The rotary assembly, therefore, continues to rotate while the stator is stationary and helps regulate speed. Stepper and servo motors are examples of DC motors that are both electromechanical devices that convert a digital pulse or voltage into rotational movement or displacement. Their performance can depend on the load size, and required speed. Pneumatic motors are driven via vacuum or compressed air to produce linear or rotational motion.
Air pressure and flow determine its speed or torque. Some common pneumatic motors include the rotary vane, axial or radial piston, turbine, V-type, and diaphragm. Positional accuracy is something that might be cited in relation to actuators — the ability to achieve the command position. Different types of motors will have different positional accuracy capabilities. Pneumatic motors are better for applications where positional accuracy is less important.
Hydraulic motors use pressurized fluid, often water, to move a piston through a tube. The pressure of the fluid and flow rate determines torque or speed. The flow rate is determined by the size of the motor's orifice, the difference in pressure between its inlet and outlet, and fluid temperature.
However, hydraulic motors are not known for producing high speeds and typical applications are in construction and mobile equipment. Actuator types vary according to the energy source, the type and speed of movement required, and its function. Actuator types do evolve and develop but it is helpful to understand the basics around some common actuators in use. Electric linear actuators use electrical energy to produce motion in a straight line using a piston that moves backwards and forwards triggered by electric signals.
They produce pulling, pushing, ejection, or lifting movements. Their motors produce high-speed rotational motion with a gearbox that reduces speed or impact. Electric rotary actuators use electrical energy to produce rotational movement, either for continuous motion or towards a fixed angle. They involve the combination of an electric motor, multistage gearbox, and limit switch. It creates rotation and torque when the current enters a magnetic field and from the force produced.
Hydraulic linear actuators use water pressure or other pressurized fluid to generate straight movements. They can produce torque strong enough to move external objects, hence their industrial applications.
Hydraulic actuators consist of pistons that move in one direction and a spring that produces the reverse motion. There are also double-acting hydraulic actuators in which pressures comes at both ends to move the piston back and forth for more uniform motion. Hydraulic rotary actuators use pressurized fluid to rotate mechanical parts.
They come in the form of circular shafts with keyways and tables — like a bolt — to mount other components. The shaft, which can be single or double, rotates when its teeth connect to the grooves in the piston and changes linear movement to rotational.
Pneumatic linear actuators use compressed air to create motion by moving pistons back and forth or by pushing and pulling a carriage through a driveway or tube. Springs are used to bring the piston back. Alternatively, fluid is sometimes used at the opposite end to push it back. Pneumatic linear actuators can produce high speed and torque for short distances and are resistant to opposing pressure like wind or explosions. Pneumatic rotary actuators use compressed air to create oscillation and they commonly use rack and pinion, scotch yoke, and vane design actuators.
For example, rack and pinion actuators use compressed air to push a piston and rack in a linear motion that turns into a rotary movement in a pinion gear and output shaft. Piezoelectric actuators utilize piezo material with electrical currents. Piezo materials are materials, such as ceramics, that expand and contract when touched by an electric charge producing energy. They are known for short, frequent, and fast response movements. Needless to say, there are a great many actuators used in different fields and they won't all be suitable for your purposes.
Here is a quick guide on finding the right one. By now, you'll realize the main two types of movement are linear and rotary. Depending on the function, you'll know if decisive linear movements are needed or if you require more dynamism in the resulting function.
Electrical actuators are very common and are gaining capabilities for an increasingly diverse series of functions. The requisite electrical current may not always be practical, however, in which case you can turn to hydraulic and pneumatic actuators eliminating the need for high voltage input. Precision levels were mentioned before and in some motors, you will need to achieve a precise command position.
A "general" rule is that heavy-duty work can bypass the need for precision but smaller, intricate and delicate tasks will require greater accuracy, such as in picking and handling. That consideration will bear significantly on the actuator you choose. The broad objective of an actuator is to move something but the force required depends on how heavy or large the subject is.
Keep in mind the dimensions of the objects your actuator must move so that you choose one with adequate load capacity. Any actuator will produce a stroke length that should be considered when choosing one for your desired purpose. Actuator speed is a fairly important consideration and actuators that need higher force will often be slower than those generating a lower force.
Actuator speeds are measured in distance per second. Actuators are frequently used in industrial applications as well as the more orderly environments of indoor labs and workshops. If you are operating within a particularly rugged environment, ensure the actuator you choose is rated well for protection.
Actuators can be mounted in different ways. For example, a dual-pivot mounting system allows the device to swivel or turn while extending and retracting. A stationary mounting system keeps the actuator more secure in one place.
There are other considerations when selecting the right actuator but the above guide should help narrow down options. Part of selecting the right actuator, or deciding if it is the right actuator once you have chosen one, is assessing its performance. There are various performance metrics relevant to an effective actuator. Here are a few to consider. Torque, which you will hear of a lot in relation to actuators, is the twisting force that speaks to the engine's rotational force.
You can consider it as simply "force" but either way it is key to actuator performance. Two metrics are relevant to torque or force — static and dynamic loads. Static load force is relational to the capacity of the actuator when it is at rest while dynamic loads refer to capacity when the actuator is in motion. Speed considerations will vary depending on the function of the actuator and so should be considered in relation to your requirements.
