小型汽車自動變速器設(shè)計,小型汽車自動變速器設(shè)計,小型,汽車,自動變速器,設(shè)計 附 錄A The Analysis of Fuller Twin Countershafts Transmission Structure Sharacteristics Fulham (Fuller) because American Eaton is twin countershafts transmission Eaton company of the 60's original products, in 1965 patent application, and then put into production, supply market. It is aimed at the condition of design: when the U.S. has gradually built highway system, in order to improve the economic benefit to freight cars, trucks, and fast pace to large, specialty direction. In the United States more prevalent mode of transportation is by the saddle type tractor trailer and car pulled the tractor is the train, the main road with heavy car models, its characteristic is short wheelbase, in addition to the U.S. highway law caps the car before hanging must not be more than 800, and consequently make twin countershafts transmission shaft to size is very limited. The needs of the development of surface but repeated requests to improve the car engine power, and corresponding enlarges the bearing capacity of the transmission, this to the traditional single axis twin countershafts transmission for, its axial dimensions must increase thus had a contradiction, double the axis is that the twin countershafts transmission in such a situation of The Times looks unfamiliar. It greatly improve the twin countershafts transmission torque capacity (Fuller products has reached 2240), largest and decreases the axial dimensions. It supply market in the United States, after the heavy car gradually replaced the traditional single axis transmission. Eighty s it almost exclusive American heavy vehicle twin countershafts transmission market (including Eaton company products accounted for about 75%). Since the mid seventy s, Eaton products in reducing noise and improve life and reliability have increased significantly. And in the twin countershafts transmission basic structure under the condition of invariable, and has successfully developed series presentation of a new generation transmission. At the same time, adjusted the original, redesign the product series and realize standardization. Eighty s has the new series production. This paper is based on the original 900 series (namely the new series 11600, both the same basic structure of RT-915) type group structure of the desktop twin countershafts transmission for an example cent fold. Figure A1 Fuller Twin Countershafts Transmission Ⅰ-The first shaft Ⅱ-Lord box box axial Ⅲ-The second Lord box in the axis R-Lord box in reverse Ⅳ Thaft axis Ⅴ-vice Box-vice box output shaft ①②③-Bhift joints set ④-Vice box high low synchronizer joints sets ⑤-Vice box super cheap synchronizer joints set of ZR2-Lord box in reverse presence wheel Attached A1 RT-915 type the basic structure of transmission Figure A1 shows is the RT-915 type twin countershafts transmission structure diagram, it consists of a main five gear box and a rear times of three gear shift combination to vice box, it has 15 forward gears and three in reverse. The Lord box and vice gearbox which is 148.43center distance they each have two sets of intermediate bearing assembly, all the gear for spur gear, often meshing type transmission , both on the output shaft gear are floating, Lord box output shaft also float. The box without the file synchronizer, vice box with high cheap locking pin type synchronizer, ultra low inertia by outer profile of mating type shift device. The box for each file mechanical hand manipulation, vice box every file adopted the pneumatic control shift. When vice box synchronizer joints set with mating set of ⑤(④) are moved to the mating position when the left ④and the twin countershafts transmission were at high speed area, low speed area, super-low speed area, equipped with five ratio for selection. Attached A2 Structure analysis Attached A2.1 Dual axis power diversion Figure A1 shows twin countershafts transmission box and vice box the Lord had two sets of the axis assembly, input power points to two road axis assembly, again by the output shaft assembly will be two road after mixing power output. Input and output shaft of the gear has at the same time two teeth on the axis of the two respectively with gear, work by load per tooth structure is concerned, because the relative single reduced 1/2, in fact, in theory, the tooth shape error, the tooth thickness error, the center distance, the error on the axis gear and corresponding mesh loading not even, make the actual reduce the value of less than 1/2. This situation than single axis transmission double the axis has obvious advantages. Attached A2.1.1 Dual axis gears life In view of the fatigue life of gear with its load of three times about square of inverse ratio, the formula is as follows: (constant) type (A1) Type: P-Gear load; N-Fatigue damage of gear tooth cycles. The type that a single tooth, A1 power twin countershafts transmission cases, gear load, the corresponding fatigue damage cycle