Why do many shafts use one locating bearing position and one non-locating position?

LILY Bearing | 2026-10-28

Best answer

Assign the axial tasks to specific support positions

JTEKT describes a common arrangement in which one bearing position locates the shaft axially and another accommodates expansion or contraction.

Both positions may still provide radial support. The distinction is about the permitted axial movement and load path, not about one bearing being loosely installed or unimportant. Movement may occur within a suitable bearing design or at a deliberately selected interface. The arrangement must also preserve the support and retention required under load. Marking one end “floating” on a drawing is incomplete unless the reviewer can identify where movement occurs, how much is available and which position reacts the relevant axial forces.

JTEKT: Selection of bearing arrangement

Draw an axial movement map before selecting the details

List the shaft, each bearing ring, the housing and the features that restrain them axially.

Then show the intended movement path during heating and cooling. For a two-support shaft, identify the locating position and ask whether the other position's actual bearing and seat arrangement permit the required relative movement. Include seals, covers and shoulders that may unintentionally block it. Do not automatically loosen an outer-ring fit to create float: the load-direction and retention requirements also need to remain satisfied. The map is a way to check the design's intent against the assembled parts before accepting a bearing or housing substitution.