Nsk Corporation

Katsutoshi Matsuoka

Ikunori Sakatani

Shin Kumagai

Tomoyuki Yanagisawa

A revolution speed of ballsconstituting the outer side row is sensed by a revolution speed sensor. Also, a rotation speed of a hubis sensed by a rotation speed sensor. A speed ratio as a ratio between a revolution speed and the rotation speed is calculated based on a sensed signal of both sensors. When the axial load is changed and then the contact angles of the ballsare changed, the revolution speed is changed and in turn the speed ratio is changed. Therefore, the axial load is calculated based on a change of the speed ratio. Accordingly, the configurations that can be manufactured at a low cost and is able to sense the axial load applied between the huband the outer ringcan be realized.

Load-measuring device for rolling bearing unit and rolling bearing unit for load measurement

The x- and y-direction vibration components of radial vibration of a rotational shaft obtained by measurement from x and y directions are transformed into frequency sample values &lcub;X Y , k&equals;0, 1, . . . N&minus;1&rcub; by discrete Fourier transform. RMS amplitude values &lcub;2 (2 &pgr;/M)&verbar;, j&equals;0, 1, . . . M/2&minus;1&rcub; are calculated at azimuths &lcub;&thgr; &equals;2 &pgr;/M, j&equals;0, 1, . . . M/2&minus;1&rcub; corresponding to 0 to &pgr; on the basis of frequency sample values at frequency points &lcub;k , i&equals;1, . . . P&rcub; corresponding to specific frequencies &lcub;fi, i&equals;1, . . . P&rcub; of NRRO vibration components selected from the x- and y-direction frequency sample values obtained by the discrete Fourier-transform. RMS evaluation values A are selected from these RMS amplitude values.

APPARATUS AND METHOD FOR EVALUATING ROTATIONAL ACCURACY OF ROLLING BEARING AND ROLLING BEARING EVALUATED BY THE ROTATIONAL ACCURACY EVALUATION METHOD, AND APPARATUS AND METHOD FOR RADIAL VIBRATION OF ROTATING BODY AND ROTATION UNIT WITH ROTATING BODY EVALUATED BY THE RADIAL VIBRATION EVALUATION METHOD

Spherical surface inspection equipment which optically examines the nature of the surface of a sphere to be examined, is made up of light illumination member including a point of light source for emitting a luminous flux, at predetermined angle of spread in a specific direction which is disposed in such a way that the exit point of the luminous flux matches a first focal point, and a curved-face mirror whose mirror surface is defined by a predetermined inner surface area which forms a part of a curved surface obtained by rotating a specific curve around a specific axis including the first focal point and includes and extends through at least 180 degrees around the axis. The spherical surface inspection equipment also includes sphere-to-be-examined drive member which retains the sphere such that its center is brought in alignment with the second focal point, and which rotates the sphere about the axis of rotation along a specific half of the meridian included between the poles on the surface of the sphere opposite to the predetermined inner surface of the curved-surface mirror; and surface nature determination member which limits the light reflected from the sphere to only the light reflected from an area corresponding to a predetermined width between the half of the specific meridian included between the poles and detects the thus-limited reflected light through use of at least one photodiode; and which determines the nature of the surface of the sphere according to the result of such detection.

Spherical surface inspection equipment for optically examining the

A frequency spectrum analyzer wherein an input signal is subjected to A/D conversion, and the converted data is multiplied by a window function; and the thus processed signal is subjected to Discrete Fourier Transform; when a user specifies a desired frequency, the square root of the sum of the squares of amplitudes of a predetermined number m of spectral lines close to the frequency is calculated; and the calculated value is outputted as a Root-Mean-Square value (RMS) of the amplitude of the spectrum of the frequency.

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Kanagawa, Japan

Katsutoshi Matsuoka