TURBOPUMP

The turbopump is a direct-drive unit consisting of an oxidizer pump, a fuel pump, and a turbine mount­ed on a common shaft. The turbopump delivers fuel and oxidizer to the gas generator and the thrust chamber. LOX enters the turbopump axially through a single inlet in line with the shaft and is discharged tangentially through dual outlets. Fuel enters the turbopump radially through dual inlets and is dis­charged tangentially through dual outlets. The dual inlet and outlet design provides a balance of radial loads in the pump.

Three bearing sets support the shaft. Matched tandem ball bearings, designated No. 1 and No. 2, provide shaft support between the oxidizer and fuel pumps. A roller bearing, No. 3. provides shaft support between the turbine wheel and the fuel pump. The bearings are cooled with fuel during pump operation. A heater block provides the outer support for No. 1 and No. 2 bearings, and is used during LOX chilldown of the oxidizer pump to pre­vent freezing of the bearings.

A gear ring installed on the shaft is used in con­junction with the torque gear housing for rotating

the pump shaft by hand, and also is used in con­junction with a magnetic transducer for monitoring shaft speed.

There are nine carbon seals in the turbopump: primary oxidizer seal, oxidizer intermediate seal, lube seal No. 1 bearing, lube seal No. 2 bearing, primary fuel seal, fuel inlet seal, fuel inlet oil seal, hot-gas secondary, and hot-gas primary seal.

The main shaft and the parts attaching directly to it are dynamically balanced prior to final assembly on the turbopump.