Abstract: A driving force transmission apparatus includes: a front housing and an inner shaft coaxially with each other and rotatable relative to each other; a main clutch transmitting torque between the front housing and the inner shaft; and a cam mechanism having a main cam and a pilot cam and using the main cam to press the main clutch. Where a circumferential gap angle between each spline tooth of the front housing and a corresponding first protrusion of outer clutch plates is ?1, a circumferential gap angle between each spline tooth of the inner shaft and a corresponding protrusion of inner clutch plates is ?2 and a circumferential gap angle between each spline tooth of the inner shaft and a corresponding protrusion of the main cam is ?3, the inequality ?1+?2??3?1.0° is satisfied.

Abstract: A driving force transmission apparatus (1) includes: a front housing (8) and an inner shaft (3) coaxially with each other and rotatable relative to each other; a main clutch (4) transmitting torque between the front housing (8) and the inner shaft (3); and a cam mechanism (7) having a main cam (70) and a pilot cam (71) and using the main cam (70) to press the main clutch (4). Where a circumferential gap angle between each spline tooth (80b) of the front housing (8) and a corresponding first protrusion (41a) of outer clutch plates (41) is ?1, a circumferential gap angle between each spline tooth (30a) of the inner shaft (3) and a corresponding protrusion (40a) of inner clutch plates (40) is ?2 and a circumferential gap angle between each spline tooth (30a) of the inner shaft (3) and a corresponding protrusion (70b) of the main cam (70) is ?3, the inequality ?1+?2??3?1.0° is satisfied.

Abstract: In a power transmitting device, projections are formed on a surface of a main cam that faces an armature. This structure causes the main cam to contact the armature only at distal surfaces of the projections. The area of the distal surfaces of the projections is in a range where the magnetic flux density generated at the distal surfaces of the projections by the electromagnet is saturated. Therefore, reduction of the responsiveness and controllability of the power transmitting device due to magnetization of the main cam is suppressed.

Abstract: In a power transmitting device, projections are formed on a surface of a main cam that faces an armature. This structure causes the main cam to contact the armature only at distal surfaces of the projections. The area of the distal surfaces of the projections is in a range where the magnetic flux density generated at the distal surfaces of the projections by the electromagnet is saturated. Therefore, reduction of the responsiveness and controllability of the power transmitting device due to magnetization of the main cam is suppressed.

Abstract: A driving force transmission system comprising: a coupling case and a shaft arranged rotatably relative to each other; a pilot clutch and a main clutch for controlling a torque transmission between the coupling case and the shaft; an electromagnet for controlling the actions of the pilot clutch and the main clutch; and oil retaining the functions of the pilot clutch and the main clutch. This system further comprises a coupling case, a shaft, a rotor, and X-ring and an O-ring isolating a coupling oil chamber, in which the pilot clutch and the main clutch are arranged, liquid-tight from the surrounding space.

Abstract: A driving force transmission system comprising: a coupling case and a shaft arranged rotatably relative to each other; a pilot clutch and a main clutch for controlling a torque transmission between the coupling case and the shaft; an electromagnet for controlling the actions of the pilot clutch and the main clutch; and oil for retaining the functions of the pilot clutch and the main clutch. This system further comprises a coupling case, a shaft, a rotor, an X-ring and an O-ring for isolating a coupling oil chamber, in which the pilot clutch and the main clutch are arranged, liquid-tight from the surrounding space.

Abstract: A driving force transmission system comprising: a coupling case and a shaft arranged rotatably relative to each other; a pilot clutch and a main clutch for controlling a torque transmission between the coupling case and the shaft; an electromagnet for controlling the actions of the pilot clutch and the main clutch; and oil for retaining the functions of the pilot clutch and the main clutch. This system further comprises a coupling case, a shaft, a rotor, an X-ring and an O-ring for isolating a coupling oil chamber, in which the pilot clutch and the main clutch are arranged, liquid-tight from the surrounding space.

Abstract: On a frictional engage surface of one of inner and outer clutch plates constructing a wet-type multi-disk clutch, a plurality of convex ridges are formed at an infinitesimal predetermined interval distance. Lubricating oil is kept between the convex ridges, so that the wedge operation in oil can be reduced, whereby the torque transfer characteristic can be improved. Further, a height of the convex ridge is set equal to or more than 1 .mu.m and the interval distance of the convex ridge is set equal to or less than 600 .mu.m, preferably.In the configuration of the clutch plate, it is made of steel as a substrate. Further, a nitrogen diffusion layer, a nitrided layer and an oxidation tunic is formed on said nitrided layer are formed on the substrate in its order therefrom.

Abstract: A driving force transmission system comprising: a coupling case and a shaft arranged rotatably relative to each other; a pilot clutch and a main clutch for controlling a torque transmission between the coupling case and the shaft; an electromagnet for controlling the actions of the pilot clutch and the main clutch; and oil for retaining the functions of the pilot clutch and the main clutch. This system further comprises a coupling case, a shaft, a rotor, an X-ring and an O-ring for isolating a coupling oil chamber, in which the pilot clutch and the main clutch are arranged, liquid-tight from the surrounding space.

Abstract: There is disclosed a drive force transmission apparatus which includes a first pressing-force generation unit for generating a pressing force in accordance with a rotational speed difference between driving and driven shafts, and a frictional clutch which is brought into an engaged state by the pressing force generated by the first pressing-force generation unit in order to transmit torque in accordance with the rotational speed difference between the driving and driven shafts. The drive force transmission apparatus further includes a second pressing-force generation unit disposed opposite to the first pressing-force generation unit with respect to the frictional clutch. When needed, the second pressing-force generation, unit is operated to bring the frictional clutch into a firmly engaged state, thereby improving the traveling performance of the vehicle under severe traveling conditions, such as an attempt to extract a wheel trapped in a gutter or the like, traveling on a rough road, traveling on sand, etc.

Abstract: A drive force transmission apparatus includes a housing connected to one of two shafts that are rotatable relative to each other, a rotary shaft rotatably supported by the housing and connected to the other shaft, and a multiple disc clutch composed of a plurality of outer plates engaged with the housing in the rotational direction and a plurality of inner plates engaged with the rotary shaft in the rotational direction. The multiple disc clutch transmits rotational torque between the housing and the rotary shaft through frictional engagement between the outer plates and the inner plates. The apparatus also includes a pressure generation mechanism for generating a pressure corresponding to a rotational-speed difference between the housing and the rotary shaft and for applying the generated force to the multiple disc clutch via a piston.

Abstract: A rotary shock absorber suitable for use in a suspension system of a vehicle. The shock absorber is provided with a housing and a rotary shaft supported by the housing for relative rotation thereto. A pressure chamber is formed in the housing and a rotor having a pair of blades is received within the pressure chamber. Further, a pair of partition walls are formed within the pressure chamber to define first and second chambers at both sides of each blade, and the first and second chambers are communicated with each other through throttles. When the rotary shaft is rotated, a high viscous fluid filled within the first and second chambers flows therebetween through the throttles. Due to the flow resistances of the throttles, pressures are generated in the first or second chambers. This pressure generation is used to generate a damping force.