January 26, 2021

Porsche

The Audi E-Tron is pictured here, but the Landjet sounds like it’ll be leagues ahead in terms of luxury.


Audi

Volkswagen Group continues to pour resources into electric cars, and in addition to affordable EVs from the Volkswagen brand, the automaker has what sounds like a mighty luxurious flagship vehicle in the works, according to a new report.

German newspaper Handelsblatt reported this past weekend the vehicle, code-named Landjet, will be a shared EV from Audi, Porsche and Bentley. It should feature three rows of seats with seating for seven. What’s unclear is if the vehicle will be an SUV or have some sort of hybrid sedan body style. Designers are starting to have fun with EV designs since the powertrain opens up a world of possibilities from a design standpoint. One source told the German newspaper the vehicle will be target the Tesla Model S, however. That’s a little peculiar since the Porsche Taycan effectively does this, but the Landjet project reportedly aims to achieve 404 miles of driving range.

According to more information from Automotive News Europe, Audi will undertake development and its version should arrive first, possibly in 2024. Porsche’s and Bentley’s own models based on the Landjet will come after. VW Group didn’t immediately respond to a request for comment on the reported information. This car is also different from the coming Audi E-Tron GT, which shares its platform with the Porsche Taycan.

Amid all of this, rumors point to Bentley transferring over to Audi management as VW Group looks to find the British automaker’s niche. And the brand will go totally electric by 2030. The Landjet could be an important part of Bentley’s future plans.


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Elon Musk’s original Tesla Roadster used a two-speed transmission. It proved problematic, so he dropped the extra ratio and still delivered cars and SUVs capable of both brutal acceleration and license-endangering top speeds. So, who needs multiple gears? Gearing an electric motor to deliver strong launch torque and then spinning it fast enough for autobahn speeds presents serious cooling challenges and reduces efficiency. Hence today’s fastest EVs—like the Porsche Taycan, the Pininfarina Battista, and Rimac C_Two—use a two-speed transmission.

Why a two-speed transmission when 10-speeds are readily available? Electric motors have a vastly broader “sweet spot” of efficient torque delivery than combustion engines, so they don’t need frequent shifting to remain efficient. A low range with roughly double the ratio of high range generally suffices for passenger vehicles. Adding a second ratio should boost overall efficiency unless the transmission adds parasitic losses like that original Tesla transmission, Porsche’s twin-clutch, and Rimac’s planetary transmissions do. That’s where this novel Ingear transmission design from Toronto-based supplier Inmotive comes in.

Chief Technical Officer Anthony Wong started out trying to improve upon a bicycle’s derailleur gears with a design that didn’t require the chain to move laterally. With the chain remaining in one plane, he reckoned, he could use a super-strong chain from a transfer case or engine valvetrain.

His brainstorm was to “assemble” the larger (lower-ratio) gear by sliding segments of it into position in the open triangle that exists between the input (pedal crank), the output (axle), and the chain tensioner (derailleur) while maintaining chain contact with the smaller (high-ratio) gear until the other gear was almost fully “assembled.” This maintains continuous torque transmission while motor-torque management ensures shift smoothness.

When shifting from high to low, the first “key” segment that slides into place includes a curved kneelike feature that guides the chain onto the larger-radius gear without kinking it. As everything rotates, four other segments slide into place. The entire shift occurs within one rotation of the output shaft, typically below 50 mph. When shifting from low to high gear, the final large-gear segment includes another kneelike guide to ease the chain down onto the smaller gear without kinking, and a simple spring tensioner controls chain slack.

The five interlocking gear segments slide on pins that transfer torque to the output shaft, and a patent-pending finger deflector engages roller pins that move each segment into or out of contact with the chain. This works like some variable-valve-lift cam-lobe-shifting devices and requires no closed-loop control to account for wear, etc.

Here’s where the Ingear concept trumps the established two-speed EV trannies: There are no losses from multiple gearsets being paired simultaneously and no rolling contact losses. Because no torque gets transmitted while the segments are moving, none is required to keep them in either position, and because the whole works is splash-lubricated, there is no need for a hydraulic pump.

Straight teeth on the gears and chains don’t generate the side loads and friction

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