Diseño de un sistema automático para ayudar a personas con movilidad reducida a levantarse de la cama

UNIVERSIDAD DE VALLADOLID ESCUELA DE INGENIERIAS INDUSTRIALES Grado en Ingeniería Mecánica Diseño de un sistema automático para ayudar a personas con movilidad reducida a levantarse de la cama. Autor: Izquierdo Conde, Carlos Responsable de Intercambio en la UVa Marta Herráez Sánchez Universidad de destino Vilnius Gediminas Technical University Valladolid, Julio 2020. TFG REALIZADO EN PROGRAMA DE INTERCAMBIO TÍTULO: Design of automated system for helping people with reduced mobilty to get up from bed ALUMNO: Carlos Izquierdo Conde FECHA: 17/06/2020 CENTRO: Faculty of Mechanics UNIVERSIDAD: Vilnius Gediminas Technical University TUTOR: Paulius Ragauskas Resumen en español (max 150 palabras) Diseño de un sistema capaz de ayudar a personas con movilidad reducida a levantarse de la cama de manera autónoma. El objetivo del sistema es colocar al usuario sentado al borde de la cama. Esto se lleva a cabo mediante la creación de dos máquinas. Primero un respaldo que coloca el tronco del usuario en una posición recta. A continuación, un sistema piñóncremallera que empuja las piernas fuera de la cama para alcanzar la posición final. Ambas maquinas son motorizadas por dos motores eléctricos. Los cálculos realizados se focalizan en las cargas soportadas y la transmisión de potencia, incluyendo el diseño de los ejes, sistema de engranajes, selección de los motores eléctricos y rodamientos. También se incluye una estimación económica del proyecto. Palabras clave: Respaldo, cama, autonomía, personas, movilidad reducida. Abstract (max 150 words) In this bachelor`s degree final work was designed a system capable of helping people to get up from bed. The main objective of the system is to put the user ln a sit position on the edge of the bed. This is fulfilled by the creation of two machines. Firstly, the back`s lift system put the user`s trunk on a straight position. This system is powered by an electric motor that transmits the power by a gear system to the back`s lift. Secondly, a pinion rack system, also powered by an electric motor, push the legs out of bed in order to get the final position. Literature review of this paper presents information about the systems used nowadays to help disabled people to move from bed and to transport them. Therefore, it is explained the advantages and disadvantages of this systems and the reason to design a new one. Calculations parts focus on the load supported and power transmission, including the design of shafts, gear system, selection of electric motors and bearings. Economical estimation is also included. Keywords: Back`s lift, bed, reduced mobility, automated, people. VILNIUS GEDIMINAS TECHNICAL UNIVERSITY FACULTY OF MECHANICS DEPARTMENT OF MECHANICAL AND MATERIAL ENGINEERING Carlos Izquierdo Conde Design of Automated System for Helping People with Reduced Mobility to get up from Bed Bachelor‘s degree final work (project) Mechanical Engineering study programme, state code 612H33001 Machine design specialisation Mechanical engineering study field Vilnius, 2020 © STUDIJŲ DIREKCIJA Vilnius Gediminas Technical University Mechanics faculty Mechanics and materials engineering department ISBN ISSN Copies No.1 Date 2020-06-10 Bachelor Degree Studies Mechanical Engineering study programme Bachelor Graduation Thesis 3. Title: Design of Automated System for Helping People with Reduced Mobility to get up from Bed Author Carlos Izquierdo Conde Academic supervisor Paulius Ragauskas Thesis language Lithuanian Foreign (English) Annotation In this bachelor`s degree final work was designed a system capable of helping people to get up from bed.The main objective of the system is to put the user ln a sit position on the edge of the bed.This is fullfilled by the creation of two machines. Firstly, the back`s lift system put the user`s trunk on a straight position. This system is powered by an electric motor that transmits the power by a gear system to the back`s lift. Secondly, a pinion rack system, also powered by an electric motor, push the legs out of bed in order to get the final position. Literature review of this paper presents information about the systems used nowadays to help disabled people to move from bed and to transport them. Therefore, it is explained the advantages and disadvantages of this systems and the reason to design a new one. Calculations parts focus on the load supported and power transmision, including the design of shafts, gear system, selection of electric motors and bearings. Economical estimation is also included. Structure: introduction, literature review, calculations,design of technological process,work safety and environmental requirements, economical estimation , conclusions and suggestions, references. Thesis consist of: 80 p. text without appendixes, 58 pictures, 38 tables, 30 bibliographical entries. Keywords: Back`s lift, bed, reduced mobility.. X (the document of Declaration of Authorship in the Final Degree Project) VILNIUS GEDIMINAS TECHNICAL UNIVERSITY Carlos Izquierdo Conde, 20195918 (Student's given name, family name, certificate number) Faculty of Mechanics (Faculty) Mechanical Engineering, MPfu-16 (Study programme, academic group no.) DECLARATION OF AUTHORSHIP IN THE FINAL DEGREE PROJECT June 11, 2020 I declare that my Final Degree Project entitled „Design of Automated System for Helping People with Reduced Mobility to get up from Bed“ is entirely my own work. The title was confirmed on March 12, 2020 by Faculty Dean's order No. 60me. I have clearly signalled the presence of quoted or paraphrased material and referenced all sources. I have acknowledged appropriately any assistance I have received by the following professionals/advisers: Doctor Paulius Ragauskas. The academic supervisor of my Final Degree Project is Doctor Paulius Ragauskas. No contribution of any other person was obtained, nor did I buy my Final Degree Project. Carlos Izquierdo Conde (Signature) (Given name, family name) List of contents 1. INTRODUCTION. ............................................................................................................. 1 2. LITERATURE REVIEW. .................................................................................................. 1 Related work. ............................................................................................................... 1 Conclusion. ................................................................................................................ 19 3. CALCULATIONS NECESSARY TO ENSURE PROPER WORK AND STABILITY OF THE OBJECT DESIGNED, DESCRIPTION OF THE DESIGN AND OPERATING PRINCIPLE OF THE OBJECT DESIGNED. ......................................................................... 