Viscous fluid type heat generator with an elongated rotor element

A viscous fluid type heat generator comprising:

• a cylindrical housing assembly defining therein a cylindrical chamber;
• a drive shaft rotatably mounted in said cylindrical housing assembly and having a substantial portion extending axially through said cylindrical chamber and an end portion extending from said substantial portion for receiving a drive force;
• an axially elongated rotor element mounted on said substantial portion of said drive shaft to be rotated therewith within said cylindrical chamber of said housing assembly, said elongated rotor element having an outer surface portion to define, within said cylindrical cheer of said housing assembly, a heat generating chamber and a heat receiving chamber fluidly separated from one another by a separating means, said heat generating chamber having inner walls thereof;
• a liquid flowing means for forming a flow of a heat exchanging liquid through said heat receiving chamber;
• viscous fluid being supplied in a space extending between said inner walls of said heat generating chamber and said outer surface portion of said elongated rotor element to generate heat in response to the rotation of said elongated rotor element;
• and wherein said outer surface portion of said elongated rotor element includes an axially continuous cylindrical surface portion having a predetermined radius "R" and a predetermined axial length "L" which are designed to satisfy such a dimensional relationship therebetween so that "L" is larger than "R", whereby said heat generating chamber comprises a cylindrical heat generating portion defined by said inner walls thereof and the axially continuous cylindrical surface portion of said elongated rotor element.