Siemens 1FK7101-2AC71-1BG1 Servo Motor: Product Description, Technical Parameters, Applications, and Related Models

1. Product Introduction

The Siemens 1FK7101-2AC71-1BG1 is identified by its model code as part of the SIMOTICS S 1FK7 family of synchronous servo motors. This product family is designed for industrial motion-control systems that require controlled speed, repeatable positioning, and reliable torque delivery.

Servo motors are used in machinery where the movement of a mechanical axis must follow a specific command. Typical tasks include moving a carriage to a programmed position, feeding material by a defined distance, coordinating several machine axes, or accelerating and decelerating a mechanism in a controlled manner.

The 1FK7 family is intended for integration with compatible servo drives and motion-control systems. Depending on the exact motor configuration, the system can support closed-loop speed and position control, allowing the machine to respond to changing load conditions and follow programmed motion profiles.

The complete model number is important when identifying the motor. Different suffixes within the same family may indicate different encoder arrangements, holding-brake options, connector configurations, winding characteristics, or other mechanical and electrical details.

Specification note: The exact ratings and mechanical dimensions of 1FK7101-2AC71-1BG1 should be confirmed against the motor’s nameplate and matching technical drawing. The information below distinguishes general 1FK7 family characteristics from variant-specific details that should not be assumed without confirmation. Where an exact value is uncertain, it is identified as requiring verification rather than presented as a confirmed specification.

2. Brand and Product Series

The SIMOTICS S product family

SIMOTICS S servo motors are designed to work as part of a complete motion-control system. The motor converts electrical energy into controlled mechanical movement, while the servo drive regulates the motor’s current and response to the control command.

Within the 1FK7 series, different frame sizes and configurations are intended for different load requirements and installation conditions. Motors with similar model prefixes may share some general design characteristics while differing in their encoder, brake, connectors, or rated performance.

For maintenance and replacement work, the complete order code should always be checked. A motor that looks similar and has a comparable power rating is not necessarily electrically or mechanically interchangeable.

3. Detailed Technical Specifications

The 1FK7101-2AC71-1BG1 configuration is a naturally cooled synchronous servo motor with a 600 V DC-link class, a nominal speed of 2,000 rpm, and a 24-bit single-turn absolute encoder with a DRIVE-CLiQ interface. It has a plain shaft and no integrated holding brake.

3.1 Main parameters

3.2 Electrical and performance parameters

These figures describe the motor’s electrical and mechanical characteristics under specified conditions. Maximum torque and maximum current are not continuous operating ratings; their permissible duration and operating range depend on the motor, drive, cooling conditions, and duty cycle.

3.3 Mechanical dimensions and weight

The confirmed shaft height is 100 mm, and the net motor weight is 23.0 kg. The complete overall dimensions should be taken from the matching mechanical drawing rather than estimated from the frame designation.

This is especially important when replacing an existing motor. Shaft geometry, flange mounting points, motor length, and connector clearance determine whether the unit can fit the machine without mechanical modifications.

3.4 Encoder and feedback parameters

The absolute encoder provides position information within one revolution. This can simplify position referencing compared with a basic incremental feedback arrangement, although the machine’s complete control design still determines whether a homing operation is required.

Because this motor uses a DRIVE-CLiQ feedback interface, it should not be assumed to be interchangeable with a motor using an incremental encoder, resolver, or different encoder interface, even if the shaft and flange appear similar.

4. Product Description and Operating Characteristics

4.1 Permanent-magnet synchronous motor design

The 1FK7101-2AC71-1BG1 uses a permanent-magnet synchronous motor design. The rotor contains permanent magnets, while the stator windings generate the rotating magnetic field needed to produce torque.

When paired with a compatible servo drive, this design supports controlled speed, torque, and positioning. It is useful in machines where a motor must follow a programmed movement rather than operate at a fixed speed continuously.

4.2 Rated torque and power

The motor has a rated torque of 20.5 Nm at a 100 K temperature rise, a static torque of 27 Nm at a 100 K temperature rise, and an optimum operating power of 4.3 kW.

