Hydromnotor / Screw problem Chinese Machine

[Rohit876]

Hi Everyone,

Another problem with a different Chinese Injection molding machine. This one is 360 ton machine from Ningbo Hengrun and is used to make single cavity 740 gramm preform. The problem is as follows:

1. Noisy hydromotor while charging specially the drain pipe.
2. Oil and grease coming out of the point where grease is inserted for the lubrication of the bearing responsible for movement of screw.
3. Rotation of the screw clockwise during injection. Although the speed and frequency is not much.

I can share videos and pictures in case anyone wants to see and gives me his / her mail id.

Thanks for reading and help.

Regards.

[Suhas]

Hello Rohit,
I think this will be difficult to answer online. Your best option is to call an experienced maintenance person and show him the problem. Sorry, but not sure we can help you here.
Thanks,
Suhas

[Pilot]

Hi,

According your description is not only hydromotor issue, maybe the morot is not in good condition - to high oil leakage from drain ..... ok temporarry solution is bigger drain with hose direct back into oil tank. Because you have a leakage under piston which is too high and during rotation is a high press under piston, and this press is going out through sealings.
Nest issue is screw roation during injection. This is not Hydromotor issue, but you have a problem with valve or servo. But for better diagmostic I need a hydraul scheme. As a first aid I can recommend to replace pilot valve on servovalve, but it is only my person tip. :-)