Nsk Corporation

Yasushi Muto

Banda Noda

Yoshihiro Sato

Tatsunobu Momono

Takanori Miyasaka

Yingyi Wen

Masayuki Kanatsu

Osamu Yoshimatsu

An information terminal is configured to extract a predetermined frequency band from a waveform of a signal of a machine component detected by a vibration sensor, to compare an analyzed frequency component and a damaging frequency resulting from a damage of the machine component, and to diagnose abnormality of the machine component. The information terminal includes a database in which the damaging frequency resulting from the damage of the machine component is preserved as a converted damaging frequency obtained by converting the damaging frequency on a basis of a predetermined rotating speed of the machine component. The damaging frequency is provided by calculating the converted damaging frequency in the database by using an actual rotating speed of the machine component. Accordingly, it is possible to keep specifications of a machine component confidential without preserving the specifications of the machine component.

Information terminal and machine component diagnosis system

An abnormal noise detection method of a steering system is configured to detect an abnormal noise from the steering system. The steering system includes a column shaft configured to rotatably support a steering wheel and is configured to steer a wheel in response to rotations of the column shaft. The method includes measuring a sound from an end portion of the column shaft on a steering wheel-side by using a microphone arranged to face the end portion of the column shaft, and generating an abnormal noise detection signal due to the steering system from a sound signal to be output from the microphone.

Abnormal noise detection method of steering system and evaluation device of steering system

A surface shape evaluation method for a spherical body comprising the steps of: providing a support hole having a smaller diameter than the spherical body and having a curved bearing surface formed on its opening to have a curvature substantially equal to the curvature of the surface of the spherical body, providing a rotation drive arm for transmitting only a rotation component to the spherical body, providing a vibration sensor having a probe with a flat tip end, rotating the spherical body on a predetermined center axis and on the opening, such that one portion in the radial direction of the spherical body comes into contact with the curved bearing surface while the portion opposite to the one portion in the radial direction of the spherical body comes into contact with the tip end of the rotation drive arm, abutting the flat tip end of the probe of the vibration sensor to a surface portion of the spherical body located on a hypothetical flat surface which is orthogonal to the center axis and passes through the central point of the spherical body to detect the surface shape from the surface portion as vibration amounts, from which the results are through a sampling process and an adding and averaging process in harmonization with rotation velocity of the spherical body, and a frequency analysis process are evaluated as a numerical value e.g. of at least displacement.

Surface shape evaluation method and device for spherical body

A rolling bearing unit having undulation on the rolling surfaces of the rolling elements where the total value of the wave components having an even number of waves per circumference is smaller than the total value of the wave components having an odd number of waves per circumference, or having undulation on the inner ring raceway and outer ring raceway, where the undulation on at least one of the raceway is conditioned such that the maximum waviness amplitude among (nZ), (nZ+1) and (nZ -1) waves per circumference is smaller than the maximum waviness amplitude among (nZ+2) and more waves per circumference, where n is a positive integer and Z is the number of rolling elements, thereby making it possible to obtain a low-cost, high-performance rolling bearing in which the vibration characteristics of the rolling bearing are improved without having to increase the precision required for manufacturing the rolling elements and inner ring raceway and outer ring raceways.

Growing community of inventors

Fujisawa, Japan

Yasushi Muto