|
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese|
PERSONAL TRANSPORT: GROUND, WATER, AIR
Velomobile. Personal transport
Directory / Personal transport: land, water, air The Laboratory of Experimental Machines of the Oryol City Palace of Pioneers named after Yu. A. Gagarin has a lot of interesting and original works. At regional NTTM exhibitions, they attract the attention of visitors of all ages. And no wonder! The range of search for young designers is wide: a training glider and a walking robot, an air car and a microtractor. When creating each new machine, the guys follow the path of true researchers: having outlined the goal, they carefully study the existing experience, then, taking into account their own capabilities, determine the technical requirements for the future design and, finally, design and build it. This is how the two-seat velomobile LEM-05 (Laboratory of Experimental Machines, 5th model) was born.
The idea of building a velomobile was prompted by a message about the creation of such machines by Vilnius enthusiasts. They began to collect information, diagrams, drawings, built a prototype. So gradually there was an idea of what our velomobile should be like. We decided to make it two-seater and four-wheeled. The body, while not as streamlined as the teardrop-shaped cockpits of sports velomobiles, should be roomy enough for a wide, car-like seat. The seated position was chosen not only as the most familiar and comfortable, but also allows better use of muscle strength. A number of transmission requirements made it necessary to abandon the usual bicycle drive - rotating pedals with a chain drive. The choice fell on a ratchet mechanism with rocking pedals> which has no dead points, and, most importantly, allows, thanks to the emphasis on the seat back, to develop an effort 1,5-2 times greater than on a bicycle. By connecting each pedal to its own ratchet, you can make all drives independent. This will allow you to work with the pedals and alternately and immediately. In addition, the drive is easily converted to "hand-drawn": the pedals are replaced or supplemented by swinging hand levers. Such a velomobile will serve as an exercise bike and a vehicle for the disabled.
The design of our LEM-05, despite the original drive, is simple. Of the standard parts, wheels and front forks from the Desna-2 bicycle are used, as well as non-deficient ball bearings. The rest is made using simple equipment and tools from available materials. When assembling, you can do without welding. The frame of the velomobile has a U-shape. Its side spars and two front cross members are made of 40X40 mm duralumin corners. The bushings of the forks of the front wheels, if they are not used from a bicycle frame, are machined from a steel pipe and have an internal d of 30 mm with a length of 200 mm. They are fixed in the front corners of the frame strictly parallel to each other. The rigidity of the whole structure is given by the longitudinal and transverse struts of the bushings, as well as the wide seat base, cut from a sheet of plywood 10 mm thick and mounted on bolts between the side spars. The spinal beam - made of a wooden bar with a section of 25x50 mm - carries two brackets of the p / left lever and a support for the half-shafts of the rear wheels.
The steering consists of a steering arm mounted horizontally in brackets. The rocking chair at its front end is connected by a pair of transverse steering rods - steel bars d 8 mm with longitudinal levers of the wheel forks. Each of them is an M10 bolt 120 mm long, screwed into the reamed hole of the fork, which previously served to mount the front fender. It seems to us that the ratio of the shoulders is the most optimal, in which the tilt of the steering lever by 60 ° leads to the rotation of the wheel by 20-25 °. The fixation of the forks of the front wheels in the frame bushings is the same as on a bicycle. The rear wheels are driven, each mounted on its own half-shaft made of a duralumin tube with an outer d of 35 mm and a length of about 470 mm. Since the inner diameter of the wheel hub is 34 mm, and the connection with the shaft for transmitting torque must be very tight, the shank of the latter is turned into a very gentle cone: approximately 1: 100. Then, when the axle bolt is tightened, the wheel hub is pressed onto the shank at least 2 / 3 of its length. The connection will be so strong that it will be possible to disassemble it only with the help of a special puller.
