With the innovative concept for rack and pinion drives, Stöber has developed a compact, easy-to-use system with process reliability that is precisely tailored to applications in machine tools, automation and robotics. By combining it with Stöber's planetary or helical bevel gear units and directly attached servo motors, users receive a wide variety of compact, highly dynamic drive solutions from a single source. The complete gear units are ready for immediate use and no assembly work is required at all.
From high flexibility to high force: With its rack and pinion drives combined with synchronous servo motors, STOBER has a unique system in its portfolio that can be adapted to different requirements in terms of load capacity and precision. The rack and pinion drives are based on case-hardened, smoothed pinions with the highest gearing quality and precisely matched gear racks from our cooperation partner Atlanta.
The user clearly benefits from the advantages of direct attachment, as adapters make drive units heavier and they require more installation space. This has a negative effect on dynamics and volume. Added to this is the increased installation effort. Drive specialist STOBER offers four different series of rack and pinion drives that can be directly attached to the synchronous servo motors of the EZ series in all sizes. The user receives a compact, easy-to-use system with process reliability from a single source – a system that is precisely tailored to their task.
Extremely strong or perhaps flexible after all?
Above all, the helical-geared ZV series is flexible. Depending on the application, the pinion can be positioned at the shaft end or the shaft shoulder. The shaft-hub connection is backlash-free and positive-locking. It can be coupled not only with a planetary gear unit, but also with helical bevel gear units from the KS series, for example. By combining it with the EZ synchronous servo motor, the customer gets an outstanding drive featuring an extremely compact housing geometry with a low weight and high volume performance. Thanks to the large, stiff output bearings, the torque of the KS gear units can also be fully converted into feed force. This makes this series predestined for automation and robotics.
Because the pinions in the ZR series are mounted without an additional flange, the user benefits from a very good price/performance ratio with this helical-geared, case-hardened and ground version. It is also very suitable for high feed velocities.
For the ZTRS series, Stöber has developed a firmly bolted support bearing holder. The stiffening ribs on the inner contour make it possible to fully utilize the gear torque of the rack and pinion drive, which improves the power density and rigidity. This series can be used for feed axes in machine tools and laser machines as well as in highly dynamic and precise handling systems. The rack and pinion drives can be combined with different gear units.
If the support bearing holder in feed axes causes an interfering contour, STOBER offers the ZTR series featuring the excellent characteristics of a small pinion diameter, high linear rigidity and low torques at high feed forces. The pinions with the welded screw flange are easy to mount and remove. The rack and pinion drives can also be combined with the PH and PHV series gear units. For example, together with the PH series planetary gear units, the ZR, ZTR and ZTRS versions achieve an excellent radial runout that, as an option, can be optimized to less than or equal to 0.01 millimeters.
The user can install the completely finished units immediately, without ever adapting the motor and pinion. Acceleration feed forces of 0.48 to 126 kN can be achieved across all series. "The reduced weight is what makes this possible, of course," explains Udo Cyrol, Head of Stöber Sales Center South-East. "This is because the rack and pinion drives usually travel along with the moving component. The lack of a motor adapter allows the units to be shorter and lighter, which also reduces the inherent flywheel mass." Stöber's One Cable Solution helps to reduce weight even further. Thanks to the future-oriented Heidenhain EnDat 3 protocol, the hybrid cable eliminates the need for an encoder cable, which means that the drag chain can be smaller.