Exclusive with the New Parker Stepped Cushion for increased performance and productivity
Faster cycle time
Reduced hydraulic shock
Reduced machine noise
Lower machine maintenance
Nominal Pressure-3000 PS
Standard Bore Sizes - 1-1/2" through 8"
Piston Rod Diameters - 5/8" through 5-1/2"
Thirteen Standard Mounting Styles
PARKER'S NEW, EXCLUSIV
Stepped floating cushions combine the best features of known cushion technology.
Deceleration devices or built-in !°cushions!± are optional and can be suppli at head end, cap end, or both ends without change in envelope or mounting dimensions. Parker cylinder cushions are a stepped design and combine the best features of known cushion technology.
Standard straight or tapered cushions have been used in industrial cylinders over a very broad range of applications, Parker research has found that both designs have their limitations.
As a result, Parker has taken a new approach in cushioning of industrial hydraulic cylinders and for specific load and velocity conditions have been able to obtain deceleration curves that come very close to the ideal. The success lies in a stepped sleeve or spear concept where the steps are calculated to approximate theoretical orifice areas curves.
In the cushion performance chart, pressure traces show the results of typical orifice flow conditions. Tests of a three-step sleeve or spear show three pressure pulses coinciding with the steps. The deceleration cushion plunger curves shape comes very close to being theoretical, with the 1/2 inch exception of the last of travel.
This is a constant shape in order to have some flexibility in application. The stepped cushion design shows reduced pressure peaks for most load and speed conditions, with comparable reduction of objectionable stopping forces being transmitted to the load and the support structure.
All Parker Hannifin cushions are adjustable.
The Series HD cylinder design incorporates the longest cushion sleeve and cushion spear that can be provided in the standard envelope without decreasing the rod bearing and piston bearing lengths.
(1) When a cushion is specified at the head end:
a. A self-centering stepped sleeve is furnished on the piston rod assembly.
b. A needle valve is provided that is flush with the side of the head even when wide open. It may be identified by the fact that it is socket-keyed. It is located on side number 2, in all mounting styles except D, DB, DD, JJ and HH. In these styles it is located on side number 3.
c. On 5” bore and larger cylinders (except for 21/2” bores with code 2 rods), a springless check valve is provided that is also flush with the side of the head and is mounted adjacent to the needle valve except on mounting style C, where it is mounted opposite the needle valve. It may be identified by the fact that it is slotted.
d. On 11/2 -4” bore cylinders a slotted sleeve design is used in place of the check valve.
e. 11/2” - 2” bore cylinders use cartridge style needle valve (see Figure A).
(2) When a cushion is specified at the cap end:
a. A cushion stepped spear is provided on the piston rod.
b. A “float check” self-centering bushing is provided which incorporates a large flow check valve for fast “out-stroke” action.
c. A socket-keyed needle valve is provided that is flush with the side of the cap when wide open. It is located on side number 2 in all mounting styles except D, DB, DD, JJ and HH. In these styles it is located on side number 3.