水果分选机分选部分设计【含CAD图纸、说明书】
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Research Paper Design of machine to size java apple fruit with minimal damage Krawee Treeamnuk a, Siwalak Pathaveerata,*, Anupun Terdwongworakula, Chanida Bupata b aDepartment of Agricultural Engineering, Faculty of Engineering at Kamphaengsaen, and The Centre of Excellence for Agricultural and Food Machinery Kasetsart University, Nakornpathom 73140, Thailand bDepartment of Postharvest and Processing Engineering, Faculty of Science and Technology, Rajamangala University of Technology Tawan- ok, PHTIC, Chonburi, Thailand a r t i c l e i n f o Article history: Received 29 March 2010 Received in revised form 28 July 2010 Accepted 3 August 2010 Published online 15 September 2010 Java apple fruit features attractive skin, sweet and crispy fl esh, and a high susceptibility to mechanical damage. The java apple produced in Thailand has gained popularity in local and foreign markets, is available almost all year round and is sold at good prices. Fruit export drives postharvest mechanisation, of which fundamentally important machines such as a mechanical sizer for java apple are still not available. This research was aimed at designing, constructing, testing, and evaluating an effi cient sizing machine for java apple. Design concepts featured a) a sizing parameters which were determined by the diameter of the fruit and b) a sizing mechanism which causes minimum damage. The sizing machine comprised a feeding unit and a diverging belt sizing unit that are powered by two 187 W 220 V 50 Hz electric motors, gear reducer and pulleys. Performance tests indicated that velocity and inclination angle of the sizing belt; feeding belt velocity and the fruit orien- tation signifi cantly affects the sizing performance at p 15 m min?1for the Tubtim- jan variety, becauseat high velocity, some fruits left the belt in an unsymmetrical manner when passing through the conical cloth tube. As a result, the fruits were not vertical when they contacted the sizing belt which caused sizing errors. 3.3.Optimum fruit orientation and damage analysis With respect to the optimum velocity, inclination angle of the sizing belt and the feeding belt velocity for a specifi c variety, assessment of the sizing machine indicated that fruit orien- tation signifi cantly affected the performance of the machine at p 0.05. Table 6 exhibits the maximum diameterplacement on the U-shape rubber produced smaller CRand smaller Q for all varieties when compared to the CRand Q for random placement. The smaller Q might be due to the care of the operator in keeping the position of the fruit in the U-shape rubber in conformity with to the B-orientation, however this practise caused some loss in time. This problem could be solved by more practise with fruit placement. Table 7 shows the group of java apple fruit sized by the diverging belt sizing machine both with and without the conical cloth tube and the control group of Tubtimjan, Tong- samsri and Toonklao varieties. All varieties of sized fruits sorted by the machine with installed conical cloth tube exhibited less damage than fruit sorted by the machine without the conical cloth tube installed. In case of the Tong- samsri variety,therewas damageat level 3 when sortedby the machine without the conical cloth tube while no level 3 damage was observed for sorting by the machine with the cloth conical tube. The apparent damage on the fruits was eitherwithinnormalparametersorabsent.Themost frequently observed levels of damage were in the minimal damage level (level 2: damage area 0.5 percent). 3.4.Continuous performance The diverging belt sizing machine was tested by continuously sizing 500 java apple fruits from each of the Tubtimjan, Table 5 e Effects of feeding belt velocity on the performance of the java apple fruit sizing machine. VarietyFeeding belt velocity (m min?1) CR* (%)Ew*(%) Toonklao155.80 ? 2.05b96.80 ? 1.22b 2011.35 ? 2.16a92.26 ? 1.99a 2516.02 ? 1.66c89.69 ? 5.36a Tubtimjan1512.13 ? 3.39b92.77 ? 2.63a 2024.24 ? 2.40c86.68 ? 5.80b 2523.16 ? 4.15c85.77 ? 4.94b Tongsamsri1518.91 ? 3.26a88.22 ? 7.64a 2020.58 ? 10.26a80.93 ? 12.08a 2520.30 ? 3.44a83.13 ? 6.08a *Means with the same letter in the same column designate insig- nifi cant difference at p 0.05. Table 6 e Effects of fruit orientation on the performance of the java apple fruit sizing machine. VarietyFruit orientationQ *(kg h?1)CR*(%)Ew*(%) ToonklaoRandom263.92 ? 11.30b17.21 ? 2.09b93.52 ? 3.00a Maximum diameter179.87 ? 4.90a9.84 ? 1.93a93.62 ? 1.83a TubtimjanRandom333.09 ? 28.51b6.47 ? 2.46b91.23 ? 10.41a Maximum diameter214.22 ? 8.37a3.16 ? 1.07a97.94 ? 0.97b TongsamsriRandom326.70 ? 33.49b14.26 ? 3.69b88.63 ? 5.30a Maximum diameter187.44 ? 5.69a8.66 ? 1.80a91.51 ? 2.70b *Means with the same letter in the same column designate insignifi cant difference at p 0.05. biosystems engineering 107 (2010) 140e148146 Tongsamsri and Toonklao varieties. CRand Q for the Tub- timjan variety were 12.2% and 195.1 kg h?1while those for the Tongsamsri variety were 16.5% and 181.7 kg/h and for Toon- klao 10.8% and149.7 kgh?1respectively. For a givenvariety, CR and Q were relatively lower than those obtained in the previous determination in paragraph 2.3.3. This might occur because in Section 2.3.3, there were equal in numbers for each size; whereas the sample preparation of the continuous performance test was dependent on what the fruit growers provided. The weight ratios of the java apple fruits of small: medium: large size of the Tubtimjan variety were 0.2: 1: 0.24, those of the Tongsamsri variety were 1: 0.99: 0.57 and those of the Toonklao variety were 0.48: 1.00: 0.33, respectively. Manual sizing of the java apples of the Tongsamsri variety, destined for export, on average achieved a performance of 107.2 kg h?1with a contamination ratio CR of 27.9% and amechanicaldamage(Eq.