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Hydraulic Rotary Actuators – SM4

The Eckart SM4 rotary actuator is a heavy-duty and highly-customizable rotary actuator designed for the toughest and most-demanding applications.

Because of its torque, angle of rotation, pressure range, positioning accuracy, stability of position, type of attachment, and its dimensions, the Eckart SM4 rotary actuator can be used in a wide range of applications. Not only is the SM4 a compact and robust unit, but it is also wear-resistant and efficient. The SM4 can be configured with an industry-leading fine and controllable end cushioning curve. Additionally, the SM4 unit can be driven via “black and white” or with proportional, control, and servo valves. For the purpose of subsequent driving, the piston end-positions at the linear cylinder and at the rotary actuator can be scanned via electronic end-position acknowledgement mechanisms. Ultimately, with the SM4, you have a high-performing product that is both robust and compact, allowing for optimal adaptation depending on your specific requirements.

Hydraulic Rotary Actuator Standard Features:

  • Torque output to 750,000 in-lb (85,000 Nm)
  • Pressure rating at 3,625 psi (250 bar)
  • Standard rotation: 90°/180°/270°/360°
  • Externally adjustable end stop ± 5°
  • Wear resistant moving parts
  • Four-point contact bearing to withstand extreme radial and axial loads
  • Adjustable home position
  • Tight backlash of 20 angular minutes

Hydraulic Rotary Actuator Optional Features:

  • End cushioning including sophisticated damping curves
  • Tighter backlash as low as 5 angular minutes
  • Position indication through encoders or proximity switches
  • Drive shaft configurations, such as spline shaft, tooth hub, hollow shaft, key shaft, etc.

Hydraulic Rotary Actuator Custom Configurations Available:

  • Drive shaft
  • Drive shaft on both ends
  • Adjustable end position rotation
  • Rotation more than 360°
  • Reversed turning direction
  • Direction connection of valving
  • Operating pressure over 2,625 psi (250 bar)
  • Operating speed
  • Mounting flanges
  • Special housing and gear materials
  • Special paint
  • Sea and saltwater resistance

Helical Spline Hydraulic Rotary Actuators:

Like all Eckart hydraulic rotary actuators, the SM4 is designed with helical spline technology. The actuator operates with a piston and a helical or sliding spline mechanism, which work in tandem to transform the piston’s linear motion into rotational movement.

High torque in a compact profile

  • Helical spline actuators deliver impressive torque within a compact construction, making them ideal for applications where space is limited.

Less risk of contamination and physical damage

  • Protective housing keeps all moving parts safe from debris and moisture, ensuring consistent operation in demanding environments, especially for mining applications.

Low maintenance and wear-resistant moving parts

  • All internal components are fully immersed in oil ensuring preventative wear.
  • Extended-period nitriding ensures a long service life of the rotary actuator.
  • Helical gears feature excellent sliding characteristics.

Reduced pinch points

  • Helical spline rotary actuators offer safer alternatives to linkages for the operator, since there are no exposed parts.

Standard Rotations:

Standard rotations are 90°, 180°, 270°,and 360°. Other rotations can be supplied on request by using the model with the next standard rotation up and limiting the stroke of the piston in accordance. Also available are special models with rotations in excess of 360°. Additional rotation is created by making the spline gears longer while maintaining the same diameter. The primary benefit to this type of product compared to alternative designs such as linkages using hydraulic cylinders (linear actuators) is its compact design.

Eckart is a supplier and rotary actuator manufacturer for various applications including construction, mechanical, marine, and industrial.


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