TANDEM FOR TWO, THREE, FOUR

TANDEM FOR TWO, THREE, FOURFor a basis we took the road bike (with “women’s” frame), set on it a longitudinal beam of the two aluminum profiles-“parts” and fixed on the beam two seats with backs so that the first rider was able to pedal the front wheel drive and the second conventional chain drive the rear wheels. So we got a double bike with the same dimensions that and serial single. Sitting in the front seat rotations”t pedal for more drive, located in the center of the front wheel, supports the balance, and also serves as the driver. The second rider works the pedals, resulting in the rotation of the rear wheel while sticking the handles on the back of the front seat.

The wheel for our bike has a specific form — stick it raised, and the configuration is changed for more convenient control. We called our tandem “Buddy”. Machine weight — 25 kg. 23…”Buddy” was built and comprehensively tested, including in rural areas.
And now more about the front wheel drive. It represents the most common single-stage planetary gear with one satellite. A crown with internal teeth is fixedly mounted on the fork of the wheel. When pedaling satellite, sitting on the arm of one of the pedals, objetivas for fixed crown with internal teeth, the forces to rotate the Central gear in the same direction, the nose speed, the greater the transfer number of times. The very same gear ratio determined by the formula:
 
 
 
 
This means that when a single revolution of the pedals the wheel will make four turns and in the same direction!
 
Central gear connected with the wheel hub through a one-way clutch. So the pedals can spin the wheel in one direction only (forward); when you stop pedaling or rotation in the opposite direction the wheel continues to rotate in the same direction, while you hear the characteristic snapping of the pins of the clutch.
 
Fig. 1. The universal planetary multiplier length of the vehicle with a muscular drive
Fig. 1. The universal planetary multiplier length of the vehicle with muscle drive:
1 – plug coils”, 2 — spoke, 3 — wheel hub 4 — star, 5 — Bush roller chain, 6 – lever 7-switch, 8 eyelet screw 9 MB 10 — Satellit (t = 2, 7=22), 1 I — coil spring (wire diameter 0.5 mm), 12 pin (steel pin 0 1.5 mm), 13 — the Central gear (m = 2, Z=28), 14 — a crown with internal gearing (m = 2,7=72), 15 – ball (GOST 8338-75, No. 1000909), 16 — ball bearings (GOST 8338-75, No. 1000903), 17 — pin 6mm diameter, 18 — cover. 19 — cover.

 
 
 R and p. 2. Tandem
 
R and S. 2. Tandem “Buddy” with a chain drive to the rear wheel and the planetary in the front.
 
R and p. 3. Velosiped triple-tandem
 
R and S. 3. Velosiped triple-tandem “Troika” with the planetary drive to the front wheels and combined (planetary chain) — on the back.
 
R and p. 4. The use of multi-purpose planetary multiplier to create a combined multi-use bike (the picture is a cargo variant with a docking of the cargo truck)
 
R and S. 4. The use of multi-purpose planetary multiplier to create a combined multi-use bike (the picture is a cargo variant with a docking of the cargo truck).
 
 
R and p. 5. Using the universal drive to create multi-seat of the recumbent.
R and S. 5. Using the universal drive to create a multi recumbent.
 
Thus, we have two independent from each other drive, one for each wheel, which can be run asynchronously, in different mode and at any pace. The speed of the Bicycle with appropriate selection of gear ratios for 10-50 M higher than the existing now.
 
A few words about the characteristics of this drive.
The entire drive mechanism is located on one side of the wheels, the pedals rotate in the same direction as the wheel. All this gave the possibility of a relatively easy to construct dvuhmestnoe wheel: one side has a planetary drive with the levers and the pedals rotating on the center wheel, and on the other side of the sprocket with a chain drive. While both drives are independent from each other (even working on one wheel) as though the Central gear of the planetary drive sprocket of the chain drive and the wheel hub sitting on the same axis, but are connected through overrunning clutches. Wheel hub, in this case the Cams on both ends.
 
By the way, this drive can be equipped with rear wheel. Then we get Trehprudny triple two-wheeled bike called “Russian Troika”. The speed of the “Troika” is likely to be more than “Friend”. The rear wheel of the “Troika” should be a solid (e.g., moped) as the load on it will be more. The mass of the tandem will amount to 30-35 lbs. Rear seat when it is better to make sliding on the two telescopic uprights.
 
The gear ratios of all drives (as well as the diameters of the wheels) may differ from each other, but it was not a big difference, because one of the riders will have to pedal fast and the other much slower. But to maintain a good speed need friendly and well-coordinated operation, as in the work on the oars.
 
Planetary drive needs to be well lubricated, adjusted for free and smooth rotation; the pins overrunning clutch should work smoothly. The whole mechanism must be close to dirt and dust protective cover of thin sheet metal. The casing is attached to the arm and rotates with it.
 
A few words about the advantages and disadvantages of the proposed actuator. From the point of view of the designer, our scheme has a number of advantages: the gear is reliable, has high efficiency of about 0.95, which is slightly higher than a chain; it is simple in design and has a small number of main parts and to the whole of such actuator can be easily assembled and disassembled.
 
The disadvantages of the actuator must be attributed primarily to the presence of a weak and unreliable link — freewheel with its pin and spring. Besides, “planetary” poorly protected from dirt, sand, moisture, which, unfortunately, can easily penetrate inside the mechanism.
 
And the last one. Of course, the drive or journey on the “Russian Troika” or “Other” fun, but require a good understanding and interaction between the crew members in order to maintain balance, teamwork, tracking the road and traffic conditions. Special responsibility for traffic safety lies with the steering. Conventional brakes, drum, control of the hand on the wheel (like racing bikes).
 
In conclusion, it should be noted that the combination of “planetary” wheel could be a universal drive for a variety of vehicles with a pedal — bikes, velomobiles, bicycles. Universal module, we think, will help many enthusiasts musculoides in the creation of new economical and speedy crews.
 
V. BUTURLIN, O. VAKHARLOVSKY,

Noticed mistape? Highlight it and press Ctrl+Enter, to inform us.

Recommend to read

  • SIT DOWN, LET’S RIDE!SIT DOWN, LET’S RIDE!
    "Together cheerfully to walk..." — sung in the nursery rhyme. And go, of course, much more interesting. This gave me the idea to make a children's bike side trailer. He also increases...
  • THE BIKE CHANGES SHAPETHE BIKE CHANGES SHAPE
    Over the two centuries since the invention of the bike any ideas arose equipping it with a variety of engines: internal combustion, electrical, flywheel, and even sails. However, the...

Spelling error report

The following text will be sent to our editors: