Turbofan engine bearing and gearbox arrangement

A turbofan engine (20) comprising:

• a fan (28);
• a fan drive gear system (60) configured to drive the fan;
• a low spool comprising:
• a low pressure turbine (50);
• and
• a low shaft (56) coupling the low pressure turbine to the fan drive gear system;
• an intermediate spool comprising;
• an intermediate pressure turbine (48);
• a compressor (42);
• and
• an intermediate spool shaft (54) coupling the intermediate pressure turbine to the intermediate spool compressor;
• a core spool comprising:
• a high pressure turbine (46);
• a compressor (44);
• and
• a core shaft (52) coupling the high pressure turbine to the core shaft;
• a combustor (45) between the core spool compressor and the high pressure turbine;
• and
• a plurality of main bearings wherein:
• a first (160) of said main bearings engages a static support (164;
• 164′) and a forward hub (236) of the intermediate spool;
• and
• a second (162) of said main bearings engages the low shaft and the forward hub of the intermediate spool;
• the first bearing and the second bearing are non-thrust roller bearings;
• and
• rollers of the first bearing and the second bearing are at least partially longitudinally overlapping.

A turbofan engine (20) comprising:

• a fan (28);
• a fan drive gear system (60) configured to drive the fan;
• a low spool comprising:
• a low pressure turbine (50);
• and
• a low shaft (56) coupling the low pressure turbine to the fan drive gear system;
• an intermediate spool comprising;
• an intermediate pressure turbine (48);
• a compressor (42);
• and
• an intermediate spool shaft (54) coupling the intermediate pressure turbine to the intermediate spool compressor;
• a core spool comprising:
• a high pressure turbine (46);
• a compressor (44);
• and
• a core shaft (52) coupling the high pressure turbine to the core spool compressor;
• a combustor (45) between the core spool compressor and the high pressure turbine;
• and
• a plurality of main bearings wherein:
• a first (160) of said plurality of main bearings engages a static support (164;
• 164′) and a forward hub (236) of the intermediate spool;
• a second (162) of said plurality of main bearings engages the low shaft and the forward hub of the intermediate spool;
• and
• an inter-shaft bearing (170) of said plurality of main bearings axially locates the low shaft.