These ratings serve different purposes. Rated torque describes a specified operating condition, while static torque describes the motor’s torque capability at standstill under the corresponding thermal conditions. Maximum torque is a separate limit and should not be treated as a continuous rating.

When selecting the motor, calculate the torque needed to move the load, overcome friction, accelerate the mechanical system, and maintain the intended speed. A machine that demands high torque repeatedly may require a different motor or a more careful thermal assessment, even if its short-duration peak torque is within the motor’s limits.

4.3 Absolute encoder feedback

The motor is fitted with an AS24DQI absolute encoder featuring 24-bit single-turn resolution and a DRIVE-CLiQ interface.

This feedback arrangement provides the drive with position information for closed-loop control. It is useful for applications that need repeatable positioning and accurate coordination between the motor and the machine controller.

The encoder interface is a key part of the motor’s identity. When replacing the unit, check that the drive supports the encoder and the corresponding motor configuration.

4.4 Natural cooling

The motor uses natural cooling, meaning that heat is dissipated through its housing and the surrounding installation rather than relying on a separate forced-air motor cooling unit.

This can simplify the machine design and reduce auxiliary equipment. However, sufficient space must be left around the motor for heat to escape. Restricted airflow, high ambient temperatures, or prolonged operation at high torque may reduce the permissible continuous load.

4.5 No integrated holding brake

The 1BG1 configuration does not include an integrated holding brake.

This is suitable for many axes that are mechanically supported or do not need to remain locked in position after the drive is disabled. It requires additional consideration for vertical axes or mechanisms where a load could move under gravity.

If the machine must hold a load when power is removed, an appropriate external mechanical holding device or a suitable brake-equipped motor configuration may be required. The motor’s energized torque should not be treated as a substitute for a safety-rated load-holding arrangement.

4.6 IP65 protection

The motor’s IP65 rating provides dust-tight protection and protection against water jets under the conditions specified for that rating.

IP65 does not mean that the motor can be submerged in water or exposed to every type of industrial cleaning process. For installations involving aggressive fluids, high-pressure washdown, or corrosive environments, the motor’s suitability should be checked against the actual operating conditions.

5. Applications

5.1 CNC machine tools

The motor can be considered for controlled feed mechanisms and positioning axes in machine tools where the torque and speed requirements match its ratings.

Typical uses include:

• Feed-axis movement.

• Positioning of machine carriages.

• Coordinated movement of auxiliary axes.

• Automated tool-positioning mechanisms.

• Repeatable movement during programmed machining cycles.

The achievable accuracy depends on the complete machine system, including the encoder, drive tuning, mechanical stiffness, transmission, and backlash.

5.2 Packaging and converting machinery

Packaging machines often need precise control of material feeding, cutting, positioning, and synchronization.

Potential applications include:

• Material-feed mechanisms.

• Indexing units.

• Cutting and sealing mechanisms.

• Product-transfer systems.

• Positioning of packaging components.

For these applications, the machine’s operating cycle matters as much as the rated power. Frequent acceleration, deceleration, and stopping can increase peak torque and thermal loading.

5.3 Automated assembly equipment

In automated assembly, servo motors can move parts into fixtures, position components for joining, and coordinate the movement of different machine sections.

The 1FK7101-2AC71-1BG1 may be suitable for positioning slides, rotary mechanisms, and transfer systems where its feedback and torque characteristics meet the application requirements.

For pressing or force-sensitive work, the motor’s torque rating alone does not determine the permissible pressing force. The transmission, mechanical structure, and control method must also be evaluated.

5.4 Material handling and transfer systems

The motor can be evaluated for material-handling mechanisms that require controlled speed changes and repeatable stopping positions.

Examples include transfer units, automated feeding stations, sorting mechanisms, and positioning platforms. If the driven load has high inertia, the acceleration and deceleration requirements should be calculated before selecting the motor.

5.5 Printing and paper-processing machinery

Printing and converting systems often need synchronized movement to maintain material feed and repeatable cutting or positioning.

Servo control can be useful for feed rollers, registration mechanisms, cutting units, and other controlled axes. The absolute encoder can support position feedback where the drive and machine controller are designed to use the relevant interface.

