Development of a V-belt speed sensor for the CVT-CK2

Transcription

1 Development of a V-belt speed sensor for the CVT-CK2 van Eck, A.J. Published: 01/01/2005 Document Version Publisher s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. The final author version and the galley proof are versions of the publication after peer review. The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal? Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Download date: 20. Aug. 2018

2 Development of a V-belt speed sensor for the CVT-CK2 A-J. van Eck DCT Traineeship report Coach: Supervisor: Ir. B. Bonsen Prof. Dr. P.A. Veenhuizen Technische Universiteit Eindhoven Department Mechanical Engineering Automotive Engineering Science Eindhoven, May 2005

3 Contents Contents 2 1 Introduction 4 2 Problem Definition Problem Requirements Compact system Use with original belt Easily mountable and removable Follow displacements of the belt High accuracy Sensor choice Sensor requirements Operation frequency Oil and temperature resistance Sensor dimensions Different sensors Functioning principle of the conductive sensor Development of sensor mounting system Sensor placement Belt displacements X displacement Z displacement Rotation about Z-axis Rotation about Y -axis Design Translation in Z-direction Rotation about Z-axis Translation in X-direction Sensor framework Development of a V-belt speed sensor for the CVT-CK2 2

4 Contents Rotation about Y -axis Mounting sensor system to transmission-house Materials Conclusions 25 Bibliography 26 A Sensor specifications 27 B Belt displacement M-file 30 C Belt angle M-file 32 D 3-D views 34 E Exploded view 36 F How to build in 37 G Working plans 38 Development of a V-belt speed sensor for the CVT-CK2

5 Chapter 1 Introduction The section Power Trains of the master track Automotive Engineering Science (AES) of the faculty Mechanical Engineering does much research on the subject of continuous variable transmissions, CVT s. The greatest advantage of the application of these transmissions is that the vehicle speed and the engine speed can be partly decoupled. This means that the motor can always be used in its most ideal working point. So performance and overall efficiency of the car can be improved. The working principle of a CVT is based on a plain principle. This principle is initially developed by Hub van Doorne and is many years old. It was applied in the old Daf Variomatic, this was the first private car which was driven by a CVT-belt. The principle contains three main parts, two pulleys and one V-belt. The V-belt runs through the two pulleys. The belt is driven by the primary pulley, the secondary pulley is driven by the belt. The pulleys contain one fixed sheave and one movable sheave. The fixed sheave is a part of the shaft on which the pulley is mounted. The movable sheave can move in and outward over the shaft. When the sheave moves inwards the space between the movable and the fixed sheave becomes smaller. The radius of the pulley will increase, because of the constant belt length the running radius of the opposite pulley has to decrease. This means that de space between the movable and the fixed sheave has to increase; the movable sheave of the opposite pulley has to move outwards. With the changing running radii the ratio of the transmission is changing. This principle can be seen in figure 1.1. In the upper figure the belt is running on a large radius on the left pulley and a small radius on the right pulley. When the left pulley moves outwards you can see in the lower figure that the running radius of the left pulley decreases. The running radii of the belt on the both pulleys determine the theoretical ratio of the transmission. The running radius of a pulley is determined by the space between the fixed and the movable pulley sheave. This space can be measured with a special position sensor. The actual ratio of the transmission can be determined by measuring the speed of the ingoing shaft and the outgoing shaft. The proportion of these speeds give the actual ratio of the transmission. When the theoretical ratio and the actual ratio do not correspond there will be slip in the transmission. When slip occurs in the transmission there will be a higher Development of a V-belt speed sensor for the CVT-CK2 4

6 Chapter 1. Introduction 5 Figure 1.1: working principle of a CVT power loss. This has a negative effect on the efficiency of the transmission. The slip can be prevented by using a higher clamp force on the movable pulley sheave. If the clamp force is high enough no slip will occur. The disadvantage of a higher clamp force is also a higher power loss. The most efficient situation can be realized when the clamp force is exactly high enough to prevent slip in the transmission. To determine this clamp force it is necessary to exactly know the slip in the transmission. The slip in the transmission can be measured using the rotation speed and the radius of the ingoing pulley. From these two data the theoretical belt speed can be calculated. When you can compare the theoretical belt speed with the actual belt speed the slip can be determined. So far there is still no suitable method at the TU/e to measure the actual belt speed in a CK2. The goal of this internship is to develop and realize a measurement system for the belt speed. First the conditions where the system must satisfy to are determined. The next step is to choose a suitable sensor for the system. Finally the mounting system for the sensor has been developed. Development of a V-belt speed sensor for the CVT-CK2

