Transmission Cases, like engineblocks, are all automotives key components. Also, transmission case is afundamental part of transmission. It generates Input assembly, Take-off assembly,and gearshift assembly of transmission together as a whole according to certainrelative position. In addition, it supports the output shaft for torque outputaccording to certain relationships of transmission ratio. The machining qualitydirectly affects the accuracy of assembly, performance of movement, flexibilityof gear shifting, noise of gears, sealed performance and lifetime forTransmission Assembly. Therefore, the performance of transmission assembly isdetermined by the machining quality of Transmission Cases.

Transmission Cases are often not in a regular shape with multiple partsfor machining, and the machining techniques are so complex that variousmachining operations needed to complete the machining. Double intermediate shafttransmission case is a typical grey cast iron part with thin-walled. Its mainbody includes main tank and vice tank. There are three center holes in thefloor. The vice tank is opening on one side, with 5 through holes on it withthe size of 510mm * 350mm * 480mm. The workpiece material is HT 200. (Grey CastIron with HB180)

Face milling

Tool：FMD02-080-A27-PN11-08

Insert：YBD152/PNEG110512R-CM

Cutting data：Vc=120m/min，fz=0.3mm/z

Hole-making

Tool：1534SU03 series drill

Cutting data：Vc=60～80m/min，fr=0.2mm/r

Counterboring

Tool：GM-4E Series Solid Carbide Endmills

Cuttingdata：Vc=80m/min，fz=0.15mm/z

Hole Chamfering

Tool：1143SC90-2000

Cutting data：Vc=150m/min，fr=0.2mm/r

Reaming

Tool：3102H7  seriesreamer

Cutting data：Vc=100m/min，fr=0.1mm/r

hread machining

Tool：4202C  seriestap

Cutting data：Vc=10～15m/min，fr=1.5～2mm/r

Machining for Boss Face

Tool：EMP01-032-XP32-AP11-04

Cutting data：Vc=70m/min，fz=0.1mm/z

Shallow Hole-making (Φ27)

Tool：ZTD03-250-XP25-SP07-02

YBG205/SPGT07T308-PM

YBG212/SPGT07T308-PM

Vc=80m/min，fz=0.2mm/z

Boring and chamfering (Φ27)

Tool： Tailor-made Complex Tools (Boring and Chamfering)

Cuttingdata：Vc=80m/min，fr=0.15mm/r

Thread machining

Tool：ThreadMilling Cutters

Cutting data：Vc=100m/min  fr=0.2mm/r

Internal Chamber

Taperangle Machining

Tool：Tailor-madeComposite Tapper Drills

Cutting data：Vc=35m/min，fr=0.15mm/r

Boring

Tool：Double-edged Modular Rough Boring Tools

Insert：YBD152/CCMT120408-HM

Cutting data：Vc=120m/min，fz=0.2mm/z

Internal BackBoring

Tool： New type Finish Boring Tools

Cutting data：Vc=150m/min，fz=0.1mm/z