PRESENTATION ON BEARING

WHAT IS BEARING ?

bearing is a machine element that constrains relative motion and reduces friction between moving parts to only the desired motion. The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis.

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When there is relative motion between two machine parts, one of which supports the other, the supporting member is called Bearing. It is a very important element of any machine

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SUPPORTING MEMBER

BEARING

FUNCTION OF BEARING

The Functions of bearing are as follows:1. It bears the load. Bearing must be capable of bearing

dead as well as the live load of the machine2. It locates the moving part in correct position and does

not allow the axis of shaft to move in either direction.3. It minimizes unnecessary motion of the shaft by keeping

less clearance between bearing and shaft4. It provides free motion to the moving part by reducing

friction. More friction consumes more power, which generates more heat and more wear and tear in bearing

Classification of Bearing

1. Sliding contact bearing,2. Rolling contact bearing.

1.Sliding Contact Bearing :Bearings, which run under sliding friction with shaft, is called Sliding Contact Bearing.Bush bearing is a type of bearing coming under this category.

Advantages of Sliding contact bearing

1. It takes less radial space2. It becomes quieter in operation particularly after a suitable running period3. It has unlimited life4. It has less sensitive to injury from contamination and foreign particles5. It is best suited for overloading6. It is easy to manufacture7. It has low cost8. It remains from rust and corrosion

Limitations of Sliding Contact Bearing

1. It requires more attention,2. It requires higher starting torque,3. More lubricant is needed for lubrication,4. Loss of lubricant is more,5. More power is needed for driving,6. More axial space is required.

Rolling Contact Bearing

Bearings, which run under rolling friction with shaft, is called Rolling Contact Bearing. Ball and Roller Bearings are coming under this category of bearing.

Advantages of Rolling Contact bearings

· It requires less starting torque· It consumes less power· It generates less amount of heat· It generates less friction· It has low wear and tear of bearing· It requires less attention· It requires lower axial space required,· It requires less lubricant for lubrications,· It has easy maintenance,· It has more axial rigidity in this case· It is available in various types

Limitations of Rolling Contact Bearing· Manufacturing Process is complex in nature,· Cost of manufacturing is higher,· It has limited life in terms of millions of revolutions,· More sensitive to foreign bodies.· Becomes noisy after some running period· Requires skill full hands while mounting on shaft and machine· If breaks, it can damage shaft, housing, etc.

Why Internal clearance?

Steel will expand with increased temperature. In operation, the temperature of the various parts of a bearing will not remain uniform and resulting in varying degrees of expansion which is compensated by the internal clearance.

( Πx Δ x N XT)

The end