The course syllabus and the academic weekly planning may change due academic events or other reasons. Machines Technology. Study: Bachelor in Industrial Technologies Engineering Department assigned to the subject: Department of Mechanical Engineering. Type: Compulsory.
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Embed Size px x x x x Notes: There are a number of design considerations that can be included in this problem. Someexamples are considered here, but the student should not be restricted in the types of solutionspursued.
This type of problem is an excellent opportunity for brainstorming, where a group isencouraged to provide all possible answers to the problem regardless of feasibility.
For example,the materials considered could include wood barrels, ceramic jugs or foil or plastic bags, as inintraveneous fluid containers. Solution:The transport containers for milk should be easy to handle and store as well as being easy to pourfrom without spilling. The material should be recyclable or be able to be burned leaving harmlesscombustion products.
The obvious material choices are paper or plastic materials, although glassbottles and metal cans can be considered as possibilities.
For a one liter container the standardtype Pure Pac or Tetra Pac Bric made of plastic carton is a good design. A one gallon container has to be compact to be easily stored in a refrigerator.
The width,depth, and height should be similar in size, which would be about mm x mm x mm. That size is too large to grip with one hand.
Therefore, a one gallon container is preferably madeof a plastic with an integral handle. It should be able to accommodateboth a winter coat and a pair of trousers. It should function well but also be asinexpensive as possible. Solution:If they are not hung simultaneously, a steel wire frame of triangular shape with a hook at.
The horizontal portion could be covered with a high friction coating or tapeor glue to keep the trousers from sliding off. For coats, a sturdier frame is needed, requiring either a larger gage of wire or pursuit ofanother alternative such as wood or plastic hangers. If the bearings got too hot, they would attain a noticeable odor, and an oilerwould give the bearing a squirt of lubricant at the next train stop.
What design philosophydoes this illustrate? In this case, adry bearing becomes hot, and the bad smell indicates a loss of lubricant before the bearing failureis catastrophic. It should be noted that other answers are possible. For example, the principal of uniformsafety suggests that the level of safety of all components be kept at the same level. If failure of. Which design philosophy isbeing incorporated into the towing system design? Solution:Since the safety chain is used in addition to the towbar, it is an example of redundancy,.
Furthermore, it is an example of a fail-safe design, because if thetowbar fails, the towed vehicle will follow the car and will not swerve into other lanes and collidewith other vehicles. Depending on the number of hours the drill is expected to be used before it isscrapped, different bearing arrangements will be chosen.
A rubber bushing has a hrlife. A small ball bearing has a hr life. A two bearing combination of a ball bearingand a cylindrical roller bearing has a 10, hr life. The cost ratios for the bearingarrangements are What is the optimum bearing type for a simple drill, asemiprofessional drill, and a professional drill? Notes: This problem is fairly subjective, but there should be a realization that there is an increasein expected life for a professional drill versus a simple drill.
In fact, for certain users, a 50 hourlife is probably sufficient. Solution:Notice that the cost per time is highest for the rubber bushing and lowest for the ball bearingcylindrical bearing combination.
However, the absolute cost is higher for the longer lastingcomponents, so the expected life must be assessed. Rough estimates based on expected lives areas follows. The time from first spall to when the wholerolling-contact surface is covered with spalls is hr, and the time from then until a ballcracks is hr. What is the bearing lifea If high precision is required? Notes: This problem is fairly subjective, but there should be a realization that there is a decreasein expected life for the high precision drill, etc.
Solution:a For high precision, no spall should be allowed so the life is hrs. However, safety allowances of hours may be reasonable. Themaximum force transmitted from one foot to the ski is N, but the snow conditionsare not known in advance, so the bending moment acting on the skis is not known.
Theweight of the skier and equipment is kg. Estimate the safety factor needed. Notes: There are two different approaches, that of section 1. Solution:Using the approach of section 1. Therefore, the largest safety factor, if there ispoor control of materials and loading, and if the consequences are sever, is given by Equation 1.
If the weight of skier and. This means that no overstressing should ever occurdue to bending of the ski, so the safety factor could be chosen just above one. The allowable normal tensilestress in the wire gives an allowable force of ,N. Find the safety factor that shouldbe used. If the wire breaks, people can be seriously hurtand expensive equipment can be destroyed.
If the wire breaks, no peopleor expensive equipment can be damaged. Notes: Equation 1. Therefore, the required safety factor is obtained from Equation 1. Therefore, therequired safety factor is obtained from Equation 1. Solution:Examples of fail safe products are: 1 electric motors, which fail to move and cause no hazardswhen they fail. Examples of fail unsafe products include: 1 Bungee cords, as in bungeecord jumping from bridges and the like; 2 parachutes, which cause a fatal injury in the vastmajority of failures, and 3 A fan on an exhaust hood over a fume producing tank, such as anelectroplating tank.
Failure of the forced air circulation system exposes plant personnel to harmfulfumes. Thecost of the container is proportional to the container wall thickness. The safety can beincreased either by making the container wall thicker or by mounting a reserve tray underthe container to collect the leaking acid.
Which is less costly, to increase the wall thickness or to mount. View Download 37 Category Documents. Chapter 1 Introduction 1. Notes: See the notes to problem 1. Solution:If they are not hung simultaneously, a steel wire frame of triangular shape with a hook at the top could be used.
Solution:The most obvious design philosophy is the Doctrine of Manifest Danger. This philosophy suggests that systems be designed so that a failure can be detected before it occurs. If failure of one component, in this case a bearing, is imminent, then extra maintenance on this bearing isjustified by the principal of uniform safety.
Solution:Since the safety chain is used in addition to the towbar, it is an example of redundancy, and it is a passive system. Notes:This is an open-ended problem, and many different solutions are possible. Shabana Jacobson Jewellery Documents. Martin Solu Documents. Jacobson Presentation Documents. Append17Dec2k8 solu Documents. Alex schmid Education. Jacobson Wooden Containers Documents. Relajacion jacobson Spiritual. Kia Jacobson Portfolio Documents. Jacobson Overview Documents.
BIBLIOGRAFIA Bernard J Hamrock Elementos de máquinas
Embed Size px x x x x Notes: There are a number of design considerations that can be included in this problem. Someexamples are considered here, but the student should not be restricted in the types of solutionspursued. This type of problem is an excellent opportunity for brainstorming, where a group isencouraged to provide all possible answers to the problem regardless of feasibility. For example,the materials considered could include wood barrels, ceramic jugs or foil or plastic bags, as inintraveneous fluid containers.
SOLU Elementos de Maquinas - Hamrock, Bernard J. Jacobson, Bo Schmid, Steven R
Mc Graw Hill. Prentice Hall. Mc Graw-Hill. I only think of how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong. Richard Buckminster Fuller Image: A dragline lifts a large load in a mining operation.