20 Anthropometric data. ................................................................................................. 20 Back`s lift design. ...................................................................................................... 21 Arms` lift design. ....................................................................................................... 23 Static study. ................................................................................................................ 23 Fatigue study. ............................................................................................................. 26 Electric motor. ........................................................................................................... 33 Gear system. ............................................................................................................... 34 Shearing of the teeth. .......................................................................................... 36 Wear on surface. ................................................................................................. 39 Shafts. ........................................................................................................................ 42 Input shaft. .......................................................................................................... 42 Output shaft. ....................................................................................................... 44 Bearings. .................................................................................................................... 45 Protective casing. ................................................................................................... 47 Gear lubrication. ..................................................................................................... 48 Shaft shoulder. ........................................................................................................ 48 Legs pusher design. ................................................................................................ 49 Pinion and rack. ...................................................................................................... 49 Shaft. ................................................................................................................... 51 Bearings. ............................................................................................................. 52 Shaft support. ...................................................................................................... 52 4. DESIGN OF MANUFACTURING TECHNOLOGICAL PROCESS FOR THE INPUT SHAFT. .................................................................................................................................... 53 Material. ..................................................................................................................... 54 Machines. ................................................................................................................... 55 Tools and inserts. ....................................................................................................... 56 Machining process. .................................................................................................... 60 Operation 1: Rough facing. ................................................................................ 61 Operation 2: Rough turning ∅51x215 . .............................................................. 61 Operation 3: Finishing ∅50x215. ....................................................................... 62 5 - Electric Crane AKSTB05007 Electric crane to transport a person safely and effortlessly, a single person can do it so by simply pressing a button. The legs are opened with a pedal for greater stability or to approach chairs or sanitary facilities, etc. After its use it can be fold up in seconds without tools. Batteries do not need maintenance and they are charged automatically. Characteristics: Maximum height:2 m. Weight:38 kg. Maximum load:150 kg. Width: 61 cm. Total length: 120 cm. - Mobile crane for general use-TB05009 Figure 2.4. Sunlift Major Crane. Figure 2.5.Electric Crane AKS. 6 Mobile crane of general use with 1 wheel on each leg and double front wheels. It is detachable, it has a two pieces harness, hammock for separated legs. Electric lifting system for the radial arm. Characteristic: Max load:135 kg. Weight:33,8 kg. - Oxford Voyager 550TB05013 Transfer crane, it increases caring of the sick quality and gives maximum security to user in his daily routine. Easy handling. Different rails to avoid every obstacle. Different Figure 2.6. Mobile Crane. Figure 2.7. Oxford Voyager 550. 7 type of harnesses allows to transfer from bed to wheelchair, transfer to bathroom, nappy change, transfer to shower. Different sizes for every harness. - Molift Quick RaiserTB05014 Biped station crane with platform to support the feet, padded support for knees and special belt that is placed under the armpits. Weight: 30 kg. - Oxford Stand aid - TB05015 Electric crane designed to transport the person in semi-erguid position. Patient rests knees on crane so it goes perfectly attached, feeling much safer and more comfortable than on a conventional crane. Features: Available in foldable version, lightweight and easy to carry. Maximum load: 135 kg. - Fixed Crane Curator - TB05016 It is installed on the room or bathroom`s wall to do the transfers from the bed to wheelchair, shower, WC. Its measurements were studied for the case to be installed in a double room could do the transfer between the two beds. Figure 2.8.Molift Quick Raiser Figure 2.9.Oxford Standaid. 8 - Fixed Crane PoolVirTB05018 Fixed Crane for swimming pool and bathroom, with two pieces harness and separated legs hammock. Hydraulically operated radial arm lifting system. Two types of bases anchored to the ground or recessed. The whole set is removable which allows us to have several bases and have more than one point of use. Characteristics: Max weight. user: 185 Kg. Crane weight: 39 Kg. - Oxford Mermaid - TB05019 Figure 2.10. Fixed Crane Curator. Figure 2.11. Fixed Crane PoolVir 9 Its small size and versatility define this crane as an indispensable help to do the bath transfers. It lifts and descend the seat inside the bath. The seat turns in the highest position. Characteristics: Material: Steel. Maximum load:127 kg. Weight: 32 kg. - Carix CraneTB05021 This crane is specially indicated for no mobility people and they must be transferred on a stretcher. Characteristics: Total length:120 cm. Total height: 136 cm. Width: 60 to 120 cm. Maximum user height: 190 cm. - Letix Crane - TB05022 The crane introduces o mobility people onto the bath. It is suitable with all stretchers available on market. It can be hydraulic or electric. Characteristics: Total length: 188 cm. Total height: 119 cm. Widht:57 a 65 cm. Figure 2.12. Oxford Mermaid. Figure 2.13. Carix Crane. 