Design Principles

The design of the adjacent construction is essential for the performance of AXRY-NGS bearings. Particular attention must be paid to the accuracy of the connection surfaces, as deviations in the connection areas affect the accuracy of the roller bearing and the performance of the axis system. The recommended tolerances must not be exceeded.

Press Fits

An excessively tight fit increases the radial preload, leading to the following effects:

Increases

  • Raceway surface pressure
  • Bearing friction
  • Wear

Reduces

  • Maximum speed
  • Bearing life

Clearance Fit

When a rotating bearing ring lacks full surface support, the axis of rotation may shift relative to the worktable axis. When the outer ring rotates, the same applies to the clearance fit between the outer diameter and the worktable.

Warning

Clearance between the fitting surface and the bearing bore causes a shift of the rotation center. An inner ring without support or with insufficient support leads to undefined operating conditions, such as vibration, radial runout errors and repeatability positioning errors.

Clearance fit eccentricity diagram
Eccentricity caused by a clearance fit

Intentional Clearance (Bewusstes Spiel)

An intentional clearance fit to compensate for ring expansion is feasible, but requires:

  • Precise knowledge and control of the temperature of each ring
  • Attention to roundness errors and shift of the rotation center

Min. Wall Thickness of the Table

To ensure sufficient rigidity and support, the worktable structure should meet the following minimum wall thickness requirements:

Wall thickness dimension diagram
Definition of wall thickness and passage dimensions
Legend
  • Min. wall thickness: Minimum thickness of the worktable housing bore wall (mm)
  • Max. passage: Maximum permissible passage dimension of the worktable housing bore (mm)
Bearing Size Min. Wall Thickness [mm] Max. Passage [mm]
AXRY 120-NGS (-SBI) 19 82
AXRY 200-NGS (-SBI) 22 156
AXRY 260-NGS (-SBI) 26 209
AXRY 325-NGS (-SBI) 27 271
AXRY 395-NGS (-SBI) 27 340
AXRY 460-NGS (-SBI) 30 400
AXRY 580-NGS (-SBI) 36 508
AXRY 650-NGS (-SBI) 45 560

Related Sections

ESC