hydraulic cylinder ends

[scarecrow55]

Does the lug on a hydraulic cylinder or fork in the mating part usually have a bush, or does the pin locate straight to the metal (in cases where the movement might only be infrequent, say once per day)
What do the rams that are used on JCB type machines have?

 

[unclesyd]

I have seen it both ways though I believe the tendency now is to have a bushing looking at new equipment. Your case leads to some additional thought about the operating conditions. If the movement was truly just once a day then I would question the need for a bushing but if there is any vibration transmitted through the connection I would seriously consider a bushing. Normally not a problem but the material of construction could also play into equation.

I think the bushing is a good idea as I have a friend that has made a small fortune weld repairing and machining connections on hydraulic equipment.

Here are two people that supply the bushings that you might want to look at.

http://www.connexusa.com/

http://www.rollpin.com/ProductInformation/TensionBushings/index.html

 

[BillPSU]

Usually the attachments for hydraulic cylinders should have spherical bearings to avoid side loading of the cylinder. Depending on the load that is being moved and operating conditions I have seen cylinders knock out seals and even break the clevis from the rod due to side loading. Depending on design, there are times when spherical bearings cannot be used or are deemed too expensive to use. Efforts should be taken to reduce and deflection between the two mounting points and make sure the orientation of the pinning is the most advantageous to reduce side loading.