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1. Design a pair of spur gears to transmit 20KW from a shaft rotating at 1000

rpm to a parallel shaft which is to rotate at 310 rpm. Assume the Number of

teeth on Pinion is 31 and 200 full depth involute tooth form.

2. It is required to transmit 15 KW power from a shaft running at 1200 rpm to a

parallel shaft with speed reduction of 3. The centre distance of shafts to be300mm. The material used for pinion is steel ( d=200MPa) and for gear is

(d=140MPa). Service factor is 1.25 and tooth profile is 200 full depths

involute. Design the spur gear and check for dynamic and wear load.

3. A compressor requiring 90KW to run at 250 rpm. The drive is V-belt by from

an electric motor running at 750rpm. The diameter of the pulley on the

compressor shaft is 1m, while the centre distance between the pulleys is

limited to 1.75m. the belt should not exceed 1600 m /min. Determine the

number of V-belts required to transmit the power if each belt has a cross

sectional area of 375mm2 and density of 1Mg/mm3 and has an allowable

stress of 2.5N/ mm2. The groove angle of pulley is 350 and the Coefficient offriction between the belt and the pulley is 0.25.

4. Select a 6X19 steel rope to lift 15 KN of debris from a tunnel 200m deep. The

bucket weighs 8 KN. The velocity of the rope is 100m/min to be attained in 20

seconds. What will be the maximum load on the rope when there is slack of

10m in the rope?

5. A roller chain is to transmit 66.24 KW from a 17 tooth sprocket to a 34 tooth

sprocket at a pinion speed of 300 rpm. The loads are moderate shock. The

equipment is to run 18 hours/ day. Specify the length and size of the chain

required for a center distance of about 25 pitches.

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1.

Design a bronze spur gear 81.4MN/m2 and mild steel pinion 101 MN/m2 to

transmit 5 KW at 1800 rpm. The velocity ratio is 3.5:1. Pressure angle is 14

. Not less than 15 teeth are to be used on either gear. Determine the moduleand face width. Also, suggest suitable surface hardness for the weaker

member based on dynamic and wear considerations.

2.

In an automobile gear box, the second speed gear shaft is to be driven from

main shaft with velocity ratio 1.5:1. Main shaft transmits 12 kw at 3000 rpm.

The shaft centre distance = 80mm Pinion material is cast steel heat treated

and gear material is cast steel untreated. Profile of the gear is 20 Stub

involute. Determine a) Module, b) face width c) Number of teeth on pinion

and gear.

3.

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A nylon core flat belt 200mm wide weighing 20 N/m, connecting a 300mm

diameter pulley to a 900mm diameter driven pulley at a shaft spacing of 6m,

transmits 55.2 kw at a belt speed of 23m/sec I ) calculate the belt length and

the angles of wrap ii) compute the belt tensions based on a coefficient of

friction 0.38.

4.

Select a V- belt drive to transmit 10 kw of power from a pulley of 200mm

diameter mounted on an electric motor running at 720 rpm to another pulley

mounted on compressor running at 200rpm. The service is heavy duty varying from

10 hours to 14 hours per day and centre distance between centre of pulleys is

600mm.

5.

Select a suitable wire rope to raise a load of 10kN through a height of 400m. The

desired velocity of 20m/min is to be achieved while traversing through a distance of

10m from the start.

6.

Select a chain drive to a actuate a compressor from 10kw electric motor at 970rpm,

the compressor rpm being 350. Minimum centre distance should be approximately

560mm. The chain tension may be adjusted by shifting the motor on rails.

Compressor is to work for 10 hours/day.