antifriction bearings

SPM POLYTECHNIC KUMTHE , SOLAPUR

Antifriction Bearings

SEMINAR ON

Sachin B. Salgar

Roll no :- 1240

A bearing is a machine element which support another moving

element (known as journal).

It permits a relative motion between the contact surfaces of the members,

while carrying the load.

INTRODUCTION

FUNCTIONS OF BEARINGS

The bearing supports the shaft as the axle and holds it in correct position with respect to frame or casing

The bearing ensure free rotation of the shaft or axle with minimum friction.

The bearing takes up the forces acting on the shaft or the axle and transmits to the frame or casing.

Sliding contact bearingHydrodynamic bearingHydrostatic bearing

Rolling contact bearing.Ball bearingRoller bearing

classification of bearings

According to nature of relative motion between two contacting surface

Hydrodynamic bearing

Load supporting high pressure fluid film is created due to the shape and relative motion between the two surfaces

HYDROSTATIC BEARING

The load supporting fluid film is created by an external source, like pump.

GUIDE BEARING

The relative sliding motion between the two parts is linear

Eg.. Guide ways of lathe machine

JOURNAL (SLEEVE) BEARING

If the relative sliding motion between the two parts is of rotation and the pressure on the bearing is perpendicular to the axis of the shaft, then the bearing is known as journal or sleeve bearing.

THRUST BEARING

If the relative sliding motion between the two parts is of rotation and the pressure on the bearing is parallel to the axis of the shaft, then the bearing is known as thrust bearing

ROLLING CONTACT BEARING

Ball bearing

In ball bearing spherical balls are used as a rolling element.

The contact between the inner race and the ball or the outer race is a point contact.

So it is higher pair.

ROLLER BEARING

The roller bearings use the cylindrical rollers, taper rollers, or spherical rollers as the rolling elements.

The contact between the two race is line contact.

APPLICATIONS OF ROLLING CONTACT BEARING

o Industrial and automotive gear boxes and at different automobile.

o Electric motors.

o Machine tool spindle.

o Small size centrifugal pumps.

o Automobile front and rear axles.

ADVANTAGES Ability to resist the shock load.

Easy for mounting.

Low starting and running friction except high speed

More accuracy in shaft alignment.

Compact required less space.

Low maintenance cost because no lubrication required during operation.

CONCLUSION

Bearings are necessary while transferring the motion from one shaft to another for avoiding the friction and reducing the losses due to friction.

For heavy axial load with high rotational speed rolling contact bearings are suitable.

REFRENCE

http/google.com/Hydrodynamic Bearing Construction, Working and Advantages of Hydrodynamic Bearings.htm

http/google.com/Bearing (mechanical) - Wikipedia, the free encyclopedia.htm

Design of machine element- S.D.Ambatkar Machine design –R.S.Khurmi, J.K. Gupta

THANK YOU !!!