2. Definitions
▪ A rotary actuator is an actuator that
produces a rotary motion or torque.
▪ An actuator that directs force in a circular
motion. Rotary actuators are sometimes
called motors.
▪ A rotary actuator is the most compact device
available for producing torque from hydraulic
or pneumatic pressure.
3. Actuator power sources
▪ Stepper motors
a form of electric motor that has the ability to move in discrete steps of a fixed size.
▪ Servomotors
a packaged combination of several components motor | gear train | position encoder
▪ Fluid power actuators
drived as an actuator, internally constructed both hydraulic and pneumatic power.
▪ Vacuum actuators
vacuum powered rotary actuators, without pneumatic power.
5. Applications
General Industry
camming
indexing
clamping
braking
tensioning
positioning
tilting
safety closure systems
Marine
opening and closing hatches
swinging cargo handing gear
opening and closing fire and
collision bulkhead doors
valve operation
positioning hydrofoils
steering control
Robotics
rotation and positioning
Materials Handling
switching conveyors
turning and positioning
container clamps on lift
trucks
tensioning and guiding
operating valves
braking
lifting
Metals Processing
upending coils
turnstiles
walking beams
immersion/agitation mechanisms
6. Servomechanism as a Rotary Actuator
Small R/C servo mechanism
1. electric motor
2. position feedback potentiometer
3. reduction gear
4. actuator arm
7. Rotary encoder
A rotary encoder, also called a shaft encoder, is an electro-mechanical device
that converts the angular position or motion of a shaft or axle to an analog or
digital code.
Hinweis der Redaktion
The simplest actuator is purely mechanical, where linear motion in one direction gives rise to rotation. The most common actuators though are electrically powered. Other actuators may be powered by pneumatic or hydraulic power, or may use energy stored internally through springs.
Stepper motors are a form of electric motor that has the ability to move in discrete steps of a fixed size.
A servomotor is a packaged combination of several components: a motor (usually electric, although fluid power motors may also be used), a gear train to reduce the many rotations of the motor to a higher torque rotation, a position encoder that identifies the position of the output shaft and an inbuilt control system.
Both hydraulic and pneumatic power may be used to drive an actuator, usually the larger and more powerful types. As their internal construction is generally similar , they are often considered together as fluid poweractuators
Where a supply of vacuum is available, but not pneumatic power, rotary actuators have even been made to work from vacuum power. The only common instance of these was for early automatic windscreen wipers on cars
A rotary actuator consists of a short cylindrical chamber, enclosing a vein affixed to a central shaft and a shoe which partitions the chamber into compartments on either side of the vein. The chamber is born by a body boarder closed at each and buy ahead which supports the shop to some believe in an anti-friction bearing specially compounded seals help prevent leakage past issue in vain. A fluid pressure differential between the chamber compartment acts upon the vein to car shop rotation through in park . the majority a rotary actuators are constructed with one or two veins but they are available with three or more veins for special applications. the rotary actuator simple and efficient.
Rotary actuators are used in a vast range of applications. These require actuators of all sizes, power and operating speed. These can range from zero power actuators that are only used as display devices, such as air core gauges.
Others include valve actuators that operate pipeline and process valves in the petrochemical industry, through to actuators for large civil engineering projects such as sluice gates and dams.
servo, is an automatic device that uses error-sensing negative feedback to correct the performance of a mechanism and is defined by its function. It usually includes an in-built encoder.
A simple 3 pin-rotary encoder above, and wtih a hand drawn schematic short circuit with the theoretical output pulses on the right. R1 and R2 are the pull up resistors.
Pin A will be first shorted to GrouND and then pin B in the Right wise .
Same way, Pin B will be first shorted to GrounND and the pin A int he Left wise.
Turning of the knob will causing a noise in wave, so decoupling capacitors are placed.
There are two main types of rotary encoder as absolute and incremental, and this 3pin rotary encoder is an example of incremental encoder
