Anti-Friction Bearings

Question 1

What are the main functions of the rolling elements?

Answer 1

• To support the load
• Roll at all times
• To replace sliding friction with rolling friction

Question 2

What factors affect the bearings ability to carry load?

Answer 2

• area of contact
• direction of load
• degrees loaded zone

Question 3

What is the area of contact on a ball bearing versus a roller bearing?

Answer 3

Ball bearing- circular until load applied to ball then elliptical

Roller bearing- narrow rectangle, contact areas larger as rolling element size decreases

Question 4

What are the three directions of load?

Answer 4

Radial load, axial load, and combination load

Question 5

What is the loaded zone on what factors can change it?

Answer 5

Area loaded on the bearing. Depends on direction of load, internal clearances

Question 6

List some characteristics of single row deep groove ball bearings

Answer 6

• general purpose
• mostly for radial load
• supports combination and moderate axial loads
• Contact angle changes with direction of load
• tolerates a small amount of misalignment

Question 7

What is different about a maximum capacity deep groove ball bearing?

Answer 7

• loading slots are machined into the raceways to accept more balls
• higher radial load capacity, lower axial load capacity
• sensitive to misalignment

Question 8

What is different about a double load deep groove ball bearing?

Answer 8

• Provides higher radial load capacity without increasing radial dimensions
• Restricted to radial loads

Question 9

What are some characteristics of internally self-aligning ball bearings?

Answer 9

• used when alignment is impractical or impossible to maintain possibly due to shaft deflection
• often used at coupling end of overhung shaft in combination with other bearing
• supports only small thrust in either direction
• speed rating is same as single row deep groove ball bearings
• available with tapered bore and can be located anywhere on shaft
• used in high-speed high-accuracy applications

Question 10

What are some characteristics of externally self-aligning ball bearings

Answer 10

• Spherically ground outer ring mounts into special housing

- outer ring allows for misalignment in mounting

Question 11

What are some characteristics of single row angular contact bearings?

Answer 11

• accommodate radial and thrust loads
• can mount in tandem
• axial load capacity increases with increase in contact angle
• Low shoulder allows higher number of balls
• Inner and outer rings can be moved to adjust clearance
• Available in standard or precision series

Question 12

What are three arrangements for pairs of single row angular contact bearings?

Answer 12

• face to face
• back to back
• in tandem

Question 13

What are some characteristics of double row angular contact bearings?

Answer 13

• takes heavy radial and axial loads in both directions
• speed rating is lower than deep groove or single row angular
• cannot tolerate misalignment

Question 14

What are some characteristics of the four point angular contact ball bearing?

Answer 14

-Can only be used for axial or combination loads
Can handle reverse axle loads (Gothic Arch)
-it is a separable bearing with a split inner ring
-Can be manufactured with large number of balls
Often used as thrust bearing with radial clearance
-tolerates minimalmisla

Question 14

What are some characteristics of the four point angular contact ball bearing?

Answer 14

-Can only be used for axial or combination loads
Can handle reverse axle loads (Gothic Arch)
-it is a separable bearing with a split inner ring
-Can be manufactured with large number of balls
Often used as thrust bearing with radial clearance
-tolerates minimalmisla

Question 14

What are some characteristics of the four point angular contact ball bearing?

Answer 14

• Can only be used for axial or combination loads
• Can handle reverse axle loads (Gothic Arch)
• it is a separable bearing with a split inner ring
• Can be manufactured with large number of balls
• Often used as thrust bearing with radial clearance
• tolerates minimal misalignment

Question 15

What are some characteristics of a ball thrust bearing?

Answer 15

• Pure thrust only
• One or two direction thrust or one direction self-aligning thrust
• non self-aligning cannot tolerate misalignment between shaft and housing
• speed limit is half the limit for a radial load bearing
• intended for slow speeds

Question 16

What are four types of roller bearings?

Answer 16

• cylindrical
• needle
• tapered
• spherical

Question 17

What are some characteristics of cylindrical roller bearings?

Answer 17

• Separable in two directions and can only bear radial loads
• Larger contact area than ball bearing in same diameter
• Can only handle small amount of misalignment

Question 18

What are three common types of needle bearings?

Answer 18

• no cage or inner ring
• drawn steel cup and no inner ring
• Machined inner and outer rings

Question 19

What is the difference between a roller and a needle rolling element?

Answer 19

Needles are similar to rollers but they are two and a half to 10 times length to diameter ratio

Question 20

What are some advantages of needle bearings?

Answer 20

• their smaller diameter allows use wherespace is limited

- extended length gives high load capacity

Question 21

What are some characteristics of tapered roller bearings?

Answer 21

• tapered raceways allow heavy combined loads in one direction
• used in pairs to accommodate reversing loads and avoid separation
• their tapered design allows internal clearances to be set by moving cup and cone closer or further apart
• tolerate little misalignment