BMW Patents New Rear-Wheel Steering System

[spikes111]

New Rear-Wheel Steering System Will Make Future BMWs Better To Drive And Easier To Park

More angle is now possible, and the future system will take up less space too.

In filings uncovered by CarBuzz, the German automaker has applied for a new invention with the United States Patent and Trademark Office. Herein, the Bavarian brand claims that existing systems are too unwieldy. This is because most systems use a track rod to adjust the toe of each rear wheel, but in this space, the vehicle must also house a subframe, an axle, and additional components like a differential and side shafts. This limits angles to, "at most 5 degrees," says BMW. The solution? An additional wheel carrier on each hub, with each featuring an actuator on the lower portion that is maintained by a grooved guide. According to the documents, this could allow for as much as 10 degrees of rear-wheel angle without adding to the space constraints of the rear subassembly.

If the invention makes it to production, it could have benefits across the automaker's range. On something like a BMW M4, one could dramatically reduce the virtual wheelbase, thereby vastly enhancing low-speed tight-turn handling. Naturally, high-speed stability is also improved, but we suspect that this technology will likely first do duty in a large vehicle like a new 7 Series. These luxury machines are getting larger every year, and parking them is certainly not easy. With a shortened virtual wheelbase thanks to this enhanced rear-axle steering system, monstrosities like the XM could be a little easier to live with on a daily basis.

[MadBimmeRad]

Now all they have to do is to fix the grille

[Msparta]

When adjustable grille sir?

[Boostedphil698]

Wonder how much this will cost when it breaks.

[Teutonic]

I am always excited to read this kind of stuff. This should improve vehicle’s handling a lot.
It should be called 4WS - Four Wheel Steering…

[cfm56d7b]

"The Prelude was the first active 4WS car sold in the U.S., but Nissan’s Japanese-market R31 Skyline came earlier, launched in late 1985."

https://www.autoweek.com/car-life/a1...g-demystified/

[MadBimmeRad]

Originally Posted by cfm56d7b

"The Prelude was the first active 4WS car sold in the U.S., but Nissan's Japanese-market R31 Skyline came earlier, launched in late 1985."

https://www.autoweek.com/car-life/a1...g-demystified/

Mazda MX6 also had it in 1985/6 (in Australia anyway)

It was a fad that swept the Japanese manufacturers and faded away very quickly due to technical challenges and horrendous repair costs

[beachBmmr]

Cant wait for $900 alignments

[heavyD^2]

Originally Posted by MadBimmeRad

Mazda MX6 also had it in 1985/6 (in Australia anyway)

It was a fad that swept the Japanese manufacturers and faded away very quickly due to technical challenges and horrendous repair costs

The 3000GT VR4/Stealth and 300ZX had it in the early 90's as that's kind of where it peaked.

[NorCalAthlete]

Mitsubishi 3000GT had this too.

edit - damn, beat me to it while I was typing.

[NightWriter]

I can understand the theoretical improvements for parking lot maneuvers, but would rotating the rear wheels more than 5 degrees really be useful (safe) at speed?

[ihbase]

Originally Posted by spikes111

[B]New Rear-Wheel Steering System Will Make Future BMWs Better To Drive And Easier To Park

These luxury machines are getting larger every year, and parking them is certainly not easy. With a shortened virtual wheelbase thanks to this enhanced rear-axle steering system, monstrosities like the XM could be a little easier to live with on a daily basis.
Attachment 2764301

Yeah, they have sensors and cameras ... parking is pretty damn easy.

It is almost like consumers are buying vehicles that are larger than they can actually operate.

-Michael

[stein_325i]

This will easily be a welcome addition to vehicles like the 7-Series and would make the car better to drive and much easier to maneuver. I've tested out MB's 10-Degree RWS on the new S-Class and EQS and it makes maneuvering such a large car much easier, and it decreases the turning circle to as little as the sub-compact A-Class.

[cfm56d7b]

Originally Posted by cfm56d7b

"The Prelude was the first active 4WS car sold in the U.S., but Nissan's Japanese-market R31 Skyline came earlier, launched in late 1985."

https://www.autoweek.com/car-life/a1...g-demystified/

In so many ways, everything old is new again.

[Longboarder]

RWS was one of the many changes to the Porsche 991 chassis that made it leaps and bounds better than 997. But the reason for adding it was performance. Not parking.

[Machtavian]

The 300zx didn't have this. It had Hicas and it adjusted the toe in and out while turning. This looks like it just adjusts the camber not toe in or out.

[heavyD^2]

Originally Posted by Machtavian

The 300zx didn't have this. It had Hicas and it adjusted the toe in and out while turning. This looks like it just adjusts the camber not toe in or out.

Nobody said it had this exact method of 4WS. It was simply noted that rear wheel steering was used in several cars in the late 80's and early 90's. HICAS still turned the wheels.

[Project_F87]

Originally Posted by Machtavian

The 300zx didn't have this. It had Hicas and it adjusted the toe in and out while turning. This looks like it just adjusts the camber not toe in or out.

The hell are you talking about? Guessing you think the figures are side view when they are in fact top view. No camber adjustment, only steering adjustment as has been stated.

[Machtavian]

Originally Posted by Project_F87

The hell are you talking about? Guessing you think the figures are side view when they are in fact top view. No camber adjustment, only steering adjustment as has been stated.

You're right, I was looking at it wrong.