Abstract: An optical system (LS) includes lenses (L22,L23) satisfying the following conditional expressions, ndLZ+(0.01425×?dLZ)<2.12, and ?dLZ<35.0, where ndLZ: a refractive index of the lens with reference to d-line, and ?dLZ: Abbe number of the lens with reference to d-line.

Abstract: There are provided a piezoelectric body of ytterbium-doped aluminum nitride, having a greater piezoelectric coefficient d33 or g33 than those not doped with ytterbium, and a MEMS device using the piezoelectric body. The piezoelectric body is represented by a chemical formula Al1-xYbxN where a value of x is more than 0 and less than 0.37 and having a lattice constant ratio c/a in a range of 1.53 or more and less than 1.6. The piezoelectric body with such a configuration has a greater piezoelectric coefficient d33 or g33 than those not doped with ytterbium.

Abstract: A damper device includes a first rotor, a second rotor, an elastic coupling part elastically coupling the first and second rotors in a rotational direction, and a hysteresis generating mechanism. The hysteresis generating mechanism generates a hysteresis torque and includes a friction member. The friction member is configured to make frictional contact with the first or second rotor. The friction member does not make frictional contact with the first and second rotors in a first torsion angular range where torsion is caused from a neutral condition to a first side and a second side in the rotational direction. The friction member makes frictional contact with the first or second rotor so as to generate a hysteresis torque in a second torsion angular range exceeding the first torsion angular range. The friction member is set in a neutral position by actuation of the elastic coupling part in the neutral condition.

Abstract: Provided is a scandium-doped aluminum nitride with nitrogen polarity. The nitride material is represented by the chemical formula ScXMYAl1-X-YN. M is at least one or more elements among C, Si, Ge, and Sn, X is greater than 0 and not greater than 0.4, Y is greater than 0 and not greater than 0.2, and X/Y is less than or equal to 5. The nitride material has piezoelectricity with a polarization direction of nitrogen polarity opposite to the direction of thin film growth.

Abstract: A torque limiter includes a first side plate, a second side plate, a friction disc, a pressure plate, and a biasing member. The first side plate includes an attachment surface. The attachment surface faces in an axial direction so as to be attached to a flywheel. The second side plate has a smaller outer diameter than the outer diameter of the first side plate. The second side plate is disposed so as to not overlap the attachment surface as seen in an axial direction. The second side plate is attached to the first side plate.

Abstract: A damper device includes a damper unit and a torque limiter unit. The damper unit includes first and second plates each including a plurality of window portions, a hub flange including a plurality of window holes, and a stopper mechanism. The first plate includes an engaging portion and a fixing portion fixed to the second plate. The engaging portion and the fixing portion are disposed radially outside the plurality of window portions. The hub flange includes a protrusion disposed circumferentially between and radially outside adjacent two of the plurality of window holes. The stopper mechanism is configured to be actuated by contact of the protrusion with the engaging portion. A fixation member, by which the first plate and the torque limiter unit are fixed, is disposed circumferentially between adjacent two of the plurality of window portions as seen in a direction along a rotational axis.

Abstract: [Problem] There is provided an exhaust system capable of sufficiently exhausting a fuel leakage gas leaked from a marine internal combustion engine without diffusing the fuel leakage gas into an engine room. [Solution] An exhaust system according to an aspect of the present disclosure includes: an exhaust duct provided above a marine internal combustion engine installed in an engine room of a ship; and a suction fan that sucks a fuel leakage gas leaking from the marine internal combustion engine into the inside of the exhaust duct from an engine upper unit side of the marine internal combustion engine. The exhaust duct exhausts the fuel leakage gas sucked by the suction fan to the outside of the engine.

Abstract: A damper device includes a torque limiter unit, a damper unit, and a positioning structure. The torque limiter unit includes a damper cover fixed to a surface of a flywheel on a first side of the flywheel in an axial direction. The damper unit is disposed such that an outer peripheral end thereof is located on a second side of an inner peripheral end of the damper cover in the axial direction. The damper unit transmits mechanical power together with the flywheel therebetween. The positioning structure radially sets the damper unit in place with respect to the torque limiter unit by making an outer peripheral surface of a core plate of a friction disc contactable with an inner surface of the damper cover of the torque limiter unit. The damper device is intended to inhibit displacement in radial position of a damper unit with respect to a torque limiter unit.

