Are you designing a log splitter, modernizing a front loader (TUR), or perhaps building a hydraulic press? Besides the appropriate lifting force, you need to know how quickly your machine will perform its task.
A cylinder that's too slow leads to frustration due to low efficiency. One that's too fast poses a safety risk and cavitation hazard. BRhydraulic's free calculator will help you determine the precise piston speed and the total extension and retraction time.Cylinder Speed and Cycle Time Calculator
Calculate extension/retraction speed and full cycle time.
Why is cylinder retraction always faster than extension?
If you input data into our calculator, you'll notice a very important relationship: for the same flow parameters (L/min), the cylinder retracts significantly faster than it extends. At the same time (as you know from our Force Calculator), it generates less lifting capacity during retraction.
This phenomenon directly results from the fact that standard double-acting cylinders are what are known as differential (asymmetric) cylinders. During extension, the pump must fill the entire cylinder space with oil (piston surface area). During retraction, part of this space inside the cylinder is already occupied by the rod (piston rod).
With less volume to fill, a hydraulic pump delivering oil at the same capacity will fill the chamber faster – hence the higher retraction speed.
How to calculate it yourself? (Engineering Formulas)
The formula for piston speed is closely related to the volume of fluid supplied to the cylinder.
Formula for speed (v):
v = (Q * 16.667) / A
Where:
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v– piston speed in cm/s
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Q– pump oil flow in L/min
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A– working area of the piston or annular area in cm²
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16.667– constant conversion factor from L/min to cm³/s
Formula for movement execution time (t):
t = L / v
Where:
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t– time in seconds (s)
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L– total cylinder stroke in centimeters (cm)
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v– previously calculated speed in cm/s
How to control cylinder speed?
Does the calculator result show that the cylinder will move too fast (jerking the machine) or definitely too slowly? You have several options to modify your system:
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To speed up the cylinder: You need to increase oil flow. To do this, replace the hydraulic pump with a model with higher efficiency (more liters per minute) or increase the RPM of the engine driving the current pump.
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To slow down the cylinder: You can use proportional directional control valves that precisely meter oil flow, or install throttle valves (or restrictor check valves) in the line.
BRhydraulic offers everything you need to make your machine work smoothly and at the ideal pace:
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Solenoid Valves: Ensure precise control of oil direction and flow in your system.
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Cylinders: A wide selection of ready-made cylinders with various strokes and diameters, ready for work in the toughest conditions.
- CETOP Blocks: Modular manifold plates and blocks to facilitate the construction of compact and efficient hydraulic systems.
