ptonsparky
Tom
- Occupation
- EC - retired
I have a couple hydraulic motors that I would like to start/stop via a solenoid. What basic info do I need to know about the hydraulics. GPM, pressure? A link for reading?
Electric over hydraulic
- Thread starter ptonsparky
- Start date
- Status
- Location
- Massachusetts
For sure GPM and pressure but don't forget you are not going to just close the line off like a water or air line, you need a valve body that redirects the flow back to the return.
- Location
- Massachusetts
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Are you looking to have the slam on/off that a solenoid will provide or would it work just as well if the on/off action was more like a ball valve? (I was thinking an electrically actuated ball valve).
- Location
- Massachusetts
You can't just block off the line. If you do you will raise the line pressure up to the set point of the relief valve and likely overheat the hydrulic fluid. Or if there are other motors on the same hydrulic circuit they will speed up.
Keep in mind that hydrulic pumps are 'positive displacement pumps' the fluid has to flow or the pump will stall the electric motor driving it.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
I understand that, and assumed there would be a pressure relief valve set to return product back to the tank in the event the pump was dead heading. At least that's the way I always did it.
That's why I would install the pressure relief valve. If there is only 1 hydraulic pump feeding more than one hydraulic motor, something has to be done to regulate the pressure during less than all pumps on operations.
- Location
- Massachusetts
Why would you want to operate against the relief valve all the time? :huh:
When I worked on hydraulics the valve used would simply reroute the flow back to the supply tank without raising the pressure to the point of opening the relief.
Maybe I was mistaken, it has been a while.
- Location
- Illinois
- Occupation
- retired electrician
It is not uncommon to use a relief device as the recycle method, especially where there are multiple devices operated by the hydraulic system.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
So in the case of the OP, the solenoid valve would be more like a 3-way (instead of off/on) in that it would either feed the pump or feed back to the tank. How did the system insure that when the motor was bypassed that the flow rate of the diverted hydraulics was not higher than the motor usage? If the bypass allowed a higher GPM than the pump, the system pressure would drop, no? That in turn would seem to be an issue for any other hydraulic devices that were looking for a certain pressure.
I've always enjoyed hydraulics. Many ways to do things, and you better be thinking.
ptonsparky
Tom
- Occupation
- EC - retired
Seems like I spend more time learning than working.
GeorgeB
ElectroHydraulics engineer (retired)
- Location
- Greenville SC
- Occupation
- Retired
I do this for a living for some local organizations ... and most of the answers so far are right ... in SOME cases. Post more info, or PM me and I'll help you define your needs. If the system is designed for "closed center" loads, valving designed for "open center" loads won't work very well. Similarly, if the system is designed for "open center" loads, valving designed for "closed center" loads won't work very well.
George
- Status