7 Chapter 2 Problem Denition 2.1 Problem A measurement system for the belt speed has to be developed. The section Power Trains of the master track Automotive Engineering Science has already a sensor to measure the belt speed. This sensor has much disadvantages. The sensor can only be used with a special adapted belt. It takes a lot of time and money to make these belts. The second disadvantage is the size of the sensor and its mounting system. The sensor is much too large to build in in an existing CVT. To make a new useful sensor first we look to the requirements of the new system. 2.2 Requirements The sensor system has to fulfil to these requirements: compact system; possibly to build in in the existing transmission, the Jatco CK2 possibility to use the original belt the system has to be easily mountable and removable the sensor has to follow the displacements of the belt high accuracy In the following 5 paragraphs a short explanation on these requirements will be given. Some requirements are discussed extensively in chapter Compact system There is not much space in de CVT transmission. To fit the new sensor system into the original transmission-box the system must be very compact. The exact available space in the Development of a V-belt speed sensor for the CVT-CK2 6

8 Chapter 2. Problem Denition 7 transmission depends on the place where the sensor system is placed. This exact place is discussed later in chapter Use with original belt The sensor system must use the original belt without any adaptations. When the original belt is used the sensor system can easily build in in each random CVT transmission without adaptations. Secondly when the belt is worn out the belt can easily replaced by a new one. This is the greatest advantage of the use of a original belt. There are no additional costs because the system can be used in every existing transmission without adaptations Easily mountable and removable The sensor system in used for optimization of the existing transmission. The sensor is only used to make a better control system for the clamp forces of the pulley. It is not necessary to build in the sensor systems in passenger car for normal use. The transmissions that are available at the section Power Trains of the TU/e are used for different aims, so the sensor only has to build in when measurings are done to the belt speed. So the sensor system must be easily mountable and removable Follow displacements of the belt When the transmission ratio changes from low to over-drive the belt is also moving. The sensor system must follow these displacements. If the sensor is placed on a fixed point, so it will not follow the belt displacements, the sensor can never give a accurate result. The sensor can not measure the belt speed accurate when the belt angle with respect to the sensor changes. The exact displacements of the belt and the sensor system are discussed in chapter High accuracy The belt speed is used to determine the slip of the belt in the transmission. When the slip is known a better control system for the clamp force can be made. The slip of the belt is determined using the belt speed, the running radius and the rotation speed of the pulley. The rotation speed of the pulley is measured using a sensor that gives 24 pulses for each rotation. The belt speed must be measured at least this accurate. When counting all the links on the belt separately the measuring frequency is much higher than 24 pulses per rotation. Development of a V-belt speed sensor for the CVT-CK2

9 Chapter 3 Sensor choice For the measuring of speed different sensors are available. All the sensors can be divided in two main groups, sensors that make contact with the object which speed should be measured and sensors that make no contact with the object. To prevent friction between the V-belt and the sensor the choice has been made to use a sensor which make not direct contact with the V-belt. The sensors that are left can also divided in two groups, optical sensors and inductive sensors. These sensors can measure the speed of the V-belt using the links of which the V- belt is made. The V-belt exist of many loose links that held together by nine or twelve rings. Each link is 1.8mm thick. On the inside of the V-belt there is a space of 0.5mm between the links, the sensor must be able to make make a distinction between the different links. The speed of the V-belt can be determined by counting all the links that will pass the sensor during a specific time. 3.1 Sensor requirements The sensor must meet the following conditions: 1. High operation frequency 2. Resistant against an oil/air mixture and high temperatures 3. Fit into the original CVT transmission In the next paragraphs an explanation on these requirements will be given Operation frequency First the operation frequency is discussed. The minimal and maximal link-pass frequency can be found with the next formules [4]: f min = V belt(min) d (3.1) Development of a V-belt speed sensor for the CVT-CK2 8