times. When double teeth power transmission, every single tooth load, a former theory, that is, the lower half of the corresponding fatigue damage at this time, that same cyclic number transfer torque, double teeth power transmission , the fatigue life of gear can be increased greatly. If keep gear fatigue life, that is, the constant,, this shows that the fatigue life of gear equal, double teeth power transmission , every single tooth can be increased by the load to, can improve a times. If the worst of the actual situation, according to consider, two teeth load distribution non-uniform coefficient for 0.6, by calculating know that the torque capacity still can be increased by 67%. This is double the axis on the basis of which the design principle of the twin countershafts transmission facts. Attached A2.1.2 Double the axis center distance transmission The axis of gear twin countershafts transmission of center distance to the following formula Type (A2) Type: B-the load distribution non-uniform coefficient (for 0.52 ~ 0.60); By typeA2, it is known that the center distance gear is single axis structure reduce 15 to 20%, this to improve the twin countershafts transmission efficiency and lightweight has the important meaning, we know that gear center distance is reduced, quality can reduce a lot. Therefore, the center distance gear is gear twin countershafts transmission in the design the most basic parameters, it affects the twin countershafts transmission many of the important performance index, and direct and gear twin countershafts transmission and structure design of carrying capacity has close relationship. For a long time, to reduce the twin countershafts transmission of the domestic and foreign traditional gear from center made unremitting efforts, eventually because of bearing, material by technological level and shift the design and manufacture of synchronizer into the technical level of the check and little progress. The axis of the structure of the double appear, because power diversion has greatly improved the gears, bearings and the axis, the loading condition, and may reduce the processing accuracy requirement, and can therefore do not only ensure the twin countershafts transmission performance, and reduced the gear from the center. Due to the stress of gear twin countershafts transmission gear with a more traditional nearly half, it can be reduced to about 40% of the reduced width, already reduced the twin countershafts transmission shaft to size, and keep the bearing capacity of the gear, with improved load of the tooth, and to improve the distribution of gear life. Attached A2.2 Gear floating The box on the output shaft gear at the same time and the two symmetrically arranged on the axis of gear engagement, it in two gears can be along radial direction between floating, rely on meshing round self-centering, vice box also is such. This is because of the structure of the double Fuller twin countershafts transmission characteristics, its advantage is: (1) to make the output shaft gear and two on the axis gear meshing, and correct evenly distributed load. (2) tell the traditional twin countershafts transmission output shaft in all often mesh in the needle bearing. The needle bearing is the weaknesses in traditional twin countershafts transmission structure, cancel it, to improve the twin countershafts transmission of life and the working reliability have obvious function. (3) on gear precision, accuracy and the shaft bearing hole position precision can reduce requirements. (4) make tooth shape by the error of dynamic load less of an effect. (5) test shows that the meshing can reduce the floating strong resonance noise intensity. Attached A2.3The arrangement of the shaft and stress The second shaft for the box floating structure, two axis back end and vice box drive gear spline connection, and through the bearing can support on the enclosure; Shaft front shaft neck and oil bearing radial clearance of the big (shaanxi automobile wheel factory measurement for the 0.9), the shaft is the fulcrum, front after floating. Therefore, the second shaft gear are floating, shift, in the second shaft of the outer profile of engagement with floating, facilitate change gear shaft. Figure A1 shows, the axis of the centre of the attachment and the Angle between horizontal, Fuller 19° Angle, this is too small, if will make the width dimension increase, stir oil loss increases, the loss is the main factors of influence twin countershafts transmission efficiency; If too much, is the size, and increase the height above bearing bad lubrication condition. Symmetrical arrangement of the axis make first shaft, double the second shaft gear by radial force balance each other, make this second shaft under bending moment, and are not only bear torque, put can make the first axis, the second shaft diameter. 