Cabin motorcycle

 

Initial concept for a vehicle that is supposed to use negative emission ammonia engine (detailed description will be published at a later date, mention of it can be found at the bottom of this post). “Rider” sits just like driver of a car, while "pillion" is tucked bellow and slightly rearwards of the “rider”. Drive of rear wheel is parallel clutchless hybrid system (lithium-ion capacitors act as energy storage), while front wheel has a electric motor/generator attached to it that acts as series hybrid system  (motor/generator is there mostly to achieve regenerative braking, but some power can be send to it, making this vehicle a 2WD motorcycle). Main power producing part of the engine, along with an electric motor/generator (connected to the ICE “directly” via single-speed internally geared transmission) and gearbox (car-type 6-speed automated  “manual” with simplest possible cone synchromesh, “two-stroke” engine is used, so no reverse gear is required) are located under “pillion’s” seat, while NH3 tank, gases separation systems and condensers of exhaust water are located above or around the rear wheel. 

On both sides of the rear wheel additional small side wheels are located (their axes probably should be slightly more forward than rear wheel’s axis), they deploy when motorcycle is traveling at slow speed. Deployment of those side wheels should be achieved via hydraulic means. Decent hydraulic system is required, so it can also be used in hydropneumatic suspension of the main wheels (high pressure pump and additional systems, including high pressure compressor, that would allow not only regulation of suspension height but also its stiffness, can be located above front wheel). Front headlights should be placed on actively moving structure that levels them during leaning, and redirects light inside the curves (directional headlamps). I imagine suspension of each wheel as double wishbone system (four bar parallelogram linkage). Turning mechanism of the front wheel can be achieved as a variation of hub-center steering, in which large bearing is located around the wheel (possibly higher than the wheel's axis), allowing it to turn (almost) 90 degrees to either side, greatly reducing turning radius. Vehicle that I present has a quite long wheelbase, so caster angle should be quite small.

I propose full ride-by-wire system should be implemented (including steering), so to control this motorcycle “rider” has to provide only three main inputs (plus some shifting of his/her/their weight distribution): turning steering wheel [resembling aeronautic yoke] left and right to move front wheel, add power to the wheels by pressing a lever with fingers of right hand (lever should provide linear response from 0 kW to the wheels to around 10 kW [max power], computers tries to find optimum engine speed and torque to achieve required power, and changes gears accordingly [different modes of operation like sport, balanced or economy should be present]) and brake with a lever on the left side of the steering wheel (linear response is again desirable, at first computer tries to perform regenerative braking, only when the lever is pressed firmly regular disc brakes engage). Because this motorcycle is fully enclosed and quite high, sudden gusts of wind from sides could pose a problem. To alleviate this, I propose that a set of two additional gyroscopes be present onboard. They would be spinning in the same direction as main wheels and could turn left and right, just as the front wheel can, but this turning would be restricted by springs (possibly pneumatic ones) and dampers (hydraulic ones), so when some large force tries to rotate vehicle, those gyroscopes provide some counterforce. Actuators could be present in the gyroscopic system (most likely integrated with hydraulic dampers), so “countersteering” could be performed without moving the front wheel (additional levers under thumbs could be used to operate this system). 

To access interior of the motorcycle a set of two doors on one side should be implemented, resembling the ones found in Mazda RX-8 (but much thinner, without roll up windows). To ease the access to the “pillion’s” seat, front seat has to be movable (it would be placed on top of single “beam” that comes out of the floor, the “beam” has to move in respect to the floor). I would like to keep dry weight of the motorcycle below 200 kg so lightweight materials like carbon composites, polycarbonate and high strength alloys must be used (those materials are expensive, but only small amounts of them would be used). 

To increase comfort of the occupants, heat exchanger that redirects the engine exhaust heat to the cabin can be installed, as well as air conditioner. Similarly to BMW C1, occupants would wear seat belts, allowing them not to wear helmets, reducing the chance of a neck injury (this applies only to some jurisdictions). Airbags should be installed and interior covered in a foam, just as the interior of a motorcycle helmet is. This vehicle will be underpowered (I estimate top speed of only 100 km/h), but it actually is not a bug, but an inherent safety feature!

Nevertheless, this motorcycle would be better suited for long distance travel than an electric car, as you can just refill the NH3 tank after it empties (range at top speed would be about 300km, much more at lower speeds), instead of waiting for hours at a charging station (there are fast chargers out there, but they are more expensive and cause more rapid battery degradation). Note that drawings in motor_7.odg are just rough drafts, and the vehicle should be be made more round and wider, especially next to the “rider’s” elbows. There have to be some protrusions at the back of vehicle, that would allow installation of well cooled condensers (after power stroke ends, large amounts of water are injected into the cylinder, rapidly cooling engine and exhaust steam). 

This motorcycle could be made into single-seater autonomous vehicle by replacing “rider’s” seat with large mass (battery most likely) that can move to the left or right, and adding LIDARs, radars, cameras, and a powerful computer. 

Cabin motorcycles could be a part of the crewed lunar program (idea of using single-track vehicle on the Moon was contemplated during the Apollo program). In the lunar version, motorcycle would use weak electric motors to power the wheels (there is no aerodynamic drag and gravity is lower on the lunar surface). Water that absorbs waste heat and is then evaporated/sublimated must be present onboard. Cabin of the motorcycle would hold single rider in bulky spacesuit. Cabin should be able to provide environment pressurized with oxygen, so movement of the rider is less restricted and emergency life-support is provided. Above the rear wheel, unpressurized cargo space would be present, that allows another cosmonaut in a spacesuit to sit in it facing backwards and be transported during emergency.

Files:

cabin_motorcycle_pre_v1.zip, mirror, SHA256: 55af84532d3c36d316cb1f3b81b8f7f7963230edc13f8bed03954ae766a03a2a