10 Chapter 3. Sensor choice 9 f max = V belt(max) d d is the thickness of one link. The belt speed V belt can be found with: (3.2) V belt = R pri N pri (3.3) The diameter R pri is the diameter of the primary pulley. This diameter varies from 32mm up to 79mm. The rotational speed of the primary pulley N pri (rad/s) can be found with: N pri = N 2π (3.4) 60 The rotation speed of the pulley in this formula must be given in rounds per minute. With the following data this leads to: min max N(rpm) N pri (rad/s) R pri (m) V belt (m/s) f(hz) To obtain a good measuring it is necessary that the minimal operation frequency is at least two times the link-pass frequency. If the sensor operates at a lower frequency it is possible that the sensor will only measure the the gaps between the links or only the links self. From these data the sensor speed can not be determined. In this case a measure frequency of approximately 100KHz will give a good result Oil and temperature resistance The sensor must be resistant against oil and high temperatures. Because the sensor is places in the belt-box it comes in contact with oil. The oil temperature in the CVT can run up to 130 degrees celsius. The greatest problem is the oil itself. Almost every sensor will react if oil fly between the V-belt and the sensor. Sensors that react on oil are not applicable in the system. This means that optical sensors are not applicable on forehand Sensor dimensions As a last the sensor must have small dimensions because the sensor must fit in the original transmission. The available space in the transmission is very small. The exact available space is discussed in chapter 4. Development of a V-belt speed sensor for the CVT-CK2

11 Chapter 3. Sensor choice Dierent sensors To choose the best sensor different sensors are evaluated. The sensors are evaluated on the basis of the following qualities: dimensions, measure frequency, oil/temp resistance and price. sensor type dimensions High measure resistance price frequency against oil/temp. RS inductive 22mm 6mm yes,up to 200MHz yes 10euro RS optical 10mm 15mm yes no 46euro RS hall 30mm 27mm no, 3Khz yes 27euro The only sensor that meets all these requirements is a conductive sensor. For the rest of the design of the V-belt speed sensor system a sensor of RS-components is used. The choice for this specific sensor has been made after consultation with VDT. VDT have been already busy with the development of a V-belt speed sensor and had good results with this sensor. One disadvantage of the inductive sensor is the required minimal surface speed. If the surface speed, in this case the belt speed, is to low the sensor will give no output signal. So the belt speed can only measured accurate for speeds above 2.5m/s. For more details of the sensor see appendix A. Development of a V-belt speed sensor for the CVT-CK2

12 Chapter 3. Sensor choice Functioning principle of the conductive sensor The inductive sensor exist from a number of simple components. The most important components are the permanent magnet en the pole piece. Figure 3.1 shows a cross-section of the inductive sensor. Figure 3.1: Cross-section of the inductive sensor A permanent magnet inside the sensor projects a magnetic field to the area immediately in front of the sensor pole piece. Any ferromagnetic actuator moving through this area, or suddenly leaving it, alters the reluctance state and produces a voltage output. The actuator in this case is the belt with its links. Provided the actuator passes through the sensing area with sufficient speed, the sensor generates an electrical signal of useful level. The amplitude of the signal is proportional to the speed of the actuator. The signal will have a waveform that agrees to the links and the air gaps between the links. At the output s zero crossover the centerline of the pole piece and that of the actuator are precisely aligned. The zero crossover is a well defined point and can used as a reference, see figure 3.2. The output voltage of the sensor must be measured over a high resistance, for example 100kΩ. Figure 3.2: actuator/sensor orientation to output zero crossing By counting these points during a certain time the V-belt speed can be calculated. The signal must possibly be filtered and can be converted to a block-signal for easier use. Development of a V-belt speed sensor for the CVT-CK2

