Wheels Of Grace Magazine

Volume 11, Issue 6

Issue link: https://cp.revolio.com/i/1298026

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Page 12 of 36

12 | WheelsOfGrace.com | Issue 52 Harley-Davidson has filed a patent for a new engine design that uses variable valve timing. Officially, the patent is not specifically for a VVT system but rather for a modular engine balancer that mounts on either side of a crankshaft. The patent does however describe how the VVT phase timing is incorporated into the balancer module. The patent uses a rough drawing of a Fat Bob, but only as a general example of a motorcycle. The engine details, however, show clear differences from exis ng Harley-Davidson engines. The new engine design s ll uses overhead valves, but with pushrods running on opposite sides of each cylinder, which matches a design in a separate patent. Both patents were originally filed with the U.S. Patent and Trademark Office in early 2019, with Harley-Davidson engineer Johann Voges as the only credited inventor, making it likely they're for the same engine. The drawings show air-cooling fins, though the fins have uneven contours, curving in and out at different spots around the cylinder. There's also no oil filter at the front of the engine. It's difficult to get a sense of propor on in these patent illustra ons, but it's possible we're looking at the replacement for the ancient Sportster engine. The engine balancer unit (#74) transfers the rota on of the cranksha to rotate the two camsha s. Each camsha li s its own pushrod, one for each cylinder. A second balancer unit on the other side of the cranksha ac vates a second pair of pushrods. The key to this patent is the engine balance module (#74 in the diagrams). The cranksha is connected to gear #154 which rotates cam gear #158. The cam gear is connected to a second, smaller toothed gear #170 which rotates a chain (#178). The chain in turn spins a balancer sprocket which rotates a balance weight (#86) around the cranksha in the opposite direc on of the crank's rota on to counteract the reciproca ng mo on of the pistons. The VVT unit (#98) controls the phasing of the toothed wheel #162 which drives the cranksha s (#90). A variable valve ming unit (#98) connected to the cam gear adjusts the ming of the cams, affec ng the ming of both the intake and exhaust valves rela ve to the cranksha . Generally speaking, adjus ng the intake ming can op mize power and torque delivery at higher or lower revs, but the likely goal for Harley-Davidson is to reduce emissions. As it stands Harley- Davidson's exis ng engines, the Sportster line-up especially, will not meet Euro 5 standards, meaning they will no longer be allowed in Europe by the end of the year. Several manufacturers have asked for the deadline to be extended due to delays caused by the pandemic, which that may give Harley some breathing room if the new engine is not yet ready. Harley -Davidson Files Patent 12 | WheelsOfGrace.com | Issue 52

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