Stresses of a Hydraulic Cylinder Fig

Hydraulic pressure = 315 atm, respectively Pj sideration of the sign for pressure in the calculation. 

The cylinder is made of cast steel GS 52 with a yield point of = 3,100 kg/cm.  

The extrusion power is transmitted via two integrally cast column sleeves which are connected with the cylinder through four walls being subjected to bending and tangential stresses. 

The cylinder is subjected to a repetitive stress by the hydraulic pressure. Approx. 40 strokes are performed per hour so that after an assumed life of the press of 30 years, and two 8-hour shifts per working day, and 300 working days per year, the number of load alternations = 30 X 300 X 2 X 8 X 40 = 5,760,000 is attained. Therefore, the fatigue limit has to be calculated as per Wohler s diagram. 

In its upper part the cylinder represents a closed vessel, in its lower part an open vessel. The alternation is caused by the gradual transition of the axial stresses from the wall of the cylinder to the column sleeves. 

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