DOUBLE WISHBONE SUSPENSION
Many parts can be used to create the
upper and lower control arms including simple beams and lift arms, but
there are also a number of special purpose parts available. The
long Formula-1 style links shown in black first appeared in 2000, but
these appeared in only a few sets. The left dark gray control arm
appeared in 1988 and was replaced with the one on the right in
2008. The arm shown in yellow has appeared in a large number of
sets since 1994.
SOURCE:http://www.technicopedia.com/ |
ACKERMAN STEERING SYSTEM
Ackerman steering geometry is used to change the dynamic toe setting, by increasing
front wheel toe out as the car is turned into the corner. Racers are interested because of
the potential to influence the handling of the car on corner entry and mid corner.
Springs, anti-roll bars and shock absorbers come first. Even though WTW vehicle dynamics theory will remain the back bone of our set ups, we hope to develop procedures with respect to steering and suspension geometry have equally general application. SOURCE:http://www.technicopedia.com/ |
WORM GEAR ANIMATION
A worm gear (or screw) can be thought
of as a gear with a single tooth. The LEGO®
worm gear
operates on an axle which is perpendicular to a mating spur gear.
Worm gears have some special properties which make them differ from
other gears. Firstly, they can achieve very high gear reductions
in a single stage. Because the worm gear has only one tooth, the
gear ratio is simply the number of teeth on the mating gear. For
example, a worm gear mated with a 40 tooth spur gear has a ratio of
40:1. Secondly, worm gears have much higher friction (and lower
efficiency) than the other gear types. This is because the face
of the worm gear's tooth is constantly sliding across the teeth of the
mating gear. This friction gets higher the more load is on the
gear. Finally, worm gears cannot (generally) be backdriven.
In the animation below, the worm gear on the green axle is driving the
blue spur gear on the red axle.
SOURCE: http://www.technicopedia.com/ |
BEVEL GEAR MECHANISM Bevel gears operate on axes which are not parallel. Bevel gears can be made specifically for axles at virtually any angle, but LEGO® bevel gears are all made for perpendicular axles (90 degrees). In the animation below, the red gear on the yellow axle is driving the blue gear on the green axle. The axles are turning at the same speed because the gears have the same number of teeth. Bevel gears have complex tooth shapes which also generate complex forces on the supporting axles. Therefore, it is even more important than for spur gears that there are proper bearings for support of the axles. In general, you want at least 2 bearings supporting each axle to balance the gear tooth loads, although it is possible to use just one axle pin with reduced efficiency. The closer you can locate the bearing to the gear, the more efficiently it will provide support. In the animation, a special gearbox is used specifically for this purpose. Spur gears are the second most common gear type in Technic.
SOURCE:http://www.technicopedia.com/ |
SPUR GEAR TRANSMISSION
A spur gear is a type of cylindrical gear with straight teeth that are cut parallel to the axis of rotation. They are the simplest and most common type of element in mechanical drive systems. Spur gears transmit power and motion between two parallel shafts. In order to do so, both the pitch and the pressure angle of both gears must be the same. Spur gears can increase or decrease the speed and torque of the rotating shaft depending on the sizing and arrangement of the gears. The teeth of a spur gear are cut using a gear hobbing machine or a gear shaping machine. Spur gears can be produced from various materials, including steel, brass, bronze, or plastic, and depending on the application, they can be hardened based on the requirements for strength and durability. |
RACK AND PINION GEAR MECHANISM
A rack and pinion are used when converting rotational movement to linear motion (or vice versa). A bar shaped gear with an infinite (flat surface) radius of a cylindrical gear is called a rack, and a meshed spur gear is called a pinion. A rack can be used by extending it combining as many racks with machining operation on the end faces when necessary. Gears transmit power by rotating one gear to move the gear that is meshed with it. On the other hand, in rack and pinion, the combination of rack gear in the form of a gear stretched in a rod form and a small diameter gear (pinion gear) converts rotational motion into a linear motion to transmit power. For example, in a case where the pinion gear is stationary and the rack moves, the pinion is often connected to the output shaft of motors. The driven side of the rack is supported by a separate structure of machine elements. The pinion gear’s repetitive rotational motion produces a repeated forward-backward motion of the rack. |