Question

A portion of a shaft where a gear is to be mounted has diameter of 50 mm. The gear transmits 335 N-m of torque. The shaft is to be made of SAE 1040 cold-drawn steel. The gear is made from SAE 8650 OQT 1000 steel The width of the hub of the gear mounted at this location is 45 mm. Design the key. The standard key dimension for a 50-mm-diameter shaft would be 14mm '9 mm Q-1 a rectangular. Material selection is a design decision. Let's choose SAE 1018 steel with s 372 MPa Q-2 It is required to design a square key for fixing gear on a shaft of 25 mm diameter. 15 kW power at 720 rpm is transmitted from the shaft to the gear. The key is made of steel 50C4 (sy 460 MPa) and the factor of safety is 3. The yield strength in compression can be assumed to be equal to the yield strength in tension. Determine the dimensions of the key D 25 mm P W = H 6.25 mm Q-3 A shaft 80 mm diameter transmits power at maximum shear stress of 63 MPa. Find the length of a 20 mm wide key required to mount a pulley on the shaft so that the stress in the key does not exceed 42 MPa.Follow the instructions given in red. DO NOT TYPE IN THESE RED BOXES!

Answer 1

Q-1

yield strength Cald- deawrmsteel ahwing matertal ield SABR680 ORT 100 Steet more yield streugth kay れength. P& key matesrial y Sy 2 3 72 mPa SAB 1018 Steel 2 50 mm ky material, Compression Assume 2 T2 335 Mm Lu 2 45 mw thi yield stamgfh assumed to be egucl Cam be mmt fo tue yield strength m tengion. WメH2 14x9 w2 14 vmw H2 9mm 3T2 Pesuissi ble sPr Cammpressiul au 4+9045 2 3 (63uu 2 194 MP Horl coe teuke fact t sufety a StAsstmeoy of foilube mari wm ACC-to Permudssi ble Ssy 62 mPa Shpar Stass au. 2 4 T Noa x 335x1 6e)aus 2 (24 3 LXSOX9 2 24.0143 mm (て)al. 2 Mows 2x 335 xlO 2 622 人メ50 x |4 2 (8.43 #t mm usuully But Hesre LH46mm th hub (ength of a 9etatr thanm Rar Hameter. or stability. Ha Rey is made 2qual M (emgth Huerotsre hour ounelr hub it ould 4+ 9emgth smce coouls phobeutly Asewer be 4B mm. 50 Limansion 4 Keyt xHx 2 4X9A 45 mm しfnscuee

Q- 2

Perucissible Compriessive Shecar 412985 460 M/mm2 2 6e2 Syc 60 2 (53-3333 Mpe alla 3 Strs6s fueduy Acconding to Sheur maxiuum fuilures 95y20.5 5yt2 03x480 2230 m 230 2 6-606MP aLLL 3 GOP Torgur tremsuitted T2 6 60X10X15 (34943.63 2. w2H2 G.a5m Kay dimanstous ue hawr giORm Horer Etex Qx (399 43.6 2 76.6667 40 Tall 2 1MP 2 34. 6Omm 4T 4 x 194343. 8 2 6aau 2 153-3333 BX6.25 x 2 the lemgth the dimunsions ot tha koy Key shauls be 6X 6x35 mm. 35mm. aure

Perucissible Compriessive Shecar 412985 460 M/mm2 2 6e2 Syc 60 2 (53-3333 Mpe alla 3 Strs6s fueduy Acconding to Sheur maxiuum fuilures 95y20.5 5yt2 03x480 2230 m 230 2 6-606MP aLLL 3 GOP Torgur tremsuitted T2 6 60X10X15 (34943.63 2. w2H2 G.a5m Kay dimanstous ue hawr giORm Horer Etex Qx (399 43.6 2 76.6667 40 Tall 2 1MP 2 34. 6Omm 4T 4 x 194343. 8 2 6aau 2 153-3333 BX6.25 x 2 the lemgth the dimunsions ot tha koy Key shauls be 6X 6x35 mm. 35mm. aure