FAQ

Yes, corrosion-resistant ball screws are available for use in humid, aggressive, or hygienic environments. Both the screw and the nut are made of stainless steel, often martensitic or austenitic steels. The balls are also manufactured from stainless steel or ceramic to further reduce corrosion. Additionally, special coatings and corrosion-resistant lubricants are used to increase the service life.

Yes, corrosion-resistant ball screw drives made of stainless steel or ceramic can be used in the food industry and in medical technology. It is important that all materials, lubricants, and coatings meet the relevant hygiene and cleanliness requirements, such as FDA or EU standards. Such ball screw drives enable precise, low-wear motion, even in environments with moisture, cleaning processes, or chemical disinfectants.

A ball screw drive can be powered in various ways, depending on the installation situation, spindle length, and dynamic requirements. Often, the spindle itself is rotated by a motor, with the nut remaining stationary, thereby generating linear motion. Alternatively, the nut can be driven directly while the spindle remains fixed, which is particularly advantageous for long spindles or high dynamic demands. Further options include driving via belts, gears, or transmissions to flexibly transfer rotational motion or compensate for deflection angles. The choice of drive type influences the precision, speed, load capacity, and installation flexibility of the ball screw drive.

The bearing arrangement of a ball screw drive should be designed to reliably accommodate axial forces while simultaneously avoiding stresses. In practice, a fixed/floating bearing arrangement is typically employed. The fixed bearing accommodates axial forces in both directions and ensures high rigidity, while the floating bearing guides the spindle radially and compensates for thermal length changes. The bearings must be precisely aligned, preloaded without play, and sufficiently rigidly mounted in the housing to prevent runout, vibrations, and premature wear.

Ball screw drives can be lubricated with either oil or grease. The choice depends heavily on the application. Grease lubrication is used most frequently because it is easy to handle, offers good adhesion, and provides reliable lubrication even at low speeds. It is particularly suitable for standard applications, moderate speeds, and closed systems. Oil lubrication is preferred at high speeds, with high heat generation, or in highly dynamic applications, as oil dissipates friction and heat more effectively and thus enables more uniform lubrication. The key is to match the lubricant type and relubrication concept to speed, load, environment, and the manufacturer’s recommendations in order to achieve optimum service life and smooth running.

Yes, ball screw drives can generally be repaired, provided the wear or damage is not too severe. Typical repairs include replacing or reconditioning the nut, replacing the balls, readjusting or renewing the preload, and cleaning and relubricating. However, if the thread flanks are severely damaged or high accuracy is required, replacement is often more economical than repair.

Compared to a sliding screw drive, a ball screw drive offers significantly higher efficiency, as the force is transmitted via rolling balls rather than sliding surfaces. This results in less friction, reduced wear, greater positioning accuracy and improved dynamics. Furthermore, ball screw drives can be preloaded with virtually no backlash and are particularly suitable for precise and rapid movements.
On the other hand, they involve higher purchase costs, greater sensitivity to dirt, and greater lubrication and maintenance requirements. Linear guide screws are more robust, cost-effective and, due to their low efficiency, can exhibit self-locking behaviour, which is an advantage in certain applications.

A ball screw drive offers several advantages over a trapezoidal thread: It operates very efficiently because force is transmitted via rolling balls, which keeps friction and wear low. Furthermore, it enables high positioning accuracy and low backlash. Disadvantages include higher acquisition costs, greater sensitivity to dirt and impacts, and a generally more complex design.

A ball screw with a driven nut offers several advantages: Since the screw is stationary and only the nut is moved by a motor, the moving mass is reduced, leading to higher dynamics, faster acceleration, and lower load capacity. This design also allows for the use of long or heavy screws, simplifies installation in cramped or complex machine layouts, and improves the positioning accuracy and precision of the drive through the direct drive of the nut.

The accuracy grades IT1, IT2, IT3, etc. in accordance with ISO 286 specify the manufacturing tolerances for the size, form and position of workpieces. The lower the number, the higher the precision. For thread drives, a distinction is made between lead accuracy, which indicates how precisely the linear feed movement per spindle revolution is, and form and positional tolerances, which define the geometric form of the thread as well as the relative position of spindle and nut. While the IT grades define the manufacturing tolerances, lead and form/positional tolerances influence the functional precision, smooth running and backlash of the thread drive.