5.6 Industrial automation systems

The motor can be used as one axis within a larger automated machine. A compatible servo drive and motion controller can coordinate its movement with conveyors, feeders, actuators, and other servo axes.

The main selection considerations are the required torque, operating speed, load inertia, feedback interface, mounting dimensions, and duty cycle.

5.7 Maintenance and replacement projects

For maintenance teams, the full model number is essential when replacing a motor. A replacement should be checked against the original unit’s nameplate, drive configuration, shaft geometry, flange pattern, connector arrangement, and feedback type.

A motor with the same shaft height and similar torque rating may still require changes to the electrical configuration or machine controls if its encoder, winding, or brake arrangement differs.

6. Main Advantages

6.1 High-resolution absolute position feedback

The 24-bit single-turn absolute encoder provides fine position information within one revolution. With a compatible drive, this supports feedback-based control and repeatable positioning.

The actual positioning accuracy of the machine depends on more than encoder resolution. Mechanical backlash, coupling stiffness, drive tuning, and the control system all contribute to the final result.

6.2 Strong torque capability for industrial motion

The rated torque of 20.5 Nm and static torque of 27 Nm at a 100 K temperature rise make this motor a candidate for industrial axes requiring substantial torque at moderate speed.

The motor should still be sized using both continuous and peak torque requirements. Operating at a high load for an extended period may impose thermal limits even when the peak torque rating is not exceeded.

6.3 Suitable for controlled acceleration and deceleration

A servo motor and compatible drive can regulate acceleration and deceleration to suit the machine’s movement profile. This is useful for equipment that repeatedly starts, stops, changes speed, or follows programmed positions.

The resulting performance depends on correct motor selection, drive configuration, and the mechanical characteristics of the load.

6.4 Natural cooling arrangement

Natural cooling can reduce the need for auxiliary cooling equipment and simplify the overall installation.

The advantage is most useful when the motor operates within its permitted thermal limits and the surrounding machine structure allows adequate heat dissipation.

6.5 Industrial mounting options

The motor supports the IM B5 mounting arrangement, with IM V1 and IM V3 configurations within the specified design family. These mounting arrangements provide flexibility when integrating the motor into different machine layouts.

The exact flange and shaft dimensions must still be checked before installation or replacement.

6.6 Dust and water-jet protection

The IP65 protection rating makes the motor suitable for many industrial environments where dust and occasional water jets are concerns, provided the complete installation meets the applicable requirements.

Cable entries, connectors, seals, and installation practices must also maintain the intended protection level.

6.7 No integrated brake for applications that do not require one

The absence of an integrated holding brake can simplify the configuration for axes that do not need motor-based holding after power removal.

Where the machine requires a brake, however, the correct brake-equipped variant should be selected instead of treating the no-brake model as a direct substitute.

7. Five Related Models in the Same Series

The following models belong to the same general 1FK7101-2AC71 family. They are useful comparison candidates because their principal motor ratings are similar, while the feedback, shaft, brake, or connector configuration may differ.

The common torque and speed figures describe the corresponding 1FK7101-2AC71 motor family. Confirm the individual nameplate and variant-specific data before ordering. Full overall dimensions require the matching mechanical drawing.

How these related models differ

• 1FK7101-2AC71-1BG1: The reference model with a 24-bit single-turn absolute encoder and no integrated holding brake.

• 1FK7101-2AC71-1RA1: Offers a multi-turn absolute encoder and keyed shaft arrangement, making it a candidate where the mechanical coupling and control system are designed for that configuration.

• 1FK7101-2AC71-1RH1: Adds a holding brake and uses a multi-turn encoder configuration.

• 1FK7101-2AC71-1CH2: Uses a higher-information multi-turn feedback arrangement and includes a holding brake.

• 1FK7101-2AC71-1QH1: Uses single-turn absolute feedback and includes a holding brake.

The most appropriate alternative depends on the machine’s control architecture and mechanical design. Encoder resolution alone does not determine positioning accuracy, and a brake-equipped motor should only be selected where its brake rating and safety function suit the application.

