Alb Mod Anti Friction A Flashcards
Anti-friction bearings commonly have their inner ring sitting on a shaft when mounted. This inner ring is made of:
Hardened high-grade steel
The surface the rolling members roll on is ground to a fine finish to reduce friction. It is called a:
Raceway
The outer ring is similar to the inner ring except that it sits in a _____ when mounted
Housing
The rolling members support the load and ideally should roll and not slide, skid or drag. This ensures two things: (2)
- Saves power
- Reduces wear
The cage that holds the rolling elements can be mounted in 3 ways: (3)
- Mounted to inner ring
- Mounted to outer ring
- Free of both rings
What are the three functions of a cage or separator? (3)
- Prevents elements from rubbing each other
- Pushes elements through unloaded zone
- Guide elements (with minimum friction)
What are three factors that affect a bearings ability to carry a load? (3)
- Area of contact
- Direction of load
- Loaded zone
Under a ball bearing, the area of contact is circular until a load applies to the ball, then it is:
Elliptical
Under a roller, the area of contact is a narrow rectangle. The size of these areas becomes larger as the size of the ____ increases
Rolling element
The larger the area of contact, the larger the _______.
Load capacity.
Note: this is because the load is distributed over a larger area
If the nominal contact angle is 0° and the load carries at 90° to the shaft axis, the bearing is a ____ load bearing
radial load bearing
If the nominal contact angle is 90° then the load is in line with the shaft axis and the load is _____
Axial or thrust
If the nominal contact angle is between 0° and 90° then the load acts at an angle to the shaft and is considered:
Combination radial and axial
The loaded zone is the:
Section of raceway where rolling elements are under load
Loading zone also depends upon the amount of:
Internal clearance or preload
A larger load zone means that more elements are supporting the load, thus:
Increasing load capacity
This bearing is the most common type of ball bearing. Mainly intended to support radial loads, it can also support combination loads as well as moderate axial loads in both directions. Has a contact angle the changes with the direction of loading, and tolerates very little misalignment.
Single row deep groove ball bearing (or Conrad bearing)
The name Conrad comes from:
The method that Conrad invented for loading the balls into the bearing
Note: allows you to easily remove the balls to inspect raceways on a failed bearing by clamping the bearing in a vice after cutting the cage
The deep groove ball bearing is available in a maximum capacity series. The bearing is similar to a regular deep groove ball bearing, except that it:
Is assembled with more balls
When compared to a regular deep groove ball bearing, the max capacity deep groove ball bearing has a higher radial load capacity, but a smaller:
Axial load capacity
Note: the max capacity version is also more sensitive to misalignment
This type of bearing provides a higher radial load capacity without increasing radial dimensions. However, because it has filling slots, it’s restricted to mainly radial loads
double row deep grove ball bearing
This type of bearing is used when alignment is impractical or impossible to maintain, often due to shaft deflection. Can support small thrust loads, and has speed ratings similar to a single row deep groove ball bearing. Also required for shafts that operate at high speeds with extreme accuracy
Internally self aligning ball bearing
Note: these bearings an never exert a bending influence on the shaft
This type of bearing has a spherically ground outer ring that mounts in a special housing. Allows for misalignment, but does not perform well with shaft wobble.
Externally self aligning ball bearing
Compared to externally self aligning bearings, internally self aligning bearings: (3)
- support smaller axial loads
- Same speed rating
- More suitable for shaft wobble
Single row angular contact bearings can accommodate what kinds of loads?
radial and thrust
The axial load capacity of a single row angular contact bearing increases with an increase in the:
Contact angle
Note: these are available in various contact angles
The low shoulder of a single row angular contact bearing allows you to install a greater number of balls, which:
Gives higher load ratings
With single row angular contact bearings, you can move the inner or outer rings axially, which adjusts:
Internal clearance or preload
Single row angular contact bearings are available in both ___ and ___ series
Standard and precision.