13 Chapter 3. Sensor choice 12 Every inductive sensor has a optimum working point. In this point all the conditions are optimal so the sensor give the best possible output and accuracy. For the used inductive sensor this optimum working point depends on the different distances and speed. The actuator speed is optimal when it is minimal 2.5m/s. The minimum belt speed it is reached when the transmission is running in low, then the belt speed is 1.7m/s. The maximum belt speed is reached in Over Drive, then the belt speed is 49.6m/s (see chapter 3.1.1). The actuator speed is in most cases equal or larger than the optimal minimal speed. The distances are showed in figure 3.3. Figure 3.3: optimum sensor/actuator relationship The sensor operates in its optimum working point when: A D B C C 3 D E - as close as possible F D In this case with the belt as a actuator the distances are: A = 1.3mm; B = 2mm; C = 0.5mm; D = 0.4mm; E can be established as close as possible and F = 6mm. Only the third condition is not met. So the sensor will not operate optimal, but because the other conditions are met the sensor will operate almost optimal. Development of a V-belt speed sensor for the CVT-CK2

14 Chapter 4 Development of sensor mounting system In this chapter the design of the total system will be discussed. In chapter 3 a sensor has been chosen. The dimensions of this sensor are known. Now the best place in the transmission has to be determined. When the place has been determined the displacements of the belt must be determined. The sensor must follow these displacements precisely. 4.1 Sensor placement With the know sensor dimensions the best place to build in the sensor system is determined. The sensor measures the air gaps between the links of the belt. These air gaps occurs on two places on the belt. The first place is the outside of the belt in the contour of the pulley. When the belt is running over the pulleys there arise air gaps between the links. To measure the speed on this place the sensor has to be placed on the outside of the belt. Because the length of the sensor (22mm) there will not be enough space at this place. The other place where air gaps occurs is on the inside of the belt on the right piece. To use these air gaps the sensor must be placed on the inside of the belt between the two pulleys. Now there are only two places left to mount the sensor system, but one of these places is eliminated because of the presence of an oil canal. The best place to mount the sensor system is exactly between the two pulleys. 4.2 Belt displacements The global place of the sensor is know. Now the displacements on this point can be determined and the exact place can be determined. The best place is there where the belt has minimal displacements. As a first a schematic reproduction of the CVT has been made with a coordinate system, see figure 4.1 Development of a V-belt speed sensor for the CVT-CK2 13

15 Chapter 4. Development of sensor mounting system 14 Figure 4.1: schematic reproduction with coordinate system X displacement The displacement of the belt in the X-direction is calculated using a constant belt length. With a constant belt length and one know pulley running diameter the second pulley running diameter can be calculated. The total belt length is given by [1] [3]: L = R 1 α d + R 2 (2π α d ) + 2a sin α d 2 + π δ (4.1) In this equation R is the diameter of a pulley; a is the distance between the two centers of the pulley; α d is the wrap angle of the belt. The wrap angle can be calculated with [3]: cos α d 2 = (R 2 R 1 ) a (4.2) With a matlab m-file (see appendix B) the position of the belt is plotted in figure 4.2 In the figure you can see that there will be no displacement in the X-direction exact between the two pulleys. But because the the slant form of the belt and the pulleys the belt has a small displacement in the X-direction during shifting up and down. Also small vibrations in the belt can occur, therefore the displacement in the X-direction can not be neglected. The exact displacement can not be calculated for this reason an estimate has been made of a maximal displacement of 5mm Z displacement The greatest displacement of the belt is in the Z-direction. During shifting up and down the belt moves in this direction because of the displacements of the movable sheaves. From a detailed drawing of the CVT-ck2 a displacement of 8.75mm is found. In the design of the system a possible displacement in the Z-direction of 10mm is used. Development of a V-belt speed sensor for the CVT-CK2

