What are rotary systems



Pneumatic rotary actuators are a device that produces a rotary motion via a shaft to control the speed and rotation of attached equipment. At Rotomation, we manufacture high-speed, heavy-duty pneumatic and low-pressure hydraulic rotary actuators with various shaft motions. Hydraulic rotary actuators are often used for steering or as an alternative to hydraulic cylinders or motors Pneumatic rotary actuators are commonly used for material handling, product assembly, testing and quality control, packing, welding, and machine loading and unloading applications.

Intellidrives actuators & rotary systems are a good fit for applications requiring extremely high endurance, high rotational speeds, and a need for constant control of movement without the need to maintain the load in a particular position. 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. The hydraulic Rotary Actuator is a device which transform hydraulic power (pressure and flow) in rotational mechanical power (torque and speed).  For more information, be sure to visit www.intellidrives.com

The spiral-shaft rotary actuators in Figure 19-5 operate equally well on air or hydraulic power. Rotary motor actuators are coupled directly to a rotating load and provide good control for acceleration, operating speed, deceleration, smooth reversals, and positioning. 2 Fluid power actuators are of two common forms: those where a linear piston and cylinder mechanism is geared to produce rotation (illustrated), and those where a rotating asymmetrical vane swings through a cylinder of two different radii.

Pneumatic rotary actuators are commonly used to convert compressed air pressure (in the form of a cylinder stroke) into an oscillating rotary motion. These actuators can also be equipped with two opposing pistons to double the amount of torque on the output shaft as shown in Figure 5 on the right. In pneumatic rotary actuators, linear force of a piston is converted to torque by mechanisms such as rack-and-pinion or scotch yoke.

Depending on the design, the air pressure forces the piston or diaphragm to move creating linear or rotary motion. Linear actuators can be powered by air, hydraulic fluid, or electricity. With standard air pressure of up to 150 psi you can be sure that the torque they deliver keeps the actuator in place because the air pressure driving the piston locks against the gear and with less than 0.2 degrees of backlash we can assure a positive position with the accuracy of a low-cost servo motor.

Rotary DGB actuators feature a variety of DC motor and gearbox combinations for applications requiring a bi-directional shaft rotation. Their purpose is to convert the hydraulic pressure of a fluid into rotational power, and output an instant torque. Rotary vane actuators are more limited in rotation and in torque than the rack and pinion version, and are therefore more commonly used for lighter loads.

There are a wide range of rotary actuator designs available, including rack and pinion, piston chain, helical spine, Scotch yoke, bladder and vane rotary actuators, each suited to a specific group of applications. They can be of radial design similar to the pump of Figures 2.12 and, or in-line (axial) design similar to those of Figures 2.14 and Radial piston motors tend to be most common in pneumatic applications, with in-line piston motors most common in hydraulics. The principles of hydraulic and pneumatic devices are very similar, but the much higher hydraulic pressures give larger available torques and powers despite lower rotational speeds.

With the torque rate and displacement fixed for a chosen motor, the user can control maximum available torque and speed by adjusting, respectively, pressure setting and flow rate of fluid to the actuator. Key advantages of hydraulic rotary actuators include simplicity of design and the ability to generate high torques and low speeds. In piston-type actuators, pressurized hydraulic fluid is used to displace a piston and generate rotational motion.

Common design configurations for hydraulic rotary actuators include piston type, vane type, or gear type. Pneumatic rotary actuators utilize the pressure of compressed air to generate oscillatory rotary motions. Types of pneumatic rotary actuators include single rotary vane devices, double rotary vane devices, multi-motion rotary vane actuators, single rack-and-pinion actuators, and double or four piston rack-and-pinion actuators.

The basic method through which rotary actuators provide rotary motion is through the rotation of an output shaft through a fixed arc. Rotary actuators are compact, simple and efficient linear actuators that rotates an output shaft through a fixed arc to produce oscillating power.