products from other leading manufacturers.
