Electric Cylinder 

The M.E.A. Incorporated's Electric Cylinder delivers today's all-electric digital technology and only M.E.A., inc. offers it to you!  The Electric Cylinder eliminates all problems associated with hydraulics with no fluids to maintain. 

• No hydraulic filtration parts to purchase. No engineering, flushing or testing costs.
• Does away with fluid leaks, so there's virtually no chance of fire hazard or injury to personnel.
• Reduces operating costs up to 75% through lower power costs. Saves as much as $24,000 annually per unit!
• Delivers minimum installation costs- no hydraulic lines, pumps, motor starters, cylinders, oil coolers or oil heaters to purchase.

The M.E.A. Incorporated's Electric Cylinder relies on precision toothed timing belts, not gears; no backlash or dead band. Result? The Electric Cylinder gives better frequency response and resolution which is far superior to normal hydraulic technology!

• Delivers five years of trouble-free operation on average. No brushes on the motor. (Average mean-time between failures: five years!)
• Features "one-craft maintenance" (if maintenance is required!) Eliminates environmental hazards and waste disposal problems associated with hydraulics. Which means no problems with EPA or OSHA!
• Provides a full, three-year warranty.
• Offers a wide range of standard models and custom -engineered systems.

Technical Data for Digital-Electric Cylinder

System provides full modulating position control of components or elements in the process system and gives you infinite variable position control for more accuracy, responsiveness and stability than hydraulics.  All-electric system can be fixed or trunnion-mounted in any position:

1. horizontal
2. vertical
3. or at any desired angle.

Unit is sealed against atmospheric contamination.  High performance brushless servo motor is coupled through precision toothed timing belts and pulleys to a ball-bearing lead screw thereby increasing torque and output thrust.  Servo motor has rare-earth magnets on rotor and wound coils on stator.  Built-in resolver provides rotor position information for commutation.

Ball screw rotates at 120-150 RPM (Revolutions Per Minute).  A 15/1 speed reducer from the motor shaft is required for maximum motor speed of approximately 2000 RPMs.  Two timing belts are used to obtain this ratio.  Timing belts provide greater than 90% efficiency, quiet operation and no backlash.  No lubrication is required.  Ball screw is a precision rolled thread screw case hardened to reduce wear.  Ball nut contains circulating ball bearings sized to move the load without damage to screw thread.  Ball nut drives a plate or carriage with the output shaft as an integral part.  Teflon bushings moving on ground rods absorb ball nut torque and output shaft side thrust.

M.E.A. Incorporated Digital-Electric Cylinder is powered from a solid state digital controller with power supply built-in.  Controller operates from three-phase power between 230 to 480 volts (50 or 60 Hz). Input can be single phase with a reduction in output thrust.  Input signal to the controller can be any voltage input between +/-10 volts or +/-100mA.  Controller is tuned to the process with a conventional laptop computer.  Output position is offered in two options:

1. one provides a quadrature incremental output of 0.1% of span
2. second output uses an embedded slideware and is accurate to 0.5%

Solid state proximity sensors are used for end stroke limits.

Electric Rotary Actuator

M.E.A. Incorporated manufactures an Electric Rotary Actuator designed to rotate the steam admission valve cam shaft on large driven turbines.  The actuator rotation can be as much as 300 degrees and full rotation can be achieved in as little as two seconds.  The output torque is 6000 lbs. per inch at full speed.  The actuator positions the output shaft proportionally to a 4-20 mA input control signal.  The positioning accuracy is better than 1%.  The Actuator operates from a 3 phase AC (Alternating Current) line.  The actuator can be provided with a back-up manual driven by either a DC (Direct Current) motor or a pneumatic motor.

• A high performance servo motor is used to drive the actuator.  Maximum servo motor speed is 4000 RPM (revolutions per minute). 
• This servo motor is coupled to the input of a 160/1 harmonic drive speed reducer.  The speed reducer output shaft can rotate at 25 RPM or 0.417 RPS (revolutions per second).  The motor torque is increased 160 times. 
• The harmonic drive speed reducer is a single reduction device.  It operates at 90% efficiency and is virtually backlash free.  Any inertia of the load (cam shaft) is reduced by 15,600 allowing exceptional response to input changes.  The output shaft drives a precision rotary position transducer.  This transducer provides the position feedback signal. 
• The rotary shaft also carries to actuate end of travel limit switches.  If an emergency drive (DC motor or pneumatic motor) is provided, it is coupled to the servo drive by a timing belt.  The timing belt drives a clutch added to the main drive shaft between the speed reducer and the servo motor. 
• The emergency motor has a nominal speed of 1750 RPM and drives through a 3/1 reduction.  Thus in the emergency manual mode the output speed is about 1/6 the maximum speed.  A power supply and controller operate the servo motor from a three phase power line.  The input control to the servo motor is a +/- 10 volt signal.  An input signal of 0 volts provides no output motor motion.  10 volts positive produces 4000 RPMs in one direction while 10 volts negative produces 4000 RPMs in the opposite direction.  Any input between 0 and 10 volts produces a proportional speed.
• A signal control amplifier is also provided.  This amplifier compares the 4-20 mA input control signal with the position feedback signal from the actuator.  When these signals are equal, the actuator does not move.  If the input changes, an error signal is produced and the actuator moves to a new position.  If the load attempts to move the output shaft, the feedback transducer senses this and returns it to the input position.
• The system consists of the drive and an enclosure with the following panel mounted control:
  • Manual/Auto Selector Switch - In "Auto" position control is established by the 4-20 mA input control signal.  In "Manual", the actuator remains stationary and will only respond to manual control below.
  • Manual "Increase/Decrease" Switch - When in the manual mode this switch will increase or decrease the output rotation.

It is intended that a customer supplied control will be located in the control room.  This controller will provide the 4-20 mA control signal and should have the additional ability to provide manual control.  M.E.A. Incorporated will provide a 4-20 mA position signal that may be used on a customer provided indicator in the control room.  If the DC motor or pneumatic motor emergency drive is provided, they can be integrated into this system as required by the customer.

Electric Linear Actuator

M.E.A. Incorporated has produced three (3) models of Electric Linear Actuators.  These actuators were primarily developed to produce continuous high trust outputs in continuous modulating service.  The actuators are sized to equal or better the response of a conventional hydraulic system (cylinder, servo valve, hydraulic power unit).  The two models will produce the rated thrust at 1.25 inches per second traverse speed.  The 15k unit produces 15,000 lbs. of thrust and the 30k unit produces 30,000 lbs. of thrust.  Each of these units has been sized to operate with inertial loads 5 times greater than the thrust shown.  With these inertial loads the accelerations and deccelerations will be equal or faster than can be expected from a conventional hydraulic actuator.