Questions & Answers of Gears and Gear Trains

Question No. 46

In the gear train shown, gear 3 is carried on arm 5. Gear 3 meshes with gear 2 and gear 4. The number of teeth on gear 2, 3, and 4 are 60, 20, and 100, respectively. If gear 2 is fixed and gear 4 rotates with an angular velocity of 100 rpm in the counterclockwise direction, the angular speed of arm 5 (in rpm) is

 

Question No. 213

A gear train is made up of five spur gears as shown in the figure. Gear 2 is driver and gear 6 is driven member. N2, N3, N4, N5 and N6 represent number of teeth on gears 2,3,4,5, and 6 respectively, The gear(s) which act(s) as idler(s) is/ are

Question No. 42

A pair of spur gears with module 5 mm and a center distance of 450 mm is used for a speed reduction of 5:1. The number of teeth on pinion is _______

Question No. 150

A spur pinion of pitch diameter 50 mm rotates at 200 rad/s and transmits 3 kW power. The pressure angle of the tooth of the pinion is 20°. Assuming that only one pair of the teeth is in contact, the total force (in newton) exerted by a tooth of the pinion on the tooth on a mating gear is _______

Question No. 221

Gear 2 rotates at 1200 rpm in counter clockwise direction and engages with Gear 3. Gear 3 and Gear 4 are mounted on the same shaft. Gear 5 engages with Gear 4. The numbers of teeth on Gears 2, 3, 4 and 5 are 20, 40, 15 and 30, respectively. The angular speed of Gear 5 is

Question No. 318

Which one of the following is used to convert a rotational motion into a translational motion?

Question No. 343

It is desired to avoid interference in a pair of spur gears having a 20° pressure angle. With increase in pinion to gear speed ratio, the minimum number of teeth on the pinion

Question No. 32

A compound gear train with gears P, Q, R and S has number of teeth 20, 40, 15 and 20, respectively. Gears Q and R are mounted on the same shaft as shown in the figure below. The diameter of the gear Q is twice that of the gear R. If the module of the gear R is 2 mm, the center distance in mm between gears P and S is

Question No. 8

The following are the data for two crossed helical gears used for speed reduction:
Gear I : Pitch circle diameter in the plane of rotation 80 mm and helix angle 30º
Gear II : Pitch circle diameter in the plane of rotation 120 mm and helix angle 22.5º
If the input speed is 1440 rpm, the output speed in rpm is

Question No. 11

Tooth interference in an external involute spur gear pair can be reduced by

Question No. 34

For the epicyclic gear arrangement shown in the figure, ω2 =100rad / s clockwise (CW) and ωarm =80rad / s counter clockwise (CCW). The angular velocity ω5 (in rad/s)

Question No. 36

An epicyclic gear train is shown schematically in the adjacent figure.

The sun gear 2 on the input shaft is a 20 teeth external gear. The planet gear 3 is a 40 teeth external gear. The ring gear 5 is a 100 teeth internal gear. The ring gear 5 is fixed and the gear 2 is rotating at 60 rpm ccw (ccw=counterclockwise and cw=clockwise).

The arm 4 attached to the output shaft will rotate at

Question No. 43

Match the type of gears with their most appropriate description.

  Type of gear         Description
P Helical 1 Axes non parallel and non intersection
Q Spiral Bevel 2 Axes parallel and teeth are inclined to the axis
R Hypoid 3 Axes are parallel and teeth are parallel to the axis
S Rack and pinion 4 Axes are perpendicular and intersecting, and teeth are inclined to the axis
    5 Axes are perpendicular and used for large speed reduction
    6 Axes parallel and one of the gears has infinite radius

Question No. 62

One tooth of a gear having 4 module and 32 teeth is shown in the figure. Assume that the gear tooth and the corresponding tooth space make equal intercepts on the pitch circumference. The dimensions ‘a’ and ‘b’, respectively, are closed to

Question No. 71

A gear set has a pinion with 20 teeth and a gear with 40 teeth. The pinion runs at 30 rev/s and transmits a power of 20 kW. The teeth are on the 20° full – depth system and have a module of 5 mm. The length of the line of action is 19 mm.

The center distance for the above gear set in mm is

Question No. 72

A gear set has a pinion with 20 teeth and a gear with 40 teeth. The pinion runs at 30 rev/s and transmits a power of 20 kW. The teeth are on the 20° full – depth system and have a module of 5 mm. The length of the line of action is 19 mm.

The contact ratio of the contacting tooth is

Question No. 73

A gear set has a pinion with 20 teeth and a gear with 40 teeth. The pinion runs at 30 rev/s and transmits a power of 20 kW. The teeth are on the 20° full – depth system and have a module of 5 mm. The length of the line of action is 19 mm.

The resultant force on the contacting gear tooth in N is