US Patent 7416139 Speed limiting turbine for rotary driven sprinkler

A speed limiting mechanisms for turbine-driven fluid distribution apparatus usable with compressible fluid such as compressed air and incompressible fluid such as water. In one form, a flow restrictor is located in the turbine discharge flow path, with the turbine discharge port area selected in relation to the turbine inlet port area according to the desired turbine speed with compressed air. In another form, the incoming fluid flows downstream along the surface of the turbine stator, and is then diverted to enter the rotor chamber in the proper direction. A bleed area on the stator which permits a portion of a compressible fluid which has expanded as it flows along the stator surface to flow to bypass the turbine rotor.