Jet Engine; Geared Turbofan (GTF)
For the latest jet engine for passenger planes, the Bypass Ratio is bigger and bigger to improve the engine-performance.
In order for one of them, the Geared Turbofan (GTF) is developed. 3D model for explaining this system was designed and made.
The points of the design are;
- Compact "Fan Drive Gear System" which has 3 to 1 Reduction Ratio. (shown by color "RED" in photos)
- For the rotation of each spool, the ball bearing method and the dummy bearing method are prepared.
All stator vanes are omitted this time, because of avoiding rub of vanes and blades. And each rotor except LPT is designed with support so that it can be printed as one-piece.
The blade angle is made to agree in the spool rotational direction (View from Rear).
- HP Spool: Clockwise
- LP Spool: Counterclockwise
- Fan: Clockwise
- In addition, some parts that printing is considered difficult without support, are prepared STL file with support. The last of two digits of the file name is identified as "ws". In order to ease understanding about the contents of each part and the assembly order, parts breakdown and list are prepared.
Download files includes;
-files: STL Files
-images: Parts Breakdown for assembly Aid
-Excel File: Parts List
Purchase Parts Information;
-Bearings (Can be used Dummy BRGs instead of the followings, See Parts List)
DDL-1370ZZ (7 x 13 x 4) 2ea - For LP-Spool
689ZZ (9 x 17 x 5) 3ea - For HP-Spool and Fan
675ZZ (5 x 8 x 2.5) 2ea - Fan Drive Gear Train
See Parts List
Micro screws M1.4x3L - Appox. 60 ea - Direct screw-in to 1 mm dia hole (No nut),
Screws M2 x 6L - 4 ea, See Parts List
Screws M3 x 8L and Washer - 1 ea, See Parts List
- Standard Skill (such as Drilling, Tapping, Filing, Tightening, Painting and Gluing etc) is needed and perseverance too.
- For gears: Deburring (removing the sharp edges etc.) is very important for smooth rotation.
- HPC and LPC rotor: Take care when removing the support from the blades.
Total Net Print Time: Approx. 31HR
- (Estimated as case of PLA, 0.4mm Nozzle, 0.2mm Layer Height, 40% infill and No raft and support)
Note: When at actual print, each parameter should be adjusted by your experience.
Optional Fan; https://www.thingiverse.com/thing:2796851 - 2018.2.17
Modified Rotor; https://www.thingiverse.com/thing:2834191 - 2018.3.21