Hydraulic Force: Input & Output of Multiple Pistons

  • Thread starter Thread starter wolfy3
  • Start date Start date
  • Tags Tags
    Force Hydraulic
Click For Summary
Hydraulic systems demonstrate mechanical advantage by using a small piston to exert force on a larger piston, resulting in a greater output force over a shorter distance. In the discussed example, applying 100 lbs of force to a 3" diameter piston yields an output of 33 lbs on a 1" diameter piston, with the travel distances being inversely proportional. When multiple output pistons are involved, the input force and travel distance remain consistent, but the output force is divided among the pistons based on their sizes. Calculating the area of each piston is crucial for accurate force and pressure assessments, as the pressure varies with diameter. Understanding these principles is essential for optimizing hydraulic systems effectively.
wolfy3
Messages
1
Reaction score
0
Most examples of hydraulic mechanical advantage display a little force on a small piston traveling a long distance to move a bigger piston a short distance with a lot of force.

With the inverse, if we have an input of:
100 lbs of force on a 3" diameter piston traveling 1"
the output would be
33 lbs of force on a 1" diameter piston traveling 3"
and this is true for single pistons.

What happens if the output is forked into 2 or more pistons as my illustration shows?
To have the same travel & force on the small diameter output pistons, would the travel & force on the input piston need to change at all? Or will it stay the same (as with a single output cylinder)?
Thanks in advance.
 

Attachments

  • hyd.jpg
    hyd.jpg
    12.7 KB · Views: 473
Physics news on Phys.org
wolfy3 said:
With the inverse, if we have an input of:
100 lbs of force on a 3" diameter piston traveling 1"
the output would be
33 lbs of force on a 1" diameter piston traveling 3"

I might be a bit rusty but are you sure about this example?

100lbs on a 3" diameter piston is 14psi
33lbs on a 1" diameter piston is 38psi
 
You can't use just the diameter of the pistons. You have to calculate the area of each piston.

Piston A = 3 square inches
Piston B = 1 square inch

Applying force to Piston A to move it 1 inch will move Piston B 3 inches, with 1/3rd the output force.
Applying force to Piston B to move it 3 inches will move Piston A 1 inch, with 3 times the output force.
 

Thread 'Does acceleration affect impact energy vs constant velocity?'

I do not have a good working knowledge of physics yet. I tried to piece this together but after researching this, I couldn’t figure out the correct laws of physics to combine to develop a formula to answer this question. Ex. 1 - A moving object impacts a static object at a constant velocity. Ex. 2 - A moving object impacts a static object at the same velocity but is accelerating at the moment of impact. Assuming the mass of the objects is the same and the velocity at the moment of impact...
View full post »

Similar threads

High School How can I derive the hydraulic equation using conservation of energy and work?
  • · Replies 4 ·
Replies
4
Views
3K
Calculations for Hydraulic Jacks lifting a load
  • · Replies 2 ·
Replies
2
Views
3K
How does the compressibility of hydraulic fluid affect force?
  • · Replies 5 ·
Replies
5
Views
2K
How is the torque output calculated for an engine with two cranks?
  • · Replies 13 ·
Replies
13
Views
3K
Undergrad Resulting force on a chamfered pneumatic piston
  • · Replies 3 ·
Replies
3
Views
2K
Modeling Air Compression Cylinder
  • · Replies 45 ·
2
Replies
45
Views
6K
Total force from air spring model (double acting piston)
  • · Replies 8 ·
Replies
8
Views
3K
Automotive How to calculate hydraulic disc brake size using actuation force?
  • · Replies 15 ·
Replies
15
Views
6K
Annulus force in a Hydraulic Cylinder?
  • · Replies 2 ·
Replies
2
Views
4K
High School Can the output forces for F3 and F4 be the same as F2 in hydraulic lifting?
  • · Replies 4 ·
Replies
4
Views
1K