Ntn Corporation

Tomoya Sakaguchi

Makoto Muramatsu

Takayuki Kawamura

Tatsuya Omoto

Eiichi Nakamizo

Mitsuo Sasabe

Hideyuki Tsutsui

Michio Hori

Mitsuo Kawamura

Shoichi Hioki

Norihide Sato

Junichi Hirata

Makoto Seki

Yukio Matsubara

Kazuyoshi Harada

Yasuhiko Sakakibara

Hikaru Ishida

Tomoaki Goto

Noriaki Miwa

Nobuyuki Ninoyu

Kouma Katou

Takakazu Kitagawa

Masayuki Kawakita

Hisamitsu Maeda

Naoto Shibuya

A hub bearingincluding an outer ringthat serves as a stationary side raceway ring, a hub wheeland an inner ringserving as a rotatable side raceway ring, ballsserving as a plurality of rolling elements disposed between a raceway surface of the stationary side raceway ring and a raceway surface of the rotatable side raceway ring, and grease that lubricates a rolling contact part between each of the raceway surfaces and the rolling elements. The surface roughness of at least one raceway surface selected from the raceway surface of the stationary side raceway ring and the raceway surface of the rotatable side raceway ring in the rolling contact part is 0.03 μm Ra or less.

Hub bearing

A condition monitoring system for a wind turbine includes: each sensor to sense a condition of equipment; a monitor device configured to generate a diagnosis parameter based on a detection result of each sensor; a data server configured to diagnose a failure of the equipment based on the diagnosis parameter; and a rotation angle sensor for sensing the nacelle's rotation speed. The data server is configured to correct the diagnosis parameter based on a sensed result of the rotation angle sensor, and diagnose whether the equipment has a failure by comparing the corrected diagnosis parameter with a predetermined threshold value.

Condition monitoring system and wind power generation system using the same

A tapered roller bearing () has a plurality of retainer segments () each having a pocket to house a tapered roller (), and arranged so as to be continuously lined with each other in a circumferential direction between an outer ring () and an inner ring (). The retainer segment () is formed of a resin containing a filler material to lower a thermal linear expansion coefficient. In addition, a clearance () is provided between the first retainer segment () and the last retainer segment () after the plurality of retainer segments () have been arranged in the circumferential direction without providing any clearance. Here a circumferential range (R) of the clearance () is larger than 0.075% of a circumference of a circle passing through a center of the retainer segment () and smaller than 0.12% thereof at room temperature.

Tapered roller bearing and main shaft support structure of wind-power generator using same

A vibration analysis method includes the steps of: inputting damage data of a rolling bearing; calculating, by a dynamics analysis program, a history of an exciting force occurring to the rolling bearing due to damage when a rotational shaft of the rolling bearing is rotated; calculating, by a mode analysis program, a vibration characteristics model of the bearing device; and calculating a vibration waveform at a predetermined position on the bearing device by applying to the vibration characteristics model the history of the exciting force calculated in the step of calculating a history of an exciting force.

Bearing device vibration analysis method, bearing device vibration analyzer, and rolling bearing condition monitoring system

A roller bearing comprises an outer ring, an inner ring, a plurality of rollers arranged between said outer ring and said inner ring; and a plurality of retainer segments having a plurality of column parts extending in a direction along a shaft so as to form a pocket for holding said roller. A connection part extends in a circumferential direction so as to connect the plurality of column parts, and continuously lined with each other in the circumferential direction between said outer ring and said inner ring, in which a corner of a circumferential end face is chamfered. Also provided is a spacer arranged between the circumferentially arranged first retainer segment and last retainer segment, wherein a chamfered part is provided at a corner of a circumferential spacer end face of the space. The roller bearing can be used in a main shaft support structure of a wind-power generator.

Roller bearing, retainer segment, spacer and main shaft support structure of wind-power generator

Frequency analysis units are configured to perform a frequency analysis of vibrations detected by vibration sensors, respectively. A natural frequency detection unit is configured to detect a natural frequency of a wind turbine in accordance with a direction of a nacelle, based on results of the frequency analysis. A change ratio calculation unit calculates a decrease ratio in the natural frequency detected by the natural frequency detection unit. An abnormality detection unit determines that an abnormality is present in the wind turbine if the decrease ratio in the natural frequency calculated by the change ratio calculation unit exceeds a threshold value.

