This is Volkswagen’s new single-speed gearbox
Volkswagen Group Components produces the new single-speed gearbox for all MEB-platform vehicles. While most electric vehicles use single-speed gearboxes, the Porsche Taycan—another Volkswagen Group BEV that can be as quick around a tight circuit as a Koenigsegg from 2006—uses a two-speed unit. As usual, there are pros and cons. The Taycan, supposedly, gets more range and a higher top speed out of its self-developed two-speed unit in exchange for more complexity at a higher cost. But Volkswagen doesn’t need that complication for its ID. line of EVs, even if we’re looking at a 355-horsepower family wagon that should become reality very soon indeed.
Its new single-speed gearbox, called “the APP310 e-drive unit,” will transmit power to the driven wheels “using an extremely compact gearbox.” Volkswagen is talking about its ID.3 hatchback for now, but the principal will be the same for all derivatives.
Using a single-speed gearbox means the drivetrain acts like if you were in top gear in a combustion car. That gear has to move the car at all speeds, from 1 mph to whatever its top speed may be. And that’s fine, even considering that off-the-line acceleration could be improved by having a bonus lower gear.
However, Volkswagen calls this a “two-stage 1-speed gearbox.” What’s that? Something they would explain like this:
“When reversing the car, the direction of the electric drive system is simply reversed. In addition to various other components, power electronics is responsible for this and for the power characteristics of the drive system. In order to achieve the maximum power of 150 kW (201 horsepower), the electric drive unit must rotate at high speeds. In order to provide a high level of torque, a 10x transmission ratio is used. To save space, the gearbox has a two-stage design with two smaller cogs instead of one big one. As a result, the electric drive motor in the ID.3 provides the maximum torque of 228 pound-feet constantly over a wide range of speeds. The maximum speed of 100 mph is reached at a maximum of 16,000 rpm. For the ID.3, which is optimised for maximum range, the use of a single gear for all driving situations is perfectly adequate.”
Producing such a gearbox is a high-precision job because of the rotational speeds involved. Every moving component has to be perfectly balanced to keep noise levels low, something VW is checking at the end of the production line. For now, all drive systems for European and North American e-vehicles based on the MEB, including the single-speed gearbox, are manufactured at the component plant in Kassel. Other important parts are produced in Salzgitter, Poznań, and Hannover. Now, you know.