Analysis of Drive System for Powder Compaction – A Flex             Body Application in MBD Simulation                    ...
Follower plate which is hinged at point A works as a cantilever, under the influence of the forcescoming through the 3 rev...
1.   Geometry in Motion View: Dosator system was extracted from CAD model of the completemachine and then it was imported ...
4.     Simulation Parameters: Two major input parameters used for simulations are•    Velocity of the cam shaft – cycle ti...
Most significant force comes at the follower plate in vertical direction that can bend it. We canchange Geometry and /or m...
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Mbd 05 analysis of drive system for powder compation_sci_tech

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Mbd 05 analysis of drive system for powder compation_sci_tech

  1. 1. Analysis of Drive System for Powder Compaction – A Flex Body Application in MBD Simulation Chandan Joardar GM (R&D) SciTech Centre 7 Prabhat Nagar Jogeshwari – West Mumbai – 400 102, IndiaAbbreviation: Dosator – An entity in a filling machine, delivering a measured amount of powderinside a capsule.Keywords : Dosator, Flex Body, MBDAbstractThe cam and follower arrangement is the source of drive in the powder compaction sub-system ofthe Dosator in the machine for filling powder in capsules. The required motion and force at theDosator comes out of the cam through the follower plate.Any deformation in the cam and / or the follower plate causes corresponding loss of motion at theDosator end. For satisfactory operation of the Dosator, it is desired to be maintained with in 50µ.We have identified the follower plate as the most potential candidate to affect this specification byway of its deformation while in motion. Accordingly we have undertaken a Flex-body analysis inMBD for this part.On the basis of analysis of results, the design of the follower plate has been modified to keep themaximum deflection below 50 µ and thereby maintaining the Dosator end deflection within 50 µ aswell.IntroductionDosator system is the most crucial part for a capsule filling machine. Deflections in acomponent due to loads of other parts can cause loss in filling the formulation powder insidecapsules body.Simulation Driven Innovation 1
  2. 2. Follower plate which is hinged at point A works as a cantilever, under the influence of the forcescoming through the 3 revolute joints, is liable to get deformed if not strong enough. It was observedthat a deflection of 1 mm can cause a loss of 10% of powder filling inside a capsule body.Motion View/Motion Solve was used to perform MBD simulations and a flexible body was used toobserve the stress generated and deflections in the follower plate. Figure 1: Dosator SystemObjectives:Following were the objectives of the current study• To study the stresses and deformation generated in follower plate and then re-design anoptimum plate that satisfy the capsule filling specifications.• To set up a model for the Dosator assembly , which can be used to test under differentspecifications( varying rpm, compaction load etc)• To compare the MBD simulation results with the actual machineProcess MethodologyThe process flow mentioned in Figure 2 is used to perform this analysis. The detailed description ofeach process is mentioned below.Simulation Driven Innovation 2
  3. 3. 1. Geometry in Motion View: Dosator system was extracted from CAD model of the completemachine and then it was imported in Motion View. Various constraints and joints were applied inorder to make the model in compliance with the real machine. 2. Identify Potential Candidate: Once the model was assembled, the trend of forces andmotion flow was analyzed and it was identified that follower plate is the most likely to deform inoperation and cause loss of motion at the Dosator end that in turn can cause loss of filling in thecapsule. Accordingly, it was decided to perform flex-body analysis of this component andstrengthen it adequately to meet the performance specifications. Geometry in Identify Potential MotionView Candidate Deflections Simulation Create Equivalent Stresses &Forces Parameters Model Test correlation Results Figure 2: Process Chart 3. Create Equivalent Model: Dosator system was extracted from the main model and a pointmass body was used to model the component that apply load on the cam follower plate. Mass of thepoint mass body was half the mass of the rest of the components as there are two follower plates toshare the load and Flex-body analysis was done on a single plate. Figure 3: Equivalent ModelSimulation Driven Innovation 3
  4. 4. 4. Simulation Parameters: Two major input parameters used for simulations are• Velocity of the cam shaft – cycle time of 0.468 seconds was fixed that corresponds to desired output of the machine• Velocity of Dosator sub-systemResults & DiscussionFour important performance parameters considered for comparison with actual machine are asfollows:1. Bending Forces on follower plate2. Deformation3. Stress, and4. StrainThe results of simulations are as follows: Force Vs Time (Per cycle) Deformation Plot Strain Plot Stress Plot Figure 4: Simulation ResultsSimulation Driven Innovation 4
  5. 5. Most significant force comes at the follower plate in vertical direction that can bend it. We canchange Geometry and /or material of the plate on the basis of forces being applied on it. With thehelp of Stress, Strain and Deformation plots we have strengthen the local areas where strain is themost. By making some changes in geometry of the model deformation of the plate was restricted to100 µ for the worst case scenario (116 rpm). For the regular range of operation it will remain within50 µ.Challenges 1. Correct Identification of potential component to undertake the analysis. 2. Modeling the simulation so that it closely represents the actual working situation/boundary conditions under which the mechanism is working.Future PlanIn the future developments of machines incorporating Dosator system, we shall make an early flex-body analysis in MBD. Once the 3D CAD model is prepared it can be simulated for different sets ofparameters. Hence actual machine can be designed in accordance with the desired specifications.ConclusionMaking flex-body analysis using MBD is very useful in new developments. However, it requiresallocation of adequate time apart from other resources. But, if we don’t do this we might land upmaking trouble shooting activities during validation of the machine and eventually spending moretime than what was allocated at the beginning of the project. AcknowledgementI would like to express my gratitude and sincere thanks to Mr. Devesh Rajan, UndergraduateStudent, IIT Kanpur, Project Trainee, SciTech Centre for his valuable inputs.Simulation Driven Innovation 5

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