The Siemens 1FK7105-5AC71-1PG0 is part of the SIMOTICS S-1FK7 family of permanent-magnet synchronous servo motors built for precise, dynamic motion control. In real machines, it shows up where you want “fast, smooth, repeatable” without turning your control cabinet into a sauna: packaging lines, handling systems, robotics sub-axes, plastics machinery, and general high-performance feed axes. Siemens positions the 1FK7 range as broadly applicable across motion control tasks, especially when paired with SINAMICS S drives for commissioning speed and stable operation.
This particular MLFB (ordering code) is commonly described as a 1FK7 Compact variant with a classic flange-mount geometry and an integrated feedback solution suitable for servo operation. Like most serious servo motors, the “magic” is not just torque; it’s torque plus feedback plus a drive ecosystem that makes tuning, diagnostics, and replacement predictable over the life of the machine.
At-a-glance specifications (commonly listed for 1FK7105-5AC71-1PG0)
| Item | Value / Description |
|---|---|
| Motor family | SIMOTICS S – 1FK7 (Compact) |
| Static torque (ΔT = 100 K) | 48 Nm |
| Rated speed | 2000 rpm |
| Rated power (commonly stated) | 7.75 kW |
| Cooling | Natural cooling |
| Mounting | IM B5 (IM V1 / IM V3 orientations referenced) |
| Connector | Power/signal connector, rotatable (listed as 270°) |
| Feedback | Resolver (2-pole) with DRIVE-CLiQ interface |
| Shaft | Plain shaft, tolerance N |
| Holding brake | Without holding brake |
| Protection | IP64 (as commonly stated) |
Note: exact electrical/mechanical ratings can vary by options inside the MLFB structure; always confirm against the Siemens-generated datasheet for your exact ordering configuration when the application is safety- or performance-critical.
What makes the 1FK7 platform useful in real projects
1) Tight integration with SINAMICS drives (less “servo wrestling”)
Siemens designed SIMOTICS S-1FK7 motors to work cleanly with SINAMICS S110/S120, including digital identification and standardized connection concepts that speed up commissioning and reduce wiring mistakes. The family is explicitly described as optimized for interoperability, using DRIVE-CLiQ and an electronic rating plate concept to support fast setup and smooth operation.
A practical way to say it: you spend less time doing ceremonial incantations in the parameter menus and more time making the axis behave.
2) DRIVE-CLiQ feedback ecosystem (diagnostics that don’t hate you)
For many machine builders, the feedback/connector system is where downtime either shrinks or explodes. In the 1FK7 ecosystem, Siemens emphasizes the system interface and integrated approach to commissioning and operation.
For the 1FK7105-5AC71-1PG0, the commonly listed feedback is resolver with DRIVE-CLiQ, which is a robust choice for industrial environments.
3) Mechanical practicality: flange mount, rotatable connector, predictable integration
Servo motors live and die by mechanical integration details: flange patterns, connector orientation, shaft style, and sealing. The commonly listed configuration for this model includes IM B5 mounting and a rotatable connector—the kind of small design choice that saves real hours inside cramped machine envelopes.
Typical applications and why this model fits
Siemens describes SIMOTICS S-1FK7 motors as a common motion-control solution across multiple machine classes such as robots/handling systems, and packaging/plastics/textile machinery.
Within that landscape, a torque class around the upper end of the 1FK7 compact range is often used for:
| Application | What the motor contributes | Why it matters |
|---|---|---|
| Handling axes and gantries | Strong continuous torque and stable control | Keeps cycle time high without overshoot |
| Packaging machines | Rapid acceleration/deceleration with repeatability | Improves throughput and seal/cut quality |
| Plastics and extrusion auxiliaries | Smooth speed regulation and reliable feedback | Helps stabilize process behavior |
| Robotics sub-axes / positioners | Accurate torque delivery with servo feedback | Supports precise, repeatable positioning |
(Exact sizing depends on load inertia, duty cycle, gearbox ratio, and thermal conditions; use Siemens sizing tools when you’re near the limits.
Installation, commissioning, and reliability notes (the boring stuff that prevents fires)
Servo motors are not “plug in and vibe.” Siemens’ operating instructions stress that work should be performed by qualified personnel and that proper transport, installation, and adherence to permissible ambient conditions are necessary for safe operation.
Two practical highlights from Siemens guidance that matter in the field:
| Topic | Practical recommendation | Why it matters |
|---|---|---|
| Grounding and bonding | Ensure grounding and equipotential bonding are correctly established before commissioning | Reduces shock risk and improves EMC robustness |
| Shielding practice | Connect cable shielding at both ends (motor and converter) and keep unshielded ends as short as possible | Helps control high-frequency currents and prevents weird encoder/drive faults |
Ordering and replacement checklist (to avoid “almost the same motor” problems)
When sourcing or cross-checking a 1FK7105-5AC71-1PG0, verify these items before purchase or substitution:
| Check item | What to match | Notes |
|---|---|---|
| Full MLFB | 1FK7105-5AC71-1PG0 | Options are encoded; don’t truncate |
| Feedback type | Resolver + DRIVE-CLiQ (as listed) | Drive compatibility depends on feedback |
| Shaft / keying | Plain shaft, tolerance class | Mechanical coupling depends on it |
| Brake | No holding brake (as listed) | Safety and vertical axes may require brake |
| IP rating / sealing | IP64 listed | Environment and washdown conditions decide this |
| Connector orientation | Rotatable connector (270° listed) | Helps in tight machine layouts |
Summary
If you need a high-torque SIMOTICS S servo motor in the 1FK7 platform with resolver feedback and DRIVE-CLiQ integration, the Siemens 1FK7105-5AC71-1PG0 is a widely referenced configuration that fits demanding feed-axis and motion-control applications—especially in systems built around SINAMICS drives for consistent commissioning, diagnostics, and lifecycle support.
