ME 35 KINEMATICS OF MACHINERY

THE RAJAAS ENGINEERING COLLEGE

Vadakkangulam – 627116.

DEPARTMENT OF MECHANICAL ENGINEERING

INTERNAL TEST -II

                                     ME 35 KINEMATICS OF MACHINERY

YEAR /SEM : II/III                                                                           Max. Marks : 50

Date :17-09-‘11                                                                                   Time : 2 hours.                        PART :A

ANSWER ALL QUESTIONS                                              (10 * 2 = 20)  

 

1. Define pitch circle.
2. Define circular pitch
3. Define addendum                                                      
4. Define pressure angle
5. What is meant by velocity of sliding?
6. Define length of path of contact.
7. Define contact ratio.
8. State law of gearing.
9. What is epi-cyclic gear train?
10. What is train value?

PART :B

ANSWER ALL QUESTIONS                                              (3 * 10 = 30)

11. The following data relate to a pair of  20 º involute gear in module 6 mm, Number of teeth on pinion = 17, Number of teeth on gear = 49; Addenda on pinion and gear wheel = 1 module.

Find (a) the number of pairs of teeth in contact,

        (b)The angle turned through by the pinion and the gear wheel when one pair of teeth is in contact, and

              (c)The ratio of sliding to rolling motion when the tip of a tooth on the large   wheel (i) just making contact, (ii) just leaving contact with its mating tooth, and (iii) at the pitch point. 

       12 .A pair of spur wheels with 14 and 21 teeth are of involute profile and pressure angle 16^o.  Find maximum addenda on the pinion and gear wheel to avoid interference if module is 6 mm. Also find the maximum velocity of sliding on either side of the pitch point if pinion runs at 300 rpm.

       13. Two shafts A and B are coaxial. A gear C with 50 teeth is rigidly mounted on shaft A. A compound gear D-E gears with C and on internal gear G. Gear D has 20 teeth and gears with C. Gear E has 35 teeth and gears with an internal gear G. Gear G is fixed and is concentric with the shaft axis. The compounds gear D-E is mounted on a pin which projects from an arm keyed to the shaft B.

            a) Sketch the arrangement.

            b) Find the number of teeth on internal gear G, assuming that all gears have the same module.

            c) If shaft A rotates at 110 rpm, find the speed of shaft B.