in Screw compressor for balancing of forces Acted on rotor(cause by pressure difference on inlet and out let), rotor pulled through inlet. bearing use for this perpuse but when pressure difference become high we shold use some mechanism to help bearing... by use on balancing mechanism(like balance piston) we can overcome 98% of forces acted on bearing... but some time this balancing mechanism fail to act properly and compressure failed( dameged ) . what may be the cause?