26 include working portions 60 and 61 respectively which have interior surfaces proximate to the working surfaces of flanges 33 and 34 coupling disc 12 includes inside working surfaces 35 and 36 and outside working surfaces 37 and 38 and further includes edge surfaces 62 and 63 which may be working surfaces working portions 60 and 61 of housing members 25 and 26 respectively include surfaces which are spaced apart from but closely adjacent to the working surfaces of coupling disc 12 as is well known in the art the close proximity of these surfaces defines a working chamber 64 which surrounds the flanges 33 and 34 and within which a working fluid may be received a working fluid received within working chamber 34 will provide for a force transmission between the coupling disc 12 and housing 11 as is known in the art the working fluid may be selected from any of the number of fluids known to be useful for this purpose in a first condition fig6 of the fluid shear coupling 10 the coupling disc 12 is rotating from the connection through drive pulley mount 14 with the engine drive pulley assembly without the presence of working fluid in working chamber 64 the housing 11 remains motionless as working fluid is introduced into working chamber 64 the angular momentum of the coupling disc 12 is inparted to the housing 11 through the medium of the working fluid and a corresponding rotation of the housing 11 results a considerable amount of heat is generated within the working fluid while it is within the working chamber 64 due to the relative rotation of housing 11 and coupling.