10 - Aquatic Lifter Hydraulic lift that facilitates access to water for people with physical limitations. User can do it by himself. The seat can be placed perpendicular or parallel to the edge of the pool. Only a water intake with a pressure of 3.5 kg per cubic centimetre is required for operation. Easy to install. It has a single-control shower built in so that the user can shower before and after the bath without great effort. Maximum load of 120 kg. - Domus craneTB05028 Crane suitable for use in homes, especially those whose architectural characteristics prevent the use of a portable crane. Its dimensions and arm articulation system allow it to be used for transfers from the wheelchair to the bed, the bath, the sofa. By using various supports and due to the ease of placement of the crane and its folding system Figure 2.14.Letix Crane Figure 2.15. Aquatic Lifter. 11 and reduced weight, all transfer needs in a home can be covered. It can rotate more than 180 degrees depending on the placement of the bracket. Maximum load: 130 kg. - Driver Crane-TB05029 This crane has been designed to be installed on all type of vehicles. Easy transfer between wheelchair and vehicle. It is connected to the car`s battery system, Maximum load: 120 kg. As seen before, there are different kind of systems to transfer people from one place to another. There are mobile cranes like the top of the list above. Basically, it is a two-leg structure with wheels to move it, and a hydraulic or electric arm with a harness attached to it. Then, fixed cranes are the same system but instead of wheels it is attached to the wall. It can hold more weight than the mobile ones. There are aquatic cranes too, to transfer people to bath or Figure 2.16. Domus Crane. Figure 2.17.Driver Crane 12 swimming pool, t made of stainless steel. And finally, other systems not related to this topic like cranes to move people from the driver seat to a wheelchair and systems of bipedsation, to hold people on a standing position. Beds Although there are lots of different cranes to help patients to get up from bed like it is seen before, the bed itself can help to do the required task. Along history, hospital beds have been improved to offer comfortability and a better performance, both to patient and nurse. First pushbutton hospital beds were created in the 40s (figure 18a). The bed movements were inspired by the principle of foil movement, inspired by the movements when nurses change patients’ position. In 1946, after a plane crash, Howard Hughes created a hospital bed adapted to him. It consisted on 6 sections, 30 electric engines and cold and hot water flow . In the 50`s, the Hill-Rom company, built and marketed its first electrical beds (figure 18b). In the 60`s and 70`s appeared different models for special care cases, such as the Circ-O`lectric bed (figure 18c). This design allowed the caregiver to control body rotation by electric actuators. Figure 2.18.a) Example of one of the first pushbutton hospital beds. 1945 b) Hill`s first bed with electric engine, 1952. c)CircOèlectric bed 1958. 13 From 1970 all hospital beds incorporated rails with control panels. The first mattresses for preventing pressure ulcers appeared. The use of hospital beds for home use increase in this time. During 80`s and 90`s medical devices suffered a great improvement. Some patents included a weighing scale incorporated to bed (figure 19). Others included new systems to call nurse for disabled patients. In the 90`s, more beds with improved mechanical systems appeared, such as the possibility of sitting in a chair position to exit the bed (figure 20). The voice control system is mentioned in some patents during this time. However, its efficiency in the 90`s was limited compared to present ones. The first regulation on medical devices appears in 1993 (the Council Directive 93/42/CEE), and the first standard for electrically operated hospital beds is published. In 2000 the European standard EN1979, was published. Then, the ISO standard was published in 2009 and enforced in 2013, dealing with basic safety and essential performance of medical beds. The analysis of the timeline of hospital beds allows highlighting some conclusions: - Increasing delegation of functions. Easing the work of caregivers and facilitating the independence care of user. - Growing specialization in different models of electric beds, with morphologic, functional aspects made for specific environment and groups of patients (for hospitals, private homes, geriatrics…) - At last, there is a growing trend towards relocating and re-discovering new implementations for the increasing range of technologies available. This fashion will attain the advances for current marketplace demands, such as: inclusion of tactile interfaces, functions of connectivity and complex real-time monitoring, as properly as of recent sensors and actuators. These factors permit the creation of new and improved Figure 2.20. Images of a 1994 paten t showing a weighing scale included in the wheels. Figur e 2.20. Hill-Rom Total Care model of 1998. 14 versions of those devices, making a new way for builders to advocate new editions of added value for this family of products (focused in the experience of the user), while preserving the equipment’s basic functions. This synthesis and technological growth have changed the visible face of the market of high complexity mechatronic beds in the last decades. Basic structure The electric bed movements were based on the study of the biomechanics of the care givers, which was translated to technological principles. Figure 2,21 shows the support structure of a conventional electric bed. The surface of support is divided in three sections that can be driven by the user or caregivers: Back, thighs and calves. In this kind of product is typical to have a fourth section fixed to an end of the back and another one to the thighs support. This allows to avoid significant deformation in the mattress, even when all sections are in limit position. Two different actuator drive individually the back and leg section. movement of the las one allows to achieve chair position. There is a high risk of suffering falls for patients, when the support level is elevated, both when trying to enter or exit the bed. This situation led to the development of a new segment of ¨ low beds ¨ in the market, especially created to avoid those problems. Likewise, it turns appropriate for the medical personnel to be able to rely on ways that set the elevation of the Figure 2.21. View in perspective an electrical bed, with 4 s ections a support surface and elevation control. 