PURPOSE: To provide a friction generating mechanism which can generate large friction.

CONSTITUTION: An annular part 18a is disposed between a first friction member 14 and a second friction member 15, and an engagement part 18b of a second plate 18 is inserted in respective cut grooves 5b formed at the inner periphery of a flange 5. As a result, the second plate 18 is engaged with the flange 5 so as not to make relative rotation in the peripheral direction and so as to move freely in the axial direction. In this friction generating mechanism 8, when a clutch plate 3 rotates relatively to the flange 5, the first friction member 14 slides between the clutch plate 3 and an annular part 17a of a first plate 17. The second friction member 15 slides between the annular part 17a and the annular part 18a of the second plate 18, and a third friction member 16 slides between the annular part 18a and the flange 5. This friction generating mechanism has three friction surfaces as described above, so it is possible to obtain large friction.