Project ForgeA power transmission mechanism consists of a belt drive (250mm pulley on the input shaft driven at N=2500 rpm by a 150mm pulley) and a gear train: gear 2 (18T, on the 250mm-pulley shaft) meshes with gear 3 (44T); gear 4 (15T, same shaft as gear 3) meshes with gear 5 (33T); gear 5 meshes with gear 6 (36T); gear 7 (16T) is on the same shaft as gear 6. The speed and direction of rotation of gear 7, respectively, are
- 255.68 rpm; clockwise
- B255.68 rpm; anticlockwise
- C575.28 rpm; clockwise
- D575.28 rpm; anticlockwise
Explanation
Belt: shaft-A speed = 2500×(150/250) = 1500 rpm. Gear2(18T)→Gear3(44T): shaft-B speed = 1500×18/44 ≈ 613.6 rpm. Gear4(15T, same shaft as gear3)→Gear5(33T): shaft-C speed = 613.6×15/33 ≈ 278.9 rpm. Gear5(33T)→Gear6(36T): shaft-D speed = 278.9×33/36 ≈ 255.68 rpm = gear7's speed (same shaft as gear6). Direction follows from the open-belt connection (no reversal) plus three successive external-gear-mesh reversals, matching the key's clockwise sense.
Source: GATE ME 2021 Session 2 (ME-2) (2021)
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