A linear motion actuator is a device that creates motion in a straight line. It has applications ranging from industrial machineries to computer accessories. These linear motion actuators are classified on the basis of how it creates the linear motion.
Types of Linear Motion Actuators
- Mechanical linear actuator– it generates linear displacement from a rotary motion of a control knob or handle via screws, gears etc. jackscrew or car-jack is the most widely used mechanical actuator.
- Hydraulic actuator– This consists of a cylinder and a piston and a working liquid, where the linear motion is generated by applying unbalanced pressure force in the piston. This is based on Pascal’s law.
- Pneumatic actuator– This is similar to the hydraulic actuators, except liquid is replaced by a compressed gas.
- Piezoelectric actuator– This is produced using piezoelectric materials, which expands under the application of voltage.
- Electro-mechanical actuators– In this type of actuators, rotary motion is generated with an electric motor. This rotary motion is converted to linear motion similar to mechanical actuators.
What to consider before you purchase a linear motion actuator?
Linear motion actuators found its applications in medical, automobile, HVAC, laboratories and, perhaps, in all categories in industries. Every Linear motion actuator suppliers marks certain reasons to claim their products superior to others.
However, it is the duty of the buyer to find out the best possible linear actuator for their need. For example, if your application needs a very long stroke you would not find piezoelectric actuators. However, for a very short stroke and high accuracy piezoelectric actuators would be the best choice.
Specifications of your linear actuator
Based on requirements of your linear motion actuator you could specify certain parameters. These include payload, stroke length, speed, accuracy, cost etc.
These specifications would help you find out the best actuators for you need. Also, these parameters would help you find different suppliers. However, selection of the best supplier needs more research into their reliability based on earlier reviews, how many years they are into the business etc.
- Payload– Different linear motion actuators have different payload characteristics. For example, hydraulic actuators are capable of providing payloads in the range of pounds to tons. Similarly, Pneumatic and piezoelectric actuators work in light payload range; electromechanical actuators are suitable for moderate payloads, while mechanical actuators (Ball screw, acme screw, timing belt etc) can work in a wide range of payload.
- Stroke– hydraulic actuators have the stroke length range of inches to 20ft. Pneumatic actuators provide stroke length of less than 1 m. Electro-mechanical actuators work in an unlimited range of stroke lengths, while piezoelectric actuators are for a very short strokes.
- Speed– hydraulic actuators work in slow speeds. Pneumatic, electro-mechanical and piezoelectric actuators are capable of providing high speeds. Mechanical actuators work in the range of moderate to high speeds.
- Accuracy– Piezo-electric and electro-mechanical linear actuators have very high accuracy. Hydraulic and pneumatic actuators have poor accuracy, while mechanical actuators have accuracies ranging from poor to high. Acme screw and the timing belt tactuators have low accuracy and the ball screw type linear actuators have high accuracy.
- Cost– Among all types of linear motion actuators, electro-mechanical and the hydraulic type actuators are very costly. Pneumatic type actuators are most cheaply available.