Question

A hydraulic press must be used to press-fit two components together in an assembly process. the system must generate at least 775 lb of force to perform the press fit. the piston at the input cylinder is pushed with a force of 250 lb and has an area of 30 in.2 . the output can use up to 15 cylinders that are each 30 in.2 . how many cylinders are needed?

Answer 1

The pressure generated by the piston at the input cylinder must be:

p = F / A = 250 lb-f / 30 in^2


The pressure generated by the piston at the output cylinders is p = F / A = 775 lb-f / A.


Pascal principle rules that both pressures are equal, so:


250 lb-f / 30 in^2 = 775 lb-f / A => A = 775 lb-f * 30 in^2 / 250 lb-f = 93 in^2


Gvien that each output cylinder are 30in^2 you need 93 / 30 = 3.1 cylinders.


Which means that at least you need 4 cylinders to generate a force at least of 775 lb-f.


Answer: 4