POWER TRANSMISSION AND SHAFTS Flashcards
Describe the function of a shaft and give an application
Shafts transmit power to a location outside the machine.
Example: A drill Spindle consist of a shaft with a cutter attached.
List four (4) types of Shaft Materials
Cold Rolled Steel
Hardened Steel
Chrome Plated Steel
Stainless Steel
Describe the function of a bearing
The function of a bearing is to Support and guide a moving machine member with minimum amount of friction.
Define three (3) types of bearing loads
Radial
Thrust
Combination
For radial loads, use at least _______ bearings to secure the position of the shaft.
Two
What are the (2) Bearings Categories
Plain Bearings ( Journal bearing) Anti-Friction Bearings ( roller/ball Bearings )
Describe two (2) methods of mounting a shaft bearing
Pillow Block
Flange
A ______ Load acts in a direction that is perpendicular to the direction of force transmission.
Radial
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
Plain
Describe the function of a coupling
A coupling Connects one shaft to another.
EX: connecting electric motors and other prime movers to driven devices like pumps and gear reducers.
Name (4) categories of
mechanical couplings
Rigid Couplings
Flexible Couplings
Universal Joints
Clutches
Describe the operation of flexible jaw coupling
Flexible coupling connect 2 shafts and allow misalignment
What coupling allows zero misalignment
Rigid Coupling
______ Couplings are designed to connect (2) shafts that are not coaxially aligned
Universal Joint
Name (2) types of shaft misalignment
Angular misalignment
Parallel Misalignment
Standard round stock is often not precise enough so designers select _________ stock for most shaft applications.
accuracy
The diameter of the accuracy stock shaft is always ______ than the nominal diameter, due to its precision grinding.
Less
An _________ load is often called a cantilever load.
overhang
All electric motors have________ bearings, one on each side of the housing. These bearings support the motor’s rotor and shaft.
Two
The two major categories of bearings used are ______ bearings and anti-friction bearings.
Plain
________ 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.
Plain
___________ bearings rotate with the moving machine component by using rollers or balls that rotate within the bearing.
Anti-friction
There are four general categories of mechanical couplings: rigid couplings, __________ couplings, universal joints, and clutches. They are used to connect one shaft to another.
Flexible
_______ 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.
Rigid
________ couplings connect two shafts together and allow for some misalignment. Used in applications that require two independently supported coaxial shafts to be coupled together.
Flexible
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.
Universal
________ are designed to allow two turning shafts to connect and disconnect from each other.
Clutches
Excessive __________ is known to be a main cause of early failure of equipment.
Vibration
Shaft alignment corrects angular and ________ misalignment which is measured on the horizontal and vertical planes.
Parallel
To correct the _________ angular misalignment, add shims to the front or back of the motor.
Vertical
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.
Feeler
