Abstract: A phenol resin for a wet friction material of the invention contains a resol-type phenol resin having, in one molecule, a structural unit A which is derived from a phenol compound having one phenolic hydroxyl group and a structural unit B which is derived from a polyfunctional phenol compound having two phenolic hydroxyl groups.

Abstract: An excessive torque releasing type clutch apparatus comprises an outer ring, an inner ring arranged radially inside and coaxially with the outer ring and rotatably relative to the outer ring, a torque transmitting portion capable of transmitting torque between the outer ring and the inner ring, and a restricting mechanism for restricting excessive torque from being input from an input torque transmitting member to a driving ring of the outer ring and the inner ring and restricting excessive inverse torque that is input to a driven ring of the outer ring and the inner ring from being input to the input torque transmitting member. Treatment steps for securing strength of constituent members of the clutch apparatus in manufacturing be simplified or omitted.

Abstract: A clutch apparatus comprises a first race, a second race arranged coaxial with and rotatable relative to the first race, and an engagement mechanism provided between the first race and the second race for engagement of the first race and said second race. The engagement mechanism comprising a first clutch allowing rotation of the first race in only one direction, and a second clutch arranged axially adjacent to the first clutch, the second clutch comprising a rotary member that is provided on the second race in a rotatable and axially immovable manner and a movable member that is movable in the axial direction, and a cam mechanism disposed between the rotary member and the movable member, and the movable member being engaged with the first race by being moved in the axial direction by the cam mechanism.

Abstract: A structure of a ratchet type one-way clutch that enables a reduction of the installation space along the direction of the center axis and high torque setting. The structure includes a securing member arranged on the center axis of a ratchet type one-way clutch and having a holding portion opposed to the ratchet type one-way clutch in the axial direction. The outer race of the ratchet type one-way clutch is provided with a first fit portion including a plurality of through holes. The holding portion is provided with a second fit portion including a plurality of projections that is in fitting engagement with the first fit portions, respectively.

Abstract: An annular member stopping structure for a friction engaging device includes an end plate 212, a plurality of projecting sections 218 projecting in a radial direction at intervals in a circumferential direction on the end plate 212, a drum 112 having hook parts 220 configured to engage with the projecting sections 218, the drum 112 being non-rotatable relative to the end plate 212, an annular groove 214 provided in the drum 112, and a C-shaped snap ring 216 configured to fit in the annular groove 214. A circumferential direction abutting section 226 freely abutting with circumferential direction end 216a of the snap ring 216 is provided in the end plate 212.

Abstract: A one way clutch comprises an outer race including a radially outer first annular part to which rotation is input from outside and a radially inner second annular part capable of rotating when receiving rotation from the first annular part, an inner race provided radially inside the outer race and rotatable relative to the outer race, a plurality of torque transmission members provided between the outer race and the inner race to transmit torque between the outer race and the inner race, and a coupling mechanism that couples the first annular part and the second annular part together to make them integrally rotatable when the speed of rotation input from outside is lower than a specific speed and decouples them when the speed of rotation exceeds the specific speed.

Abstract: A phenol resin for a wet friction material of the invention contains a resol-type phenol resin having, in one molecule, a structural unit A which is derived from a phenol compound having one phenolic hydroxyl group and a structural unit B which is derived from a polyfunctional phenol compound having two phenolic hydroxyl groups.

Abstract: An object is to provide a compact and lightweight clutch apparatus by using a mechanical clutch. A clutch apparatus includes a one-way clutch and a mechanical clutch arranged in parallel in an axial direction, in which the mechanical clutch is movably retained in the axial direction, and when the mechanical clutch moves in the axial direction due to pushing means, the mechanical clutch engages with an end surface of an inner wheel of the one-way clutch.

Abstract: A one-way clutch apparatus of torque input-switching type in which torque capacity can be secured without increasing an axial dimension. The one-way clutch apparatus of drive input-switching type, includes a plurality of first torque transmitting members interposed between a shaft 3 and an intermediate ring 7 at circumferential predetermined intervals, and provided for transmitting torque between the shaft 3 and the intermediate ring 7, and a plurality of second torque transmitting members interposed between the intermediate ring 7 and an outer ring 5 at circumferential predetermined intervals, and provided for transmitting torque between the intermediate ring 7 and the outer ring 5, in which either the torque input into the shaft 3 or the torque input into the outer ring 5 is transmitted to the intermediate ring 7, in which the first torque transmitting member is a sprag 23 and the second torque transmitting member is a roller 29.

Abstract: Provided is a multiplate wet clutch having capability of preventing damage of an axial groove portion formed in an inner cylindrical portion of a shaft. An inner cylindrical portion 3 of the shaft is formed with an axial groove 75 which is opened to a circumferential groove 53 and with which other members of the multiplate wet clutch for regulating movement of a retaining ring 55 toward axially on the other side are to be engaged. A pressure plate 35 is formed, on a surface 36b axially on the other side thereof, with a recessed portion 77 axially opposed to an opening portion 81 of the axial groove 75 through the retaining ring 55.

Abstract: Since one end of a spring is received by a planar portion of a spring seat provided on any one of an outer plate and an inner plate, it is possible to support the spring with a planar member without machining a bottom wall face of the outer plate into a planar shape. Since the spring seat has seat guide portions that contact the outer plate, it is possible to suppress the fluctuation of the spring seat and the fluctuation of the spring by the seat guide portions, so it is possible to reliably prevent interference of the spring with its peripheral portion. Therefore, a load on the spring is reduced, so it is possible to improve the durability of a one-way clutch.

