Air cycle machine with axial rotors and integrated cabin air compressor
An ACM having a motor with front and aft ends; a compressor coupled to the front end; a turbine coupled to the aft end; a shell having a shell front part that surrounds the compressor and defines a shell inlet, a shell aft part that surrounds the turbine and defines a shell outlet, and a shell middle part that surrounds the motor; an outer flow passage is defined within the shell, surrounding the compressor, the motor and the turbine; a shaft extends between the compressor and turbine to define a shaft front end coupled to the compressor, and a shaft aft end coupled to the turbine, and the motor includes a rotor that is mounted to the shaft.
1 . An air cycle machine (ACM),
comprising: a motor having a front end and an aft end; a compressor coupled to the front end of the motor; a turbine coupled to the aft end of the motor; a shell having a shell front part that surrounds the compressor and defines a shell inlet, a shell aft part that surrounds the turbine and defines a shell outlet, and a shell middle part that surrounds the motor, wherein an outer flow passage is defined within the shell, surrounding the compressor, the motor and the turbine; a shaft extending between the compressor and the turbine to define a shaft front end that is coupled to the compressor, and a shaft aft end that is coupled to the turbine; and the motor includes a rotor that is mounted to the shaft, and
wherein the motor has a motor case that includes a first front conical end that diverges aft of the shell front part, a first aft conical end that converges aft toward the shell aft part, and first middle portion that is cylindrical; and the shell middle part has a second front conical end that diverges around the first front conical end of the motor case, a second aft conical end that converges around the first aft conical end of the motor case, and a second middle portion disposed around the first middle portion of the motor case and is cylindrical.
2 . The ACM of claim 1 , wherein the compressor is an axial compressor.
3 . The ACM of claim 1 , wherein the turbine is an axial turbine.
4 . The ACM of claim 1 , wherein the turbine comprises a turbine high pressure stage and a turbine low pressure stage that is aft of the turbine high pressure stage.
5 . The ACM of claim 1 , wherein the compressor includes a compressor low pressure stage and a compressor high pressure stage that is aft of the compressor low pressure stage.
6 . The ACM of claim 5 , wherein the compressor low pressure stage is a cabin air compressor.
7 . The ACM of claim 4 , wherein
the shell front part has a first forward portion surrounding the compressor low pressure stage and a first aft portion surrounding the compressor high pressure stage.
8 . The ACM of claim 7 , wherein the first forward portion of the shell front part diverges toward the first aft portion of the shell front part.
9 . The ACM of claim 7 , wherein the first aft portion of the shell front part converges toward the shell middle part.
10 . The ACM of claim 4 , wherein
the shell aft part has a second front portion surrounding the turbine high pressure stage and a second aft portion surrounding the turbine low pressure stage.
11 . The ACM of claim 7 , wherein the second forward portion of the shell aft part diverges toward the aft portion of the shell aft part.
12 . The ACM of claim 7 , wherein the second aft portion of the shell aft part converges aft of the front portion of the shell aft part.
13 . The ACM of claim 1 , wherein:
the shaft is a hollow shaft and defines and a shaft passage extending between the shaft front and aft ends;
the shaft aft end defines a shaft inlet and the shaft front end defines a shaft outlet; and
the shaft provides for backflow from the turbine to the compressor, via the shaft inlet and outlet, for cooling of the motor.
14 . The ACM of claim 13 , wherein the shaft inlet is an axial aperture.
15 . The ACM of claim 13 , wherein the shaft outlet is an axial aperture.
16 . The ACM of claim 15 , wherein:
the turbine comprises a turbine high pressure stage and a turbine low pressure stage that is aft of the turbine high pressure stage; and
the shaft inlet is a radial aperture disposed at the turbine low pressure stage.
17 . The ACM of claim 1 , wherein the shell, end to end, is formed of two unitary half-shell members, coupled to each other by one or more of hinges and fasteners.