21 The mass center of the superior part can be also calculated. The position of the mass center of each part is showed in the following picture: It is assumed that the arm ends in the bottom part of the cylinder that represents the trunk to ease the calculations. It is only needed the y position; it is assumed that the body is perfectly symmetric, and the origin is situated on the symmetry axis at the bottom of trunk`s cylinder. The mass of the arm and forearm is distributed in proportion to the length. 𝑌𝑐𝑚 = ∑ 𝑚 ∙ 𝑦  ∑ 𝑚  (3.1.5) Where Ycm is position of the absolute mass centre, cm; y is position of the mass centre of each part of the body, cm; m is the mass of each part of the body, kg. The result is Ycm=34,15 cm. Back`s lift design. The mass centre of it should be as close as possible to the position calculated before to avoid inertia problems .It must have a part to support the head while the system is moving in order to avoid any back injuries. It must be light and strong enough to bear the loads are going to be applied. Taking these into consideration a first design of it is made on Solidworks. Figure 3.1 . Mass centre positions of different parts of human body. 22 Figure 3.2.Views of the back`s lift. Figure 3.2 shows the design of the lift. It has a curved shape to be ergonomic and improve the comfortability of the user. The holes at the sides are for the arms that transmit the rotational movement. It is shell in order to be as light as possible. This first design is 1-meter width from 50cm diameter holes centre and 750 cm length. Material chosen is polypropylene copolymer (see properties of the material on Table 3.1). Table 3.1. Properties of Polypropylene Copolymer. Properties Name: PP Copolymer Model type: Linear Elastic Isotropic Tensile strength: 2,76e+07 N/m^2 Elastic modulus: 8,96e+08 N/m^2 Poisson's ratio: 0,4103 Mass density: 890 kg/m^3 Shear modulus: 3,158e+08 N/m^2 It is light and can bear the different loads applied. Weight of the piece is P2=52,0631 N. 23 Arms` lift design. The arms have a ∅50.4 standard profile. Standard tubular profiles are shown on Table 3.2. In order to choose the material of them, a static and fatigue studies are carried out. Static study. References: [13], [14], [15], [16], [17] Figure 3.3 shows a distributed force called “P” that represent the weight of the patient`s body and of the back`s lift. It doesn’t consider the part for the head, so it is irrelevant and simpler to calculate. For this part it is assumed that the mass centre of body and lift coincide. ”L” is the Figure 3.3.Representation of the loads applied to the arm. Table 3.2. Tubular section properties. 24 length of the lift in cm and d is the distance between the lift and the end of the arm. Blue part is the piece that join the arm with the rotation axis. Most critical section is on point “a”. There is a change of section and a discontinuity that can lead to fatigue problems even to a break of the piece. Momentum respect point a is calculated:  𝑀 = 0 (3.4.1) 𝑀  = 𝑃 ∙ 𝐿 ∙ ( 𝐿 2 + 𝑑 ) (3.4.2) Where 𝑀 is the bending moment respect the point a, Nm; P distributed force, N/m; L is distance of distributed force, m; d is distance from P to point a, m. L=0,5 m, P=1184,40 N/m, d=0,05 m, Ma=177,66 Nm It is also considering the torque produced on the arms by the load P. 𝑇 = 𝑃 ∙ L 𝑡 (3.4.3) Where T is torque, Nm; Lt is the distance between the centre of the arm and the mass centre of the group lift and body, m. Lt=0,535 m. T=316,83 Nm .Now the maximum flexion strength “𝜎" and maximum torsional strength "𝜏" can be calculated. Figure 3.4. Torque produced in one of the arms. 25 𝜎  = 32 ∙ 𝑀 𝜋 ∙ 𝐷  (3.4.4) 𝜏  = 16 ∙ 𝑇 𝜋 ∙ 𝐷  (3.4.5) Where D is the external diameter of the arm, m ; 𝜎 is the maximum flexion strength, MPa; 𝜏 maximum torsional strength, MPa. D=0,05 m; 𝝈𝒎𝒂𝒙=14,48 MPa; 𝝉𝒎𝒂𝒙=12,91 MPa Then, Von-Misses criteria can be applied. 𝜎  = 𝑆  𝑛 (3.4.6) Where Sy is yield strength of material, MPa; n is the safety coefficient and "𝜎" is equivalent strength,MPa: 𝜎  =  𝜎   + 3 𝜏   (3.4.7) In this case the loads can be calculated, and the operation of the machine is taking place on common environments, like a house, safety coefficient value is n=2. Result of equation 3.4.7 is 𝝈𝒆𝒒=26,65 MPa. Replacing on eq 3.4.6 ,Sy is calculated, Sy=53,3 MPa. 26 Fatigue study. First step is to represent the loads within the time. Figure 3.5 shows the movement of the arm along the 𝜃 angle (0º to 85º), where G is the centre of mass of the group body and lift and F is the distributed force P concentrated on the centre of mass. 𝑀 ( 𝜃 ) = 𝐹 ∙ 𝐿 / 2 ∙ 𝑐𝑜𝑠𝜃 (3.5.1) F=592,20 N, L=0,5 m. Bending moment depending on θ is represented on figure 3.6. Figure 3.5. Representation of the movement and loads of the system. -200 -150 -100 -50 0 50 100 150 200 0 10 20 30 40 50 60 70 M(Nm) Time (s) Momentum-time Figure 3.6. Representation of momentum vs time. 27 On figure 3.6 the maximum momentum coincides with the alternating momentum “Ma”(Ma=177,66 Nm ) and the medium value is zero. The Torque is also represented on a figure 3.7. In this case, torque does not depend on time so in the graphic is a straight line. On figure 3.7 medium torque “Tm” (Tm=316,83 Nm) has a constant value and alternating torque is zero. Goodman criteria is applied, in order to get the ultimate strength in tension of the material, Sut. 𝜎   𝑆  + 𝜎   𝑆  = 1 𝑛 (3.5.2) Where Se is the endurance limit, PA; 𝜎  is the equivalent medium strength,MPa; 𝜎 is the equivalent alternating strength,MPa; 𝑆is the ultimate strength limit, MPa; n is the safety coefficient. Firstly, piece is defined, that means to calculate Se value, 𝑆𝑒 = 𝐾𝑎 ∙ 𝐾𝑏 ∙ 𝐾𝑐 ∙ 𝐾𝑑 ∙ 𝑆𝑒 ` (3.5.3) Where K values are coefficients and Se` is endurance limit estimation, MPa. 0 50 100 150 200 250 300 350 0 5 10 15 20 25 Torque (Nm) time(s) Torque-time Figure 3.7. Representation of torque vs time. 28 - Ka: Surface finish factor, Table 3.3. 𝐾  = 𝑎 ∙ 𝑆   (3.5.4) Part will be manufactured by turn machining. - Kb: Size factor, Table 3.4 Diameter is expected to be between 2,79 and 51 mm. - Kc: Reliability factor, Table 3.5. It is supposed a reliability of the 99%. Table 3 . 3 . Surface finish factor valu es . Table 3.4.Size factor values. Table 3.5. Reliability factor values. 29 - Kd: Temperature factor, Table 3.6. The machine will work on standard conditions. Factor values chosen are shown on Table 3.7. Table 3.7. Different factor values used for the fatigue calculations. Factor values Ka 4 , 51 ∙ 𝑆𝑢𝑡   ,  Kb 0,81 Kc 0,814 Kd 1 Se`: Endurance limit estimation, 𝑆𝑒 ` = 0 , 504 ∙ 𝑆  (3.5.5) With all the values mentioned before, Se can be calculated depending on Sut (eq. 3.5.2). After defining the piece, load can be defined. By replacing Ma and Tm on the equations number 3.4.4 and 3.4.5, respectively, 𝜎 and 𝜏 can be calculated. 