2. Tutorial: Engineering technology Topic: Drive shafts Prepared by: Ing. Jaroslav Hábl Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.

3. Drive shafts They transmit loading by bending or torsion momentum. engine Connecting shaft gearbox Operating machine En flow Input shaftCounter shaft Output shaft

4. Mobile shafts There are made two types of tension shaft stressing by torsion and by bending at the same time.

5. Example of drive shaft design

6. DRIVE SHAFTS - CALCULATION Due to σ and τ are perpendicular to one another, it is not possible to add their values together. We calculate vector sum of these tensions but because of the reason of lower material durability to torsion than to bending, this vector sum is modified so that torsion has a higher influence to final tension than to bending. Final tension is called reduced tension: Correction factor: Výpočet průměru hřídele: Reduced moment: Calculation of shaft diameter

7. Drive shafts - calculation Calculated shaft diameter always means core diameter, non- reduced by constructional detail : Shaft core with key seat d = calculated diameter D = offered diameter

8. DRIVE SHAFTS - MATERIALS Due to higher straining, shafts are made of wrought – steel. Simpler, less strained shafts, are made of construction carbon steels of the class 11 (e.g. 11 500, 11 600, 11 700) or the class 12. More stressed shafts are made of alloyed steels (mostly the class 14, 15 and 16). Due to the requirement of higher shaft strength and resistance of shaft surface against shaft wearing, they are often heat conditioned. Cementation (for low carbon steels), quenching and heat treatment (for high carbon steel).

9.  Stroje a zařízení I, J. Doleček, P. Gajdoš, V. Novák  Strojnictví I, J. Doleček, Z. Holoubek  Strojnictví II, J. Doleček, Z. Holoubek  Moderní strojírenství, Josef Dilinger a kolektiv

10.  How are mobile shafts stressed?  Write down at least 3 examples of drive shaft usage.  What materials are used for shaft’s production?