Sugawara Labs Bearing Inspection Systems: Ball wavimeter

SUGAWARA Roundness measurement device BWM-102 and SWA-31

Makes high-speed, high-precision measurements of the surface waviness of a rotating ball.

Sugawara Ball Wavimeter03The ball wavimeter measures surface waviness and the roundness of a ball bearing in the manner required for practical applications. A ball is mounted on the front end of the spindle and the velocity sensor is pressed against the ball to measure vibration velocity. Waviness is obtained as a value for vibrations per rotation. Roundness is evaluated by removing the spindle’s vibration component from the value obtained for waviness.


Ball Wavimeter ftrs&msrmnt


Sugawara Ball Wavimeter02

graphic data display

For download the full Bearing Inspection System brochure please click here

StructurewvmtrWaviness is a surface condition. Vibrations in a rotating bearing are known to be closely linked to the waviness along the circumferential surfaces of bearing components, including the inner ring, outer ring, and ball/roller. Waviness in a circumferential surface refers to fluctuations in the radii (radii from axis to surface). The amplitude of these fluctuations, however, has no correlation with absolute radii. In the bearing component manufacturing process, waviness in circumferential surfaces must be measured and controlled to maintain adequate bearing quality.

Waviness is measured either by fixing the workpiece and rotating the sensor or by fixing the sensor and rotating the workpiece. We use the latter method. Waviness is evaluated based on the value obtained after passing through a band-pass filter. The lower area of the band contains the evaluation of the shape, while the higher area contains evaluations of roughness. Various bands are used according to the intended bearing application. The following units are used to quantify waviness:

?Wcla: Micron Wcla
Mean value of waviness displacement in ?m
?m: Micro meter
RMS value of waviness displacement in ?m
?inch: Micro inch
RMS value of waviness displacement in ?inch
?PC: Mu PC
Integrated absolute values of waviness displacement in ?m
?m/rad: Micrometer per radian
RMS value for waviness displacement differentiated with respect to central angle


Yoichi MORI – Group Leader, The Export Sales Group
Sugawara Laboratories Inc.
8-2 Minami-Kurokawa, Asao-ku, Kawasaki-shi,
Kanagawa, Japan  215-0034
Tel: +81-44-989-7320
Fax +81-44-989-7338
Email: [email protected]