Siemens 1FK7101-2AF71-1QA0 SIMOTICS S 1FK7-CT 4.9 kW 27 Nm 3000 rpm Servo Motor

The Siemens 1FK7101-2AF71-1QA0 is a SIMOTICS S 1FK7-CT synchronous servo motor rated 4.9 kW, delivering 27 Nm standstill torque (M0, 100K duty) at a 3000 rpm rated speed with an 8-pole, 11.6 A design. It is naturally cooled, IMB 5 flange-mounted, and fitted with an absolute single-turn 20-bit encoder on a DRIVE-CLiQ interface, IP64-rated, without a holding brake.

Selection Notes

The -2AF71 code sets this motor to a 3000 rpm rated speed within the 1FK7-CT line, the higher-speed winding compared with the -2AC71 version rated to 2000 rpm at the same 27 Nm standstill torque; the trade-off shows in the 1.44 Nm/A torque constant here, lower than the 2000 rpm winding, so the drive needs the full 11.6 A rated current to hold the same 27 Nm. The -1QA0 suffix means no integrated brake, keeping moment of inertia at 79.0 kgcm2 and weight at 23.0 kg, lower than the brake-equipped configuration in this frame, and keeping the 1.62 ms mechanical time constant as fast as this design allows. Choose this non-brake configuration for horizontal axes or where an external holding mechanism already covers power-off retention; for vertical or gravity-loaded axes, a holding-brake version of this motor is the safer choice. The 164,000 Nm/rad torsional stiffness supports a stiff, high-bandwidth position loop at the 3000 rpm rated speed and 4.9 kW rated power.