2 the axis also this by bending moment, can make the shaft decrease 1/2 ensure enough (this is intermediate bearing stiffness design should be the main consideration question), to improve the working conditions of the gear and bearing, this to raises gear and bearing life and reduce the noise is favorable. Attached A2.4 Solve the bearings use life problem By that, input shaft and the output shaft bearings by composition of radial force to zero, twin countershafts transmission gears for straight teeth, no axial force, bearing under gravity only; The axis of the bearing by radial force nearly 1/2, reduce without axial force. All bearing load conditions have been great improvement, this is caused such twin countershafts transmission bearing life long basic factors. In addition, the one end of the intermediate bearing vice box still used bearing capacity of strong roller bearing, already won the benefits of large capacity, but also because of the axis must be adopted to support, and separate swimming type type bearings with convenient fold to. The box is a common type though bearing the rest, but compared with the traditional twin countershafts transmission coefficient of its life, but many high. Deputy box output shaft is made up of two the outfit's circular cone roller bearings, according to the analysis of the main support is to enhance the cantilevered shaft stiffness and stability, and increase the bearing capacity. In bearing load is small, as far as possible increase bearing capacity, can rise already bearing life, to that of the twin countershafts transmission adapt to life always; And enhance the stiffness, strengthen the functioning of the shaft rigidity, ensure gear meshing, improve the correct life and reduce noise. The new series of products to reduce noise, and the new design, so as to improve the bearing the bearing quality. The actual application result: Fuller double central axis in the twin countershafts transmission within 480000 kilometers, the life without changing bearing the same level in the value of the world's best level in transmission. AttachedA2.5 The Lord without synchronizer and the box, type clutch cooperate with shifted gears Fuller double the axis twin countershafts transmission box has not adopted the synchronizer, but the outer profile of mating type shift device. Normally, for large capacity for the twin countershafts transmission torque, due to the large inertia gear, big, shift in entering when the speed of the difference of the larger meshing between gear from the impact is big also, cause shift difficult. Therefore, we should add synchronizer. But the synchronizer, to solve the current problem of its service life. Big torque capacity of the single axis twin countershafts transmission is west Germany government is world famous products, there are still a synchronizer early damage, the problem in the world each production manufacturer also have been solved. Fuller double the axis twin countershafts transmission box has not adopted the synchronizer, but from a device with pull model, with a simultaneous shift. It is in the box on the first shaft installed a friction brake disc, when shift separation clutch, separate fork pulled back bearings, will friction brake disc pressure to the first axis, brake first shaft cover, to speed up the process, according to the gear synchronous this, it can only make the first shaft for, so can only slow movement in place the start up and use, and can't shift in downward shift when used. In the design principle, structure and calculation on the practice of exploratory, from the principle and structure can be done on the up and down when shift all can use. According to the analysis, the device in the simplified operation, shorten the time shift, a simultaneous shift on can be as effective as synchronizer similar role, but for this structure does not have synchronizer is the lock function, to realize no impact shift, but also depends on the driver of the operation of proficiency. Eaton company claimed that the shift in institutions of the engagement of the set, the spline tooth ends and the corresponding spline gears between a big hole are design Angle pouring in shift, it can play a certain process lock up the role. This kind of unique shift agencies from the United States, heavy duty truck generally use the situation, is successful, if via improved. Expected to completely replace the synchronizer function, to cancel synchronizer purpose. So the benefits of the obvious, it avoided the synchronizer this difficult problem, and transmission , improve the life the weaknesses in the work of transmission , simplify the structure reliability transmission , make its axial dimensions cut short, quality, reduce the ease of technology and materials to demand higher parts, make the twin countershafts transmission cost reduced. Attached A2.6 The straight teeth gear transmission Fuller double the axis twin countershafts transmission box and Lord of all gear vice box USES the straight teeth gear meshing twin countershafts transmission at home and abroad, often