Variable torque split aircraft gas turbine engine counter rotating low pressure turbines

摘要

An aircraft gas turbine engine includes a low pressure turbine having a low pressure turbine flowpath and low pressure inner and outer shaft turbines with counter rotatable low pressure inner and outer shaft turbine rotors, respectively. The low pressure inner and outer shaft turbine rotors include low pressure first and second turbine blade rows disposed across the turbine flowpath which are drivingly connected to first and second fan blade rows by low pressure inner and outer shafts, respectively. At least one row of low pressure variable vanes is operably disposed across the low pressure turbine flowpath between the low pressure inner and outer shaft turbines. The low pressure first turbine blade rows of the low pressure inner shaft turbine may be in tandem with or interdigitated with the second turbine blade rows of the low pressure outer shaft turbines.