Page 88 - Paker - Medium Duty Hydraulic Cylinders

Catalog HY08-1130-4/NA Medium Duty Hydraulic Cylinders
Cushioning Series 3L Engineering Data

An Introduction to Cushioning Cushion Length
Cushioning is recommended as a means of controlling
the deceleration of masses, or for applications where Cylinder Rod Cushion Length
(Inches)
Bore
Ø
Rod
1
piston speed is in excess of 4 in/sec and the piston will (Inches) (Inches) Number Head 1 Cap
make full stroke. Cushioning extends cylinder life and 0.500 1 0.88 0.75
reduces undesirable noise and hydraulic shock. Built-in 1.00 0.625 2 0.88 0.75
“cushions” are optional and can be supplied at the head 0.625 1 0.88 0.81
and cap ends of a cylinder without affecting its envelope 1.50 1.000 2 0.88 0.81
or mounting dimensions. 0.625 1 0.88 0.81
2.00 1.375
Standard Cushioning 1.000 2 1 0.88 0.81
0.88
0.81
Ideal cushion performance shows an almost uniform 2.50 1.750 2 0.88 0.81
absorption of energy along the cushioning length, as 1.000 1 1.13 1.00
shown. Many forms of cushioning exist, and each has its 3.25 2.000 2 0.81 1.00
own specific merits and advantages. 1.375 1 1.13 1.00
4.00
In order to cover the majority of applications, 3L 2.500 2 0.81 1.00
cylinders are supplied with profiled cushioning as 1.750 1 1.13 1.00
standard. Final speed may be adjusted using the 5.00 3.500 2 0.81 1.00
cushion screw. The performance of profiled cushioning 1.750 1 1.38 1.25
is indicated on the diagram below. 6.00 4.000 2 1.06 1.25
2.000 1 1.06 1.25
Note: Cushion performance will be affected by the use of 8.00 5.500 2 0.94 1.25
water or high water based fluids. Please consult factory 1
Head end cushions for rod diameters not listed have cushion lengths
for details. within the limits shown.
Cushion Length
Where specified, 3L cylinders incorporate the longest
cushion sleeve and spear that can be accommodated
within the standard envelope without reducing the rod
bearing and piston bearing length. See cushion lengths
at right. Cushions are adjustable via recessed needle
valves.

Cushion Performance

78 Parker Hannifin Corporation
Industrial Cylinder Division
www.parker.com/cylinder Des Plaines, Illinois