Condition monitoring apparatus for wind turbine

A condition monitoring system for a wind turbine comprises: a sensor which senses a condition of a yaw bearing; a monitor device which generates a diagnosis parameter based on a detection result of the sensor; a sensor which senses a rotating angular velocity of a nacelle and that of a main shaft; and a data server which diagnoses a failure of the yaw bearing based on the diagnosis parameter. The data server diagnoses whether the yaw bearing has a failure, based on a variation of the diagnosis parameter from an initial value thereof when the nacelle has a rotating angular velocity within a non-zero, first prescribed range and the main shaft has a rotating angular velocity within a second prescribed range.

Condition monitoring system and wind power generation system comprising the same

Retainer segment for a roller bearing for supporting a main shaft of a wind-power generator

A roller bearing comprises an outer ring, an inner ring, a plurality of rollers arranged between the outer ring and the inner ring, and a plurality of retainer segments having a plurality of column parts extending in a direction along a shaft so as to form a pocket for holding the roller, and connection parts and extending in a circumferential direction to connect the plurality of column parts, and continuously lined with each other in the circumferential direction between the outer ring and the inner ring. The column part is positioned at an circumferential end of the retainer segment. Here, a circumferential outer side end face of the column part positioned at the end is flat, and a circumferential inner side end face of the column part positioned at said end is provided with a recess recessed in the circumferential direction to reduce the thickness of the column part.

Roller bearing, retainer segment of roller bearing for supporting main shaft of wind-power generator

An effective value operation unit calculates an effective value of a vibration waveform of a bearing, the vibration waveform being measured by using a vibration sensor. An envelope processing unit performs envelope processing on the vibration waveform measured by using the vibration sensor, thereby generating an envelope waveform of the vibration waveform. An effective value operation unit calculates an effective value of an AC component of the envelope waveform generated by the envelope processing unit. A diagnostic unit diagnoses an abnormality of the bearing based on the effective value of the vibration waveform calculated by the effective value operation unit and the effective value of the AC component of the envelope waveform calculated by the effective value operation unit.

Abnormality diagnostic device for rolling bearing, wind turbine generation apparatus and abnormality diagnostic system

A status monitoring system for accurately determining the contaminant water concentration in a lubricant oil used in a rolling device includes a contaminant water concentration monitoring device configured to monitor the contaminant water concentration in the lubricant oil. The contaminant water concentration monitoring device includes an electrostatic capacitance detector and an oil temperature measuring instrument, which are configured to detect the electrostatic capacitance and the oil temperature of the lubricant oil, respectively, and a water concentration calculation section configured to calculate the contaminant water concentration from the detected electrostatic capacitance and oil temperature in accordance with a predetermined rule.

Status monitoring system and status monitoring method for rolling device

The method for calculating rotational torque between inner and outer rings of a four point contact ball bearing assembly includes an individual torque calculation step for calculating the rotational torque for each of rolling elements and a total sum calculation step for determining the rotational torque. In the individual torque calculation step, data on a contact condition representative of the extent of approximation to the two point contact state or four point contact state is used. For the contact condition data, the four point contact ratio C, which is the ratio of surface pressure of one of respective maximum contact pressures Pand Pbetween two partial raceways in an inner ring or outer ring, which one is higher than the other of the maximum contact pressures Pand P, relative to a surface pressure of the other of the maximum contact pressures, is used.

Torque calculation method, calculation device, and calculation program for four-point contact ball bearing

Roller bearing, retainer segment, spacer and main shaft support structure wind-power generator

When it is determined that a blade is rotating, a control device operates a braking device, and acquires a rotation angle (first rotation angle) from a rotation angle sensor. Then, the control device reverses a nacelle and acquires again a rotation angle (second rotation angle) from the rotation angle sensor. Then, the control device determines whether or not the difference between the first rotation angle and the second rotation angle is greater than a threshold value. When it is determined that the rotation angle difference is greater than the threshold value, the control device determines that a gear or a bearing of a gearbox is worn out.

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Kuwana, Japan

Tomoya Sakaguchi