𝝈𝒂=14,48 MPa; 𝝉𝒎=12,91 MPa. To correct their values, next formulas are used: Table 3.6. Temperature factor values. 30 𝜎   = 𝐾  ∙ 𝜎  (3.5.6) Where Kf is the notch correction factor; 𝜎 is the corrected alternating strenthg,MPa. Kf: Notch correction factor. 𝐾  = 1 + 𝑞 ∙ ( 𝐾  − 1 ) (3.5.7) Where q is the notch radius, mm. For the case of a chamfer with sharp edge, Kf=2,5 [B] For torque the same is done. 𝜏   = 𝐾  ∙ 𝜏  (3.5.8) Where 𝜏  is the corrected medium torsional strength, MPa. Kf is the same. q=0,95;Kt=1,4;Kf=1,38. 𝝈𝒂 𝒄𝒐𝒓𝒓=36,21 MPa; 𝝉𝒎 𝒄𝒐𝒓𝒓=32,38 MPa Finally, the equivalent strengths can be calculated. 𝜎   =  𝜎   + 3 𝜏    (3.5.9) 𝜎   =  𝜎   + 3 𝜏    (3.5.10) 𝝈𝒎 𝒆𝒒=55,92 MPa; 𝝈𝒂 𝒆𝒒=36,21 MPa Replacing all on equation 3.5.2, Sut is calculated. Sut =337,8 MPa. Strenthg limits are shown on Table 3.8. Table 3.8. Strength limits of the arm. Strength limits of the arm. Sut (MPa) 337,8 Sy (MPa) 53,3 37 On the abscissa axis is represented number of teeth. On the ordinate axis is represented the stress concentration factor. x curves represent the displacement tool distance, in this case x=0.The intersection between the number of teeth value Z, and x=0 provides the value of Ysa=1,98. Figure 19. Stress concentraion factor [ BIBLIOGRAFIA Figure 3.13. Stress concentration factor. 38 On figure 3.14 is represented number of teeth on the abscissa axis and size factor on the ordinate axis. The intersection with the x=0 curve provides a value of Yfa=2,3. Knowing that: b=40 mm; m=4; cos(Ba)=1; n=1,5 rpm ;Z=65 for the pinion. Replacing these values on equation 2.7.1.2 results on 𝝈𝒃𝒍𝒊𝒎=2,24 daN/mm2. Replacing it on equation 3.7.1.1 with Cs=1 (on the limit), 𝑺𝟏𝟎𝟕=4,44 daN/mm2. With this value, the material can be found in figure 3.15. Figure 3.14. Size factor graphic. 39 So, the material for the pinion will be grey-cast iron. Doing the same for the secondary gear the following results are obtained: Table 3.12. Specifications of gear system. Specifications of gear system. Z n(rpm) Ysa Yfa σ (daN/mm 2) S  Pinion (1) 65 1,5 1,98 2,3 2,24 4,44 Secondary(2) 100 0,95 2,05 2,2 2,2 4,51 The other data is the same for pinion and secondary. Secondary gear material will be also greycast iron with an ultimate tension strength, SUT, bigger than 23 daN/mm2 Wear on surface. Wear on surface strength, 𝜎, is obtained from the following equations: 𝑃𝑎𝑑𝑚 = 10   1 , 96 ∙ 𝜎   ∙ 𝑏 ∙ ( 𝑚 ∙ 𝑧 )  ∙ 𝑖 𝑖 + 1 ∙ 𝑛 𝑍   ∙ 𝑍   ∙ 𝑍   (3.7.2.1) Where 𝜎 is wear on surface strength, MPa; Z are different factors: Figure 3.15. Ultimate strength of different materials. 40 - 𝑍: Driving Factor 𝑍  =  ( 4 − 𝜀  ) 3 (3.7.2.2) - ZE: Elastic Factor. 𝑍  =  0 , 175 ∙ 𝐸 (3.7.2.3) Where E:Elasticity modulus. - ZH: Geometrical Factor. 𝑍  =  2 ∙ 𝑐𝑜𝑠𝐵𝑎 𝑠𝑒𝑛𝛼 ∙ 𝑐𝑜𝑠𝛼 (3.7.2.4) Factor values are presented on Table 3.13. Table 3.13. Factor values and strength of gear system. Factor values and strength of gear system. Z n(rpm) 𝑍  ZE ZH 𝜎  (daN/mm2) Pinion (1) 65 1,5 0,85 107,55 2,49 24,13 Secondary (2) 100 0,95 0.85 150,6 2,49 2,69 Knowing wear on surface strength value , stiffness of the material needed can be found on figure 3.16. 41 On the abscissa axis Brinell Hardness is represented and on the ordinate axis wear on surface strength limit , 𝜎.Material will be grey-cast iron with more than 100 HB stiffness for both gear and Sut bigger than 23 daN/mm2. Exact specifications are obtained from Table 3.14 . Gear will be made of ASTM 25 grey-cast iron. Figure 3.16 . Brinell hardness for different materials depending on wear on surface strength. Table 3.14. Properties of different types of greycast iron. 42 Shafts. References:, [14], [16], [17], [20] , [20]. Shafts will be design considering the fatigue study. Material for both shafts will be Steel 4130 tempering at 540 Cº, Sut=1030 MPa. The minimum diameter capable of bear the external forces will be calculated using Goodman Criteria. Input shaft. Input shaft critical sections are shown on figure 3.17. First, exterior forces are calculated. Radial force applied from the electric motor (section A) can be calculated as: 𝐹  = 𝑇 2 ∙ 𝑑 (3.8.1) Where Fr is the radial force applied from the electric motor, N;T is the torque applied to the shaft, Nm ; d the diameter of the shaft, m. Figure 3.17. Input shaft critical sections. 43 Gear apply a torque, T, same as before, and radial Force, F (Section C). 𝐹  = 𝑇 𝑟  (3.8.2) Where Ftg is tangential force,N: rg is radius of gear. 𝐹 = 𝐹  𝑐𝑜𝑠𝛼 (3.8.3) Where F is the normal force produced by gear, N; α is the pressure angle=20 º. 𝑭𝒕𝒈=±2238,8 N; F=±2383,5 N In this case, Goodman criteria is like: 𝜎   𝑆  = 1 𝑛  (3.8.4) The forces are alternating so 𝜎=0. Se is obtained from equation 3.5.3, but a new term is added: 𝐾𝑒=  , where Kf is the notch factor. For keyways it is Kf=1,6 and for security rings grooves it is Kf=2,2. Security factor nf is 2. Most critical section is D. In section D, T=Ta=𝟑𝟎𝟎 𝑵𝒎. Calculating the bending moment in section D as: 𝑀 =  𝐹  ∙ 𝑑  (3.8.5) Where M is the bending moment over the section,N; Fi forces applied on other sections, N; di between section D and sections where are forces applied (A y C), m. Figure 3.18. Vectorial scheme of the forces over gear. Figure 3.19 . Breakdown of forces over the gear. 44 𝑴=𝑴𝒂=(𝟐𝟒 𝒅+ 𝟏𝟒𝟐,𝟗𝟓 )𝑵𝒎. 𝜎 and 𝜏(eqs 3.4.4 and 3.4.5) are calculated in function of d. Then , they are replaced on equation 3.4.7 to get 𝜎.For Se , factors are obtained the same way as previously mentioned in this paper but adding the new factor Ke. Table 3.15. Correction factors for the input shaft. Ka 0,71 Kb 0,87 Kc 0,814 Kd 1 Ke 0,45 Se`(MPa) 519,12 Se=118,68 MPa Replacing everything on equation 3.8.4 and calculating the diameter, d=48,97 mm. In order to get standard items d=50 mm. Output shaft. Critical sections of the output shaft are shown on figure 3.20 Most critical section is D. Forces are applied on sections A and C. Bigger bending moment is placed on section Equations are the same as before, results are presented on Table 3.16: Figure 3.20. Output shaft critical sections. 45 Table 3.16.Results for calculations of output shaft. Fr (N) 462 2 𝑑 Ftg (N) ± 2264 , 7 F (N) ± 2410 , 05 Ma (Nm) ( ,   + 144 , 603 ) Ta(Nm) 462 Ka 0,71 Kb 0,87 Kc 0,814 Kd 1 Ke 0,45 Se`(MPa) 519,12 Se (MPa) 118,68 d 53,7 mm In order to get standard d=55mm. Bearings. References: [14], [15], [16] , [20], [21]. The shafts will be held by two ball bearings each. Failure criteria will be: 𝐶 ∙ [ 10  𝐿  ]   = 𝐶  ∙ 𝐹  (3.9.1) Where C is the Dynamic rating, N ; L10 is Rating life, h; a=3 ; Cserv is the Service rating; Feq are Equivalent forces, N. 𝐹  = 𝐹  + 𝐹 (3.9.2) 46 Cserv is obtained from Table 3.17. For commercial gears the factor is Cserv=1,3.Rating life is obtained from Table 3.18. For short-operation machine L10=8 kh. Input Shaft Output shaft C (kN) 1,415 1,718 Knowing this value, it is possible to go to the manufacturer catalogue, SKF in this case, and choose the ball bearings. Table 3.17. Service rating factors. Table 3.18.Rating life for different operations. 