Electric drives

Rotary actuators

Festo electric rotary actuators include rotary modules of the ERMB series (sizes 20, 25, and 32) and electric rotary drives of the ERMO series (sizes 12, 16, 25, and 32). The ERMB modules are designed for direct integration into handling systems and provide defined rotary motion without an additional gear stage. The ERMO series offers electrically controlled swivel movements in the ST-E configuration for control signals and is available in four sizes for different torque requirements.

7 items
1 manufacturer
Net prices plus VAT

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Rotary Drive ERMO-32-ST-E - Festo 3008528
€1,049.58
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Rotary Module ERMB-32 - Festo 552708
€1,716.29
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Rotary Module ERMB-20 - Festo 552706
€1,232.60
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Rotary Drive ERMO-16-ST-E - Festo 3008526
€908.28
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Rotary Module ERMB-25 - Festo 552707
€1,500.81
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Rotary Drive ERMO-25-ST-E - Festo 3008527
€1,002.50
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Rotary Drive ERMO-12-ST-E - Festo 3008525
€834.29

Buying guide

How to choose Rotary actuators

What matters when choosing: properties, comparison and typical applications.

Technical features of rotary actuators

⚙ ERMB rotary modules, sizes 20/25/32 - compact design for direct mounting on handling units

✓ ERMO rotary drives, sizes 12/16/25/32 - ST-E version with electrical control for angular positioning

⛤ Electric drive - programmable rotation angles without mechanical stops required

⚡ System integration - matched to Festo linear axes and handling modules for multi-axis systems

📦 Compact design - minimal installation space for integration in robot wrists and transfer systems

ERMB and ERMO series overview

Series	Sizes	Version	Feature
ERMB	20, 25, 32	Rotary module	Compact electric rotary module, direct integration
ERMO	12, 16, 25, 32	ST-E	Electric rotary drive with control input

Typical applications

Typical applications: Swivel and rotary sequences in multi-axis handling systems, positioning workpieces at defined angles in assembly machines, rotary motion at robot wrists and combined linear axis units, and orientation tasks in inspection and camera guidance systems.

FAQ

Frequently asked questions about Rotary actuators

What are Festo rotary actuators and where are they primarily used in industrial automation?

Festo rotary actuators (Schwenkantriebe) are precision electric drive systems that convert electrical input into controlled rotational motion for industrial automation applications. These units like the ERMB and ERMO series deliver accurate angular positioning typically required in automotive assembly lines, packaging machinery, material handling systems, and semiconductor manufacturing equipment. The actuators provide repeatable positioning with high torque density, making them essential for applications requiring precise rotational movement such as valve control, workpiece orientation, and automated sorting mechanisms in manufacturing environments.

What technical specifications should I consider when selecting between Festo ERMB and ERMO rotary actuator series?

Selection between Festo ERMB and ERMO rotary actuators depends primarily on bore size, torque requirements, and control interface needs. The ERMB series offers bore sizes of 20mm, 25mm, and 32mm with modular design for flexible mounting configurations, while the ERMO series provides bore sizes from 12mm to 32mm with integrated stepper motor control (ST-E variants). Operating torque ranges typically from 0.5 Nm for smaller units to over 20 Nm for larger actuators, with positioning accuracy generally within ±0.1° and repeatability of ±0.05° across the product range.

Which international standards and certifications apply to Festo electric rotary actuators?

Festo electric rotary actuators comply with EN 60034 for rotating electrical machines, ISO 9409 for mechanical interfaces, and IEC 61131 for programmable controller compatibility. The units meet CE marking requirements under the Machinery Directive 2006/42/EC and EMC Directive 2014/30/EU for electromagnetic compatibility in industrial environments. Safety certifications typically include UL recognition for North American markets, while environmental protection follows IP65 rating standards according to IEC 60529, ensuring reliable operation in demanding industrial conditions with exposure to dust and water ingress.

How do Festo ERMB modular rotary actuators differ from ERMO integrated drive units in terms of functionality?

Festo ERMB modular rotary actuators feature separate drive electronics and mechanical units, allowing flexible controller placement up to several meters from the actuator via cable connections, while ERMO integrated units combine stepper motor, encoder, and control electronics in a single compact housing. ERMB systems provide higher customization options with interchangeable gearheads and mounting configurations, whereas ERMO-ST-E variants offer plug-and-play installation with built-in motion control and positioning feedback. The modular ERMB design suits applications requiring distributed control architecture, while integrated ERMO units excel in space-constrained installations requiring minimal wiring complexity.

What installation requirements and system compatibility considerations apply to Festo rotary actuators?

Festo rotary actuators require 24VDC power supply with current capacity ranging from 2A to 8A depending on unit size, and support standard industrial communication protocols including EtherCAT, PROFINET, and CANopen for PLC integration. Mounting interfaces conform to ISO 5211 and ISO 9409 standards with M5 to M8 mounting bolts depending on actuator size, while electrical connections use M12 or M23 circular connectors with IP67 rating. Installation clearances typically require 50mm minimum around the unit for cable routing and heat dissipation, with ambient temperature operation from -10°C to +50°C and relative humidity up to 85% non-condensing.

What IP protection rating and operating temperature range specifications apply to Festo electric rotary actuators?

Festo electric rotary actuators maintain IP65 protection rating according to IEC 60529 standards, providing complete dust ingress protection and resistance against low-pressure water jets from any direction. Operating temperature range spans from -10°C to +50°C ambient with storage temperatures from -25°C to +70°C, while relative humidity tolerance reaches 85% non-condensing without performance degradation. The actuators withstand vibration levels up to 2G according to IEC 60068-2-6 and shock resistance to 30G per IEC 60068-2-27, ensuring reliable operation in demanding industrial environments including automotive production lines and packaging machinery installations.

What maintenance intervals and service life expectations apply to Festo rotary actuator installations?

Festo rotary actuators require preventive maintenance inspection every 12 months or 1 million operating cycles, whichever occurs first, including verification of mounting bolt torque, cable connection integrity, and encoder signal quality. Expected service life reaches 5 million cycles under rated load conditions with proper lubrication maintenance, while encoder systems typically provide 10 years of reliable operation before replacement consideration. Critical maintenance tasks include annual lubrication of gear reducers using Festo-specified synthetic oils, quarterly inspection of cable flexibility at connection points, and biannual verification of positioning accuracy within ±0.1° tolerance through calibrated measurement equipment and PLC diagnostic functions.