pneumatic cushioning system,
Unique self-adjusting pneumatic cushioning system promises dramatic reduction in machine set-up times
News Release from:
Festo has developed a unique self-adjusting pneumatic cushioning system, which is now available as a build to order option for the company's popular DSNU series round cylinder pneumatic actuators. The new system employs innovative, patented air channel geometry to provide phased venting of the cushioning air. The system automatically adapts its characteristics to suit the cylinder's prevailing load and speed conditions, to provide optimum end-position cushioning.
Festo is initially offering the new self-adjusting cushioning system on its popular DSNU family of round cylinders. Models available with the new system span diameters from 16 to 63 mm, with stroke lengths up to 500 mm – and delivery is usually within 24 hours. The DSNU series of pneumatic actuators already offers users a choice of polymer (P) or manually-adjustable pneumatic (PPV) end-position cushioning, for applications involving low and high impact energy levels, respectively. The new self-adjusting (PPS) cushioning is primarily intended for medium impact energy applications, involving loads up to about 5 kg and speeds up to approximately 1 metre/sec. PPS cushioning is also available on Festo’s CRDSNU corrosion-resistant stainless steel round-line cylinders, which offer the additional benefit of cleaner lines for improved wash-down by eliminating any potential for dirt entrapment around a cushioning screw.
Because the exhaust flow of the pneumatic cushioning chamber changes over the damping stroke, Festo’s PPS system works with most commonly permissible speed and mass combinations, making it suitable for a wide range of applications. As Steve Sands, Festo’s Product Manager, points out, “Round cylinders account for a significant proportion of our pneumatic actuator sales, and about 60 percent of the DSNU cylinders that we sell are equipped with PPV cushioning; of these, about 80 percent are used for applications that would benefit directly from our new PPS self-adjusting cushioning. Given that the PPS system actually costs less than our manually-adjustable technology, saves setting-up time and is always providing the optimum cushioning, we expect it to be a very popular choice with machine builders.”
The advantages of self-adjusting end-position cushioning are considerable. Manually adjusting the end-position damping of linear actuators is time-consuming, and can only be done effectively once the actuator is in-situ and under operating load conditions. By then the automation supplier is invariably under pressure to complete the task as quickly as possible. It also frequently involves two people – one to operate the appropriate pneumatic valve, the other to adjust the actuator’s damping characteristics. As with all moving parts, access can be potentially hazardous, which means that safety considerations dictate that only experienced personnel should perform these adjustments. Actuators are often less than perfectly adjusted, with under-damping resulting in higher end-position impacts, higher noise levels and increased wear, or with over-damping resulting in increased machine cycle times.
Festo estimates that on average, the new PPS self-adjusting end-position cushioning system will help users shave five minutes off a cylinder’s installation and set-up time. For a typical application, such as a package sorting system with, say, 60 cylinder-driven routing stations, this would result in savings of five man-hours.
Festo’s PPS self-adjusting end-position cushioning provides a complete ‘fit and forget’ solution. Since it has no settings to change it is completely tamper-proof, and it offers a long, maintenance-free service life. Festo DSNU pneumatic cylinders equipped with the new PPS system are 100 percent interchangeable with the company’s manually-adjustable DSN-PPV models.