In the world of industrial automation, pneumatic rodless cylinders can now be found just about anywhere; from food and beverage packaging to pharmaceutical and chemical production lines. They have a significant advantage over more conventional rod-type cylinders because they are fast, efficient, capable of supporting high direct and cantilever loads and are smooth-running. In addition, they require only about half the space compared to their traditional counterparts.
They are also easily adjustable and offer air cushioning at the end positions. This serves to dampen the piston as it reaches the end of its travel, thereby slowing down the speed of the load at the end of the stroke to prevent unnecessary impact or shocks. Without the right setting, the service life of the overall system will be considerably shorter and generate potentially problematic vibrations throughout the entire assembly line.
Adjustable cushioning can be tailored to specific applications and is, therefore, more efficient than cushioning preset by the manufacturer, which can only assume a standard load and the speed at which it needs to travel. By adjusting the cushioning settings, which is known as “ideal cushioning”, the piston is decelerated to zero velocity at the end of the stroke, thereby dissipating all kinetic energy in the load. Therefore, shorter cycle times are achieved because, with no piston bounce, no time is lost due to shock or vibration. System wear is reduced as the ideal cushioning eliminates shocks to the cushioning sleeve, thereby increasing the lifetime of the cylinder. Productivity is also ultimately improved when the system is at optimal operation, working well on a continuous basis without force, shocks or vibrations.
Adjusting the end-position cushioning
Let us take a look at the correct way to adjust the end position cushioning on a Parker ORIGA OSP-P pneumatic rodless cylinder to ensure shorter cycle time, less wear, higher productivity and longer product lifetime. This is recommended for any Parker rodless pneumatic cylinder before first use.
It is recommended that six-bar of operating pressure is used for the adjustment process; any variations in pressure will require a slightly modified adjustment process.
The adjustment screw is located at the cylinder's end caps.
All you will need to perform the adjustment is a small slotted screwdriver.
With the fine thread of the cushioning screw, there is a high degree of sensitivity and set-up can be completed very accurately. The cushioning screw itself is secured against completely unscrewing. The factory setting of a Parker rodless cylinder cushioning adjustment screw is approximately one half turn open.
Firstly, loosen the cushioning adjustment screw by one full turn.
The piston re-bounces from the air cushion causing it to vibrate.
Cushioning must be slowly adjusted by loosening the screw turn-by-turn.
Cylinder noise will increase slightly but the piston vibrations will immediately start to decrease.
The vibrations will continue to decrease as you loosen the cushioning screw.
The noise will continue getting louder - this is completely normal for the adjustment process.
Continue to slowly loosen the cushioning screw until the vibrations stop.
The cylinder will now become quieter until the noise is barely perceptible.
The piston will gently move into the end position.
The adjustment process is complete.
The ideal cushioning will increase productivity and output and will reduce costs at the same time.
To find more information on how to adjust the end position cushioning of the Parker ORIGA Series of pneumatic rodless cylinders, please see this video:
Article contributed by Dieter Winger, product manager, Pneumatic Rodless Actuators, Pneumatic Division Europe, Parker Hannifin Corporation