Radial Bearing Damage 2017-12-14T16:31:27+00:00

Project Description

Radial Crash

Radial crashes are the most common form of air bearing and dicing spindle failures. In a dicing, back grinding or other type of air bearing the rotating shaft is “floating” on a cushion of air. This allows for super precise rotation. However, when the air supply is insufficient our when forces exceed the ability of the air cushion to support the shaft, it can contact the bearing journal. This is a crash.

These crashes damage the radial bearing surfaces and jets. They can be caused by excessive feed-rate, mis-alignment, improper program input and contamination in the spindle air supply.  HST has developed several technics for restoring radial bearing to like new condition regardless of the cause of the crash.

Air Bearing spindle repair and rebuild_radial bearing

Left Photo: Radial Bearing damage resulting from a hard crash.
Right Photo: Radial Bearing repair result of HST expertise

When the spinning shaft contacts the radial bearing it can result in galling and damage to the bearing surface area. The crash can also cause material to fill in and damage or clog the bearing jets. Conversely, clogged jets can result in a radial crash by reducing the lift.

The photo below is a closer look at the above left photo. It shows a crash that was the result of excessive feed rate. The spinning steel shaft rubbed and galled the softer brass material. The damage is obvious.

Air Bearing spindle repair and rebuild_clogged journal jets_radial bearing

Somewhat less obvious is the material clogging the journal jets. Often these repairs require the removal of the axial bearing and replacement of journal jets.

Crashes can also occur when contamination in the spindle air results in clogged journal jets. This results in loss of lift and allows the spinning shaft to contact the bearing surface.

The journal jets on this radial bearing became clogged over time. Apparently there was some moisture in the spindle supply air that allowed mineral deposits of some type to actually grow in the jet orifices. In time the jets became so clogged that the airflow could no longer support the rotating shaft.  We had to replace most of the jets.

Air Bearing spindle repair and rebuild_radial bearing_clogged jet

Left Photo: We removed this radial bearing from the housing to repair clogged journal jets.
Right Photo: Clogged journal jet magnified 200X.

Crashes can result in lost production. However, HST can quickly repair damaged caused by crashes and get you back up and running in just a few days.