Electric Cylinder Guide | Selection, Applications & How It Works
Electric Cylinder Guide | Selection, Applications & How It Works
What Is an Electric Cylinder? How Does It Work and Where Is It Used?
An electric cylinder is an electromechanical actuator that converts the rotary motion of an electric motor into controlled linear motion. Electric cylinders are widely used in industrial automation, machine building, robotics, pressing applications, packaging equipment, automotive manufacturing, testing systems, and other applications where precise and programmable linear movement is required.
Compared with conventional pneumatic or hydraulic cylinders, electric cylinders can provide precise positioning, programmable speed, controlled acceleration and repeatable motion profiles.
Choosing the right electric cylinder requires more than simply selecting a cylinder based on force. Load, stroke length, speed, acceleration, duty cycle, mounting configuration, operating environment, required service life, motor selection, and control requirements should all be considered.
How Does an Electric Cylinder Work?
The operating principle of an electric cylinder is based on converting rotary motion into linear motion.
An electric motor generates rotary torque, which is transferred to a mechanical screw system. The screw and nut mechanism converts the rotary movement into linear movement, causing the actuator rod to extend or retract.
The basic operating sequence is:
Electrical Power → Electric Motor → Screw Mechanism → Linear Motion → Controlled Force and Position
Different screw technologies can be used depending on the application. Ball screw and planetary screw technologies, for example, offer different performance characteristics in terms of speed, force, efficiency, precision, and service life.
Bosch Rexroth offers electromechanical cylinder solutions including EMC models with ball screw technology and EMC-HP models designed for higher-force applications using planetary screw technology.
Main Components of an Electric Cylinder
An electric cylinder is part of a complete electromechanical motion system. Depending on the application, the cylinder can operate together with a servo motor, motor drive, PLC, motion controller, and feedback system.
- Electromechanical Cylinder
The cylinder body contains the mechanical components responsible for converting rotary motion into linear movement.
The mechanical design directly affects:
- Maximum force
- Stroke length
- Maximum speed
- Positioning accuracy
- Load capacity
- Service life
- Duty cycle
- Electric Motor
The motor provides the torque required to move the actuator.
Depending on the application, electric cylinders can be combined with servo motors, AC motors, DC motors, or stepper motors.
Servo motors are particularly useful when the application requires precise control of position, speed, acceleration, and torque.
- Motor Connection
The motor can be mounted directly to the electric cylinder or connected through a suitable mechanical transmission system.
The motor orientation and mounting configuration should be selected according to the available machine space and mechanical requirements.
- Motor Drive and Control System
The electric cylinder can be controlled through a motor drive, PLC, servo controller, or motion control system.
Depending on the system architecture, parameters such as:
- Position
- Speed
- Acceleration
- Deceleration
- Torque
- Direction
- Cycle time
can be programmed and controlled.
Electric Cylinders for Precision Positioning
One of the key advantages of an electric cylinder is its ability to provide controlled and repeatable positioning.
Because the actuator movement is directly related to motor rotation and screw movement, the cylinder can be programmed to stop at defined positions.
This makes electric cylinders suitable for applications such as:
- Automated assembly
- Robotic equipment
- Pressing systems
- Testing machines
- Packaging machinery
- Material handling
- Precision adjustment systems
When combined with a servo motor and suitable feedback system, an electric cylinder can provide highly controlled positioning and repeatable motion.
Electric Cylinder Speed Control
Electric cylinder speed depends on motor speed, screw pitch, actuator design, and the applied load.
By controlling motor speed, the actuator's linear speed can be adjusted throughout the motion cycle.
For example, an electric cylinder can:
- Move rapidly during the approach phase.
- Slow down before contacting a component.
- Apply controlled motion during the working stroke.
- Decelerate before reaching the final position.
This type of motion profile can help reduce cycle time while improving process control.
Electric Cylinder Force Control
The force generated by an electric cylinder depends on motor torque, screw technology, mechanical efficiency, actuator design, and operating conditions.
In servo-driven applications, motor torque can be controlled to achieve a desired force profile. Where more accurate force measurement is required, a load cell or force sensor can be integrated into the system.
Electric cylinders can therefore be used for applications such as:
- Pressing
- Clamping
- Assembly
- Riveting
- Forming
- Crimping
- Testing
- Force measurement
For higher-force industrial applications, heavy-duty electromechanical cylinder solutions can provide an alternative to conventional pneumatic systems and, depending on the application, hydraulic systems.