Abstract: A damper device includes a first rotor, a second rotor, and an elastic coupling part elastically coupling the first and second rotors in a rotational direction. The elastic coupling part includes first and second elastic members that are each initially disposed in a compressed state in a neutral condition without relative rotation between the first rotor and the second rotor. The first elastic member is transitioned from the compressed state to a free state and then further compressed when torsion of the first rotor with respect to the second rotor is caused from the neutral condition to a first side in the rotational direction. The second elastic member is transitioned from the compressed state to the free state and then further compressed when the torsion of the first rotor with respect to the second rotor is caused from the neutral condition to a second side in the rotational direction.

Abstract: A damper device includes first and second rotors, and an elastic coupling part elastically coupling the two rotors. The elastic coupling part includes first and second elastic members initially disposed in a compressed state in a neutral condition without relative rotation between the two rotors. The first elastic member is transitioned from the compressed state to a free state and then further compressed when torsion of the first rotor with respect to the second rotor is caused from the neutral condition to a first side. The second elastic member is transitioned from the compressed state to the free state and then further compressed when the torsion of the first rotor with respect to the second rotor is caused from the neutral condition to a second side. Each of the first and second elastic members is transitioned from a one-side contact state to a both-side contact state when actuated in compressed.

Abstract: A damper device includes a damper unit and a torque limiter unit. The damper unit includes first and second plates each including a plurality of window portions, a hub flange including a plurality of window holes, and a stopper mechanism. The first plate includes an engaging portion and a fixing portion fixed to the second plate. The engaging portion and the fixing portion are disposed radially outside the plurality of window portions. The hub flange includes a protrusion disposed circumferentially between and radially outside adjacent two of the plurality of window holes. The stopper mechanism is configured to be actuated by contact of the protrusion with the engaging portion. A fixation member, by which the first plate and the torque limiter unit are fixed, is disposed circumferentially between adjacent two of the plurality of window portions as seen in a direction along a rotational axis.

Abstract: A torque limiter embedded damper device includes a torque limiter unit and a damper unit. The damper unit includes a first rotor, a second rotor, and a stopper mechanism. The second rotor includes a flange axially opposed to the first rotor. The stopper mechanism restricts an angle of relative rotation between the first rotor and the second rotor to a predetermined angular range. The stopper mechanism includes a cutout and a stop pin. The cutout is provided in the flange of the second rotor. The stop pin is fixed to the first rotor. The torque limiter unit includes a friction plate having an annular shape. The annular friction plate is fixed at an inner peripheral part thereof to an outer peripheral part of first rotor or the second rotor by a fixation member. The fixation member is fastened in a state of penetrating the cutout of the flange.

Abstract: A damper device includes a first rotor, a second rotor, and an elastic member. The first rotor includes a contact surface. The contact surface faces a circumferential direction and extends in a radial direction. The second rotor is disposed to be rotatable relative to the first rotor. The second rotor includes a stopper surface extending in the radial direction. The stopper surface is opposed to the contact surface at an interval in the circumferential direction. The elastic member elastically couples the first rotor and the second rotor.

Abstract: A damper device includes a first rotor, a second rotor, a plurality of elastic members and a stopper mechanism. The stopper mechanism includes a first stopper hole, a second stopper hole and a plurality of stop members. The first and second stopper holes are provided on both circumferential sides of each of a plurality of first window holes of the second rotor so as to circumferentially extend therefrom. One or both of the first and second stopper holes communicates at one end thereof with each first window hole and extends at the other end thereof to a position radially outside one of a plurality of second window holes of the second rotor. The stop members are fixed to the first rotor. Each stop member axially penetrates each of the first and second stopper holes and is circumferentially movable within each of the first and second stopper holes.

