hi there i am new to this forum. I am building hydropneumatic suspension on to my 4x4 i have mounted 2 hydraulic rams on the front. And am now trying to calculate what size accumulators are required. My rams hold 750ml each and i have roughly worked out it will take 400psi on either side to lift the truck. In an ideal world i need to be able to bottom out the rams till the axle hits the bump stops without blowing anything. Am i right in thinking if you halved the size of a area the pressure would double? Any input would be much appreciated. Cheers
Talk to Folliard hydraulics T: +44 (0)1953 603699 E: sales@hydraulics.uk.com W. http://hydraulics.uk.com/components_formula.php as they really are experts on hydraulic accumulators in automotive applications.
Welcome to the forum. Pressure = force/area, so if you halve the area of a ram you'll need twice the pressure to generate the same force.
Thanks for the reply please could you elaborate as I don’t understand. My ram is roughly 700mm long and has a internal bore of 40mm and is rated at 750ml full. The truck weighs 1.7 ton so i was working on roughly 2 thirds of that as it is for the front. Cheers octobox
Your original question was Basically physics says yes you'd need to double the pressure to get the same force from your ram if you halve the area of the piston. Throwing arbitrary values at the formula P= F/A (and ignoring units) for a force of 8 with an area of 2, P = 8/2 = 4, if you halve the area to 1 then to generate a force of 8 P = 8/1 = 8, ie you need to double the pressure. Of you're talking about a piston used to generate pressure (such as in a pump): Lets say an area of 8 and an applied force of 16, P = 16/8 = 2. If you halve the area of the piston to 4 and keep the same force of 16, P = 16/4 = 4, ie the pressure generated would double The whole application is more complicated as you have to take into account the displacement of the pistons, so really you need to speak to experts in this particular field.
Thanks for the reply i see what you are getting at now. I had already calculated the pressure reqired to lift the truck. I cheated and used a online hydraulic ram calculator. Thanks for the info though its always good to know the maths behind the madness. Cheers octobox