Product Details:

REXROTH 0608720040 (4GE59 SZ4) is a precision planetary gear unit for Kollmorgen / Rexroth servo nutrunner spindle, designed to match the servo motor of tightening system for torque amplification and stable low-speed output. It adopts high-precision helical planetary gear structure, optimized reduction ratio to boost continuous torque and improve tightening repeatability for medium and heavy bolt fastening tasks. This gear unit is a spare component of legacy tightening systems, and most available stock on the market are replacement parts for old assembly lines.

This gearbox transfers torque from the servo motor to the output square drive, reducing output speed and multiplying torque. It is used together with servo spindle and tightening controller to complete closed-loop torque and angle fastening. The gear profile is ground with high precision to minimize backlash and maintain consistent angular transmission accuracy. Separate flange interface matches standard Rexroth tightening servo motors and output adapters for quick assembly swap.

This variant is non-brake mechanical gear unit without integrated holding brake. It is widely fitted on fixed automated tightening spindles and rotary multi-station fastening fixtures where static locking is handled by external brake or fixture. The standardized output interface supports quick-change socket adapters to shorten product changeover time. The internal gear and bearing are filled with long-life high-temperature grease, suitable for continuous cyclic operation under fluctuating tightening load. The gear housing reaches IP54 protection grade to resist workshop dust and minor splash. Optimized gear tooth design suppresses vibration and torque ripple greatly, keeping stable torque transmission for safety-critical bolt joints.

It works cooperatively with Rexroth tightening controller and servo motor, all tightening strategies and parameters are configured via Rexroth tightening software. Compact inline layout saves installation space inside narrow rotary indexers. Every finished gear unit passes factory validation before shipment, including backlash test, torque loading endurance test, noise inspection and vibration test to guarantee stable performance in multi-shift automotive fastening production lines.

It is widely deployed on automotive powertrain assembly stations, new energy battery module fastening lines, heavy mechanical component bolt joining equipment and multi-spindle tightening automation cells. Typical application axes include servo tightening spindle transmission modules, rotary fastening driving units, mixed-model assembly bolt driving stations and high-precision torque loading fixtures. Automation integrators select this 4GE59 SZ4 gear unit for its low-backlash transmission, compact footprint and seamless matching with Rexroth nutrunner servo spindles.