Abstract: A damper device includes a damper unit and a torque limiter unit. The damper unit includes a first input plate, a second input plate, a fastening portion fastening the first and second input plates, an output plate, and an elastic member elastically connecting the output plate and the first and second input plates. The torque limiter unit includes a first side plate, a second side plate, a friction plate, and a first friction material disposed between the friction plate and the first side plate. The first input plate includes an outer peripheral end disposed on a first side of an inner peripheral end of the first side plate in an axial direction. The first input plate has an outer diameter greater than an inner diameter of the first side plate. The fastening portion is disposed on the first side of the first side plate in the axial direction.

Abstract: A method of assembling a damper device includes overlapping a first support portion of a first rotor and a first accommodation portion of a second rotor to eliminate an axial offset therebetween; disposing a first elastic member in the first support portion and the first accommodation portion; overlapping a second support portion of the first rotor and a second accommodation portion of the second rotor to eliminate an axial offset therebetween by simultaneously compressing the first elastic member and rotating the second rotor relative to the first rotor to a first-side in a rotational direction; disposing a second elastic member in the second support portion and the second accommodation portion; and simultaneously compressing the second elastic member and rotating the second rotor relative to the first rotor to a second-side in the rotational direction by angle corresponding to the offset between the first support portion and the first accommodation portion.

Abstract: A damper device includes a first rotor, a second rotor, and an elastic coupling part. The elastic coupling part has a first torsional characteristic, a second torsional characteristic, and a third torsional characteristic. The first torsional characteristic is exerted with a first stiffness in a first actuation range of a torsion angle that ranges differently on the positive side and on the negative side. The second torsional characteristic is exerted with a second stiffness, which is greater in magnitude than the first stiffness, in a second actuation range of the torsion angle that ranges on the positive side of the first actuation range. The third torsional characteristic is exerted with a third stiffness, which is greater in magnitude than the first stiffness and different in magnitude from the second stiffness, in a third actuation range of the torsion angle that ranges on the negative side of the first actuation range.

Abstract: A damper device, disposed between an engine and a drive unit, includes an input rotor, an output rotor, an elastic coupling part, and a hysteresis torque generating mechanism. The hysteresis torque generating mechanism generates a hysteresis torque together with the input rotor or the output rotor therebetween. The damper device is in a neutral condition when a torque is not transmitted from both the engine and the drive unit, in a first torsional condition when the torque is transmitted from the engine, and in a second torsional condition when the torque is transmitted from the drive unit. The hysteresis torque generating mechanism is configured not to generate a hysteresis torque when the damper device is in the first torsional condition, and not to generate the hysteresis torque in a first range of torsion angle less than a first angle when the damper device is in the second torsional condition.

Abstract: A damper device includes first and second rotors, a first pre-damper, and a first main elastic member. The second rotor includes a hub and a flange. The first pre-damper elastically couples the hub and the flange in a rotational direction, and is actuated in a first range of torsion angle between the first and second rotors. The first main elastic member elastically couples the first and second rotors in the rotational direction, and is actuated in a greater second range of torsion angle. The first pre-damper includes first and second subordinate elastic members. The first subordinate elastic member is compressed in a neutral state, and urges the flange to a first side in the rotational direction with respect to the hub. The second subordinate elastic member is compressed in the neutral state, and urges the flange to a second side in the rotational direction with respect to the hub.

Abstract: A power transmission device includes a flywheel and a damper device. The flywheel includes a plurality of fixation holes. The damper device includes an input rotary member, an output rotary member, and a pair of first elastic members. The input rotary member and output rotary member each include a plurality of assembling holes disposed in corresponding positions to the plurality of fixation holes of the flywheel. The plurality of assembling holes are arranged in a circumferential direction such that two pairs of the assembling holes, each pair including two adjacent assembling holes, are each disposed at a larger interval than remaining assembling holes to produce a pair of accommodation spaces. A pair of first accommodation portions, accommodating the pair of first elastic members, is disposed radially outside the pair of accommodation spaces.