16 Chapter 4. Development of sensor mounting system Figure 4.2: pulley diameters and belt Rotation about Z-axis The rotation about the Z-axis can also be calculated using equations 4.1 and 4.2. With the M-file from appendix B the wrap angle α d is calculated. The rotation of the belt is given by [3]: β = (180 α d) (4.3) 2 The belt angle versus the primary pulley diameter is plotted in figure 4.3. In figure 4.3 you can see that the minimum angle is -16 degrees, the maximum angle is 16 degrees. The total maximum rotation in relation to the transmission house is 32 degrees Rotation about Y -axis In theory there will be no rotation about the Y -axis. For safety the rotation freedom about the Y -axis has not been fixed. So the sensor can follow optimal the belt if it will rotate in this direction. In the design an angle of maximal 5 degrees has been taken into account. When the sensor can rotate free about the Y -axis it s also much easier to mount the sensor in the transmission house. Now it is not necessary to mount the slider mechanism exact parallel to the belt. A small deviation in the mounting system will give no problems. Development of a V-belt speed sensor for the CVT-CK2

17 Chapter 4. Development of sensor mounting system 16 Figure 4.3: Belt angel in relation to the transmission house 4.3 Design All the displacements are known now. The mounting system of the sensor must be able to make the displacements. First there is looked to the design of a construction that can follow the biggest displacements. That are the displacements in the Z-direction and the rotation about the Z-axis. Later there is looked to the smaller displacements in the X-direction and the rotation about the Y -axis. 3-D drawings of the total system can be found in appendix D. The complete working plans of all the components can be found in appendix G Translation in Z-direction The displacement in the Z direction relative big. There are different manners to make such a big translation possible [5]. A few options are discussed and the best design is chosen. The first option is a very simple one rod mechanism. One side of the beam is fixed hinged to the edge of the transmission. The sensor will be fixed hinged to the other side of the rod. A simple schematic drawing is shown in figure 4.4. Development of a V-belt speed sensor for the CVT-CK2

18 Chapter 4. Development of sensor mounting system 17 Figure 4.4: One-rod mechanism Figure 4.5: four-rods mechanism The advantage of this system is that it is very simple to make. The greatest disadvantages are the big dimensions of this rod because of the great displacement it must make. In the transmission there is no place for such a big rod. The second disadvantage is the displacement in the other directions. When the sensor moves in the Z-direction it will also moves in a direction perpendicular on this movement. So the movements in different directions have been coupled. This coupling can be deleted by using a two or four rod system (see figure 4.5). The disadvantages of this options are the big dimensions to realize such a system. Also the many joint points is a disadvantage. It is very difficult to make these joints without margin. The third option is to make a slider mechanism. A great advantage of such a system is that it can be build very compact. For this application two different designs are made. The best one is chosen. In figure 4.6 and 4.7 you can see the different designs. In both designs there are two vertical round slides, these two round slides prevent the mechanism to rotate. These two rounds can also be replaced by one slide with a different form, for example square or triangular. So the system can be made with less components. The disadvantage of this forms is that a considerable friction appears as soon as a force comes that is not in the same direction of the movement freedom. When this friction becomes to high the total system will not be able to move anymore. The intention is that the measurement system wont have any influences on the belt, so friction must be avoided. From the two options in figure 4.6 and 4.7 the second one is chosen. Option 1 has different disadvantages. The construction is build around the belt, so it is difficult to mount and remove the system. Furthermore the construction is very large because the sensor must be able to rotate and move freely with the belt, so there must be enough space between the two slides. The block-system that shove among the two sliders should only move in the Z-direction, for this reason 5 freedom degrees must be fixed. One slider will fix 4 degrees of freedom, the displacement in the X and Development of a V-belt speed sensor for the CVT-CK2

19 Chapter 4. Development of sensor mounting system 18 Y -direction and the rotation about these axis. Only the rotation about the X-axis should be fixed. Therefore the second slide is add, to prevent these to fix also 4 degrees of freedom the hole in the block-system is not circular [5]. This can be seen in figure 4.8. Figure 4.6: two slides, option 1 Figure 4.7: two slides, option 2 Figure 4.8: view from above of the block Rotation about Z-axis The wrap angle of the belt about the Z-axis is calculated in paragraph The belt is in the X-direction 15mm wide. The neutral point of the belt, where the belt moves minimal is calculated in paragraph The belt rotates about an fictitious line, see figure 4.9. This line lies 4mm from the lower part of the link. The turn point of the sensor framework must must lie on 1 line with this line. In the final design the rotation about the Z-axis is combined Development of a V-belt speed sensor for the CVT-CK2

