Rolling Contact Bearings, Spur Gears and Helical Gears topics include: Bearings and its types, load carrying capacities, sliding contact bearings, viscosity, spur gears and its terminology, gear trains and helical gears. Here's what you should know about spur gears, helical gears, and rolling contact bearings: Spur gears: A cylindrical gear with teeth that are parallel to the shaft. Spur gears are the most popular type of cylindrical gear and are used to transfer mechanical motion. They are simple, efficient, and versatile, and are often used in applications where the rotational motion... Show more

Rolling Contact Bearings, Spur Gears and Helical Gears topics include: Bearings and its types, load carrying capacities, sliding contact bearings, viscosity, spur gears and its terminology, gear trains and helical gears.

Here's what you should know about spur gears, helical gears, and rolling contact bearings:
Spur gears: A cylindrical gear with teeth that are parallel to the shaft. Spur gears are the most popular type of cylindrical gear and are used to transfer mechanical motion. They are simple, efficient, and versatile, and are often used in applications where the rotational motion between two shafts needs to be parallel and coplanar.
Helical gears: A simple machine that controls the direction or strength of a force. Helical gears are used in applications that require high speeds, significant power transmission, or noise reduction. They are known for their smooth and efficient power transmission, making them a popular choice in industries such as automotive, manufacturing, and robotics.
Rolling contact bearings: When choosing bearings, consider the rated speed, dynamic axial or thrust load, and dynamic radial load. Helical gears require thrust or roller bearings, which are typically larger (and more expensive) than the simple bearings used with spur gears.

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Machine Design Practice Test: Rolling Contact Bearings, Spur Gears and Helical Gears

Time left 00:00

25 Questions

1. Deep groove ball bearings creates a lot of noise.

They create very less noiseNo reference frame for comparison is mentionedDepends on the applicationYes

2. A gear train consist of spur gear as shown. Gear A receives 4kW of power at 750rpm through its shaft and rotates in CW direction. Calculate the torque on the gear B.

0Infinity47N-m51N-m

3. Needles bearing consist of rollers of small diameter and very small length.

MaybeDon't KnowTrueFalse

4. Cylindrical load bearing has lower load capacity as compared to deep groove ball bearing.

FalseTrueMaybeDon't Know

5. The bearing is subjected to a radial load of 4000N. Expected life for 90% bearings is 9000h and shaft is rotating at 1500rpm. Calculate the dynamic load capacity.

35.22kN37.29kN42.21kN26.33kN

6. For a hydrostatic thrust bearing,
Thrust load=450kN, shaft speed=730rpm, shaft diameter=450mm, recess diameter=310mm,film thickness=0.15mm,viscosity of lubricant=160SUS and specific gravity=0.86.
Calculate power loss in pumping.

2.68kW2.6kW3.35kW4.2kW

7. Which of the following are true for worm gears?

Worm imposes high thrust loadsThreads on the worm have small leadCharacterised by low speed reduction ratioWorm is in the shape of threaded screw

8. Backlash is defined as

Difference in the width of tooth space and engaging tooth thicknessOther name for interferenceNone of the listedAmount by which engaging tooth thickness exceeds the tooth space

9. Which of the following are true about epicyclic gear train?

Fixed gear is called sun gearRotating gear are called earth gearCrank is called sun carrierNone of the listed

10. There are ____ standard systems for the shape of gear teeth.

3124

11. A gear train consist of spur gear as shown. Gear A receives 4kW of power at 750rpm through its shaft and rotates in CW direction. A gear train consist of spur gear as shown. Gear A receives 4kW of power at 750rpm through its shaft and rotates in CW direction. Calculate the torque on the gear C if number of teeth on gear A, B and C are 40, 70 and 30.

53N-m68N-m66N-m45N-m

12. Fitted bearing must be partial bearing.

NoNo lubricating space is requiredTrueCan’t be stated

13. Sliding contact bearings, also called plain bearings have no problem of wear.

MaybeFalseDon't KnowTrue

14. In hydrodynamic lubrication, film thickness remains unaffected by change in speeds.

Disappear as the speed tends to infintyDecrease with increase in speedTrueIncrease with increase in speed

15. Newton law of viscosity states that shear stress is proportional to rate of shear at any point in the fluid.

Don't KnowFalseTrueMaybe

16. A pair of spur gears consist of 25 teeth pinion meshing with a 115 teeth gear. The module is 5mm. Calculate the addendum.

4.75mm5.25mmNone of the listed5mm

17. A compound gear train consists of at least 3 shafts connected to each other.

TrueDon't KnowMaybeFalse

18. Diameteral pitch is 5, then calculate module of the gear.

1050.20.4

19. For a hydrostatic thrust bearing,
Thrust load=450kN, shaft speed=730rpm, shaft diameter=450mm, recess diameter=310mm, film thickness=0.15mm, viscosity of lubricant=160SUS and specific gravity=0.86.
Calculate flow requirement

38.94l/min0.89l/s28.8l/minNone of these

20. In cycloidal gears contact area is

Comparatively smallerCan’t be determinedComparatively largerNone of the listed

21. A planetary gear train is shown in the figure. Number of teeth on the sun gear A, planet gear B and fixed ring gear D are given by 30, 70 and 140 respectively. Module is taken as 5mm. Calculate the length of the arm C.

Missing data330mm240mm250mm

22. Which of the following have stronger teeth?

Stub teethBoth have equal strengthFull depth teethCan’t be determined

23. If driving gear rotates CW, driven gear will rotate?

Both CW and ACWCWCan’t be determinedACW

24. The angular play bearing must be mounted without axial play.

Can’t be statedLittle tolerance is adjustedYesLittle tolerance is necessary

25. The teeth of the helical gears are cut parallel to the shaft axis.

MaybeFalseTrueDon't Know