Abstract: A measurement method for measuring a state of a device in which lubrication between components is performed by a lubricant, the method including: applying an AC voltage to an electric circuit formed of the components to be lubricated by the lubricant; measuring an impedance of the electric circuit and a phase angle at the time of applying the AC voltage; and deriving an oil film thickness and a metal contact ratio between the components based on the impedance and the phase angle, in which the oil film thickness and the metal contact ratio between the components are derived by using a calculation formula in which a capacitance of the contact region is defined by a probability density function of a surface roughness between the components in a contact region between the components.

Abstract: A water intrusion detection method for detecting intrusion of water into a lubricant in a device in which a plurality of portions are lubricated using the lubricant, includes: measuring an impedance of an electric circuit including the plurality of portions by applying an AC voltage to the electric circuit while sweeping a frequency; and detecting the intrusion of water into the lubricant by comparing characteristics indicated by a real part and an imaginary part of an impedance measured in a state in which water is not mixed into the lubricant with characteristics indicated by a real part and an imaginary part of the impedance measured by the measurement.

Abstract: A lubricant supply control method for a device that lubricates a plurality of portions using a lubricant includes: measuring an impedance of an electric circuit including the plurality of portions by applying an AC voltage to the electric circuit; deriving an oil film thickness and a breakage rate of an oil film between the plurality of portions based on the measured impedance; and controlling at least one of a supply amount and a supply timing of the lubricant to the device based on the derived oil film thickness and breakage rate of the oil film so that a lubrication state between the plurality of portions becomes a predetermined lubrication state.

Abstract: A state diagnosis method for a bearing device including a plurality of rolling bearings which are electrically connected, the method includes measuring an impedance of the plurality of rolling bearings as a whole by applying a voltage to the plurality of rolling bearings by an AC power supply while changing a frequency, deriving an impedance of each of the plurality of rolling bearings by fitting the impedance measured in the measurement step based on an equivalent circuit in which the plurality of rolling bearings are connected in series, and diagnosing a state of each of the plurality of rolling bearings based on the impedance of each of the plurality of rolling bearings derived in the derivation step.

Abstract: A detection method for detecting a state of a bearing device including a tapered roller bearing includes applying an AC voltage to an electric circuit including an outer member, an inner member, and a plurality of rollers in a state in which a predetermined load is applied to the bearing device; measuring an impedance and a phase angle of the electric circuit when the AC voltage is applied; and based on the impedance and the phase angle, deriving an oil film thickness and a metal contact ratio between the inner member and the plurality of rollers or between the inner member and at least one of the plurality of rollers by using a calculation formula corresponding to the electric circuit.

Abstract: A detection method for detecting a state of a bearing device including a slide bearing includes: applying an AC voltage to an electric circuit including the slide bearing and a rotation shaft; measuring an impedance and a phase angle of the electric circuit when the AC voltage is applied; and deriving an oil film thickness and a metal contact ratio between the slide bearing and the rotation shaft based on the impedance and the phase angle, in which the oil film thickness and the metal contact ratio are derived by using a calculation formula corresponding to an electric circuit constructed by a line contact generated between the slide bearing and the rotation shaft.

Abstract: There is provided a state detection method for detecting an oil film state according to a lubricant in a device configured to lubricate a plurality of parts with the lubricant, the method including: a measurement step of measuring impedance and a phase angle of an electric circuit by applying an AC voltage to the electric circuit configured with the plurality of parts while changing a frequency; and a derivation step of deriving an oil film thickness according to the lubricant and a parameter indicating an electrical characteristic according to the oil film thickness, based on a relative dielectric constant at a high frequency limit of the lubricant defined based on a composition of the lubricant, and the impedance and the phase angle measured in the measurement step.

Abstract: A detection method for detecting a state of a bearing device including an outer member, an inner member, and a plurality of rolling elements, the detection method including: applying an alternating current voltage to an electric circuit including the outer member, the rolling element, and the inner member while a predetermined load is applied to the bearing device; measuring an impedance and a phase angle of the electric circuit applied with the alternating current voltage; and deriving an oil film thickness and a metal contact ratio between the inner member and the plurality of rolling elements or between the inner member and at least one of the plurality of rolling elements based on the impedance and the phase angle.

Abstract: A detection method for detecting a state of a bearing device including a plurality of rollers and first and second members configuring rolling surfaces of the rollers, the method including: applying an AC voltage to an electrical circuit configured by the rollers and the first and second members; measuring an impedance and a phase angle of the electrical circuit when applying the AC voltage; and deriving, based on the impedance and the phase angle, an oil film thickness and a metal contact ratio in at least one of between the first member and the rollers and between the second member and the rollers, in which the oil film thickness and the metal contact ratio are derived using a calculation equation corresponding to an electrical circuit configured by a line contact occurring between a roller and at least one of the first and second members in the bearing device.

Abstract: A method for diagnosing a rolling device (10) including an outer member (1), an inner member (3), and rolling elements (5) includes: applying an AC voltage to an electric circuit including the outer member (1), the rolling elements (5), and the inner member (3); measuring an impedance and a phase angle of the electric circuit when the AC voltage is applied; and measuring a dielectric constant of a lubricant at least one of between the outer member (1) and the rolling elements (5) and between the inner member (3) and the rolling elements (5) based on the measured impedance and the measured phase angle.