20 Chapter 4. Development of sensor mounting system 19 Figure 4.9: side and front view of one link with rotation line with the translation in the X-direction so the rotation point is always exact on the fictitious rotation line. This is explained in the next paragraph. To create a rotation point exactly on this line two rods are mounted on the slider block Translation in X-direction The displacement of the belt in the X-direction is very small. For this translation there are the same options as for the translation in the Z-direction, see paragraph Because of the very small available space in the transmission box there is also chosen for a slider mechanism. The slider mechanism exist from two slots in the rods that are mounted on the slider block. Two protrusion on the sensor framework slide in these two slots. The protrusions are circular so that the sensor framework can also rotate in the two slots about the Z-axis. The design in this stadium is shown in figure Sensor framework The sensor framework is a framework that is made around the belt. This framework fits around the belt with a minimal clearance so there is minimal friction between the framework and the belt. The framework follows all the displacements of the belt. On this framework the sensor is placed. The framework exists from a block where the sensor is mounted on and two belt slides. The slides ensure that the belt is followed. The slides push the block with the sensor against the inside of the belt. The slides press against the iron rings of the belt. There is chosen to press to these rings and not to the links because of the friction. The surface of the rings is very smooth and therefore there will be less friction. To ensure that the framework follows the belt and that the belt will not get stuck while the belt is running there is chosen for a so-called three points imposition [5]. The framework makes contact with the belt on three points on each side of the framework. This is realized by making the block with the sensor as small as possible and the slides as wide as possible. At both ends of the slides a small circular protrusion is made to create two points where the slides make Development of a V-belt speed sensor for the CVT-CK2

21 Chapter 4. Development of sensor mounting system 20 Figure 4.10: situation sketch rotation about z-axis and translation in x-direction contact with the belt. The third contact with the belt is made on the inside of the belt with the block with the sensor in it. In the figure below you can see the three contact point with the belt (figure 4.11). Figure 4.11: contact points between belt and sensor framework Development of a V-belt speed sensor for the CVT-CK2

22 Chapter 4. Development of sensor mounting system Rotation about Y -axis As last the rotation about the Y -axis has been added to the design. To make it possible for the sensor framework to rotate about the Y -axis two attachments are added. The two attachments together are circular, see figure On the attachments is a rectangular protrusion to prevent the attachments to rotate about the Z-axis. The protrusion slides in the rectangular slot in the rod that is mounted on the slide block. Because the sensor framework must be able to rotate (see 4.3.3) a hole in the lower part of the attachment is made. The protrusions on the sensor framework will fit in these holes, see figure Now the whole sensor framework can rotate about the Y -axis and translate in the X-direction. Figure 4.12: The two attachments that form a circle. Development of a V-belt speed sensor for the CVT-CK2

23 Chapter 4. Development of sensor mounting system 22 Figure 4.13: connection between attachment and belt slider Mounting sensor system to transmission-house The connection between the sensor system and the transmission-house is made by two blocks. These blocks can be mounted to the transmission-house with two bolts. Exact between the two pulleys the transmission house makes a bow. The blocks have exact the same shape as the transmission-house. By means of this form the two blocks will lie always exact above each other. Because the transmission-house is not complete parallel to the belt and perpendicular to the pulleys maybe some extra rings must be place between the transmission-house and the upper block. A small deviation can be caught by the system itself. The upper block has two longer protrusions because of the transmission-house consist out of two parts. The upper part, the cover of the transmission-house, must be removed to place the sensor. Therefore nothing can be mounted to the cover. A short description how to build in the sensor system can be found in appendix F. Development of a V-belt speed sensor for the CVT-CK2

