22.322 mechanical design ii
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22.322 Mechanical Design II. Spring 2013. Exam #1 Re-do Problem Solutions. Problem 3. N2=35 N3=(2.5)(10) = 25 N4=55 N5=(7)(5)=35 N6=(9)(5)=45. +2. +2. +2. Exam #1 Re-do Problem Solutions. Problem 4. Lecture 18. Balancing. - PowerPoint PPT PresentationTRANSCRIPT
Learning with Purpose March 20, 2013Learning with Purpose March 20, 2013
22.322 Mechanical Design II
Spring 2013
Learning with Purpose March 20, 2013
Exam #1 Re-do Problem Solutions
Problem 3
N2=35N3=(2.5)(10) = 25N4=55N5=(7)(5)=35N6=(9)(5)=45
+2
+2
+2
Learning with Purpose March 20, 2013
Exam #1 Re-do Problem Solutions
Problem 4
Learning with Purpose March 20, 2013
Rotating parts should be designed to be inherently balanced by their geometry.An unbalance in machines is attributed to irregularities such as machining errors, size variation in bolts, nuts, welds, etc., wear and particle accumulation.To balance a shaft, disk, or gear, we need to determine the size and location of the eccentric mass.Then, to correct the problem we can make the mass distribution symmetrical by adding or removing weightUnbalance in rotating machines occurs when a rotating member does not possess symmetry with respect to massExamples: automobile tire, washing machine
Lecture 18
Balancing
Learning with Purpose March 20, 2013
Lecture 18
w2R
mw2R
V2
R
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Lecture 18
F
kx cx
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Lecture 18
Learning with Purpose March 20, 2013
For a car, tire and rim balancing is necessary from time to time.A static wheel balance entails placing the wheel in a horizontal plane suspended by a cone through its center hole.A bubble level is attached to the wheel and weights are added to the rim until the wheel sits level.This type of balancing is generally no longer done because it neglects the effect of unbalanced moments.
Lecture 18
Learning with Purpose March 20, 2013
Lecture 18
Learning with Purpose March 20, 2013
Lecture 18
Learning with Purpose March 20, 2013
Lecture 18
Learning with Purpose March 20, 2013
To perform a dynamic balance of an automobile wheel, the following setup is typically used:
Lecture 18
Learning with Purpose March 20, 2013
Lecture 18
Example