53 4. DESIGN OF MANUFACTURING TECHNOLOGICAL PROCESS FOR THE INPUT SHAFT. This section defines the technological conditions and operations by which the different parts are achieved. The component selected for this study is the Input Shaft of the gear box. The shaft is machined from a round bar stock of Steel 4130 tempering at 540 Cº, with 55 mm diameter and 265 mm length. The stock presents an offset of material in order to avoid any surface imperfection. Surface roughs values for typical applications are shown on Table 4.1, Figure 4.1.Input shaft views. 54 The final surface roughness of the external surface is Ra=0,8 μm and for the keyways Ra=2 μm. Material. References: [25], [26]. Material for the part was chosen before (see section 2.8.1).AISI 4130 steel is a chromemolybdenum series low alloy steel with high strength, toughness and hardenability. It is usually used in quenched and tempered condition. Chemical composition of the AISI 4130 is presented on Table 4.2. AISI SAE 4130 alloy steel can be made into steel plate, steel sheet, steel pipe or tube. In this case stock is obtained from a round bar. Material properties are presented on Table 4.3. Table 4.2. AISI 4130 Chemical Composition. Table 4.3.AISI 4130 properties. Table 4 . 1 . Approximate values of surface roughness for fits. 55 Its high tensile strength allows the shaft to work properly fatigue conditions. Machines. References: [27]. Machining process of the shaft consists in turn operations in order to get the revolution shape and in mill operations to get the keyways. Machining operations are performed on the JYOTI AX 200 Turn-Mill Center. Its specifications are shown on Table 4.4. This election is made in order to perform all operations in the same machine, without losing time changing the part between turn and mill machines. The shaft will be hold by a three jaw chucks in order to get the part`s axis aligned with turn`s rotation axis. Table 4.4. Turnmill machine specifications. 56 Tools and inserts. References: [28]. The inserts and the corresponding tools are chosen using Sandvik Tool guide, introducing the values required for each operation. - ISO SNMG 12 04 12-PR 4325;ISO DSSNR 2020K 12 Specifications presented on Table 4.5 and Table 4.6. Figure 4.2. Three jaw chucks. Table 4.5.Insert specifications. Table 4.6.Tool specifications. 57 Squared insert suitable for external rough turning operations like facing or chamfered. - ISO SNMG 25 07 24-PR 4325;ISO DSDNN 4040S-25 Specifications presented on Table 4.7 and Table 4.8. Squared insert suitable for external rough turning operations. Table 4.7. Insert specifications. Table 4.8. Tool specifications. 58 - ISO CP-B1108-M5 4325; ISO CP-25BR-2020-11 Specifications presented on Table 4.9 and 4.10. Rhombic shape insert suitable for turn finishing operation. - ISO N123E2-0200-0002-GM 4325; ISO N123E20-25A 2 Table 4.9. Insert specifications. Table 4.10. Tool specifications. 59 Specifications presented on Table 4.11 and 4.12. Insert suitable for grooving operations. - ISO R390-11 T3 12E-PM 1130; ISO RA390-016M19-11L Specifications presented on Table4.13 and 4.14. Table 4.11. Insert specifications. Table 4 .12. Tool specifications. Table 4.13. Insert specifications. Table 4 .14. Tool specifications 60 Insert suitable for milling operation. - ISO QD-NE-0200-0003-CR 1125; ISO QD-NR2E26-25ª Specifications presented on Table 4.15 and 4.16. Machining process. References: [28], [29]. The machining process begins in the turn machine, following the next steps: - Face rough of 4 mm. - Turn rough of 51 mm diameter and 215 mm length. - Turn finish of 50 mm diameter and 215 mm length. - 2xGroove of 47 mm diameter and 2,15 mm length. After using the turn machine, the shaft is finished on the mill machine: - Groove of the keyways. Finally, the shaft is part off the stock bar. Table 4.15 Insert specifications. Table 4.16. Tool specifications. 61 Operation 1: Rough facing. First operation is the facing of both sides of the initial stock. In order to choose the rotational speed of the turn machine next formula is used: 𝑉𝑐 = 𝐷𝑚 ∙ 𝜋 ∙ 𝑛 1000 (4.4.1.) Where Vc: cutting speed; n:rotational speed. The cutting speed Vc is obtained from the corresponding insert table. When n is calculated (must be less than the maximum speed of the machine, 4500 rpm in this case), machining time is obtained from next formula: 𝑇𝑐 = 𝑙 𝑓𝑛 ∙ 𝑛 (4.4.2) Where Tc: machining time; l: machined length; fn:feed per revolution. Feed per revolution value is also obtained from insert table. Choosing the recommend values of fn and Vc and respecting the maximum value of rotational speed , Table 4.17 is completed for each operation. Where ap is depth of cut in mm. Table 4.17. Op1: Rough facing. OPERATION 1:ROUGH FACING INSERT SNMG 12 04 12-PR 4325 TOOL ISO DSSNR 2020K 12 Pass l(mm) n(rpm) ap(mm) Dm(mm) fn(mm/rev) Vc(m/min) t(s) 1 4 1500 - 55 0,41 259,05 0,390243902 Operation 2: Rough turning ∅51x215 . Machining parameters presented on Table 4.18. Table 4.18 .Op2: Rough Turning 51x215. OPERATION 2:ROUGH TURNING ∅ 51x215 INSERT SNMG 25 07 24 - PR 4325 TOOL DSDNN 4040S - 25 Pass l(mm) n(rpm) ap(mm) Dm(mm) fn(mm/rev) Vc(m/min) t(s) 1 215 1250 2 55 1,04 215,875 9,923076923 62 Operation 3: Finishing ∅50x215. Machining parameters presented on Table 4.19 Table 4.19 .Op3: Finishing 50x215. OPERATION 3:FINISIHING ∅ 50x215 INSERT CP-B1108-M5 4325 TOOL CP-25BR-202011 Pass l(mm) n(rpm) ap(mm) Dm(mm) fn(mm/rev) Vc(m/min) t(s) 1 215 2250 0,5 51 0,59 360,315 9,717514124 Operation 4: 2xGroove 2,15x1,5. Machining parameters presented on Table 4.20. Table 4.20 .Op4:Groove. OPERATION 4:2xGROOVE 2,15x1,5. INSERT N123E20200-0002GM 4325 TOOL N123E2025A 2 Pass l(mm) n(rpm) ap(mm) Dm(mm) fn(mm/rev) Vc(m/min) t(s) 1 2 1530 1,5 50 0,07 240,21 1,120448179 2 0,15 1530 1,5 50 0,103 240,21 0,057110223 Operation5: Milling keyway 16x6x50. Machining parameters presented on Table 4.21. Table 4.21. Milling keyway 16x50. OPERATION 5:MILLING KEYWAY 16x6x50 INSERT R390-11 T3 12EPM 1130 TOOL RA390-016M1911L Pass n(rpm) ap(mm) fz(mm) Vc(m/min) 1 3910 2,47 0,0992 195 2 3910 4,94 0,124 195 3 4470 0,0625 0,25 200 4 4410 5 0,32 220 5 4470 0,0625 0,312 200 69 Where Ct are the transportation costs, Eur; Ps are the supplies costs, Eur. Ct=82,98 Eur. Total costs of supplies will be Cs=912,78 Eur. The necessary equipment for manufacturing and construction will be hired for two weeks. Except casting process of the grey cast iron and plastic parts, that will be carried out by subcontractors. Equipment costs are presented on Table 6.4. Table 6.4.Equipment costs. Nr Equipment (including transportation) Price (Eur/year) 1 CNC JYOTI AX 200Turn-Mill Center 2000 3 Drill IBARMIA A35 1850 4 