Sunday, July 19, 2020

Interview question on bearing

Interview question on bearing

What is bearing and why is it used?

Bearing is machine element, it is use for reduce the friction between two part of the machine, it is also increase the reliability and availability of a machine, and use for increase the life of machine and reduce the down time. There are many factors considered during the selection of appropriate bearing for a machine.

What factors are considered during selection of the machine?

there are many factors needed to be considered during the selection of a bearing are that is mentioned below. Equipment speed, equipment operating load, shaft torque, temperature of services fluid, availability of lubrication system, viscosity of the services fluid, type of load to be act on the machine and others.

What is function of bearing?

The main function of bearing are reducing the friction, support the machine shaft, smooth operation, increase reliability and availability of the machine parts.

How many type of bearing?

Three are many types of bearing but mainly two types of bearing mentioned below.
  • Rolling element bearing

    1. Ball bearing

      1. Deep groove ball bearing
      2. Angular contact ball bearing
      3. Self-align ball bearing
    2. Roller bearing

      1. Taper roller bearing
      2. Cylindrical roller bearing
      3. Needle roller bearing
      4. Spherical roller bearing
  • Plane bearing

    1. Sleeve bearing
    2. Thrust bearing
    3. Flange bearing
    4. Mounted bearing
    5. Spherical bearing
types of bearing


For father classification follow the link basics of bearing

How to calculate bearing life?

The bearing life calculation is based on operating load, operating speed and operating hours. According to ISO 281 the basic bearing rating calculation formula mentioned below, whereas c= basic bearing dynamic rating, p= exponent for bearing life, 3 for ball bearing and, 10/3 for roller bearing, P= dynamic bearing load, L10= basic bearing life (at 90% reliability) millionth of revolution.

bearing life calculation

What is L 10 bearing life?

L 10 means basic bearing life (at required % load reliability) millionth of rotation.

Where are bearings use?

The bearings are used in (small, medium, and heavy) machinery like pump, compressor, turbine, automobile, electrical motor, agriculture machinery, stitching machine, and all types of rotating machinery.

What is the application of bearing?

There are many applications of bearing according to their function. These are mentioned below.
  • Agriculture machine
  • Automobile (heavy and light)
  • Aeroplane
  • Plant machinery like, pump, compressor, turbine, blower and other type of rotating equipment.
  • Power generation equipment and others.

How to select bearing?

For bearing selection there are many factors need to considered
  • Rpm of the equipment
  • Carrying load of the machine shaft
  • Difficulty of installation of bearing
  • Space required for installation
  • Angular and parallel misalignment tolerance
  • Rigidity of the shaft and bearing both
  • Torque generates during operation
  • Lubrication availability
  • Easy to installation and dismantle
  • Thrust generate during operating
  • Viscosity of the fluid

Which alloy metals used to make bearing?

There are many types of alloy used for make bearing like, bronze, aluminium, zinc, lid, tin, antimony and other types of white alloy. These types of alloy are also used for heavy load and high-speed application.

Which type of bearing is used for heavy load and high-speed application?

Ball bearings are used for high speed application and minor misalignment tolerance, due to its point contact configuration. But for more load or heavy-duty application use for roller bearing. During the selection of bearing mainly 3 factors needed to consider temperature, speed and load.

What is radial play in bearing?

The radial play means, balls clearance within the bearing both cages, it is indicated by C1 to C5. Where C1 is tightened and C5 is looser than C2 > C3 > C4 > C5.

How to select lubricant for bearing?

There are three factors that must be considered during selection of bearing that is temperature, speed, and loads carried by the shaft.

What type of bearing use in overhang centrifugal pump?

Mostly angular contact ball bearing and deep groove ball bearing are use in overhang centrifugal pump.

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