Abstract: A wet clutch device for selectively transmitting the rotation of a rotatable pulley to a driven shaft which rotatably supports the pulley. The wet clutch device includes an oil chamber which encloses a predetermined amount of oil and which is defined by the pulley and a cover which is secured to the pulley, driving clutch plates which are axially movably supported by the pulley in the oil chamber, driven clutch plates which are axially movably supported by the driven shaft in the oil chamber to selectively come into engagement with, and disengagement from corresponding driving clutch plates, and actuating device for bringing the driving clutch plates and the driven clutch plates into engagement with each other.

Abstract: A tapered-land thrust bearing device including a disk-shaped bearing member and a race member. The bearing member has a tapered-land face on which tapered surfaces and flat-land surfaces are successively formed, along the peripheral direction. The race member is arranged to contact the tapered-land face of the bearing member.

Abstract: A bored thrust bearing having a bearing face formed in series with tapered lands for forming a thrust load-carrying oil film, each tapered land being formed with a foot surface having a given sloping angle (.beta.) and an upper surface having a gentle sloping angle (.alpha.) less than the given sloping angle, the foot surface and the upper surface having therebetween a rounded boundary.

Abstract: A bored thrust bearing having a bearing face formed in series with tapered lands for forming a thrust load-carrying oil film, each tapered land being formed with a foot surface having a given sloping angle (.beta.) and an upper surface having a gentle sloping angle (.alpha.) less than the given sloping angle, the foot surface and the upper surface having therebetween a rounded boundary.