Abstract: A ball screw device that is capable of transmitting an axial load between the screw portion and the holding member without shortening the life of the ball screw device is provided. The stopper 5 is externally fitted to the fitting shaft portion 10 of the screw shaft 2 having an outer diameter smaller than that of the screw portion 9, which is provided adjacent to one side in the axial direction of the screw portion 9 provided with the shaft-side ball thread groove 12 on the outer-circumferential surface, so as not to be able to rotate relative to each other. The driving member 6 which is a holding member is arranged adjacent to the one side in the axial direction of the stopper 5 such that the stopper 5 is held in the axial direction between the driving member 6 and the screw portion 9. An axial load is transmitted between the driving member 6 and the screw portion 9 without applying a moment to the stopper 5.

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 motor control device includes a third harmonic calculation unit configured to calculate a first third harmonic on a basis of an average value between a voltage command value of a maximum phase with a maximum duty ratio and a voltage command value of a minimum phase with a minimum duty ratio among three-phase voltage command values; an amplitude calculation unit configured to calculate an amplitude of the three-phase voltage command values; a third harmonic conversion unit configured to convert the first third harmonic into a second third harmonic on a basis of the first third harmonic and the amplitude; a correction unit configured to correct the three-phase voltage command values by subtracting the second third harmonic from the three-phase voltage command values.

Abstract: Provided are a method for assessing hydrogen environment severity of a rolling device during operation and a method for predicting likelihood that white structure damage occurs to the rolling device as a result of operation. A hydrogen environment severity assessment method is a method for assessing, among operating conditions of a rolling device including two rolling members coming into rolling contact with each other and having at least one of the two rolling members being a steel rolling member, hydrogen environment severity, the hydrogen environment severity being an index representing magnitude of influence exerted by hydrogen.

Abstract: The ball screw device has a nut having a guide concave groove on the outer-circumferential surface capable of engaging with a rotation restraining member in the circumferential direction, a housing provided with an insertion hole having a retaining concave groove on the inner-circumferential surface capable of engaging with the rotation restraining member in the circumferential direction, the rotation restraining member configured by a shaft-shaped member extending in the axial direction, the rotation restraining member having an outside portion in the radial direction arranged inside the retaining concave groove and an inside portion in the radial direction arranged inside the guide concave groove, so as to be able to slide in the axial direction.

Abstract: Provided are an oil receiver (20) having an annular recess portion (52) which faces an entire circumference of an outer circumferential edge of a concave spherical portion (36), and a guide member (21) which guides lubricating oil, which has flowed out from a spherical engagement portion between a convex spherical portion (24) and a concave spherical portion (36), toward an annular recess portion (52).

Abstract: A magnetic sensor arranged close to a component of a rolling machine element measures magnetic flux density in the axial direction and/or radial direction of the component, then the amount of change in magnetic flux density is calculated based on a reference magnetic flux density corresponding to the magnetic flux density before the start of use of the component, and the progression of fatigue of the rolling machine element is determined from the amount of change.

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: 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: An assembly of a gear and rotating shaft, comprising: a gear having teeth on an outer peripheral surface thereof, and a center hole penetrating in an axial direction through a center portion thereof; and a rotating shaft including a serrated shaft portion having a male serration portion on an outer peripheral surface thereof and press-fitted into the center hole, and a guide shaft portion provided adjacent to one side in the axial direction of the serrated shaft portion and having an outer diameter capable of being internally fitted in the center hole with a clearance fit.

Abstract: A two-speed transmission includes: an input member; an output member; a rotating member; a first engaging device switching engagement between first and second friction plates to switch the input member and the rotating member to an integrally rotating state or a relatively rotating state; a second engaging device switching the rotating member to a rotatable or non-rotatable state; an elastic biasing means applying a force pressing the first and second friction plates; a pressing device releasing the pressing force; a first bearing between the elastic biasing means and the pressing device; a second bearing between the rotating member and the pressing device or the fixed portion; and a planetary speed reduction mechanism having a sun element connected to the input member or the rotating member, a carrier connected to one of the input member or the rotating member and the output member, and a ring element connected to the other.

Abstract: An assist mechanism includes: an electric motor; a shaft-shaped member in which a worm engaged with a worm wheel is formed; and a coupling that couples an output shaft of the electric motor and the shaft-shaped member to each other. The smallest rotation order among rotation orders of the electric motor and a rotation order of the worm are prime to each other. The smallest rotation order among the rotation orders of the electric motor and a rotation order of the coupling are prime to each other. The rotation order of the worm and the rotation order of the coupling are prime to each other. The rotation order of the worm is 3. The rotation order of the coupling is 5 or 7.

