Hydraulic Top Link

[rujib]

Hi,

Any ideas on how to control the speed of the downward stroke on my hydraulic top link when dropping a heavy impliment.
Example, I drop the lift arms on my 7745 with drum mower attached. Once the lift arm have reached to bottom position I need to drop the mower drums to the ground by extending the hydraulic top link. The problem is the weight of the mower causes the top link to open much too quickly resulting in the mower hitting the ground with an almighty bang. Not good for the mower.

Any ideas on how to restrict the speed at which the ram opens.

Thanks

 

[treaney]

Hi Rujib,

You could "feather" the top link control i.e. move it very small increments to allow the mower to drop more slowly. You've probably tried this...

From what you say, I would hazard a guess that your top link is single acting. If you convert it to double acting, the restriction provided by the oil exiting will allow your mower to drop more smoothly.

 

[rujib]

Tom,

Thanks for that. Yes, I have tried to feather with the lever, but as soon as I move the lever even a few mm to start the down stroke, the weight of the mower, just pulls the ram open at too much speed for the good of my mower. No problem in controling the speed of the ram if there is no weight on it. I can jog it open a few mm at a time.

I am not sure what you mean by converting from single to double acting. I have connected the two hoses in the only real option availible to me. One to pressure line and one to return, using the ports available to me on the tractor (7745).
Do you mean that I would get better control if I added an auxilliary spool valve, and connect the top link through that?

Rgds

Rujib.

 

[ixer0]

Hi Rujib

You have a couple of options to slow it down.

A one-way flow control valve is available which only restricts the flow one way.
or
Weld one of the unions up and drill a smaller hole for the oil to flow through. Only problem is, it will lift slower also. Start off small with the hole size and drill it out until the mower moves at a sensible speed.

Regards

Mike

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