Bearings

Bearings
• The interface between moving parts that should minimize friction and wear.

Plain Bearings
• Generally used in low speed machines.
• The main bearing action comes from the lubricant.

Solid Bearings
• This looks like a section of tube that is placed in a hole, and the shaft rotates inside.
• Typical materials are,
- bronze
- sintered bronze (with graphite)
- cast iron
• Made for slowly rotating equipment
• lubrication is required, and problems will arise when not properly maintained.
• Available in standard sizes.

Split Bearings

• Used on large machines at low speeds.
• The two halves of the bearings are adjusted in position using shims.
• Typical materials include,
- bronze
- bronze with babbitt
- babbitt lined metal
• Oil grooves are used for lubrication.



Thrust Bearings
• Opposses axial thrusts of rotating shafts.
• Uses shoes of a variety of shapes,
- flat
- kidney shaped
• An oil wedge approach is used to support the bearing.

Rolling Bearings
• Advantages,
- low friction at all times
- compact
- high accuracy
- low wear
- come in standard sizes

Ball Bearings
• Low friction, high speeds, low loads.
• ball bearings are packed between two rotating rings.
• The grooves that contain the ball bearings is given different shapes for different loading conditions.

Roller Bearings
• For heavy loads at medium or high speeds.
• The various roller bearings are designed for loads (radial and axial) and packing space.

Thrust Bearings
• A set of rollers or balls are held between two washers.
• Designed mainly for lower speed axial loads and occasionally light radial loads.