Patent ID: 6942081
Filing Date: 2005-09-13
Classification: F16D

Abstract:
1. A torque transmission apparatus comprising input and output coupling members arranged on a common axis of rotation, said coupling members bring provided within a fluid housing and wherein each said coupling member is formed with a cylindrical portion that extends parallel to said axis of rotation, the inner surface of said cylindrical portion of a first of said coupling members being of a larger diameter than the outer surface of said cylindrical portion of the second of said coupling members, the cylindrical portion of said second coupling member being received within the cylindrical portion of said first coupling member so as to define a cylindrical gap therebetween, wherein an electrorheological fluid is provided in said fluid housing and filling the cylindrical gap between the coupling members, and means being provided for applying an electric field to said electrorheological fluid, said apparatus further comprising electromagnetic means for bringing a drive shaft into and out of engagement with said first coupling member and comprising a coil arranged around said drive shaft, and wherein said first coupling member is provided with a permanent magnet, whereby upon application of a current to said coil said drive shaft is moved into or out of magnetic engagement with said first coupling member.