Bearing Maintenance

Question 1

Rapid oxidation of bearing lubricant occurs above _____ degree Celsius.

Answer 1

55

Question 2

If you cannot hold onto the bearing housing surface for more than one second, then the temperature must be at least _____ degrees Celsuis.

Answer 2

60

Question 3

ToF. While a bearing is being run in, the temperature will rise for a few hours then return to normal.

Answer 3

True

Question 4

You can do a quick inspection of dirty oil placing submerging a clean magnet and inspect it for _____ particles.

Answer 4

Magnetic

Question 5

Cause of this bearing noise: Growling

Answer 5

Rollers and/or raceways are deteriorating

Question 6

Cause of this bearing noise: Loud hollow

Answer 6

Too much internal clearance

Question 7

Cause of this bearing noise: High-pitched

Answer 7

Too little internal clearance

Question 8

Cause of: Lubrication oxidation rate doubling every 10 degrees

Answer 8

Bearing temperature exceeding 55 degrees C

Question 9

Cause of: Bearing is too tight for housing bore

Answer 9

Undersized bore or bearing not concentric

Question 10

Cause of: Sludge or varnish present

Answer 10

Lubricant breakdown

Question 11

Cause of: Brinelling

Answer 11

Hammer blows during installation

Question 12

Cause of: False Brinelling

Answer 12

Static bearing subjected to vibration

Question 13

Cause of: Contamination introduced during the assembly/reassembly of machine components

Answer 13

Built-in Contamination

Question 14

Cause of: Bearing contamination

Answer 14

Biggest cause of bearing failure

Question 15

Dust entering through faulty seals

Answer 15

Ingested contamination

Question 16

A device that converts mechanical vibration into an electrical signal is called a _____.

Answer 16

Transducer

Question 17

Bearing Lubrication Method: Oil is circulated through the bearing with a pump, Oil is supplied to the bearing by a slinger ring of by a splash

Answer 17

Hydrodynamic Lubrication

Question 18

Bearing Lubrication Method: Uses pressure rather than velocity to force the lubricant into the loaded area, Lubrication is strictly dependent on an external source of pressure.

Answer 18

Hydrostatic Lubrication

Question 19

Bearing Lubrication Method: A combination of hydrostatic and hydrodynamic

Answer 19

Hybrid Lubrication

Question 20

The hydrostatic supply in an oil lift application is called jacking _____.

Answer 20

Oil

Question 21

ToF. The loaded area of a journal bearing is greater than an anti-friction bearing.

Answer 21

True

Question 22

Sequence of anti-friction bearing lubrication:

Answer 22

1. The surfaces of the rolling elements are wetted by an oil-bath, splashing, oil jet or oil mist.
2. As the bearing rotates, an oil wedges is formed between the rolling elements on each raceway.
3. As the lubricant is forced in to the extreme pressure area under a loaded rolling element, its viscosity suddenly rises to its elasto-dynamic state.
4. As the rolling element passes the load point, the lubricant is released and goes back to its original viscosity.

Question 23

In a closed loop system, air flowing through a fixed orifice will experience a pressure _____ (rise/drop).

Answer 23

Drop

Question 24

In a closed loop system, air flowing through a fixed orifice will experience a velocity _____ (rise/fall)

Answer 24

Rise

Question 25

Lubricant is drawn into the air stream in a oil mist system utilizing the _____ effect.

Answer 25

Venturi