8. Five Other Siemens Servo Motor Models to Consider

These additional models offer alternatives within the broader servo-motor range. They are comparison candidates rather than guaranteed direct replacements for the 1FK7101-2AC71-1BG1.

Comparing the alternatives

The 1FK7101-2AC71-1PB2 is a useful comparison when a resolver-based feedback system or a holding brake is required. However, it is not a direct replacement for the reference motor unless the drive supports its feedback arrangement and the brake configuration suits the machine.

The 1FK7101-2AC71-1CA1 is another related configuration, but its exact feedback and mechanical options should be checked before use.

The 1FK7100-2AF71-1RH1 belongs to a different 1FK7 configuration and should be compared using its own torque-speed data and mechanical drawing. The 1FK7083 model has a different frame size, so its mounting dimensions and output capability must be evaluated independently.

The 1FT6 model offers another servo-motor family to investigate where the machine design permits a different motor configuration. Compatibility with the existing drive, feedback interface, and mechanical mounting must be established first.

Key selection criteria

9. Installation and Commissioning

9.1 Mechanical installation

Install the motor on a rigid mounting surface and ensure that the driven shaft and motor shaft are aligned correctly. Poor alignment can increase vibration, bearing loads, and coupling wear.

Before installation, check the shaft dimensions, flange pattern, and total motor length using the exact mechanical drawing. Leave enough room for the power and signal connectors and their cable bend radii.

9.2 Electrical connection

Use the appropriate motor power cable and feedback connection for the specified encoder. Check grounding, shielding, connector fit, and cable routing in accordance with the machine’s electrical design.

Because the model uses a DRIVE-CLiQ absolute encoder, the selected drive and feedback configuration must support this interface.

9.3 Drive configuration

Configure the servo drive with the correct motor and encoder data. Motor identification, current limits, control parameters, and feedback settings must match the installed variant.

During commissioning, check the direction of rotation, feedback operation, current behavior, acceleration response, and positioning performance. A motor should not be operated under load until the configuration and safety functions have been verified.

9.4 Brake and load safety

The reference 1BG1 motor has no integrated holding brake. For a vertical axis or a load that could move under gravity, an appropriate external holding or safety arrangement may be necessary.

A brake-equipped alternative should be considered only after confirming its brake rating and suitability for the machine’s required safety function.

9.5 Thermal management

Natural cooling requires adequate heat dissipation. Do not block the motor housing with surrounding equipment or enclose it in a way that prevents the heat from escaping.

For applications involving repeated acceleration, frequent stopping, or sustained high torque, calculate the thermal load rather than relying solely on the optimum power rating.

10. Maintenance Recommendations

Regular inspection can help identify mechanical wear, electrical connection problems, and changing load conditions before they result in an unexpected stoppage.

Always follow the machine’s isolation procedures before handling connectors or carrying out mechanical work. Repeated drive faults should be investigated rather than simply reset.

11. Final Summary

The Siemens 1FK7101-2AC71-1BG1 is a SIMOTICS S 1FK7-CT synchronous servo motor with a 24-bit single-turn absolute encoder and DRIVE-CLiQ interface. It has a plain shaft, natural cooling, IP65 protection, and no integrated holding brake.

Its principal technical ratings include a rated speed of 2,000 rpm, rated torque of 20.5 Nm, static torque of 27 Nm at a 100 K temperature rise, and optimum operating power of 4.3 kW. The motor has a 100 mm shaft height and a net weight of 23.0 kg.

The motor is suitable for consideration in CNC equipment, packaging machinery, automated assembly, material handling, and other industrial motion-control applications where its torque, speed, feedback, and mechanical characteristics match the requirements.

The most important points to confirm before purchase or replacement are the exact mounting dimensions, the drive’s compatibility with the AS24DQI encoder, the permitted operating limits, and the machine’s need for a holding brake.

The related 1FK7101-2AC71 models provide useful alternatives when a different encoder or brake arrangement is required. Other 1FK7 and 1FT6 models can be evaluated for different installation or performance requirements, but each must be checked against its own complete technical specification before being selected.