Inspection tools 60 5 Tools and consumables 400 Total(Eur) 4310 The approximate costs of the manufacturing tasks, labour included, for the manufacturing of one unit are shown in Table 6.5. Table 6.5. Manufacturing costs. Nr Task Price(Eur) 1 Turning 30 2 Milling 80 3 Drilling 50 4 Casting 500 5 Assembling 40 Total 700 Consumables needed for the system to work properly are in table 6.6. Price for 2 weeks. Table 6.6. Consumables costs. Nr Item Price (Eur) 1 Gear Lubricants 100 2 Greases for bearings 100 70 A local is rented in order to manufacture the product. Its costs are shown in Table 6.7. Table 6.7. Workspace costs. Nr Item Price (Eur/month) 1 Local renting 2000 2 Electricity costs 400 3 Others 300 Total 2700 Some previous works are carried out on the workspace before manufacturing starts. Costs shown on Table 6.8. Table 6.8. Previous works costs. Nr Item Price (Eur/year) 1 Coordination costs 200 2 Workshop tuning 600 3 Machines tuning 400 4 Personal protective equipment 200 5 Unanticipated additional costs 1000 Total(Eur) 2400 The total project cost will be: 𝐶𝑇 = 𝐶𝑠 + 𝐶𝑒 + 𝐶𝑚 + 𝐶𝑐 + 𝐶𝑤 + 𝐶𝑤𝑝 (6.1.2) Where Ce are the equipment costs, Eur; Cm are the manufacturing costs per unit, Eur; Cc are the consumables costs, Eur; Cw are the workspace costs,Eur; Cwp, are workspace previous works,Eur. CT=11222,78 Eur. The net profit per unit will be approximately the 20% of the unit cost: 𝑁𝑝 = 𝐶𝑢 ∙ 0 , 2 (6.1.3) Np=2244,55 Eur. The market price of the product will be P=13467,33 Eur. 71 Figure 6.1. Pie chart of costs per unit. Break even point calculation. Firstly, is needed to separate the fixed and variable costs, like shown on Table 6.8. Fixed costs related to equipment is calculated like the depreciation costs related to the equipment. 𝐷 = 𝐶𝑒 𝑡 (6.1.4) Where D is depreciation cost, Eur; t is time of usage, it is supposed t=5 years. Table 6.9. Fixed and variable costs. Fixed Costs Variable Costs Depreciation of equipment 862 Eur Material 912,78 Eur Consumables 200 Eur Manufacturing 700 Eur Workspace total costs 5100 Eur Then this formula is used: 𝑂𝑝 = 𝑃 ∙ 𝑄 − 𝑉𝑐 ∙ 𝑄 − 𝑇𝑜𝑡𝑎𝑙 𝐹𝑐 (6.1.5) Where Op is the operating profit ,Q is quantity of units; Vc are the variable costs per unit, Eur; Fc are the fixed costs per unit. Eur. Breakeven point indicates when the product start to be profitable. In order to calculate how many units are needed to be produced and sold in the period specified, two weeks. Operating 7% 32% 5% 1% 17% 20% 18% Supplies Costs Equipment Manufacturing Tasks Consumables Net Profit Worspace costs Previous works 72 profit is set to zero and Q is calculated. Providing a value of Q=0,52. In one year is necessary to product 14 units of the product. Payback period. Initial investment for the project will be of 150.000 Eur (including designing costs, taxes, consultancy, marketing).Payback period is calculated following next formula: 𝑃𝑝 = 𝐼𝑉 𝑃𝑝𝑟 (6.3.1) Where Pp is payback period, years; IV is initial investment, Eur; Ppp is profit per year, Eur. To calculate profit per year, first is necessary to calculate EBIT, Earning before interest and taxes, which is calculated by: 𝐸𝐵𝐼 𝑇 = 𝑃 − 𝑉𝑐 − 𝐹𝑐 (6.3.2) EBIT=5692,55 Eur. This is the earnings for two weeks. In one year, total profit will be: 5692 , 55 € 2 𝑤𝑒𝑒𝑘𝑠 ∙ 52 𝑤𝑒𝑒𝑘𝑠 𝑦𝑒𝑎𝑟 = 148006 , 3 𝐸𝑢𝑟 𝑦𝑒𝑎𝑟 (6.3.3) Replacing on formula 6.3.1 Payback period=1,01 years=12,16 months. Almost in one year the product becomes profitable. Figure 6.2. Payback period`s graphic. 73 7. CONCLUSIONS AND RECOMMENDATIONS. The initial conception of this project comes from the idea of trying to improve dependent people`s life by designing a system that helps them to get up from bed . Like it is mentioned on the literature review, it already exists systems like transfer cranes which help dependant people to move from bed to another place, but always requiring another person`s help to manage the crane. - System designed can be managed by the patient himself. - It does not need previous works to be installed. - It can be adaptable to different beds and person size. - It can be portable. - The system can work until 160 kg. - In 26 seconds can put a person in a sitting position. These objectives have been achieved by designing two independent machines managed by a remote control. Some improvements can be done in future projects related: - Shafts have been studied in a fatigue case, not in a static one like it was done with the arm. Static study could be done to the shafts with a more restrictive criteria than the Von-Misses one, which is more optimistic than others. - Back’s design can be more ergonomic doing a proper anthropometric study. - Back could move out of bed in order to allow user to sleep more comfortable. - Protective casing could be lighter improving its design and making it thinner. - Wheels could be added in order to ease system`s displacement. - Costs could be reduced by mass production and doing better materials study. 74 ANNEXES MBP 20 00 01 00 000 GD MBP 20.00.01.02.000 MBP 20.00.01.01.000 AD MBP 20.00.01.03.000 MBP 20.00.01.04.000 MBP 20 00 01 00 000 GD Format Zone Position Marking Name Quantity Remark Documentation A1 General view Subassemblies A1 Gear Box Back`s Lift Pinion system Rack system General view Litera Page Pages 1 1 VGTU MPfuc-16 SOLIDWORKS Educational Product. For Instructional Use Only. MBP 20.00.01.01.000 AD MBP 20 00 01 01 000 AD MBP 20.00.01.01.000 AD MBP 20.00.01.01.010 Format Zone Position Marking Name Quantity Remark Documentation A1 Assembly drawing Subassemblies A1 Gear Box Parts 1 BOTTOM PROTECTIVE CASING 1 2 INPUT SHAFT 1 3 MIDDLE PROTECTIVE CASING 1 4 OUTPUT SHAFT 1 5 TOP PROTECTIVE CASING 1 A3 10 INPUT SHAFT COVER 1 11 OUTPUT SHAFT COVER 1 Standard parts 6 DIN EN 24018 - M8 x 25-WC 16 7 HEXAGON FLANGE NUT DIN 6923 - M8 - C 16 8 PLAIN WASHER M8 ISO 7089 16 9 KEY A 16X10X50 DIN 6885 2 12 ISO - SPUR GEAR 4M S65A75H50L50 1 13 ISO - SPUR GEAR 4M S100A75H50L55 1 14 PLAIN WASHER M12 ISO 7089 16 15 DIN EN 24018 - M12 x 45-WC 12 16 Hexagon Flange Nut DIN 6923 - M12 - C 12 17 ISO 15 RBB - 2250 2 18 ISO 15 RBB - 2255 2 19 Circlip DIN 471 - 50 x 2 2 20 Circlip DIN 471 - 55 x 2 2 21 Fill Plug SKF 487016000 1 Asembly drawing Litera Page Pages 1 1 VGTU MPfuc-16 SOLIDWORKS Educational Product. For Instructional Use Only. 75 List of tables. Table 3.1. Properties of Polypropylene Copolymer. ...................................................... 22 Table 3.2. Tubular section properties. ............................................................................ 23 Table 3.3. Surface finish factor values . ......................................................................... 28 Table 3.4.Size factor values. ........................................................................................... 28 Table 3.5. Reliability factor values. ................................................................................ 