HX RANGE THRUST BEARINGS

For high boost applications the design and quality of the thrust bearing and thrust collar are of utmost importance.

The thrust bearing is put under heavy strain when high boost pressures are used, in particular with large size compressor wheels. Then it requires maximum load carrying capability.

Many manufacturers of conventional turbochargers use a 270 degrees thrust bearing and a one piece thrust collar-oil slinger combination.

Experience in practice has learned, that this 270 degree design is less suitable for high boost application and high thrust loads.

Reason why various aftermarket suppliers sell modified 360 degrees thrust bearings plus thrust collars for racing- and high boost applications, as an upgrade for conventional builds of turbochargers that still used the 270-degree thrust design.

              

                            270 degrees                         360 degrees

These 360 degrees bearing assemblies are expensive and additional machining often is required if they are fitted. 

The advantages of a 360-degree thrust bearing include a full circle of lubrication, improved orifices to lubricate the thrust collar, instead of the smaller ones for the 270-degree unit and an updated pad strategy to better disperse oil where it is needed. 

The entire HX range comes ‘standard’ with a 360 degrees thrust bearing, so it is a build-in feature.

On top of this we, where required, install larger diameter thrust collars to even improve the high load capabilities of the 360-degree standard HX thrust bearing section.

Pictures of HX range thrust bearings:

     

                                              From left to right thrust bearing
                                         HX35/40-HX50-HX60/H3B-HX82-HX80

   1/2  3

       HX60 larger thrust collar/HX60 replaces 4LGK           Garrett TA45/51 270 degrees

1 - In all HX60 models, the standard thrust collar has been replaced by a larger diameter collar, which improves the high thrust load capability.

2 - In various H3B production models an older style 4LGK thrust bearing has been used. These have also been modified with a HX60 model thrust bearing and the larger thrust collar. Some machining work is required.

3 - Garrett TA45/TA51 270 degrees thrust bearing.

Also note, that most 270 degrees thrust bearings have only 3 thrust- and lubrication lands, compared to the 5 or 6 full circle lubrication- and thrust lands of the HX range thrust bearings. Furthermore the oil lubrication feed holes of the HX models have clearly larger diameters.

HX RANGE ‘LEFT HAND’ THREADED LOCKNUTS FOR IMPELLERS

Another point worth to mention is, that all HX range locknuts for compressor wheels are ‘left hand’ threaded.

With older types of turbochargers, where right hand threaded locknuts were used, there was a tendency to lock these with a higher torque, with the risk and sometimes the result that the thrust collar deformed, causing disturbance of the tolerances for the thickness of the oil films between the respective thrust parts.

Applying extra torque to left hand threaded locknuts is not advisable and should be done according to the specifications of the manufacturer.