Higher weighted loads will naturally be slower. However, a good way of comparing speed performance metrics is to look at the actuator's speed when it is not carrying any load, as long as it has the capacity to carry the types of objects relevant to its required function. Durability is very much a consequence of actuator type and design.
Heavy-duty actuators will be naturally more durable, such as hydraulic actuators, and so will naturally perform better for industrial uses. All other things considered, the actuator should have a good design with components that fail to wear easily and are sized well. If you're newly introduced to actuators and mechanical engineering, bear in mind assessing this metric comes with experience. There are centers, however, that carry out push-pull tests and assess quality and safety, which can be helpful when procuring an actuator.
Energy efficiency is important for a multitude of reasons, not least for sustainability and environmental considerations and also costs. As a rule of thumb, less required energy to get an actuator to carry out its function is a good indicator of performance. The types of actuators and the functions they relate to are broad.
It follows, there is unlikely to be a blueprint or universal instruction manual when it comes to connecting actuators. However, a common actuator, electric linear actuators, are relatively simple to connect and can be useful in varied household functions. Here is a rundown of connecting one to a device or a control mechanism like a rocker switch.
Some electric linear actuators have four pins that are easily connected to your device. In this instance, the process is as easy as plugging in the actuator and walking away. The control system can be controlled mechanically or electronically, software driven, or human operated. What makes motors work?
The rotor and stator assemblies. These are commonly known as the primary and secondary windings within the motor. The interaction of these two creates a magnetic field which results in motion. There are two types of motors: AC motors, which commonly move at a constant speed; and DC motors, which move at variable speeds. The speed of an AC motor is determined by the frequency of voltage applied by the number of magnetic poles. Within the AC motor are the stator assembly and the rotor assembly.
If it is a synchronous motor, the rotor and the stator move in synchronization. In DC motors, the rotor assembly rotates in an attempt to align itself with the stator assembly but is prevented by a part known as the commutator. Many electric linear actuators come with four pins these days and their connection is as simple as plugging them in. However, if your actuator does not have four pins, the process is slightly different. You will need to buy an additional connector, which often comes in 6- and 2-foot length.
Your actuator might come with wires exposed at the end. You can strip back this a bit if required before connecting to a 4-pin connector. Connect the linear actuator to the 4-pin connector by twisting the right exposed wires together and covering it up with electrical tape. Often the wires on the actuator and connector come in blue and brown colors and they can be connected accordingly. Sometimes, the colors may be different on the actuator.
For example, if the actuator has red and black wires, connect the red to the brown wire of the actuator and black to the blue. If it comes with red and blue, connect the red to the brown and blue to the blue wire on the connector. If the wires of the actuator are red and yellow, connect red to the brown wire and yellow to the blue wire.
Now you are good to go. Plugin your connector and plug in the control box to the power socket. In case you run into trouble despite this, click here for a more detailed guide on connecting actuator to a connector. Choosing an actuator and connecting it properly is only half the job done. Equally important is mounting the actuator in a method that is right for your application. Below are two common methods that are used to mount an electric linear actuator. This method involves fixing an actuator on both sides with a mounting point that is free to pivot, which usually consists of a mounting pin or a clevis.
Dual pivot mounting allows the actuator to pivot on either side as it extends and retracts, allowing the application to achieve a fixed path motion with two free pivot points. One of the most useful applications of this method is to open and close doors. When the actuator extends, the dual fixed points enable the door to swing open.
The action of the door closing and opening causes changes in angle, but the pivot provides ample space for the two mounting points to rotate. While using this method, make sure that there is enough room for the actuator to extend, without any obstacles on its way. In this method, the actuator is mounted in a stationary position with a shaft mounting bracket fixing it to the shaft. Common uses of this kind of mounting are to achieve action similar to pushing something head-on.
For instance, this form of mounting is ideal for switching a button on or off. When deciding on this method, ensure that the mounting apparatus can handle the load of the actuator. Check Out. The uses of linear electric actuators are virtually endless. Manufacturing plants use them in material handling. Cutting equipment that moves up and down and valves that control flow of raw materials are examples of this.
Robots and robotic arms within and outside the manufacturing industry also make use of linear actuator systems to achieve movement in a straight line. With home automation systems becoming popular, electric linear actuators have become useful in the function of automated window shades. Home appliances like TV can be placed at optimum height without hassle using TV lifts that make use of linear electric actuators.
There are also table lifts which use actuators to adjust the height to the needs of users. In the solar power industry, they help in moving the panels to the direction of the sunlight. Even in industries like agriculture, where heavy machinery that uses hydraulic actuators are more common, electric linear actuators are used for fine and delicate movements. Case Studies. We have detected your location to be from outside of the US, would you like to go to our Canadian Store?
Toll Free: Product Suggestions. Partnerships Sponsorship Scholarship. Linear Actuators. Control Systems. PLC Controls. Sponsorship Scholarship. Data Sheet 3D Models Blog. Learning Center. Home Actuator as a Keystone of Motion. Actuator as a Keystone of Motion. Basics Mechanism Types How to Choose How to mount Applications An actuator is a part of a device or machine that helps it to achieve physical movements by converting energy, often electrical, air, or hydraulic, into mechanical force.
View All Actuators. How does Linear Actuator work? Following are the usual components that are part of the functioning of an actuator: Power source : This provides the energy input that is necessary to drive the actuator.
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