Abstract: A wireless communication system includes a wireless sensor provided inside a metal housing; a receiver provided outside the metal housing to receive radio waves from the wireless sensor; and a passive repeater provided between the inside and the outside of the metal housing. The passive repeater includes a receiving antenna provided inside the metal housing and a transmitting antenna provided outside the metal housing. The receiving antenna of the passive repeater and the transmitting antenna of the passive repeater are electrically connected through a hole formed in the metal housing.

Abstract: Provided is a rolling bearing using a retainer, particularly a highly reliable retainer in which dimensional stability required for a retainer of an outer ring guide type, ductility required for a crown-type retainer, improvement in adhesion of grease with a poly-?-olefin oil or the like as a base oil, and deformation prevention at a high speed can be achieved. The rolling bearing includes at least an inner ring 1, an outer ring 3, a synthetic resin retainer 9, and a rolling element 7, in which the synthetic resin retainer 9 is formed of a polyamide resin composition including polyamide 410 and a reinforcing fiber material with a content of 0% by weight to 40% by weight.

Abstract: A groove curvature radius ratio Ri of the inner ring raceway groove to a ball diameter is 54% to 58%, a groove curvature radius ratio Ro of an outer ring raceway groove of an outer ring to the ball diameter is 51% to 58%, and Ri?Ro?0 points. At least an inner ring raceway groove of an inner ring has a maximum surface pressure of 4.7 GPa to 6.0 GPa when a sum of permanent deformation amounts of the ball and the inner ring raceway groove at a center of a contact portion between a ball of an angular ball bearing and the inner ring raceway groove is 1/10,000 of the ball diameter. Accordingly, it is possible to provide the angular ball bearing that can reduce the heat generation amount, and that can reduce the damage caused by the external impact load in the stationary state.

Abstract: To provide a nut that can suppress increase in the number of components. The nut according to the present disclosure includes a nut main body and a circulation component. The nut main body includes a housing part having a bow shape when viewed from an axial direction, a seat surface, a through hole, and a pair of side surfaces. The circulation component includes a circulation component main body, two arm parts extending toward both sides in a seat surface direction from the circulation component main body, ribs projecting from the respective two arm parts, and caulking parts obtained by caulking the ribs. Recessed parts that the caulking parts enter are disposed on the pair of side surfaces. A ball passage is disposed in the circulation component main body.

Abstract: There is provided a toroidal continuously variable transmission capable of ensuring processability and conveyability of a power roller inner ring while reducing oil leakage from an inner end surface of the power roller inner ring and a decrease in rigidity of the power roller inner ring. A power roller 40 of the toroidal continuously variable transmission includes a power roller inner ring 50 sandwiched between both disks 1 and 2, a power roller outer ring 60 that is provided in a trunnion 35 and rotatably supports the power roller inner ring 50, and an inner ring hole 52 provided in the power roller inner ring 50 so as to extend in an axial direction of the power roller inner ring 50, in which an end surface hole 58 communicating with an inner ring hole 52 is provided in an inner end surface 54 of the power roller inner ring 50, and the end surface hole 58 is closed by a closing member 80 separate from the power roller inner ring 50.

Abstract: A linear motion actuator has a ball screw device having a screw shaft, a nut, and a plurality of balls, a piston mounted on one end of the screw shaft, and a stroke limiting mechanism setting an operation starting point in time of the screw shaft toward a first direction pointed by the one end. The nut has one end face directed to the first direction and a protruding part protruding from the one end face.

Abstract: A steering shaft includes an inner shaft including first tooth parts, an outer shaft including second tooth parts, and a resin layer. The resin layer includes a plurality of thick film parts and at least four thin film parts. Each thick film part is disposed with a gap from one of the second tooth parts, and each thin film part contacts both one of the first tooth parts and one of the second tooth parts. At a section orthogonal to a central axis of the inner shaft, the thickness of each thin film part is smaller than the thickness of each thick film part.

Abstract: A ball bearing includes an inner ring having a raceway surface, an outer ring having a raceway surface, a plurality of rolling elements rollably disposed between the raceway surface of the inner ring and the raceway surfaces of the outer ring, and a resin cage configured to retain the plurality of rolling elements between the inner ring and the outer ring. The cage is a crown type cage having an annular base portion and a plurality of pockets formed in an axial end face of the annular base portion, in which the pockets retain the rolling elements. An axial distance between an axial position of a center of gravity of the cage and a curvature center of a spherical or cylindrical inner surface of each of the pockets is 0.6 or more times a radius of curvature of the inner surface. A hybrid vehicle transmission has this ball bearing.