Where Are Electric Cylinders Used?
Electric cylinders are used wherever controlled linear motion is required.
Industrial Machinery
Electric cylinders can be used for controlled pushing, pulling, lifting, clamping, positioning, and adjustment operations.
Automotive Manufacturing
Typical applications include automated assembly, pressing, testing, component positioning, and production equipment.
Pressing Applications
Electric cylinders can provide controlled position and force during pressing, joining, forming, and assembly processes.
Robotics
Electric linear actuators can be integrated into robotic systems where precise linear movement is required.
Packaging Machinery
Electric cylinders can perform pushing, positioning, clamping, separating, and adjustment operations in automated packaging equipment.
Food Processing Equipment
When the appropriate protection, materials, and sanitary requirements are met, electric actuators can be used in food processing machinery.
Textile Machinery
Electric cylinders can be used for positioning, adjustment, tension control, and automated movement in textile equipment.
Testing and Measurement Systems
Electric cylinders are particularly useful when a test specimen must be moved, compressed, positioned, or loaded with a controlled force and repeatable motion profile.
Electronics and Automation
Precision assembly and automated positioning applications can benefit from the programmable motion capabilities of electric cylinders.
Electric Cylinder vs. Hydraulic Cylinder
Choosing between an electric cylinder and a hydraulic cylinder depends on the application's technical requirements.
Electric cylinders are often advantageous when the application requires:
- Precise positioning
- Programmable motion
- Variable speed
- Repeatability
- Servo control
- Easy integration with automation systems
Hydraulic cylinders remain highly effective for applications requiring:
- Very high force
- High power density
- Heavy-duty operation
- Shock resistance
- Large-scale industrial motion
An electric cylinder should therefore not automatically be considered a direct replacement for a hydraulic cylinder.
The correct technology should be selected based on force, speed, stroke, duty cycle, power requirements, environmental conditions, control requirements, and total system design.
Electric Cylinder vs. Pneumatic Cylinder
Pneumatic cylinders are widely used for simple and fast linear movements.
However, compressed air is compressible, which can make precise positioning and variable-speed control more challenging in certain applications.
Electric cylinders provide direct control of motor rotation and mechanical movement, making them particularly suitable for programmable positioning and variable motion profiles.
As a general starting point:
Simple, fast linear movement → Pneumatic
Precise and programmable movement → Electric
Very high force and power density → Hydraulic
The final selection should always be based on the actual machine requirements.
How to Select an Electric Cylinder
Proper electric cylinder selection is critical for machine performance, reliability, and service life.
The following parameters should be evaluated before selecting an actuator.
- Required Force
Determine the maximum and continuous force required during the complete motion cycle.
Do not select the actuator only according to the static load. Acceleration, deceleration, friction, external forces, and dynamic loads should also be considered.
- Stroke Length
Determine the required linear travel distance.
The required stroke should account for the complete working movement as well as mechanical clearances and safety margins.
- Linear Speed
Determine the required minimum and maximum actuator speed.
Cycle time requirements can have a significant effect on motor and screw selection.
- Acceleration and Deceleration
Acceleration and deceleration can significantly affect the dynamic load on the actuator.
Heavy loads and high-speed applications require careful evaluation of acceleration forces.
- Duty Cycle
Determine how frequently the electric cylinder will operate.
Important parameters include:
- Cycles per hour
- Operating hours per day
- Operating days per year
- Continuous or intermittent operation
- Load profile throughout the cycle
High-cycle applications require particular attention to screw technology, lubrication, thermal conditions, and expected service life.
- Mounting Configuration
The mounting arrangement should be determined according to the machine geometry.
Depending on the application, fixed mounting, clevis mounting, pivot mounting, or other mechanical configurations may be required.
- Operating Environment
The installation environment can significantly affect product selection.
Consider:
- Dust
- Moisture
- Temperature
- Chemicals
- Washdown requirements
- Contamination
- Indoor or outdoor installation
- Feedback Requirements
If accurate position or force control is required, an appropriate feedback system should be considered.
Depending on the application, encoders, servo feedback, limit switches, or force sensors may be integrated into the system.
- Screw Technology
The screw technology is an important part of electric cylinder selection.
