innovations CASTING
Conversion to Ductile Iron Casting Reduces Weight, Cost, Part Numbers
A
division of SAF Holland specializing in agricul- tural tillage equipment, AerWay, Norwich, Ontario, Canada, has
converted many complex weldments and forgings to castings. After a discus- sion with a customer, a regional sales manager for AerWay began investigat- ing the possibility of converting an aera- tor trunnion bracket and bracket guard to cast iron components. T e original bracket was machined
from carbon steel barstock, and the guard included two steel ears welded to a piece of bent steel. One trunnion bracket was mounted to the implement, and a mating trunnion bracket was as- sembled to a guard with four fasteners that surround a bearing. T e AerWay design team chose 230-180-01 austempered ductile iron for the potential casting to improve wear resistance. Simplifying the component to a single cast part off ered another potential benefi t.
“We chose cast austempered duc-
tile iron to save labor and to integrate protection of the bearing,” AerWay’s sales manager said. T e initial draft of the design was suited to the implement, but it was not fully optimized as a casting. Aer- Way approached Applied Process Inc., Livonia, Mich., and Urick Foundry, Erie, Pa. to further improve the de- sign. T e natural fl owability of ductile iron could minimize section size and reduce the need for expensive alloying in advance of heat treatment. Addi- tionally, casting the components could reduce overall weight and manufac- turing requirements associated with the metalcasting facility maintaining separate return streams. In addition, the design team planned to machine the part before heat treatment to reduce costs by machining material in the soft state. After Urick Foundry and Ap-
plied Process engineers optimized the design for the casting process, the redesigned part further reduced weight and costs compared to the initial draft. Additionally, because only one of the two brackets required austempering, performed by Applied Process, AerWay could save on heat treatment by using standard ductile iron for the component with lower physical requirements.
The cast trunnion bracket guard provided more coverage when installed in the aerator. 44 | METAL CASTING DESIGN & PURCHASING | Sept/Oct 2014
The original trunnion bracket and guard included a total of eight parts.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60