24 Chapter 4. Development of sensor mounting system Materials The design of the sensor mounting system is ready. Now the best materials must be chosen. The requirements for the total system are 1. strong 2. light weight 3. hardwearing To create a light weight system the best material to use is aluminium. Aluminium has a low density and fabrication is easy. The disadvantages of aluminium are that its not very strong an not so hardwearing, so for moving objects it is not useful. To see if aluminium is suitable for the rods of the system a simple calculation is done in Unigraphics. The rods are loaded in the Y -direction and the Z-direction. The results are shown in figure 4.14 and In these figures you can see that the displacement in both directions with aluminium are almost three times bigger than with steel. The displacements of the aluminium rod are too large for this application. So for the rods aluminium is not suitable. Therefore steel has been chosen for the two rods. For the block and the two round slides two different materials are chosen. Because of the small diameter of the round slides hardened steel has been chosen. This is very strong and the surface is extremely smooth. For the block is chosen for bronze. The combination of hardened steel and bronze gives a slider mechanism with a very low friction. These two materials are also used in bearings. For the two attachments also bronze has been chosen. This material is easy to fabricate. It is also important to use different materials for the connections which slide against each other. When two different materials are used the materials will not "eat" into each other. The sensor framework is also made of steel. Because the sensor framework rotates about the two attachments. These are made of bronze, so the sensor framework must be made of a different material. The sensor framework must be hardwearing because it is continuously in contact with the running belt. If normal steel does not satisfy it is possible to apply a surface hardening. This can easily be done afterwards. The oil in the transmission ensures the necessary lubrication for the moving components. If these lubrication is not enough for the system an extra oil canal must be made in the transmission-house. The two mounting blocks are made of aluminium. Aluminium is easy to edit, so the blocks can be adapted until these fit on the transmission-house. Development of a V-belt speed sensor for the CVT-CK2

25 Chapter 4. Development of sensor mounting system 24 (a) aluminium (b) steel Figure 4.14: xation rod loaded in X-direction (a) aluminium (b) steel Figure 4.15: xation rod loaded in Z-direction Development of a V-belt speed sensor for the CVT-CK2

26 Chapter 5 Conclusions The design of the measurement system is proposed. The system meets all demands made in chapter 2. A compact, easily mountable and removable and precise system has been designed to use with the original belt. After the total design of the measurement system working plans of al the components has been made, see appendix G. All components have been made by Toon van Gils. Of some components the external form has been adapted so it was possible to make them with the available tools. These adaptations have however no influence on the functioning principle of the sensor-system. The next step is to build in the system in the CVT-CK2. During assembly a few things have to be taken into account to make the system complete. To mount the two mounting blocks there must be made four holes in transmission house. If these holes are entirely through the transmission house then hese holes must be closed with a sealing to prevent oil leakage out of the transmission. The sensor has two standard wires, they still have to be checked for resistance against oil and high temperatures. The wires must come out of the transmission house. The best place must be determined. After the installation of the system the sensor signal must be made suitable for further processing to read out the speed of the belt. If the signal is made suitable the totale system is ready to use. Test must expel if the whole system works. After the test there can be checked if new adaptations must be made to material, form or sensor signal. If the system is not hardwearing the steel components can be hardened. The developed system is cheap, easy to use and easy to make. Development of a V-belt speed sensor for the CVT-CK2 25

27 Bibliography [1] Fundamentals of Machine Elements Bernard J. Hamrock, Bo Jacobson, Steven R. Schmid. McGraw-Hill International Editions(1999) ISBN [2] Technisch tekenen volgens Nederlandse normen, 7th edition L.A. de Bruijn, F.J. Siers Educative Partners Nederland BV (1996) ISBN [3] Gedeelte Mechanische Overbrengingen, january 2000 H.J. Lammers, J.G.H. Schrouff, A.M. Klunder University Eindhoven, faculty mechanical engineering [4] Polytechnisch zakboekje, 48th edition P.H.H. Leijendeckers, J.B. Fortuin, F. van Herwijnen, H. Leegwater Koninklijke PBNA BV. ISBN [5] Constructie Principes 1, March 2000 P.C.J.N. Rosielle, E.A.G. Reker University Eindhoven, faculty mechanical engineering Development of a V-belt speed sensor for the CVT-CK2 26

