Abstract: A turbine assembly mounted to a pump rotor via mounting bolts. The turbine includes fins extending therefrom for pumping gasses and suspended particles from a semiconductor processing chamber. The tops of the bolts are recessed from the top surface of the turbine in a bolt cavity having an open end. A cap member is mounted over and seals the open end of the bolt cavity via a center bolt. The cap member has a shaped upper surface (conical, parabolic, squared, rounded) for deflecting particles away from the center of the turbine and toward the turbine's fins. The cap member's upper surface can include particle deflecting features such as fins, channels or asymmetric shapes to enhance particle deflection as the cap member rotates. The cap member can include a compressible o-ring for a friction fit mounting to the turbine.

Abstract: A turbine assembly mounted to a pump rotor via mounting bolts. The turbine includes fins extending therefrom for pumping gasses and suspended particles from a semiconductor processing chamber. The tops of the bolts are recessed from the top surface of the turbine in a bolt cavity having an open end. A cap member is mounted over and seals the open end of the bolt cavity via a center bolt. The cap member has a shaped upper surface (conical, parabolic, squared, rounded) for deflecting particles away from the center of the turbine and toward the turbine's fins. The cap member's upper surface can include particle deflecting features such as fins, channels or asymmetric shapes to enhance particle deflection as the cap member rotates.