Patent ID: 6042500
Filing Date: 2000-03-28
Classification: F16D,F16H

Abstract:
An automatic transmission comprising at least one combination of teeth and at least one multi-disc clutch which is automatically controlled between an engaged state and a disengaged and a disengaged state in order to cause the combination of teeth to operate in a first, and respectfully in a second transmission ratio, wherein said multi-disc clutch comprises a first and second coaxially rotatable members, a first group of discs made of metal, which are mounted for common rotation with the first member and alternating with discs of a second group, which are mounted for common rotation with the second member, and means for selectively axially compressing and respectfully axially releasing releasing the discs, wherein each disc of the second group comprises a single mass of carbon-based material defining two opposed friction faces, said opposed friction faces being exposed to contact with oil of an oil bath at least when the coupling device is disengaged, wherein the combination of teeth is at least partially off-loaded when the clutch is engaged, and wherein the transmission comprises means of transmitting to the clutch, in the sense of disengagement, a gearing reaction generated in the combination of teeth when said combination of teeth is under load, means for engaging the clutch under a calibrated force giving the clutch a corresponding torque transmission capability, and a means of the free wheel type to prevent the reverse rotation of a reaction number supporting one set of the teeth of said combination.