19-08-2014, 02:41 PM
DESIGN OF DOUBLE VOLUTE CASING OF MONOBLOCK CENTRFUGAL PUMP PROJECT REPORT
DESIGN OF DOUBLE VOLUTE.ppt (Size: 525.5 KB / Downloads: 9)
INTRODUCTION
This present works is done with help of the company named as Deccan Industries Ltd., Ganapathy.
The main product of company was pump sets.
They are manufacturing various type of pump for various application.
But these pumps cant use high head areas and also get low mechanical and hydraulic performance
REASON FOR MODIFICATION
Currently using the pumps having a high radial thrust force
High area of flow and also having a high velocity of flow with low pressure.
The various type of pumps is having low discharge rate and working head.
PROBLEM IDENTIFICATION
In spindle system, Increasing of spindle speed cause
Noise
Chattering
Heat generation
spindle preload
A spindle preload is one of the major factors effecting on machine tool spindle performances. The spindle preload affects its stiffness, rotating accuracy, temperature rise cutting depth and spindle life. The preload force is generated inside of spindle system by negative setting of bearings. We discuss a new method to analyze the preload quantitatively in practical manner
CONVENTIONAL METHODS
There are many methods which have been suggest and used to
monitor and control the machine tool spindle preload
DIMENSIONAL CONTROL METHOD
STARTING TORQUE METHOD
AXIAL STATIC STIFFNESS METHOD
NATURAL FREQUENCY METHOD
STRAIN GAUGE METHOD
ISSUES OF THE CONVENTIONAL METHODS
PURPOSE OF THE PROJECT
For the proper design of machines and machine parts which are subjected to vibratory forces, it is essential to estimate their natural frequencies to avoid resonance conditions.
Bridges, aircraft wings, machine tools, and all other physical structures have natural frequencies. A natural frequency is the frequency at which the structure would oscillate if it were disturbed from its rest position and then allowed to vibrate freely
The purpose of the project is an analytical method, a sample ‘C’ program for a particular type of high speed milling machine to calculate, visualize and validate the natural frequency. These functions are used in vibration analysis
DETERMINATION OF NATURAL FREQUENCY
EQUILIBRIUM METHOD [or NEWTON’S METHOD]
ENERGY METHOD
RAYLEIGH’S METHOD
RAYLEIGH’S METHOD
In this method, the maximum kinetic energy at the mean position (where potential energy is zero) is equal to the maximum potential energy (or strain energy) at the extreme position (where the kinetic energy is zero.)
NATURAL FREQUENCY OF HIGH SPEED MILLING SPINDLE
The high speed milling spindle is a spindle integrated with the motor. So, initially considering the rotor winding is uniformly distributed in shaft.
Natural frequency of milling system =
{Natural frequency of shaft
+ Natural frequency of Ball Bearing
+ Natural frequency of Casing
+ systematic Cutting Load
+ Natural frequency of node dimension ratio}
NATURAL FREQUENCY OF ANGULAR CONTACT BALL BEARING
The natural frequency of angular
contact ball bearing =
where,
=Ball Bearing frequency on the outer ring
=Ball pass frequency on the inner Bearing
= Ball spin frequency
=Cage rotation frequency
The following equations are derived for calculating the ball bearing frequency in spindles
NATURAL FREQUENCY OF SPINDLE CASING
Natural frequency of cage: (Stator casing)
Where.
E = Stator laminar young’s modulus
= Mass and Density
= Average radius of yoke (4 to 9.22 mm)
=Stator yoke thickness ( Number of turns vary from 85.8 to 99.8 mm)
α = Lap winding angle (15°)
CUTTING LOAD CALCULATIONS
Cutting load (Milling)
Where,
Ɩ = length of Tooth various from 6 mm to 15 mm
d = diameter of tooth various from 10 mm to16.88mm
=maximum bending stress
= Transverse cutting force
SYSTEM NATURAL FREQUENCY CALCULATION
Natural frequency of system =
{Natural frequency of shaft
+Natural frequency of Ball Bearing
+ Natural frequency of Casing
+ systematic Cutting Load
+ Natural frequency of node dimension ratio}
= {85 + 388 + 110 + 253 +164}
= 1000 Hz
C-PROGRAM
The program incorporate with all manual calculations instructed to numerical analysis by using of C – PROGRAM
The designer of high speed milling spindle should evaluate the natural frequency by using this program.
CONCLUSION
Natural frequency plays important role in high speed milling machineries which causes machining instability, surface roughness, and tool wear in metal cutting processes. In this project we numerically analysis the natural frequency of the high speed milling spindle and by using the C- program to evaluate the vibration analysis function for various positioning of precision bearings for the requirement of designer’s. This way of effective analysis used to reducing the chatter in machine tool.
This provision of analyzing increases the compatibility of machining operations. The wide spectrum of spindle which implies the main function of all machine tool. While, moving across industrial automation the fast and rapid movement of production needed to improve the profit. In future, the systematic software creating is useful for determining this machine tool natural frequency. this project evaluation gives source for systematic analyzing..