Thames & Kosmos Remote Control Machines, Инструкция

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9
About the Gears |
REMOTE-CONTROL MACHINES
ROTARY GEARBOX
Fig. 17
Fig. 17 is an another example showing two gears meshing as beveled gears at a right angle.
The 80T Gear with the built-in pitch holes, acts as a rotary stage here on which the frame structure can be built.
UNDERSTANDING GEARS 6
Worm gears
The gears in this kit can combine in yet another way. A worm gear and
gear wheel are combined together as a worm gearbox. As the worm
gear rotates once, the gear wheel turns only a one-tooth distance.
Take the 40-tooth blue gear as an example, the gear ratio would
reach 40:1 to achieve a huge speed reduction and torque increase.
When friction is not considered, the speed reduction reaches 40
times, and the torque increases 40 times. In addition, the structure
of the worm gearbox also has another characteristic: the transmis-
sion can only be conducted from the worm gear to the gear wheel,
but cannot be conducted in reverse. Because of this characteristic,
the worm gearbox can only be used for speed reduction and not for
speeding up. For this reason, it is commonly used in the opening de-
vice for garage doors to prevent the possibility of the door dropping
unexpectedly.
The examples below illustrate the assembly of the frames, gears,
and axles. The gears are easy to install on the rods and frames in
this kit, because the rods and frames have holes positioned in incre-
ments of ten millimeters. The pitch diameters are in multiples of 20
millimeters, and thus the distance between the center points of the
gears is in multiples of ten millimeters.
Fig. 20 Fig. 19
Gear Wheel
Worm Gear
Fig. 18 Structure of a worm gearbox
20T
80T
555004 Booklet Final 2015.indd 9 9/21/15 10:17 AM