Siemens 1FK7042-2AK71-1QB0 SIMOTICS S-1FK7 1FK7-CT 0.94kW 3Nm 6000rpm Servo Motor

The Siemens 1FK7042-2AK71-1QB0 is a SIMOTICS S-1FK7 (1FK7-CT) permanent-magnet synchronous servo motor rated 0.94 kW at 6,000 rpm, delivering 3 Nm standstill torque (M0, 100K) from a 600 V DC link. It integrates a holding brake, carries a single-turn 20-bit DRIVE-CLiQ absolute encoder (AS20DQI), and is naturally cooled in a shaft height 48, IMB 5 (IM V1/V3) housing rated IP64.

Technical Specifications

Selection Notes

Same 6,000 rpm winding as the brake-free variant of this frame, with an integrated holding brake — weight rises from 4.6 to 5.3 kg and shaft torsional stiffness drops from 15,500 to 11,400 Nm/rad. Fit it on high-speed axes that must still hold position at standstill, such as an overhung spindle or gravity-loaded rotary axis; on purely horizontal high-speed axes, the brake-free winding is lighter. The 2.5 A rated current and 0.68 Nm/A torque constant are unchanged by the brake.

Applications

Used as the servo motor in high-speed machine axes that must hold position without drive power — indexed rotary tables, overhung spindle axes, and winding stations — driven through a DRIVE-CLiQ-based servo drive via the AS20DQI single-turn absolute encoder interface. The integrated holding brake keeps the axis in position during an E-stop or power loss.