Ball screw and planetary screw technologies can provide different combinations of:
- Force capacity
- Speed
- Efficiency
- Precision
- Service life
- Duty cycle capability
The correct technology depends on the application.
- Motor and Drive Compatibility
The electric cylinder, motor, and drive should be selected as a compatible system.
Motor torque, speed, mounting interface, feedback, voltage, drive capacity, and control architecture should all be considered.
Electric Cylinder Product Selection
Selecting an electric cylinder should begin with the actual application rather than with a specific catalog model.
Before selecting a product, define:
- Required force
- Stroke length
- Linear speed
- Acceleration
- Duty cycle
- Load characteristics
- Mounting configuration
- Screw technology
- Motor type
- Feedback requirements
- Operating environment
Bosch Rexroth offers a range of electromechanical cylinder configurations for industrial applications, including EMC models and higher-force EMC-HP solutions.
Product Selection and Configuration
For product selection or to configure a new electric cylinder, you can use the Bosch Rexroth configuration tool:
Bosch Rexroth Electromechanical Cylinder Configurator
https://www.boschrexroth.com/ics/ref/config?matno=R156099998&c=us&language=en
The configurator can be used to review available product configurations and define a suitable electromechanical cylinder according to the required technical parameters.
Configuring a New Electric Cylinder
A standard electric cylinder may not always meet the requirements of a specific machine.
When a custom configuration is required, the application should first be defined in terms of:
- Required force
- Stroke
- Maximum speed
- Acceleration
- Duty cycle
- Motor type
- Screw technology
- Mounting configuration
- Positioning accuracy
- Operating environment
- Control and feedback requirements
These parameters provide the technical foundation for selecting and configuring the appropriate electromechanical cylinder.
Electric Cylinder Solutions from Hidroman
Hidroman provides industrial hydraulic and electromechanical motion solutions for OEMs, machine builders, and industrial applications.
For electric cylinder selection, we focus on the complete motion requirement rather than selecting an actuator based only on maximum force or stroke.
Our evaluation considers:
Application → Load → Force → Speed → Stroke → Duty Cycle → Mounting → Motor → Control
This approach helps identify a solution that is suitable for the actual machine and operating conditions.
If you are developing a new machine, replacing a hydraulic or pneumatic actuator, or looking for an electric linear actuator for an existing application, Hidroman can assist with the technical evaluation and product selection process.
Frequently Asked Questions About Electric Cylinders
What is an electric cylinder?
An electric cylinder is an electromechanical actuator that converts the rotary motion of an electric motor into controlled linear motion.
How does an electric cylinder work?
An electric motor rotates a mechanical screw. The screw and nut mechanism converts this rotary movement into linear movement, extending or retracting the actuator rod.
Where are electric cylinders used?
Electric cylinders are used in industrial automation, machine building, robotics, automotive manufacturing, packaging machinery, pressing systems, testing equipment, material handling, and precision positioning applications.
Can an electric cylinder replace a hydraulic cylinder?
In some applications, yes. Electric cylinders can be a suitable alternative when precise positioning, programmable motion, and automation integration are more important than extremely high force and power density. Hydraulic cylinders remain advantageous for many heavy-duty, high-force applications.
What is the difference between an electric cylinder and an electric linear actuator?
The terms are often used interchangeably. An electric cylinder is a type of electric linear actuator designed in a cylinder-style mechanical configuration. The appropriate terminology depends on the application and product design.
Can an electric cylinder use a servo motor?
Yes. Servo motors are commonly used with electric cylinders when precise position, speed, acceleration, and torque control are required.
How do I choose the right electric cylinder?
Start with the required force, stroke, speed, acceleration, duty cycle, mounting configuration, operating environment, screw technology, motor, feedback requirements, and control system. These parameters should be evaluated together rather than individually.
Are electric cylinders suitable for industrial automation?
Yes. Their programmable motion, repeatability, positioning capability, and integration with PLC and servo control systems make them well suited for many industrial automation applications.
Talk to Hidroman About Your Electric Cylinder Application
Choosing the right electric cylinder is not simply a matter of selecting a force and stroke value.
A properly engineered solution considers the complete motion profile, machine geometry, operating environment, duty cycle, motor, drive, control system, and expected service life.
Share your application requirements with Hidroman to identify the appropriate electric cylinder and electromechanical motion solution for your machine.