(Outer ring) Outer diameter concentricity measuring device based on inner diameter

The (Outer Race) Inner Diameter Reference Outer Diameter Concentricity Gauge is a comparative measurement jig that quickly and repeatedly verifies the degree to which the outer diameter of the outer race component shares its center (concentricity/eccentricity) with the inner diameter of the outer race component.

Outer diameter concentricity is not a matter of the outer diameter itself (diameter), but rather the degree to which the inner and outer diameter centers coincide (the degree of axis overlap). An increase in this value can lead to eccentric rotation during assembly, increased runout, vibration/noise, and reduced service life. Therefore, it is considered a key management item that determines actual functional quality.

The measurement principle is to fix the center with the ID and read the OD eccentricity as displacement. First, an approved (good) part is used as a sample master to establish the jig's reference conditions. The inner diameter of the outer race to be measured is secured to the dedicated reference pin/centering structure (inner diameter reference part) to establish the center. Then, a dial gauge (or digital indicator) contact is placed on the outer diameter measurement part and the part is rotated (by hand or by rotating the part). The gauge reads the maximum-minimum value as it sways (rotates according to the jig structure). This maximum-minimum displacement (TIR) is used to quickly determine how much the outside diameter is eccentric (tendency for poor concentricity) with respect to the inside diameter.