(7)of13.3%(Treeamnuk, Jarimopas, & Jantong, 2008). Percent of damaged area was found to be insignifi cantly different at p 0.05 for the mechanically sized fruit when compared with the control for every variety. This implies that the sizing machine did not incur additional noticeable damage to the sized fruits. Alter- natively, the java apple fruit mechanical sizer could be oper- ated at zero noticeable damage. Fewer errors, improved capacities and, in particular, zero noticeable damages in the sorting of fruit are considered to be a signifi cant advantage of the diverging belt sizing machine. 4.Conclusions The performance test of the java apple fruit sizing machine indicate that velocity and inclination angle of the sizing belt, feeding belt velocity and the fruit orientation signifi cantly affects the sizing performance at p 0.05. The optimum conditions for continuous mechanical sizing were dependant on the variety of the fruit. The optimum sizing performance was characterised by an error ratio of 10.8e16.5% and a throughput capacity of 149.7e195.1 kg h?1. Manual sizing of java apple destined for export feature average ratios of 27.9% in error, 13.3% in damage and a capacity of 107.2 kg h?1. The developed java apple sizing machine could be operated at “zeronoticeabledamage”,andthereforenoadditional mechanical damage to the sized fruits. Acknowledgement All authors would like to dedicate the success of this work to late Professor Bundit Jarimopas. This research grant was supported by the program Strategic Scholarships for Frontier Research Network for the Ph.D. Program Thai Doctoral degree fromthe Offi ceoftheHigherEducationCommission, Thailand. The authors would also like to express their grati- tude towards the fi nancial support received from the Post- graduate Education and Research Development Project in Postharvest Technology at Chiangmai University and the Graduate School at Kasetsart University, Postharvest Tech- nology Innovation Center (PHTIC). And fi nally we would like to thank the Rajamankala University of Technology Thanyaburi, Thailand. r e f e r e n c e s Bupata, C., Jarimopas, B., & Chantong, S. (January 22e24, 2007). Conditions infl uencing design of a java apple fruit sizing machine. In: Proceedings of the International Conference on agricultural, Food and Biological Engineering & Post Harvest/ Production Technology, Khon Kaen, Thailand. Jarimopas, B., Kongwatananon, K., Rangdang, C., & Yamashita, R. (1988). Mangosteen sizing machine. Kasetsart Journal (Natural Science Supplement), 22, 91e96. Jarimopas, B., Rachanukroa, D., & Chen, P. (November 28e30, 2002). Guava sizing machine. In: Proceedings of the 7th International agricultural Engineering Conference, Shanghai, China. Jarimopas, B., Siriratchatapong, P., Sukharom, S., Sihavong, S., & Goto, Y. (1992). Durian sizing machine. Kasetsart Journal (Natural Science Supplement), 26, 65e74. Jarimopas, B., Toomsaengtong, S., & Inprasit, C. (2007). Design and testing of a mangosteen fruit sizing machine. Journal of Food Engineering, 79, 745e751. Table 7 e Damage of the mechanically sized java apple fruit (both with and without conical cloth tube on the machine) in comparison with the control sample. VarietyLevel of damage Control setSizing with cloth conical tube Sizing without cloth conical tube Damage percentage (%) Average fruit damage (%) Damage percentage (%) Average fruit damage (%) Damage percentage (%) Average fruit damage (%) ToonklaoLevel 1a74.44e65.56e32.22e Level 225.560.12 ? 0.0934.440.09 ? 0.0467.780.11 ? 0.07 Level 3eeeeee TubtimjanLevel 136.67e65.56e26.67e Level 261.110.13 ? 0.1032.220.14 ? 0.1171.110.15 ? 0.10 Level 32.220.71 ? 0.122.220.94 ? 0.262.220.66 ? 0.06 TongsamsriLevel 188.89e85.56e68.89e Level 211.110.06 ? 0.0414.440.23 ? 0.1130.000.08 ? 0.08 Level 3eeee1.110.85 ? 0.04 a The damage of java apple was divided into 3 levels e level 1: no apparent damage, level 2: Damage area less than 0.5 percent and level 3: Damage area in excess of 0.5 percent and over. biosystems engineering 107 (2010) 140e148147 Jarimopas, B., Toomsaengtong, S., Singh, S. P., Singh, J., & Sothornvit, R. (2007). Development of wholesale packaging to prevent post-harvest damage to rose apples. Journal of Applied Packaging Research, 2(1), 27e44. Meriam, J. L. (1975). Dynamics. USA: John Wiley and Sons, Inc. Mohsenin, N. N. (1996). Physical properties of plant and animal materials. 2nd Revised and Updated ed Thailand: Gordon and Breach Publishers Peleg, K. (1985). Produce handling, packaging and distribution. Connecticut, USA: AVI. Pub. Co. Inc. Sarakan, S., Jarimopas, B., & Chantong, S. (January 22e24, 2007). Textural properties of Thai java apple fruits. In: Proceedings of the International Conference on agricultural, Food and Biological Engineering & post Harvest/Production Technology, Khon Kaen, Thailand. Treeamnuk, K., Jarimopas, B., & Jantong, S. (August 14e15, 2008). Mechanical damage analysis of mechanically sized java apple fruit. In: Proceeding of the 6th National Conference on postharvest Technologyandpostproduction,organizedbypostharvestTechnology Innovation Center and Khon Kaen University, Khon Kaen, Thailand. biosystems engineering 107 (2010) 140e148148 Machine design theoryThe machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question.Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge. If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productMust regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea. Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method. In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts. How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnels basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process. Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem: (1) designs whether this product truly does need for the people? Whether there is competitive ability (2) does this product compare with other companies existing similar products? (3) produces this kind of product is whether economical? (4) product service is whether convenient? (5) product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposal.Usually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently,seeks these better method. Recent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, workers health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes from domestic and international competition, to product service maintenance convenience request enhancement and customers aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material. Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice; If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then this kind of prototype does not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. I n the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply. In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most common reason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes. The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper; (b) has not been able to foresee and to consider the dusk year possible reasonable use (for example to have the possibility, designs the personnel also to be supposed further to forecast and the consideration because product application method not when creates consequence. In recent years many products responsibilities lawsuit case, because wrongly uses the plaintiff which the product receives the injury to accuse produces the factory, and wins the decision); (c) uses the material data not entire perhaps some data are indefinite, works as its long-term performance data is the like this time in particular; (d) the quality control method is not suitable and not after the confirmation; (e) the personnel which completely is not competent for the post by some chooses the material. Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity. May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding. GEAR AND SHAFT INTRODUCTIONAbstract: The important position of the wheel gear and shaft cant falter in traditional machine and modern machines.The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box.The passing to process to make them can is divided into many model numbers, useding for many situations respectively.So we must be the multilayers to the understanding of the wheel gear and shaft in many ways .Key words: Wheel gear;ShaftIn the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoid.The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical fears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed helical gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is ,a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand. Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.Worm gearing are either single or double enveloping. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles are equal for a 90-deg. Shaft angle.When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered. Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squr gears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often good design practice to go to the spiral bevel gear, which is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered. It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gears.A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elementsas gears, pulleys, flywheels, cranks, sprockets, and other power-transmission elements. Shaft may be subjected to bending, tension, compression, or torsional loads, acting singly or in combination with one another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to static stresses, completely reversed, and repeated stresses, all acting at the same time.The word “shaft” covers numerous variations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating, nor subjected to torsion load. A shirt rotating shaft is often called a spindle.When either the lateral or the torsional deflection of a shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses. The reason for this is that, if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are safe; it is almost always necessary to calculate them so that he knows they are within acceptable limits. Whenever possible, the power-transmission elements, such as gears or pullets, should be located close to the supporting bearings, This reduces the bending moment, and hence the deflection and bending stress.Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably comes closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment, and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability.Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two inertias
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