Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
95 Cards in this Set
- Front
- Back
What is friction |
Resistance of movement of two surfaces in contact |
|
What are the 3 common forms of friction |
Sliding Rolling Fluid |
|
What form of friction has the most friction |
Sliding |
|
What form of friction has the least friction |
Fluid |
|
What are liquids and gasses both considered |
Fluids |
|
What are 3 important jobs of lubrication |
Reduce friction, Protect against corrosion, Dissipate heat |
|
What is needed to form an oil wedge |
Minimum shaft speed |
|
What are the effects of viscosity on a machines power consumption |
Increased friction increases power consumption |
|
What is the worldwide accepted unit of viscosity measurement |
Centistoke cSt |
|
What is viscosity index |
Change in viscosity over a range of temperatures |
|
What is better a high or low VI |
Higher is better |
|
How do you determine pour point |
3 degrees over the gel temperature |
|
Does w in 10w30 mean weight? |
No |
|
What common percentage of oil are additives |
22 percent |
|
What temp are petroleum based oils stable |
Up to 55 celsius |
|
What temp are synthetic oils good to |
250 celsius |
|
In an oil bath arrangement how high should the oil bath be |
1/2 to 1/3 up the lowest rolling element |
|
What kind of lubrication system are ring and chain |
Mechanical |
|
What is the most suitable type of nozzle for high speed lubrication systems |
Mist nozzle |
|
What is the drop point |
Lowest temperature that the oil separates from the grease |
|
What are the 2 main factors of proper grease selection |
Speed, temperature, and load |
|
Do 90% of bearings fail as a result of over lubricating |
No |
|
How much should you fill a bearing housing with grease |
One third full |
|
What is a load that is perpendicular to the shaft |
Radial load |
|
What is a load in line with the shaft |
Axial load |
|
What are the 2 main functions of journal bearings |
Holds the journal in location and supports intended radial load |
|
Describe the common construction of a thin shell split bearing |
Steel backer Copper middle Babbitt overlay |
|
What 2 seats are available on a thick walled split beating |
Plain and spherical |
|
Is there a difference in load and speed capacity of a split shell vs a solid bushing |
No |
|
What can cause oil whirl |
Unsteady load at high speed |
|
What is one type of bearing that can combat oil whirl |
Lobed bearing |
|
What provides the full film lubrication on hydrostatic bearings |
External pumps |
|
What do hydrodynamic bearings rely on to create full film lubrication |
Rotation |
|
What type of thrust bearing can handle the greatest load and in what direction |
Tilting pad in the axial direction |
|
What property allows abrasives to become entrapped in the bearing material |
Embedability |
|
What property allows the bearing to not weld and seize to the journal during startup |
Compatibility |
|
What ensures good heat transfer in split bushings |
Crush |
|
What are locking tabs and notches good for |
Ensure the split bearing is located properly and will not rotate. |
|
Should you use a soft blow hammer to install a bushing |
No |
|
What are 3 methods to check bearing clearance in journal bearings |
Plastigage Lead wire Direct measurement |
|
What are the components of a roller bearing |
Seals, Raceway, Rolling elements, Outer ring Inner ring Cage |
|
|
Cylindrical roller thrust bearing |
|
|
Four point contact ball bearing |
|
|
Deep groove single row ball bearing |
|
|
Spherical roller bearing |
|
|
Single row tapered roller bearing |
|
|
Thrust ball bearing |
|
What bearing requires the least amount of radial space |
Needle bearing |
|
What rolling element has more contact area ball or roller? |
Roller |
|
What is the designation for a bore taper ratio of 12:1 |
K |
|
What shield type limits the speed of the bearing |
Rubbing seal |
|
What are 3 bearings that handle misalignment |
Carb, Spherical, Self aligning |
|
If the bearing fit in the housing or on the shaft is incorrect but the bearing is in spec what should you do |
Replace or repair the shaft or housing |
|
What type of bearing has a designation starting with 7 |
Single row angular contact |
|
What bearing has a designation of 6 |
Deep groove ball bearing |
|
What is the extra number for in a 5 digit bearing code |
Roller width |
|
What is the inner bore of a bearing with the last 2 digits 02 |
15mm |
|
What size is the bore on a bearing with the last 2 digits 03 |
17mm |
|
What 2 bearing arrangement is the most rigid |
Back to back |
|
What load does the fixed bearing in a fixed/floating setup |
Axial and radial |
|
What supports more load plain or anti friction bearings |
Plain |
|
How can the loaded zone of a tapered roller bearing be increased |
Reduce the clearance |
|
What are 2 ways of measuring how far a bearing has been driven up a tapered adapter sleeve |
Tightening angle, Dial indicator |
|
Where would you check the clearance of a double row spherical roller bearing on a bench |
The top (unloaded zone) |
|
What is the difference between residual and running clerance |
Running clearance is after thermal expansion from operation temperature |
|
If the pillow block is 43 celsius how hot are the rolling elements and inner ring? |
63 celsius rolling elements 73 celsius inner ring |
|
What is the difference between brinelling and false brinelling |
Brinelling is caused by you, false brinelling is caused without you |
|
What are 2 ways for a machine to ingest contamination |
Faulty seals Breather |
|
What are 2 sources for electric arcing in a bearing |
Poor welding procedure, Static buildup in machine |
|
What are 2 main advantages of rubbing seals |
Retain oil, Positively seals from water and fine contaminants |
|
What are 3 ways a lip is Helt to the shaft once installed |
Garter spring Interference fit Gas or liquid pressure |
|
What is most important when handling mechanical seals |
Keep them clean and free from damage |
|
Does the fixed pillow block bearing allow axial expansion |
No |
|
What direction should eccentric collars be installed |
Direction of shaft rotation and locked with a set screw |
|
Why would you use a spherical roller bearing rather than a cylindrical roller bearing |
Axial loads |
|
What needs to be done to a pillow block to control heavy horizontal radial loads |
Welded support blocks |
|
What are 2 tests that can be done to check a bearing while the machine is running |
Listen for irregular sound Vibration analysis |
|
How does the area of contact affect the load bearing ability of a bearing |
Higher contact area = more rolling elements = more load |
|
What type of load shifts through an arc of less that 180° |
Oscillating |
|
Hydrostatic bearings rely on what for lubrication |
External pump |
|
When there is a heavy reversing load what type of bearing/lube system would be needed |
Hydrostatic |
|
What is crush for |
Good heat transfer |
|
What is another name for antirotation device |
Tang |
|
What are 3 methods of measuring bearing clearance |
Bump check Plastigage Feelers |
|
What is the main function of the bearing cage |
Push rolling elements through the unloaded zone |
|
What is the distinct feature of a maximum capacity deep groove ball bearing |
Loading slots |
|
What is the designation for normal clearance |
No designation |
|
What is the most rigid 2 bearing setup |
Back to back |
|
Are cylindrical roller bearings a good choice for axial float |
Yes |
|
What are the first number and last 2 numbers on a deep groove ball bearing with a bore of 17mm |
6 and 03 |
|
What is the taper ratio of k |
12:1 |
|
What is the main disadvantage of a rubbing seal |
Increased friction Increased heat |
|
What type of fit does the rotating element require |
Interference fit |
|
Are bench and running clearance the same |
No bench is before installation and running is installed and at temperature |
|
What is the rule of thumb for setting clearance on a spherical roller bearing with a tapered adapter sleeve |
Final clearance is half of initial clearance |