Thursday, January 14, 2016

6 Reasons Why Pneumatic Vane Actuators are Superior to Rack and Pinion Actuators

Rotary vane actuators
Rotary vane actuators offer distinct design and performance advantages.

  1. Rotary vane actuators do not convert linear motion to rotary motion, unlike rack and pinion actuators. No additional gearing is required and no side loading is transferred to the actuator housing.
  2. Vane actuator lip seals are the key to long life. The double opposing lip seal design, with stainless steel expanders, provides unmatched service life by using air pressure to improve the actuators seal-to-enclosure contact, and provide a “self cleaning” effect on the epoxy or PTFE internal finish.
  3. The elimination of pressure bearing o-ring shaft seals. Rack and pinion actuators require shaft sealing o-rings that are exposed to the full supply air pressure used to operate the actuator. These o-rings wear, causing leaks, a drop in efficiency, and wasted energy through air consumption. Vane actuators' double opposing lip seals isolate the supply air pressure from the actuator shaft, requiring only a low friction bearing on the shaft.
  4. Rotary vane actuators provide superior modulating accuracy. Because of the integral vane and shaft (machine from a single casting), lost motion or hysteresis is reduced dramatically which intern provides much tighter modulation and control. The vane actuators inherent low friction also reduces hunting and sticking.
  5. Direct mount, modular design for springs, positioners, switches, and solenoids reduce space requirements and lower inventory costs. Since vane actuator accessories direct mount to various size actuators, there’s no need to inventory and keep track of mounting kits. 
  6. Rotary vane actuator spring return units are designed to be virtually indestructible. Using low stress, clock springs reduces spring tension loss and metal fatigue. The housing for vane a actuator springs are sealed from the atmosphere, preventing corrosion of internal parts. Most importantly, these type of spring units provide the lowest torque loss which enables the section of smaller (less expensive) actuators.