ELECTRIC ACTUATOR

The Technicians

Definition

It is a mechanical device that has the function of giving the needed force to move another mechanical device. The force produced by the actuaror can come from several sources: Pneumatic pressure, hydraulic pressure, motive force. Depending on their type of supply, the actuators are classified as “pneumatic”, “hydraulic” and “electric”.

Advantages

Simple in comparison to other actuators.

Ideal when it´s necessary to generate force rapidly.

Precise positioning.

Uses

Generation of rotating movements for different applications: production lines, domestic appliances, toys, tools, etc.

Automation of industrial valves.

Widely used in industrial processes.

Motors

AC Motor

DC Motor

The interaction between two magnetic fields produces the movement.

They are the most used due to:

Facility to control it.

Major power.

Performance.

Price.

Direct Operation

Advantages: Increase of efficiency. Rapid and precise positioning. Major torque at low speed.

Disadvantages: Complicated control mechanism. Special motor

Servomotors

Conformed by:

Motor.

Reducing box.

Control circuit.

Great precision.

Servomotors

Similar to a direct current motor, with the aptitude to be located in any position inside a range of operation and to be kept stable in the mentioned position.

It is frequently used in radiocontrol systems and robotics.

It´s use is not limited to these.

Stepper Motors.

Electromagnetic device that converts a series of electric pulses into discrete angular displacements.

It advances a series of degrees (steps) depending on its imputs.

Stepper Motors

Motor´s controls

Starter. Contactor. Overcharge relay. Button station.

DC Changer. Inverters.

Voltage modulation. Current modulation.

Servocontrollers. High gain amplifiers. Accuracy

Artificial Muscles

A particular type of alloy of form memory called Biometal or Nitinol (alloy of titanium and nickel) can shrink up to 4% when it reaches certain temperature.

They are activated by the heat produced by the electrical current, the time of contraction changes with the applied current.

Artificial Muscles

When the alloy gets cold it recovers it´s original form.

Disadvantage: The change is made with a very small range of temperature, which makes it difficult to control.

Solenoid

Simple form of electromagnet that consists of a wire bobbin of isolated copper, or of another appropiate conductor, who is coiled in spiral around the surface of a cylindrical body, generally with transverse circular section. When the electrical current is sent across these wound, they act as electromagnet.

The created magnetic field is the motive force used to open the valve.

Solenoid

Solenoid

Its basic function is the same of a step valve operated manually.

Due to its electrical operation, it is possible to install it on remote places and to be controlled suitably by electrical switches.

Used to control the flow of liquids or gases in completely opened or completely closed position.

Service conditions

They must be reliable in all kinds of climatic conditions.

Factors to keep in mind: Environment temperature Temperatura ambiente

(lubricant selection). Avoid the corrosion. Protection against explosions.

Thanks for your attention