Hydrodynamic brake system

Claim 1

The combination of a rotary member, particularly an idler wheel for use on vehicles, with a hydrodynamic brake system comprising a stator coaxial with said rotary member; a rotor coaxial with said stator and defining therewith a toroidal working chamber; a reservoir forming a substantially closed pressure vessel coaxial with said rotor; means for fastening said reservoir and said rotor to said rotary member for rotation therewith, said reservoir being partially filled with brake fluid so that the latter forms an annulus having a substantially cylindrical internal surface in response to rotation of said rotary member at a speed exceeding a predetermined value; conduit means connecting said chamber with said reservoir to define a closed path for circulation of brake fluid from said reservoir into said chamber and back into said reservoir whereby the fluid is heated while flowing through said chamber when said rotor rotates relative to said stator, at least a portion of said reservoir being exposed to the surrounding atmosphere to promote the cooling of brake fluid therein, said conduit means comprising a conduit which feeds brake fluid to said chamber and has an intake end communicating with said reservoir radially outwardly of said internal surface and a discharge end in the interior of said rotor, and at least one evacuating surface which admits brake fluid from said chamber to said reservoir, said evacuating conduit having an intake end facing said rotor and communicating with that portion of said chamber which is remotest from the axis of said rotor, and a discharge end; means for admitting into said reservoir a compressed gas to thereby initiate the circulation of brake fluid along said path; and normally closed check valve means disposed between said discharge end of said evacuating conduit and said reservoir and arranged to open in response to a predetermined fluid pressure in said chamber.