28 Appendix A Sensor specications Development of a V-belt speed sensor for the CVT-CK2 27

29 Appendix A. Sensor specications 28 Development of a V-belt speed sensor for the CVT-CK2

30 Appendix A. Sensor specications 29 Development of a V-belt speed sensor for the CVT-CK2

31 Appendix B Belt displacement M-le clear; format long e; syms R1 a b L L= e+002; b=168; for Rp=32:24:80 R21 = b*cos(a/2) + R1; R22 = -(R1.*a + 2.*b.*sin(a./2) -L)./(2.*pi-a); maxit= ; tol=1e-5; a=0; k=0; conv = 0; while (~conv) k = k+1; error=b*cos(a/2) + Rp--(Rp.*a + 2.*b.*sin(a./2) -L)./(2.*pi-a); a=a ; conv = (error<tol) (k==maxit); end; Rs=b*cos(a/2) +Rp; xp=-sin(1/2*(pi-a))*rp; yp=cos(1/2*(pi-a))*rp; xs=-sin(1/2*(pi-a))*rs; ys=cos(1/2*(pi-a))*rs; axis equal xpp=-rp:0.1:rp; Development of a V-belt speed sensor for the CVT-CK2 30

32 Appendix B. Belt displacement M-le 31 ypp=sqrt(rp.^2- xpp.^2); plot(xpp,ypp,'r') hold on plot(xpp,-ypp,'r') grid hold on xsp=-rs:0.1:rs; ysp=sqrt(rs.^2 -xsp.^2); plot((xsp+168),ysp,'r') plot((xsp+168),-ysp,'r') grid x=[xp,xs+168]; y=[yp,ys]; plot(x,y,'r') plot(x,-y,'r') hold on grid title('belt displacement Z-direction') ylabel('pulley radius') end Development of a V-belt speed sensor for the CVT-CK2

33 Appendix C Belt angle M-le clear; format long e; syms R1 a b L L= e+002; b=168; Rs=[]; Rp=[]; A=[]; R21 = b*cos(a/2) + R1; R22 = -(R1.*a + 2.*b.*sin(a./2) -L)./(2.*pi-a); for R1=34:2:80; maxit= ; tol=1e-10; a=0; k=0; conv = 0; while (~conv) k = k+1; error=b*cos(a/2) + R1--(R1.*a + 2.*b.*sin(a./2) -L)./(2.*pi-a); a=a ; conv = (error<tol) (k==maxit); end; ag= (a/(2*pi))*360; A=[A,ag]; R2=b*cos(a/2) +R1; Rs=[Rs,R2]; Rp=[Rp,R1]; end Development of a V-belt speed sensor for the CVT-CK2 32

34 Appendix C. Belt angle M-le 33 %plot pulley diameter versus belt angle figure(2) plot(rs,((180-a)/2)) grid title('primary pulley diameter versus belt angle') Xlabel('primary pulley diameter (mm)') Ylabel('belt angle (degrees)') Development of a V-belt speed sensor for the CVT-CK2

35 Appendix D 3-D views Figure D.1: isometric view Development of a V-belt speed sensor for the CVT-CK2 34

36 Appendix D. 3-D views 35 Figure D.2: left side view Figure D.3: top view Figure D.4: front view Figure D.5: back view Development of a V-belt speed sensor for the CVT-CK2

37 Appendix E Exploded view Figure E.1: exploded view Development of a V-belt speed sensor for the CVT-CK2 36

38 Appendix F How to build in This chapter will give a short explanation how to build in the sensor system in the CVT-CK2. First unscrew the cover of the CVT. To lift the cover also three bolts from the shaft bearing must be unscrewed. Now the cover can be lifted. Place the two mounting blocks to the transmission house using four bolts. Fit the sensor framework around the belt. This is easiest if the belt is moved out the transmission. Screw the bottom rod to the slider block. Place the slider block between the two mounting blocks and put the two round slides through the mounting blocks. (If the belt is removed it must be placed back now.) Place 1 attachment on the lower rod. Next the sensor framework can be placed on the attachment. Place the second attachment on the upside of the sensor framework. Place the second rod and screw it to the slider block. Place the cover back on the transmission-house. Development of a V-belt speed sensor for the CVT-CK2 37

39 Appendix G Working plans Development of a V-belt speed sensor for the CVT-CK2 38

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