Design of Spur Gears · Machine Design · GATE ME

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

Two mating spur gears have $$40$$ and $$120$$ teeth respectively. The pinion rotates at $$1200$$ $$rpm$$ and transmits a torque of $$20N.m.$$ The torque transmitted by gear is

The minimum number of teeth on the pinion to operate without interference in standard full height involute teeth gear mechanism with $${20^ \circ }$$ pressure angle is

Large speed reductions (greater than $$20$$) in one stage of gear train are possible through

A $$1.5$$ $$kW$$ motor is running at $$1440$$ rev/min. It is to be connected to a stirrer running at $$36$$ rev/min. the gearing arrangement suitable for this application is

To make a worm drive reversible, it is necessary to increase

In spur gears, the circle on which the involute is generated is called the

Match the following:
List-$${\rm I}$$
(A) Worm gears
(B) Cross helical gears
(C) Bevel gears
(D) Spur gears

List-$${\rm I}{\rm I}$$
1. Parallel shafts
2. Non-parallel, intersecting shafts
3. Non-parallel, non-intersecting shafts
4. Large speed ratios

Interference in a pair of gears is avoided, if the addendum circles of both the gears intersect common tangent to the base circles with in the points of tangency.

For a pinion of $$15$$ teeth, under cutting ____________( increases / decreases) with _______________(increases / decreases ) of pressure angle.

Modern gear both profile is given involute shape because

For full depth of involute spur gears, minimum number of teeth of pinion to avoid interference depends upon

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 $${20^ \circ }$$. 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 _________

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

A $${20^ \circ }$$ full depth involute spur pinion of $$4mm$$ module and $$21$$ teeth is to transmit $$15kW$$ at $$960rpm.$$ Its face width is $$25mm.$$

Given that the tooth geometry factor is $$0.32$$ and the combined effect of dynamic load and allied factors intensifying the stress is $$1.5;$$ the minimum allowable stress (in $$MPa$$) for the gear material is

A $${20^ \circ }$$ full depth involute spur pinion of $$4mm$$ module and $$21$$ teeth is to transmit $$15kW$$ at $$960rpm.$$ Its face width is $$25mm.$$

The tangential force transmitted (in N) is

A spur gate has a module of $$3mm,$$ number of teeth $$16,$$ a face width of $$36mm$$ and a pressure angle of $${20^ \circ }$$. It is transmitting a power of $$3KW$$ at $$20rev/s.$$ Taking a velocity factor of $$1.5$$ and a form factor of $$0.3,$$ the stress in the gear tooth is about

Match the type of gears with their most appropriate description

Type of gear
(P)$$\,\,\,\,\,$$ Helical
(Q)$$\,\,\,\,\,$$ Spiral Bevel
(R)$$\,\,\,\,\,$$ Hypoid
(S)$$\,\,\,\,\,$$ Rack and pinion

Description
1.$$\,\,\,\,\,$$ Axes non parallel a and non intersecting
2$$\,\,\,\,\,$$. Axes parallel and teeth are inclined to the axis
3.$$\,\,\,\,\,$$ Axes parallel and teeth are parallel to the axis
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

One tooth of 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 closest to

A gear set has a pinion with $$20$$ teeth and a gear with $$40$$ teeth. The pinion runs at $$30rev/s$$ and transmits a power of $$20KW$$. The teeth are on the $${20^ \circ }$$ full-depth system and have a module of $$5mm.$$ The length of the line of action is $$19mm.$$

The center distance for the above gear set in $$mm$$ is

A gear set has a pinion with $$20$$ teeth and a gear with $$40$$ teeth. The pinion runs at $$30rev/s$$ and transmits a power of $$20KW$$. The teeth are on the $${20^ \circ }$$ full-depth system and have a module of $$5mm.$$ The length of the line of action is $$19mm.$$

The resultant force on the contacting gear tooth is $$N$$ is

A gear set has a pinion with $$20$$ teeth and a gear with $$40$$ teeth. The pinion runs at $$30rev/s$$ and transmits a power of $$20KW$$. The teeth are on the $${20^ \circ }$$ full-depth system and have a module of $$5mm.$$ The length of the line of action is $$19mm.$$

The contact ratio of the contacting tooth is

Twenty degree full depth involute profiled $$19$$-tooth pinion and $$37$$-tooth gear are in mesh. If the module is $$5mm,$$ the center distance between the gear pair will be

A compacting machine shown in the figure below is used to create a desired thrust force by using a rack and pinion arrangement. The input gear is mounted on the motor shaft. The gears have involutes teeth of $$2$$ $$mm$$ module.

If the pressure angle of the rack is $${20^ \circ },$$ the force acting along the line of action between the rack and the gear teeth is

A compacting machine shown in the figure below is used to create a desired thrust force by using a rack and pinion arrangement. The input gear is mounted on the motor shaft. The gears have involutes teeth of $$2$$ $$mm$$ module.

If the drive efficiency is $$80\% ,$$ the torque required on the input shaft to create $$1000N$$ output thrust is

In order to test the efficiency of reducer gear train $$1kW$$ input was given at the input end at a speed of $$1440$$ $$rpm$$ and at the output end the measured torque was $$56.36$$ $$N.m.$$ If the ratio of speed reduction in this unit is $$10:1,$$ the efficiency is about