| 摘要 |
PURPOSE: A wet type friction clutch and an electromagnetic clutch are provided to suppress drag torque between clutch plates and improve fuel efficiency without affecting traveling ability. CONSTITUTION: In a wet type friction clutch and an electromagnetic clutch, a pilot clutch(61) is disposed in a magnetic loop(95) of an electromagnet(57) and is kept between an armature and the electromagnet. Upon excitation of the electromagnet, the armature is retracted to allow the pilot clutch to be coupled. The pilot clutch includes a plurality of clutch plates(87,89) which are interleaved with respect to one another for sliding movements. Adjacent clutch plates are formed with oil guide passageways(86) to create a hydrodynamic pressure effect to allow the clutch plates to be separated with a limited drag torque. Further, the clutch plate has magnetic flux path forming portions, at inner and outer peripheral sides, between which through-bores are formed to allow bridge portions to be intervened between the through-bores, with each of the bridge portions being configured such that opposing walls of the bridge portions of adjacent clutch plates have reduced contact surface areas to eliminate a leakage of a magnetic flux. |
