Renowned gearbox specialist Hewland (Booth 4050) is showing its range of transmissions for combustion-engine-powered race cars, as well as for EVs. The newest addition to its range is the PEVD-200, a performance three-shaft transmission for EVs that takes power from a single electric motor and outputs it to a limited-slip differential.
Principal engineer James Batchelor explained, “This is one variant of a bespoke offering and it’s tailored to suit whatever motor you’re using. The casing can be magnesium or aluminum. As standard, with the Integral Powertrain motor, we’re looking at a torque capacity of 450Nm and a maximum input speed of 20,000rpm, but of course, if somebody has a project with a different motor, we can gear it to suit that specific application. Same with the differential – if we’re doing a lower-torque application, we have a range of lighter diffs that we can slot straight in there for the all-important weight saving.”
Commenting on the increasing importance of EV transmissions, Batchelor said, “We’ve been really lucky – we’ve been involved with on-road EV applications for about 10 years now and we were involved with Formula E from the outset. EV applications bring new challenges such as gear efficiency and noise. Although you don’t have the complexity of multiple speeds, you do need much more complex gears because of the different ratios that we’re seeing with electric motors – the gearbox needs to cope with 20,000rpm and you need to package those large gears efficiently.”
Conventionally powered race series remain the most important, though, so Hewland is also showing a new low-cost gearbox for mid-engined sportscars, the RGT-200. The lower cost is made possible partly because it uses a Torsen differential, rather than a ‘Powerflow’ plate-type LSD. The unit was originally designed for Radical cars, but has now joined Hewland’s off-the-shelf range and can be paired with custom bellhousings to suit most applications.