Upload
sachin-salgar
View
1.705
Download
1
Embed Size (px)
Citation preview
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 !!!