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Absolute Angle Measuring System MA

Bearings with Absolute Angle Measuring System

General

With the purely inductive measuring system, a maximum system accuracy of up to ±1 μm arc length can be achieved.

The measuring system consists of a solid measuring ring with absolute code together with a measuring head containing the sensor and the evaluation electronics. Depending on requirements, single-head or multi-head scanners can be used. The measuring ring is mounted directly on the bearing inner ring.

The integrated measuring system is available for sizes 150 to 650. For some sizes, the overall height is greater than that of the standard bearing without a measuring system (see product tables). The measuring head is mounted directly on the outer ring and can be installed radially or axially. When mounted radially, the air gap is adjusted via the housing diameter of the outer ring, so no complex measurement gap setting is required.

Characteristics

Size and Encoding

  • Available in sizes 150 to 650 mm
  • Absolute encoding

Measuring Head

  • Single-head and multi-head scanners available
  • Multi-head scanning eliminates eccentricity and radial runout errors

Environmental Performance

  • Dirt resistance IP67
  • Resistant to magnetic interference fields
  • Operating temperature -10°C to +100°C

Control System Integration

  • Suitable for high-speed applications
  • Supports most CNC control system interfaces
  • Direct cooperation with AMO for rapid connection

Absolute System Advantage: The position is known immediately on power-up, with no reference travel required. The system continuously provides constant absolute position information to the control system.

Single-Head Measurement (Axial)

AXRY-MA Single-Head Measurement Diagram
Component Legend
  • 1: AXRY-MA — Bearing with measuring ring
  • 2: Measuring Head — Axially mounted inductive measuring head
No. Component Description
1 AXRY-MA Bearing with measuring ring
2 Measuring Head Axially mounted inductive measuring head

Double-Head Measurement (Radial)

AXRY-MA Double-Head Measurement Diagram
Component Legend
  • 1: AXRY-MA — Bearing with measuring ring
  • 2: Measuring Head — Radially mounted inductive measuring head
  • 3: AMO Evaluation Electronics (exact model to be confirmed with AMO)
No. Component Description
1 AXRY-MA Bearing with measuring ring
2 Measuring Head Radially mounted inductive measuring head
3 AMO Evaluation Electronics Multi-head system signal processing unit (exact model to be confirmed with AMO)

Radial Mounting Advantage: The measuring head is mounted on the housing surface of the bearing outer ring. This means the complex air gap adjustment between the measuring head and the measuring ring is no longer required.

Recommendation Distance Plates for Absolute Measuring Heads

If you want to mount the absolute measuring head directly onto the bearing outer ring, a distance plate is required. M4 threads at a spacing of 51 mm are already present on the bearing outer ring. These threads are suitable for both the absolute measuring head and the distance plate mounting.

For the absolute measuring head to measure at the correct position, the distance DP-H must be adjusted using the distance plate.

MA Distance Plate Dimension Diagram - DP-H Definition

DP-H: Distance plate height (used to adjust the axial distance between the measuring head and the measuring ring)

Column Legend
  • Bearing Model: AXRY series model
  • Size Range: Applicable nominal bearing bore (mm)
  • DP-H: Distance plate height (mm); "not required" means the measuring head can be mounted directly without a distance plate
Bearing Model Size Range DP-H (mm)
AXRY 180–395 Distance plate not required
AXRY 460 3
AXRY 580 3
AXRY 650 15

Note: For AXRY sizes 180–395, the absolute measuring head can be mounted directly without a distance plate.

MA vs MI System Comparison

The following comparison is compiled from the descriptions on the individual official pages (editorial compilation, not an official original comparison table).

Column Legend
  • MA: Absolute angle measuring system (Absolute)
  • MI: Incremental angle measuring system (Incremental)
  • Measuring ring height: Incremental (MI) 10 mm, Absolute (MA) 14 mm
  • Maximum accuracy: MA source — official MA page; MI source — official MI page
Characteristic MA (Absolute) MI (Incremental)
Maximum Accuracy ±1 μm arc length ±2 μm arc length
Position on Power-up Immediately known Reference travel required
Measuring Ring Height 14 mm 10 mm
Distance Plate Requirement Only large sizes (460/580/650) Required for all sizes
Radial Mounting Air gap adjusted via the outer ring housing diameter, no complex setup required Distance plate required
ESC