Underfriction
A roller coaster chassis has the task to roll on the rails a roller coaster and to keep you safe on the track.
- 2.1 bogie steering
- 2.2 Ackermann steering
- 2.3 Examples and variants 2.3.1 bogie design
- 2.3.2 Ackermann steering
Wheels
The chassis of a modern roller coaster usually consists of three pairs of wheels per axle, the wheels, the Sidefriction - Wheelers and Underfriction -Wheels. In most steel coasters, the wheels are designed in duplicate. Today the wheels usually are made of metal with a plastic coating for the tread. With wooden roller coasters alloy wheels usually come with plastic tread for use.
Wheels
The wheels are the wheels with which the web rolls, the most time on the track. Early roller coasters had only wheels they resembled railway wheels. Usually, the wheels are the largest as it passes through the forces carry the analog of the multiple crossbow draw in valleys.
Sidefriction -Wheels
To prevent the derailing of trains on winding roads, the side-mounted Sidefriction -Wheels have been developed in the eighties of the 19th century. Thus equipped, wooden roller coasters, the so-called side friction roller coaster had the side of the running rails attached guide boards on which ran the side wheels. The tracks went by in a kind of trough. For wooden roller coaster Sidefriction -Wheels usually resort to the inside of the rail ( see chart). At steel roller tracks, there are both variants in which engage the wheels to the outside of the steel rail, as well as those in which they are mounted inside.
Underfriction -Wheels
The Underfriction -Wheels ( also up- lift or up -stop wheels called ) are attached to the train that they attack from below the rail. This can not stand out from the rails of the train at negative G- forces. The design was patented in 1919 by John Miller. Today there are only a few tracks exclusively Sidefriction -Wheels and no Underfriction -Wheels have. In this case the trip is planned either as an employee or as a brakeman ensures that the speed is not so high that the train could derail.
With some simple roller coaster models are side and Underfriction -Wheels combines access to the wheels laterally obliquely to the rail. In other configurations ( for example, the Big Apple) the wheels concave grip around the rail and jumping out upwards is prevented by simple metal pin.
Framework
Bogie - steering
The wheels set of inner and outer rail, of which only 2 per impellers are shown here, are fixedly connected to each other. These connecting axis (B) lies on a line with the center of the curve describing the two bars, the axis of which extends radially to the curve and at right angles to the rail. This axis is rotatably connected to the carriage, such as a truck with a railway car. The connection between front and rear axle is provided on one side with a ball joint and on the other side with a " hinge ," as at a pivot steering. The hinge does not restrict the movement of the connecting rod in a plane, the ball joint. This three-dimensional twists in the car or on the roller coaster are possible.
The wagons can be coupled with ball joints to a train as shown in the drawing or a wagon is attached to the other. The two-axle wagons can of course also go alone. This construction method is well suited for low-speed and narrow curves.
Ackermann steering
All four wheels sets are rotatably disposed in a horizontal plane to the chassis as in motor vehicle axles for axle steering. The chassis itself is rotatable only in the torsional direction, otherwise the rotation of the wheels sets are rigidly fixed to each other. The axes (B ) are not radially to the rail curve and are not at right angles to each rail piece. This results in small differences in the gauge arise that need to be balanced.
Cars can also drive alone, concatenated or as built together in the drawing. This design is well suited for high speed and wide curves.
Examples and variants
Bogie design
Muskrat Scrambler
The above drawing roller coaster cars to the bogie principle 've ever two moving axes to see, especially at the Wave and Muskrat Scrambler web.
Spinning Racer
Spinning Coaster in the image as above often have a variant of the bogie construction, constructed schematically as:
The vertical axis of the spinning coaster to the nacelle rotates with the seats is not attached on a hinge at one of the two gear axes, since the two gear axes, are both connected in the manner of a ball joint having a central portion and thus symmetrical. This means the carrier does not tip over with the gondola, the spine has form instead of the hinge arm, the two additional horizontal axis. Then again moving trailers are attached, drawn in the drawing purple. These in turn rest on the additional roles of the axes. Does the car in a Torsionslage, he is right in the middle of the two axes, not so obliquely inclined to the left as the front axle and not so obliquely to the right as the rear axle, for example.
In Crush's Coaster and Spinning Racer, the trailer has a trapezoidal shape and the different inclinations is good to see the Spinning Racer. In the introductory picture of the suspension at the top of the additional wheel and the pan supports of the trailer is also good to see. It is, unlike in the drawing, all outside.
Ackermann steering
In the Inverted Coasters, eg. on the Wicked Twister, you can see the turning wheels sets very well. They are flexible as a Einkaufswagenrad about. The seats and the frame are connected on one side fixed to the axle in the two pictures above is the right axis. On the other side of the frame is a ball joint connected to the next wagon, or to the single axis at the end of the train, as shown above, which is now in each case the left axis in the two images above. The Wicked Twister in long shot and more examples:
Velocity
Swamp Thing
Jimmy Neutron's Atomic Flyer
The joint between the cars can actually be a ball joint as in Swamp Thing or with universal joint and thrust be built like Jimmy Neutron's Atomic Flyer. The Wicked Twister takes as you can see the strong torsion good on that roller coaster design also tolerates narrow peaks but no narrow plane curves. Can also be connected by a rod in the trapezoid in order to reduce the ' chatter ' of steering the wheels sets, as required by the Ackermann steering.