Abstract: There is provided a state detection method for detecting an oil film state according to a lubricant in a device configured to lubricate a plurality of parts with the lubricant, the method including: a measurement step of measuring impedance and a phase angle of an electric circuit by applying an AC voltage to the electric circuit configured with the plurality of parts while changing a frequency; and a derivation step of deriving an oil film thickness according to the lubricant and a parameter indicating an electrical characteristic according to the oil film thickness, based on a relative dielectric constant at a high frequency limit of the lubricant defined based on a composition of the lubricant, and the impedance and the phase angle measured in the measurement step.

Abstract: A condition diagnosis method includes: a measurement step of measuring relative dielectric constant of a lubricant by applying a voltage to the lubricant while changing a frequency from an AC power source; a derivation step of deriving parameters indicating electrical properties of the lubricant by applying the relative dielectric constant measured in the measurement step to a theoretical formula; and a diagnosis step of diagnosing a condition of the lubricant using the parameters.

Abstract: A detection method for detecting a state of a bearing device including an outer member, an inner member, and a plurality of rolling elements, the detection method including: applying an alternating current voltage to an electric circuit including the outer member, the rolling element, and the inner member while a predetermined load is applied to the bearing device; measuring an impedance and a phase angle of the electric circuit applied with the alternating current voltage; and deriving an oil film thickness and a metal contact ratio between the inner member and the plurality of rolling elements or between the inner member and at least one of the plurality of rolling elements based on the impedance and the phase angle.

Abstract: Provided is a temperature derivation method for deriving an oil film temperature of a lubricant in a device, the temperature derivation method including a measurement step of measuring a dielectric constant of the lubricant by applying an alternating voltage while changing a frequency to an electric circuit configured by the device, a derivation step of 5 applying the dielectric constant measured in the measurement step to a theoretical formula to derive a relaxation time of the lubricant, and a calculation step of calculating the oil film temperature by using the relaxation time.

Abstract: The rolling bearing of the present invention is lubricated with a lubricant composition which contains a fatty acid metal salt, a metal dithiocarbamate, a phosphorous-type additive, and a basic additive, and which has a total acid value of 3.7 mgKOH/g or more. The rolling bearing makes it possible to further improve anti-fretting performance, and to reduce a decrease in fretting resistance even when used under the circumstance that fluorine-type grease penetrates into the bearing using urea-type grease.

Abstract: A rotor of a rotary electric machine includes a rotor core having a magnet insertion hole and a permanent magnet. A magnet insertion hole has an inner diameter side wall surface and an outer diameter side wall surface. A permanent magnet has an inner diameter surface and an outer diameter surface. The rotor further includes a foam adhesive sheet provided at least either between the inner diameter surface and the inner diameter side wall surface or between the outer diameter surface and the outer diameter side wall surface. The foam adhesive sheet includes a foam layer and an adhesive layer stacked in a radial direction. The foam layer is closely fixed to the permanent magnet. The adhesive layer faces the magnet insertion hole. The foam layer is foamed, the adhesive layer closely contacts with the magnet insertion hole, and the permanent magnet is fixed to the magnet insertion hole.

Abstract: A lubricant composition according to the present invention contains a fatty acid metal salt, a metal dithiocarbamate, and an additive having an effect of increasing an acid value of the lubricant composition, whereby fretting resistance performances are further improved.

Abstract: A method for diagnosing a rolling device (10) including an outer member (1), an inner member (3), and rolling elements (5) includes: applying an AC voltage to an electric circuit including the outer member (1), the rolling elements (5), and the inner member (3); measuring an impedance and a phase angle of the electric circuit when the AC voltage is applied; and measuring a dielectric constant of a lubricant at least one of between the outer member (1) and the rolling elements (5) and between the inner member (3) and the rolling elements (5) based on the measured impedance and the measured phase angle.

Abstract: A stator of a rotating electric machine includes a stator core provided with a plurality of slots along a circumferential direction, coils of a plurality of phases distributedly wound around the stator core via the plurality of slots, and an insulating paper disposed between the slot and the coil. The insulating paper has an adhesive portion which fixes the coil to the stator core and a part of the coil of each phase is fixed to the stator core by the adhesive portion.

Abstract: A rotor of a rotary electric machine includes a rotor core having a magnet insertion hole and a permanent magnet. A magnet insertion hole has an inner diameter side wall surface and an outer diameter side wall surface. A permanent magnet has an inner diameter surface and an outer diameter surface. The rotor further includes a foam adhesive sheet provided at least either between the inner diameter surface and the inner diameter side wall surface or between the outer diameter surface and the outer diameter side wall surface. The foam adhesive sheet includes a foam layer and an adhesive layer stacked in a radial direction. The foam layer is closely fixed to the permanent magnet. The adhesive layer faces the magnet insertion hole. The foam layer is foamed, the adhesive layer closely contacts with the magnet insertion hole, and the permanent magnet is fixed to the magnet insertion hole.