Each semi-shaft is freely mounted on the frame on two bearings No. 207 and No. 2 200. The first one is put on with its inner ring on the semi-shaft near the wheel hub. The clip of its outer ring through the bracket (corner) is bolted to the side member of the frame. The smaller bearing is mounted inside the opposite end of the semi-shaft and rests with its inner ring on the axis-support of the frame center beam. The drive of each semi-shaft into rotation is provided by two ratchet mechanisms. The double ratchet coupling is fixed on the half-shaft with a conical pin with a nut. Its pulleys with spring-loaded pawls on the end planes are mounted on N2 207 bearings. A steel cable d 2 mm, fixed at the end of the rocking pedal, rounding the pulley three times, is connected through a return spring with a maximum force of 4-5 kg to the seat frame. With each forward stroke of the pedal, the cable turns the pulley. One of the pawls, meshing with the ratchet wheel, transmits rotation to the drive wheel shaft "Since two pawls on the same pulley cannot work simultaneously due to inaccuracies in manufacturing and assembly, their axes are shifted relative to each other by half the pitch of the ratchet wheel tooth. This gives a reduction idling pedal twice. During the reverse stroke, the return spring rotates the pulley against the rotation of the shaft. According to the principle of operation, a ratchet clutch is similar to a roller or ball overrunning clutch. If you have a ready one, you can apply it in this node. If you make this part yourself, it is better to stop at the ratchet, as the simplest. The ratchet wheel of such a clutch is easy to make from a steel plate by drilling and filing the teeth accordingly. Even a blunt disc cutter can turn into a ratchet if it is slightly reworked after deep tempering - heating to 1100-1200 ° C and cooling together with the furnace. The loads in the engagement of the parts of the mechanism are small, so that subsequent heat treatment is not required. The springs that press the pawls to the ratchet should only ensure constant contact of the parts - stronger ones will increase the noise and wear. Brakes - mechanical; levers mounted on both sides of the body next to the seat act directly on the rear wheels. If necessary, the front ones can also be equipped with brakes from a sports bike by moving the handle to control them on the steering lever.
An undoubted and very important advantage for a velomobile of a bicycle drive with a ratchet or other overrunning clutch is the possibility of a smooth change in the gear ratio. To do this, it is enough to connect the running cable to the pedal through the rocker. If the control cable pulls the rocker closer to the pedal swing axis, the force transmitted by the clutch will increase, and the stroke will decrease. The construction of the velomobile is completed by the manufacture of a lightweight plywood or plastic body. It is edged with duralumin corners and decorative overlays. A good view and protection from the wind will provide a windshield and rear window made of plexiglass, coziness and comfort - seats with foam cushions, covered with artificial leather. Of the additional equipment, it will be useful: bicycle lights, light direction indicators, a brake light powered by a battery or a bicycle generator, reflectors, a bicycle speedometer; Definitely a rear view mirror. In our car, convenience and comfort are combined with good driving performance: the velomobile moves smoothly, without jerks, the noise from the ratchets is almost inaudible. The ability to change the gear ratio and work simultaneously "in four legs" provides excellent throttle response, makes it easy to climb up to 15 ° and accelerate to a speed of 35 km / h! The guys who made this velomobile ride it with pleasure even in winter, assuring that neither half-meter snowdrifts nor ice are terrible for their car. Author: V.I.Borodchnets
▪ Bicycle cart for two surfers ▪ Guides for entering the garage
The existence of an entropy rule for quantum entanglement has been proven
09.05.2024 Mini air conditioner Sony Reon Pocket 5
09.05.2024 Energy from space for Starship
08.05.2024
▪ The tallest wooden wind generator ▪ 6 probes will go to look for life on Mars
▪ site section Electric meters. Article selection ▪ article Not an empty sound for the heart! Popular expression ▪ article Where are the highest and lowest temperatures on Earth? Detailed answer ▪ article Red or green? Radio - for beginners
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua |
We recommend interesting articles Section 
See other articles Section 
Latest news of science and technology, new electronics:
All languages of this page