28 Table 3.6. Temperature factor values. ............................................................................ 29 Table 3.7. Different factor values used for the fatigue calculations. ............................. 29 Table 3.8. Strength limits of the arm. ............................................................................. 30 Table 3.9.Specifications of different standard steels.. .................................................... 31 Table 3.10. Boundary conditions for the shaft. .............................................................. 34 Table 3.11. Dimensions of the gear. ............................................................................... 35 Table 3.12. Specifications of gear system. ..................................................................... 39 Table 3.13. Factor values and strength of gear system. .................................................. 40 Table 3.14. Properties of different types of greycast iron. ........................................... 41 Table 3.15. Correction factors for the input shaft........................................................... 44 Table 3.16.Results for calculations of output shaft. ....................................................... 45 Table 3.17. Service rating factors. .................................................................................. 46 Table 3.18.Rating life for different operations. .............................................................. 46 Table 3.19.SKF Ball bearings catalogue ........................................................................ 47 Table 3.20. TECNODIN catalogue for filling plugs. ..................................................... 48 Table 3.21.TECNODIN catalogue for drain plugs. ........................................................ 48 Table 3.22. Pinion gear dimensions. .............................................................................. 49 Table 3.23. Rack dimensions. ......................................................................................... 49 Table 3.24. Specifications of the electric motor. ............................................................ 51 Table 3.25.Results for the pinion-rack shaft calculations. ............................................. 52 Table 4.1. Approximate values of surface roughness for fits. ........................................ 54 Table 4.2. AISI 4130 Chemical Composition. ............................................................... 54 Table 4.3.AISI 4130 properties. ..................................................................................... 54 Table 4.4. Turnmill machine specifications. ................................................................ 55 Table 6.1.Standards parts costs....................................................................................... 67 Table 6.2.Stock parts costs. ............................................................................................ 68 Table 6.3. Catalogue parts costs ..................................................................................... 68 Table 6.4.Equipment costs. ............................................................................................ 69 76 Table 6.5. Manufacturing costs. ..................................................................................... 69 Table 6.6. Consumables costs. ....................................................................................... 69 Table 6.7. Workspace costs. ........................................................................................... 70 Table 6.8. Previous works costs. .................................................................................... 70 Table 6.9. Fixed and variable costs. ............................................................................... 71 150 70 50 120 85 55 6xM6x1.0 A A Ra 1,6 0,05 0,01 0,1 A 0,05 A 60 59 B SECTION A-A Ra 1,8 17 12 DETAIL B SCALE 2 : 1 ( ) Ra 3,2 R10 60 42 115 90 52 6X 12 A A 0,2 10 75 3 SECTION A-A Ra 1,6 Ra 1,6 Ra 1,6 1000 80 2x 8 5x200x 8 80 40 40 20 0,2 0,01 A B 0,01 A B A B 4 60 44 A 4 2 18 DETAIL A Ra 0,4 50 171 151 ±0,02 2x 10 25 ±0,02 2x 6 13 13 25 ±0,02 25 A A )( 0,1 0,01 A B 0,01 A B 0,01 A B A B 33 29 ±0,01 10 ±0,01 7 4 6 2 11 13 H6 30 + - 0,03 0,05 SECTION A-A )( ) ( Ra 3,2 Ra 0,8 Ra 3,2 2020.05.30 Part drawing Carlos Izquierdo Grey cast iron ASTM 25 Arm support 1:2 Resp. Dep. Inž. gr. k-dra Page en A Rev Date Drawing nr: Material Document type Title Educational Document Status Lan Scale Case No. Consultant Checked Compiled by Owner VGTU Mpfuc-16 Additional Information Carlos Izquierdo Grey cast iron ASTM 25 Part drawing 2020.05.30 Input shaft cover 1:2 Resp. Dep. Inž. gr. k-dra Page en A Rev Date Drawing nr: Material Document type: Title Educational Document Status Lan Scale Case No. Consultant Checked Compiled by Owner VGTU Mpfuc-16 Additional Information Carlos Izquierdo PP Copolymer 6/9 Part drawing Legs pusher arm 1:5 Resp. Dep. Inž. gr. k-dra Page en A Rev Date Drawing nr: Material Document type Title Educational Document Status Lan Scale Case No. Consultant Checked Compiled by Owner VGTU Mpfuc-16 Additional Information Additional Information VGTU Mpfuc-16 Owner Compiled by Checked Consultant Case No. Scale Lan Document Status Educational Title Document type Material Drawing nr Date Rev A en Page Inž. gr. k-dra Resp. Dep. 1:2 Pinion support 2020.30.05 Part Drawing 7/9 PP Copolymer Carlos Izquierdo 4/9 5/9 Paulius Ragauskas Paulius Ragauskas Paulius Ragauskas Paulius Ragauskas MBP 20.00.01.02.001 MBP 20.00.01.01.010 MBP 20.00.01.03.001 2020.05.30 MBP 20.00.01.03.002 SOLIDWORKS Educational Product. For Instructional Use Only. 55 265 55 265 4 Ra 0,8 215 261 55 51 0,1 A A 55 261 215 50 Ra 0,8 0,1 A A 55 144,15 47 50 2,15 261 19 2 261 6 50 39 Ra 2 6 45 156 261 Ra 2 211 Ra 0,8 211 Final Part 7. Parting off 6.Milling keyway 16x50 5.Milling Keyway 16x45. 4. 2xGroove 2,15x1,5 3. Finishing turning 50x215 2. Rough turning 51x215 1.Rough facing Initial stock Costs pie-chart Break even point 2020.01.06 AISI 4130 tempering at 540 ºC Additional Information VGTU Mpfuc-16 Owner Compiled by Checked Consultant Case No. Scale Lan Document Status Educational Title Document type: Material Drawing nr: Date Rev A en Page Inž. gr. k-dra Resp. Dep. Machining process of Input Shaft 8/9 1:5 Technological process Carlos Izquierdo Carlos Izquierdo Economical rates 9/9 Economical rates Resp. Dep. Inž. gr. k-dra Page en A Rev Date Drawing nr: Material Document type: Title Educational Document Status Lan Scale Case No. Consultant Checked Compiled by Owner VGTU Mpfuc-16 Additional Information 2020.01.06 MBP 20.00.01.01.002 TD Paulius Ragauskas Paulius Ragauskas MBP 20.00.00.00.000 G1 SOLIDWORKS Educational Product. For Instructional Use Only.