Are you designing a log splitter, modernizing a front loader (TUR), or perhaps building a hydraulic press? Besides the appropriate lifting capacity, 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. The free calculator from BRhydraulic will help you determine the exact piston speed and the total time for its extension and retraction.
Cylinder Speed and Cycle Time Calculator
Calculate extension/retraction speed and full work cycle time.
Why is cylinder retraction always faster than extension?
If you enter data into our calculator, you will notice a very important relationship: for the same flow parameters (L/min), the cylinder retracts much faster than it extends. At the same time (as you know from our Force Calculator), it generates less lifting capacity during retraction.
This phenomenon results directly from the fact that standard double-acting cylinders are so-called differential (asymmetric) cylinders. During extension, the pump must fill the entire cylinder space with oil (the piston's 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 flow rate 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– oil flow from pump in L/min
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A– working surface area of the piston or annular area in cm²
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16.667– constant coefficient converting 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?
The calculator result shows that the cylinder will move too fast (jerking the machine) or decidedly too slow? You have several options to modify your system:
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To speed up the cylinder: You need to increase the oil flow. To do this, replace the hydraulic pump with a model of 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 distributors that precisely dose the oil flow, or install throttle valves (or throttle-check valves) in the line.
At BRhydraulic, you will find everything you need for your machine to operate smoothly and at the ideal pace:
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Solenoid valves: Ensure precise control over oil direction and flow in your system.
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Hydraulic Cylinders: A wide selection of ready-made cylinders with various strokes and diameters, ready to work in the toughest conditions.
- CETOP Blocks: Modular manifold blocks and connection plates that facilitate the construction of compact and efficient hydraulic systems.
