Me 146 (Chap10)

Front 1

Essentially rolling friction exist within these bearing

Back 1

Rolling-element bearings

Front 2

Essentially slinding friction exist

Back 2

Sliding bearing or Sliding-element bearing

Front 3

Support rotating shafts, often reffered to as journals.

Also known as Journal bearings, Plain besrings ans Cylindrical bearings.

Back 3

Radial bearings

Front 4

Any substance that will form a film between the surfaces of a bearing.

May be liquids, solids, gases or combanition of two or all three.

Back 4

Lubricant

Front 5

Oil, Grease, Water, Silicones, Acids, Bases And other fluids.

Back 5

Liquid Lubricants

Front 6

Generaly used graphite, molybdenum disulfide, lead oxide, soap, mica, soapstone, powdered glass and plastics.

Back 6

Solid Lubricants

Front 7

Air, nitrogen, and hydrogen.

Back 7

Gas Lubricants

Front 8

Property which resist shearing of the lubricant.

Back 8

Viscosity of Lubricant

Front 9

Determined by direct measurement of the shear resistance of the lubricants.

Back 9

Absolute viscosity

Front 10

Not determined by direct measurement of shear resistance butby other means.

Back 10

Secondary viscosity

Front 11

Is absolute viscosity divided by the specific gravity of the lubricant.

Back 11

Kinematic viscosity

Front 12

Is the unit of viscosity

(1poise=1dyne-sec/cm^w)

Back 12

Poise

Front 13

Devise and assigned the symbol Z

(1centipoise=0.01poise=0.01 dyne-sec/cm^2)

Back 13

Centipoise

Front 14

The unit of absolute viscosity in English system

Back 14

Reyn

Front 15

Decrease with an increase of temperature, increase with increases pressure.

Back 15

Viscosities of lubricating oils

Front 16

Most common method of obtaining secondary viscosity

Back 16

Saybolt universal viscometer

Front 17

Measure of its change of viscosity with temperature relative to the stsndard oil which exhibits the least change of viscosity with temperature.

Back 17

Viscosity index of an oil

Front 18

Found to exhibit the most nearly constant viscosity-temperature data.

Called as 100 viscosity index oil

Back 18

Pennsylvania oil

Front 19

Exhibited the largest change of viscosity with temperature.

Called as zero viscosity index oil

Back 19

Gulf coast oil

Front 20

A lubricant for which the resisting shear force varies linearly with the shear rate, all other items being held constant.

Back 20

Newtonian lubricant

Front 21

Types of Journal bearing

Back 21

Circular and other than cicular

Front 22

Enclosing 360 deg of the journal

Back 22

Full bearings

Front 23

Enclosing less than 360 deg of the journal.

Back 23

Partial bearings

Front 24

If the diameter of the journal and partial bearing are equal.

Back 24

Fitted bearing

Front 25

Cd/D

Back 25

Diametral clearance ratio

Front 26

The product of L and D.

Back 26

Projected area

Front 27

One in which the length ratio L/D os unity.

Back 27

Square bearing

Front 28

Have length ratios over 1

Back 28

Long bearings

Front 29

Have ratios less than 1.

Back 29

Short bearing

Front 30

Product of absolute viscosity and rotational speed divided by the unit loading.

Back 30

Bearing modulus

Front 31

Lubrication procedures for bearing moduli of M3 and higher, no contract ever occurs between the bearing.

Back 31

Hydrodynamics film lubrication or Hydrodynamic lubrication

Front 32

Said to exist, For moduli of M1 and less, continuous contact occurs between the journal and bearing.

Back 32

Marginal lubrication.

Front 33

Bearings operated with length ratios between ______and______.

Back 33

0.8 and 1.5

Front 34

Designer used a value of ______ for k.

Back 34

0.002

Front 35

Exact solution of the ___________________relation yealding the relationship between the radial-load capacity of hydrodynamically libricated journal bearing and system parameters appears impossible.

Back 35

Navier-Strokes

Front 36

The simplest type of thrust bearing for horizontal shafts.

Back 36

Single collar or mutiple collar thrust bearing.