Piston Sleeve Taken Out_Poor Quality Linde Replacement HPR160 Barrel

Have you ever bought a China-made HPR130 or other models of cylinder blocks, and before it worked for a few days, the Hydraulic Pump which already replaced with brand new aftermarket parts broken down, and when you opened the broken pump, oh my God, the piston sleeve of the cylinder block was pulled out, and other internal parts such as piston shoes, ball guide, retainer plates were also broken up.  What is your feeling at that time?

Possible reasons why the piston copper sleeve is pulled out:

1. Cold pressing process

In order to save costs and simplify the processing technology, some manufacturers in China use the cold pressing process to press into the copper sleeve. That is, the copper sleeve is quickly cooled with liquid nitrogen to reduce the size of its outer circle instantaneously, and then the copper sleeve is placed into the hole of the cylinder block. This method is simple, but the usual problem is that the pressing force is very poor, and the sleevs is easy to come off.

2. The interference fit tolerance is too small

In order to ensure the qualified compression force, the interference fit of the piston sleeve and the barrel hole usually needs to reach at least 0.08~0.12mm. This tolerance requires a very high precision and roughness of machining, otherwise it is easy to overcut when pressing the copper sleeve, and even scrap some pieces of the copper sleeves. For the sake of cost considerations, some Chinese manufacturers have to reduce this tolerance fit and reduce the size, which inevitably brings that the compression force is too small, and the copper sleeve will naturally fall off.

In Super Hydraulics, the quality control requirements have always been very strict, and there will never be such problems. For some large displacement cylinder block like A4VSO355, A6VM500, PC1250 commonly used in construction machinery Hydraulic Pumps, we will use extended bushings or weld process instead of pressing. The purpose of this is to ensure the high quality and 99.9% reliability of the cylinder blocks.

Kindly work with Super hydraulics and make Super Hydraulics be your reliable, valuable, one-stop hydraulics partner in China.