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   Engineering Drawings: DS-4

DS- 4 Dynamic Slot Tensioner

The Dynamic Slotted Tensioner provides continuous pressure on the belt over the life of the drive system. Assembly and service are often easier and more accurate with a dynamic tensioner. Plus the tensioner can be locked statically into place if desired after tension is set.


Operating Characteristics
Tensioner stroke - .25 inches (6.4mm)
Range of adjustment - .80 inches (20mm)
Maximum force against belt - 5 pounds (2.3 kg) continuous, 15 pounds (6.8 kg) peak
Spring can be mounted to push on idler pulley (as shown) or to pull


* Mounting Data:
     Approximate footprint without idler pulley of .90 inches (22.9mm) wide by 3.1 inches
     (78.7mm) long
     Minimum clearance from mounting surface to bottom of pulley is .23 inches (5.8mm) except
      plastic sleeve bearings require .28 inches (7.1 mm) minimum clearance.
     Requires one hole tapped 10-32 or M5 x .8 either through sheetmetal, or blind hole with       minimum .38 thread depth. See drawing below.

If needed, mounting spacers are available from York for higher than standard belt clearances. See www.york-ind.com/spacers or contact York for details.
** Tensioner Height:
To find your tensioner height, determine Pulley Width + Belt Clearance desired = X
     If X is less than or equal to .675 (17.1mm), tensioner height is 1.000 (25.4mm)
     If X is between .675 (17.1mm) and .950 (24.1mm), tensioner height is 1.275 (32.4mm)
     If X is larger than .950 (24.1mm), consult York Engineering

York tensioners are designed to mount securely onto a flat surface with just a single screw. The tensioners allow minimal clearance between the belt and mounting surface. Tensioners also feature different shaft lengths so they are also adjustable by York to provide greater clearance heights if needed. The York website's Tensioner Configuration Tools automatically account for shaft changes, if needed, when they create the specific tensioner part number for your application. Where even greater belt clearances are needed, York can provide machined, anodized spacers to act as a raised tensioner mounting base. Spacers are available in custom thicknesses while standard catalog spacers .38 inches thick (9.7mm) for Size 4 and .25 inches (6.4mm) for Size 3 tensioners are always in stock at York. Spacers are shown below and fit within the same footprint as the tensioners themselves. The spacer part numbering system uses the last two digits of the part number to indicate the thickness in decimal inches, with a tolerance of +/- .01.