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Old 02-25-2012, 07:44 AM
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Default Hydraulic pump

I have a question regarding hydraulic pumps.

Do they work one way only?

I mean, this one uses a simple motor (dont know about others) and when the motor works the pump starts to "pump" the oil, but what if it the motor turns in the opposite direction? What happens? Does the pump starts pumping oil in the reverse direction? Would that make an hydraulic actuator "open and close"?

Im not sure if I made my question clear...
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Old 02-25-2012, 08:08 AM
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From my experience of hydraulic pumps (lifts) they do not work in reverse. And in general hydraulic seals do not like working with negative pressure so you cant really suck a ram closed reliably.
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Old 02-25-2012, 08:21 AM
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Thanks for the reply! Was planning on using this to operate the steering, using a motor connected to a servo board.

Being so, scrapped ideia!
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Old 02-25-2012, 08:25 AM
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if its that scale look your going for, i'd look at these:
http://www.junfac.com/shop/index.php...ducts _id=185
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Old 02-25-2012, 09:07 AM
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Quote:
Originally Posted by The-Gamer View Post
Thanks for the reply! Was planning on using this to operate the steering, using a motor connected to a servo board.

Being so, scrapped ideia!
It can be done but you would need a double acting ram. ie one with a fitting each end and then a valve to control the pressure each side
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Old 02-25-2012, 08:03 PM
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Quote:
Originally Posted by winner View Post
if its that scale look your going for, i'd look at these:
http://www.junfac.com/shop/index.php...ducts _id=185
Not going for the scale look! Just trying something different!
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Old 02-27-2012, 08:29 AM
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a gear pump can pump fluid either way but.

on real systems the discharge line has to be smaller than the suction to prevent cavitation

a real system has check valves that only let fluid travel one way


Im sure if you set the pump and hoses correctly it wouldnt be an issue.
the only issue I see is smoothness,It takes torque to build up the pressure to be used directly,notice mini pumps spool up before the valves/cylinders are operated,they spool up so the motor has the power and the pump has the pressure to operate smoothly.

If by having all the air bleed out the system and hooked up directly to a cylinder(double action) as soon as the pump motor starts to rotate the cylinder will move,will it be smooth or jerky at low rpm's
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Old 02-27-2012, 06:38 PM
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Quote:
Originally Posted by tomsloat View Post
with negative pressure so you cant really suck a ram closed reliably.
There's a bar not far from my house that has some women who will make you retract that statement.
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