One of the most notable cells in the Lego WeDo 2.0 educational kit contains parts that were borrowed from the Lego Technic series: spur, bevel and double bevel gears, gear racks, a worm wheel (not a wheel at all!) and a worm gear case. All this variety of parts allows you to create models of robot with mechanical gears.
In this article, we suggest to consider the basic mechanical gears that can be assembled using the details of the kit Lego WeDo 2.0. And before we proceed to their consideration, we want to note that before the appearance of such educational constructors, it was possible to get acquainted with these gears only within the framework of the special discipline at a college. Now, children have a unique opportunity to get acquainted with the principle of operation of most devices that we can face in everyday life - from the gearbox of the car to the elevator!
Spur gear Lego WeDo 2.0
The kit has two spur gears for 24 teeth, as well as 4 gears for 8 teeth. All gears are gray. The peculiarity of spur gears is that they can transmit rotation in one plane, that is, the axis of rotation on which the gears are installed must be parallel. At the age of 7-8 years, children get acquainted with single-stage spur gears, and then they master the principle of constructing multi-stage (cascade) gearboxes.
Bevel gear Lego WeDo 2.0
Bevel gears are presented in a kit as follows: two bevel gears for 20 teeth (beige color), double bevel gear for 12 teeth - 2 pcs. and 20 teeth - 2 pcs. The last four bevel gears are black. Total six bevel gears! The peculiarity of the bevel gear is that the rotation can be transmitted in different planes, that is, the axis of rotation on which the gears are mounted can intersect at different angles. The most popular option is a mutually perpendicular arrangement of axes, i.e. the angle between them is 90º.
Worm gear Lego WeDo 2.0
One of the most favorite gears for the children is worm gear. Firstly, the name of the transmission is more than memorable, and secondly, the developers of the constructor have provided a special case for the worm gearbox - therefore, there are no difficulties in assembling such a gear. At the same time, there is no special case in the Lego Mindstorms EV3 constructor and the children have to assemble the worm gear by himself. A base element - a “worm”, a detail reminiscent of all its appearance Archimedes screw. A spur gear (24 teeth) is gearing with the worm. Thus, the worm gear itself is a gear-screw mechanism, while the shaft axes are crossed at an angle of 90º. An important feature of the worm gear is the unidirectional action - we can transmit rotation from the worm to the gear wheel, and we cannot vice versa, since in this case the gear teeth are locked on the turns of the fixed worm.
Rack gear Lego WeDo 2.0
The last details in our cell are gear racks, in the amount of 4 pieces. The transmission is also very popular among children - the only transmission in the set that converts the rotational type of motion into translational. Any of the existing gears, both spur and bevel, can be gearing with gear racks. The conversion of motion from rotational to translational is reversible, depending on which element - the rail or gear is structurally fixed.
Belt drive Lego WeDo 2.0
In fact, the list of mechanical gears assembled from parts of the kit Lego WeDo 2.0 can be continued, for example, a planetary gear or a crank mechanism (and this, by the way, is already “Theoretical Mechanics”). In the following review articles, we will definitely consider the next range of mechanical gears!