torque capacity is rare in transmission. In addition to deputy box drive gear is the single diameter temperance gear outside, are more than double diameter temperance short gears, Lord box and vice box of each shift gears are one from each kind of the festival, 6/7 and 5/7 respectively, converted to 4.32/3.63 and 5.08/3.63 module (new series of the products, the modulus gear presentation is less than 1.27 the tooth shape, easy to form more slender gear meshing). The Lord all gear pair of gear box for 22 to 23 of gear teeth, all gear tooth shape by small Angle and deflection is fixed. In order to achieve the new traffic regulations for noise limit, Eaton for new products to take the following measures: (1) improve tooth shape structure; (2) improve the superposition coefficient; vice (3) improve the precision (presentation than thick tooth gear series precision high level, is make series load distribution among gear teeth uniform); (4) improve bearing quality; (5) improve the rigidity. Good results have been achieved, new series product is old products to reduce noise intensity by 5 ~ 7. Analysis the characteristics of structure above (1) all adopt the straight teeth gear, to the double integral of the intermediate bearing structure, easy to assembly assembly and collapse (2) using short teeth gear system can enhance the gear bending strength, but at the same time, they have also made the straight teeth gear coincidence, the defects of small coefficient by small teeth shape Angle and more to the teeth mesh areas, it can make up the defects, new series of products to the superposition coefficient reaches 2.2 (the traditional design superposition coefficient around 1.5) only. Sweden Scania company produces the GR860 main twin countershafts transmission adopts full inclined gear meshing transmission, its often heavy machine, coefficient of 1.45 to 1.68. The improvement of superposition coefficient can improve the gearing mesh performance, test shows that: (1) to reduce the noise; (2) make is the influence of surface fatigue life of gear was obviously improved (for tooth face pressure decrease); (3) the coincidence degree coefficient of large gear impact resistant ability than superposition coefficient low gear (by the former load distribution is more homogeneous), this ability is heavy auto twin countershafts transmission is required. (3) with small teeth shape Angle will reduce the strength, the root is adopted deflection is modified, in order to enhance strength of tooth root gear. (4) in order to guarantee the box on the axis with the first two gear shaft, the second shaft gear can at the same time, also make the second shaft meshing gears can will load on evenly distributed to two axis, so should guarantee the first axis, the second shaft gear the number of teeth are even on the gear axis all have a tooth is located in the same longitudinal plane inside, and all of the same modulus gear. (7) for gear teeth smaller diameter, wide is narrower, facilitate the pull teeth and shaving teeth and other high efficient processing method production. The road test results show that: the average operation 640000 kilometers of the new series products, the reliability coefficient was 92%, 90% at 800000 km. Not only that such twin countershafts transmission of simple structure, good technology, and reliable work, life index in the advanced world level, durable, easy to make a successful example. Attached A2.7 The Lord box, vice box and the structure characteristics The Fuller double the axis twin countershafts transmission series is two kinds of the center distance (135.128 and 148.43) of the five gear box for basic, take the Lord box and click unit variant combination principle, and different combination, realize after vice box serialization of products standardization many varieties, production figure 1 box in the structure design is very distinctive, the variant is to keep away from the same center in gear and the rest of the parts in addition to the gear basic don't change in the 18 to gear different combinations, to get eight different ratio of combination of Lord box. And as shown in figure A1 shows, in the full set of parts does not change, only change geargear, gearandassembly and position, and also can get after exchange with the overdrive Lord box, so that the entire series products DuoZhong increase. Variant need to replace parts to take the combination of the spline connection structure; The first axis, the second shaft all gear hole for the same specifications of the spline hole, make gear according to need conversion installation; And so the tooth of the engagement of shift institutions and each file, general. Main box easy to realize the form, also can realize for strength. Because the entire product parts generalization degree is as high as 70% above, great show, where production for high economic performance. The two vice box in the axis axis and the main box two reverse gear axis line, the deputy