plain bearings

Question 1

What are two types of plain bearings?

Answer 1

Journal and thrust bearing

Question 2

What are the two main functions of journal bearings?

Answer 2

To support radial load and hold the journal in location accordingly

Question 3

It’s hydrodynamic bearing suitable for slow speed? Why our why not?

Answer 3

No, because the oil wedge will not develop.

Question 4

What must be done before start up to ensure there is no damage to an oil lift bearing?

Answer 4

Jacking oil must be brought up to pressure.

Question 5

Why is circumferential groove required in reciprocating plain bearings?

Answer 5

To distribute the lubricant.

Question 6

List four advantage of Babbitt as a plain bearing material?

Answer 6

High wettability, inexpensive,excellent bondablity, good corrosion resistance, high embeddability, good thermal conductivity.

Question 7

How do you check the contact area of a bearing?

Answer 7

By lightly coating the journal with Prussian. Blue and rotating it inside the shell.

Question 8

How can clearance be adjusted on some connecting rods?

Answer 8

With shims

Question 9

Stationary load means?

Answer 9

One direction (gravity)

Question 10

Oscillating load means?

Answer 10

Load changes less than 180°

Question 11

Reciprocating load means?

Answer 11

Load changes more than 180°

Question 12

3 type of radial loads?

Answer 12

Stationary,oscillating,reciprocating

Question 13

Types of radial bearings?

Answer 13

Split bearing (thin shell type)

Split bearing(thick wall construction) and spherical seat

Question 14

Types of bushings?

Answer 14

Wrapped bushing, solid bushing, floating bushing, water lubricated, pre lubricated,dry lubricated,

Question 15

Wrapped bushing have high fatigue strength true or false?

Answer 15

True

Question 16

Solid bushing they can accommodate deep lubricant grooves. True or false

Answer 16

True

Question 17

Floating bushings supports lightly loaded high speeds shafts such as turbo charges. True or false

Answer 17

True

Question 18

The porous bronze bushing also called sintered or oilite bushing is pre charge with oil by soaking the bushing in oil at ___°C or ___ °F for half hr

Answer 18

90°c or 194°F

Question 19

What are dry lubricated bushing made of slippery material such as?

Answer 19

Graphite or PTFE

Question 20

Hydrodynamic bearings are one of the most widely used types of plain bearing? True or false

Answer 20

True

Question 21

Bearings that reciprocate may include a circumferential oil distribution groove in the middle of the bearing. This groove actually reduces the load rating to about 1/2? True or false

Answer 21

True

Question 22

What is oil whip?

Answer 22

Unsteady load at high speed

Question 23

Plain hydrodynamic bearings are commonly used in?

Answer 23

Turbines of all sizes, gearboxes of all sizes, engines of all sizes, compressors of all sizes and types.

Question 24

Hydrostatic bearings there it’s no minimum speed a load supporting film can be provided at zero speed.True or false?

Answer 24

True

Question 25

Hydrostatic bearings ensures no wear at start up true or false?

Answer 25

True

Question 26

Hydrostatic bearings are used where the shaft load may change suddenly, but shaft position must be accurately maintained?True or false?

Answer 26

True

Question 27

Hybrid bearings they can support a full load only when both hydrodynamic action and hydrostatic action are operating together? True or false

Answer 27

True

Question 28

Types of thrust bearings?

Answer 28

Flate plate,tapered land,tilting pad.

Question 29

What the function of a thrust bearing?

Answer 29

To hold a shaft axial in the required position

Question 30

The tilting pad thrust bearing it’s also known as what?

Answer 30

Kingsbury bearing

Question 31

Babbitt, also be referred to as a white metal alloy, is composed of soft alloys such as?

Answer 31

Tin, lead, copper,antimony.