Where ever possible we like to avoid having to fit coolers to hydraulic systems. The cause of a hot system can be boiled down to one thing, wasted energy.
It is possible to waste energy in many ways and I would guess that the most common for hydraulic systems is blowing oil across a relief valve.
No hydraulic system is 100% efficient and any inefficiency will result in heat generation but often this can often be kept to a minimum and dissipated by convection and radiation. A large tank can help ensuring good air flow around its surfaces.
Pumps can play a significant role. Variable displacement pumps can provide the exact amount of flow needed without wasting fluid across the relief valve.
System design is critical in preventing heat generation by using unloading circuits, accumulators and correct sizing of components.
Regards
Bob
More at www.hydraulicbrain.com
Thursday 28 July 2011
Thursday 21 July 2011
Getting great traffic to our new site
We launched our new website only a couple of months ago and I am thrilled with the traffic and response we are getting.
I am continuing to add more and more hydraulic content and intend to make this the largest hydraulic website available and help those with hydraulic problems, involved with dsign or are trying to learn more about the subject.
Those that have not visited the site please give it a try for Free!
Check out www.hydraulicbrain.com
All your comments are very welcome.
Thanks
Bob
I am continuing to add more and more hydraulic content and intend to make this the largest hydraulic website available and help those with hydraulic problems, involved with dsign or are trying to learn more about the subject.
Those that have not visited the site please give it a try for Free!
Check out www.hydraulicbrain.com
All your comments are very welcome.
Thanks
Bob
Why Rams Creep
So often I come across the problem of rams that creep out and this can be due to a few reasons.
Using a control valve with a centre position of all ports blocked is the most common cause. With this valve the blanked P port is under pressure and some leakage will pass either side to A&B, this will extend by displacing the rod area.
Another cause can be temperature. When the ram is locked in position using PO check valves or ball valves any temperature rise in the oil will cause expansion. If the piston seal is not 100% leak free the ram will creep forward. Without piston leakage the pressure could rise to an alarming value and cause damage to the ram.
Any load on a ram will make it creep over time. All valves have metal to metal sealing and the oil is the source of lubrication and leakage. As the running parts wear the leakage will increase and the ram will creep even more.
Always best to design with leakage in mind.
Cheers
Bob
More hydraulic stuff on www.hydraulicbrain.com
Using a control valve with a centre position of all ports blocked is the most common cause. With this valve the blanked P port is under pressure and some leakage will pass either side to A&B, this will extend by displacing the rod area.
Another cause can be temperature. When the ram is locked in position using PO check valves or ball valves any temperature rise in the oil will cause expansion. If the piston seal is not 100% leak free the ram will creep forward. Without piston leakage the pressure could rise to an alarming value and cause damage to the ram.
Any load on a ram will make it creep over time. All valves have metal to metal sealing and the oil is the source of lubrication and leakage. As the running parts wear the leakage will increase and the ram will creep even more.
Always best to design with leakage in mind.
Cheers
Bob
More hydraulic stuff on www.hydraulicbrain.com
Sunday 10 July 2011
Quick release couplings
Quick Release Couplings can be extremely useful for applications where you are frequently connecting and disconnecting hoses; however they can also present some serious problems.
I have experienced occasion ions where the coupling has become worn or damaged (often by being thrown about on the floor) and will either only partially open or in the worst case will not open at all.
These couplings rely on a mechanical valve being forced open when pushed together. By their nature they often have a high pressure drop and also are an ideal source for dirt and contaminant to enter the system.
There have even been occasions on some systems when they become hydraulically locked and will not open.
I have nothing personal against quick release couplings, all I say is use them only where absolutely necessary, protect them from damage and keep them scrupulously clean.
Very best
Bob
www.hydraulicbrain.com
I have experienced occasion ions where the coupling has become worn or damaged (often by being thrown about on the floor) and will either only partially open or in the worst case will not open at all.
These couplings rely on a mechanical valve being forced open when pushed together. By their nature they often have a high pressure drop and also are an ideal source for dirt and contaminant to enter the system.
There have even been occasions on some systems when they become hydraulically locked and will not open.
I have nothing personal against quick release couplings, all I say is use them only where absolutely necessary, protect them from damage and keep them scrupulously clean.
Very best
Bob
www.hydraulicbrain.com
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