Abstract: A one-way clutch 1 includes: an inner race 3; an outer race 5; a plurality of cams 7 interposed between an inner race outer peripheral surface 11 and an outer race inner peripheral surface 13 and serving to transfer a torque to between the inner race 3 and the outer race 5; a retaining mechanism retaining the plurality of cams 7; and a spring member 15 biasing the plurality of cams 7 to torque non-transfer positions, and the retaining mechanism includes a first retainer 9 fixed to the outer race 5 and having a cylindrical retaining portion 21 retaining the plurality of cams 7 at a predetermined interval in a circumferential direction, and a second retainer 29 disposed on an inner diametrical side of the cylindrical retaining portion 21, retaining the plurality of cams 7 in a swingable manner, and elastically deformable corresponding to the swings of the plurality of cams 7 when swinging in a torque transferring direction upon engagements of the plurality of cams 7 with the inner race outer peripheral surface

Abstract: A friction plate has a plurality of friction material segments circularly fixed on an annular core plate, wherein each of the friction material segments includes an oil groove having an opening that opens in the direction of an outer circumferential edge of the friction plate and an end portion that ends between an inner circumferential edge and the outer circumferential edge, oil passages in communication in the direction of the inner and the outer circumferential edges of the friction plate are provided among the friction material segments, and at least some of the oil passages have a first shape, the width of which in a circumferential direction decreases from the inner circumferential edge of the friction plate toward the outer circumferential edge thereof.

Abstract: A roller type one-way clutch includes an outer race in which at least one pocket having a cam surface on an inner periphery thereof is formed, an inner race which is spaced away from the outer race on an inside diameter side in a radial direction and which is relatively rotatably disposed concentrically with respect to the outer race, a roller which is disposed in the pocket and which engages with the cam surface to transmit a torque between the outer race and the inner race, a spring which is disposed between the outer race and the roller in the pocket and which urges the roller in a direction in which the roller engages with the cam surface, and a side plate secured to be in contact with one end surface in an axial direction of the outer race. The side plate has a non-circular shape, the one end surface in the axial direction is annular, and at least a portion of the one end surface in the axial direction of the outer race is exposed in a state in which the side plate is secured.

Abstract: An annular member stopping structure for a friction engaging device includes an end plate 212, a plurality of projecting sections 218 projecting in a radial direction at intervals in a circumferential direction on the end plate 212, a drum 112 having hook parts 220 configured to engage with the projecting sections 218, the drum 112 being non-rotatable relative to the end plate 212, an annular groove 214 provided in the drum 112, and a C-shaped snap ring 216 configured to fit in the annular groove 214. A circumferential direction abutting section 226 freely abutting with circumferential direction end 216a of the snap ring 216 is provided in the end plate 212.

Abstract: A one-way clutch is disclosed, which improves durability while reducing a drag torque and restraining burning of a block bearing. The one-way clutch includes: a torque transfer mechanism disposed between an outer race 2 and an inner race 3 so disposed in the outer race 2 as to be spaced inwardly in a diametrical direction, and hindering the outer race 2 and the inner race 3 from making a relative rotation in a predetermined direction; and block bearings 6 disposed between the outer race 2 and the inner race 3 together with the torque transfer mechanism, and keeping the outer race 2 and the inner race 3 in a concentric state, in which each block bearing has a slide surface 6f contiguous with an axis-directional surface of the outer race 2 or the inner race 3, and at least part of the slide surface 6f is a roughened surface.

Abstract: A friction plate is formed by circularly fixing a plurality of friction material segments to a substantially annular core plate. A through groove that penetrates from an inside diameter side to an outside diameter side of the core plate is formed between the friction material segments, and each of the friction material segments has a circumferential groove that opens to the through groove, extends in a circumferential direction, and terminates in the friction material segment.

Abstract: A friction plate is formed in such a manner that a plurality of friction material segments fixed to an annular core plate, wherein a passage extends through from an inner diameter side to an outer diameter side and is defined between the plurality of friction material segments, and a forming portion for retaining air is provided on a bottom surface of the passage.

Abstract: A one-way clutch allows unlocking torque input to a movable retainer to be made low, thereby enabling downsizing of an external apparatus that inputs unlocking torque to the movable retainer. The one-way clutch includes an inner ring, an outer ring, first rollers used to transmit torque between the inner ring and the outer ring provided in an annular space between the inner ring and the outer ring, and fixed retaining portions of a fixed retainer and a movable retaining portions of a movable retainer that are arranged alternately. The one-way clutch also includes second rollers provided between the movable retaining portions and the first rollers adapted to transmit unlocking torque from the movable retaining portions to the first rollers and the inner ring as the movable retaining portions move in a clockwise direction.

Abstract: A ratchet type one-way clutch includes an outer race having a pocket, an inner race having a notch, a pawl member housed in the pocket to transmit torque between the inner race and the outer race, and having a tip portion engaging with the notch and a circular portion; and a spring urging the pawl member to the inner race is provided. A central angle of the circular portion is 180 degrees or greater. An angle between a segment between both ends of an opening of the circular arc portion and a segment between the circular portion of the pawl member and a contact point at which the tip portion engages with the notch is greater than 90 degrees, and an angle between the spring and a segment between the center of the circular portion and a center of the ratchet type one-way clutch is greater than 45 degrees.