schwing 34 meter Slow change over
ted 04-12-2005 comment profile send pm notify

I have been operating the same machine for the last 5 years and it has now developed a real problem with change over it is very slow.It had fitted to it a new back plate cutting ring kidney plate not schwing parts .When the machine was first started up in the work shop the fitters had to rev the arse out of it to get it to change over.There answer was you will have to put up with it untill they order the original parts.Three months later and change over a little better the new parts where fitted.Change over still slow check valves changed cumilator charged spools move freely.(could it be cumilator pump).All worked well untill the first bits where put in.Flow test on pump still to be done.

CE1 04-13-2005 reply profile send pm notify

Just because you have accumulator pressure does not mean that the accumulator is charged. With the machine turned off you need to check the nitrogen in the accumulator bottle. (refer to the Schwing service/safety manual)Nitrogen charge should be 100 Bar, after that has been set the accumulator hydraulic pressure should read 200 bar on the gauge.

ted 04-13-2005 reply profile send pm notify

Thank you tim for the information.That was the first thing we where told to do all the pressure is set as it should be. It now points to the v10 pump for the change over.We will know for sure once the pump has been flow tested.

CE1 04-14-2005 reply profile send pm notify

If you are seeing 200 Bar hydraulic pressure on the gauge and you are sure there is 100 Bar nitrogen in the accumulator bottle, the unit should shift fine. There is a slight possibility the valve in the accumulator is defective..... to test this you would hit an E-stop after you read 200 bar on the gauge, the gauge should bleed off and you should hear a distinctive sound coming from the accumulator area of oil bleeding off. If you hit an e-stop and the gauge immediately drops to zero there is a problem. Also make sure the gauge is not giving you a false reading when the machine is shut off.

ted 04-14-2005 reply profile send pm notify

Thank you CE1 for the advice. but all that seems ok after the E stop is pressed. it all works as it should do. Thanks for your help.

newbe 04-14-2005 reply profile send pm notify

Hi Ted, for starters if you have been running this same pump for five years and this is the first time the A10V bug has bitten you consider yourself lucky. If you are registering Zero accumulator pressure at a stand still,(engine off key in pocket) and then 200 bar after clearing E-stop, what happens during the shift? Does this pressure drop to zero? It should only drop to maybe 130-140 at worst. Check this and then if every thing seems okay fire it up clear E-stop and have someone else step into the cab and push the clutch in (only) while you watch the gauge, it should drop gradually then you will hear a distinctive Thump and the needle will fall the rest of the way to zero instantly. The point at which the needle fell from is your Nitrogen Charge pressure, in most cases it SHOULD be between 90 and 100 Bar. If yet everything still seems to check out OK and the drop between shifts (130-170 Bar) seems to be completely caught back up to 200 Bar while the engine is idling and the volume set to Max,Should you suspect a valve assembly being too tight Note: On most if not all the -5 models(stacked main pumps) the pump may not cycle at full volume at Idle due to the electronics destroking the pumps to make up for the engines lack of sufficient torque while idling. Whatever the case may be Flow testing is a pure waist of time as you can tell all you need to know just by knowing what to look for.I hope this helps. JIMMY