POWER TRANSMISSION AND SHAFTS

Question 1

Describe the function of a shaft and give an application

Answer 1

Shafts transmit power to a location outside the machine.

Example: A drill Spindle consist of a shaft with a cutter attached.

Question 2

List four (4) types of Shaft Materials

Answer 2

Cold Rolled Steel
Hardened Steel
Chrome Plated Steel
Stainless Steel

Question 3

Describe the function of a bearing

Answer 3

The function of a bearing is to Support and guide a moving machine member with minimum amount of friction.

Question 4

Define three (3) types of bearing loads

Answer 4

Radial
Thrust
Combination

Question 5

For radial loads, use at least _______ bearings to secure the position of the shaft.

Answer 5

Two

Question 6

What are the (2) Bearings Categories

Answer 6

Plain Bearings ( Journal bearing)
Anti-Friction Bearings ( roller/ball Bearings )

Question 7

Describe two (2) methods of mounting a shaft bearing

Answer 7

Pillow Block

Flange

Question 8

A ______ Load acts in a direction that is perpendicular to the direction of force transmission.

Answer 8

Radial

Question 9

A _____ Bearing is the type of bearing in which the surface of the other machine component slide over the bearing surface separated by a film of lubrication

Answer 9

Plain

Question 10

Describe the function of a coupling

Answer 10

A coupling Connects one shaft to another.

EX: connecting electric motors and other prime movers to driven devices like pumps and gear reducers.

Question 11

Name (4) categories of

mechanical couplings

Answer 11

Rigid Couplings
Flexible Couplings
Universal Joints
Clutches

Question 12

Describe the operation of flexible jaw coupling

Answer 12

Flexible coupling connect 2 shafts and allow misalignment

Question 13

What coupling allows zero misalignment

Answer 13

Rigid Coupling

Question 14

______ Couplings are designed to connect (2) shafts that are not coaxially aligned

Answer 14

Universal Joint

Question 15

Name (2) types of shaft misalignment

Answer 15

Angular misalignment

Parallel Misalignment

Question 16

Standard round stock is often not precise enough so designers select _________ stock for most shaft applications.

Answer 16

accuracy

Question 17

The diameter of the accuracy stock shaft is always ______ than the nominal diameter, due to its precision grinding.

Answer 17

Less

Question 18

An _________ load is often called a cantilever load.

Answer 18

overhang

Question 19

All electric motors have________ bearings, one on each side of the housing. These bearings support the motor’s rotor and shaft.

Answer 19

Two

Question 20

The two major categories of bearings used are ______ bearings and anti-friction bearings.

Answer 20

Plain

Question 21

________ bearings are designed to support either radial loads or axial (thrust) loads. The surface of the moving machine component slides over the bearing surface. Ex. the crankshaft of a car engine.

Answer 21

Plain

Question 22

___________ bearings rotate with the moving machine component by using rollers or balls that rotate within the bearing.

Answer 22

Anti-friction

Question 23

There are four general categories of mechanical couplings: rigid couplings, __________ couplings, universal joints, and clutches. They are used to connect one shaft to another.

Answer 23

Flexible

Question 24

_______ couplings couple two shafts together rigidly so that the shafts act as a single continuous assembly and does not allow any misalignment. Used in applications that need very long shaft lengths.

Answer 24

Rigid

Question 25

________ couplings connect two shafts together and allow for some misalignment. Used in applications that require two independently supported coaxial shafts to be coupled together.

Answer 25

Flexible

Question 26

The ___________ joint allows two shafts that are not coaxially aligned to be connected. Ex. papermaking machine requires a motor to drive a roller that is offset from the motor shaft.

Answer 26

Universal

Question 27

________ are designed to allow two turning shafts to connect and disconnect from each other.

Answer 27

Clutches

Question 28

Excessive __________ is known to be a main cause of early failure of equipment.

Answer 28

Vibration

Question 29

Shaft alignment corrects angular and ________ misalignment which is measured on the horizontal and vertical planes.

Answer 29

Parallel

Question 30

To correct the _________ angular misalignment, add shims to the front or back of the motor.

Answer 30

Vertical

Question 31

Four methods of measuring misalignment in order from least accurate to most accurate: straight edge & ______ gauge method, face and rim method, reverse indicator method, and laser alignment.

Answer 31

Feeler