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This may be a stupid question but, is there a reason cars don't just have a single blade that goes straight across, rather than wiping in this arc motion? It se
by darawk 7y ago
This may be a stupid question but, is there a reason cars don't just have a single blade that goes straight across, rather than wiping in this arc motion? It seems like it'd do a much better job of wiping and avoiding streaks if it just went straight across.
- deleted 7y ago[deleted]
- usaphp 7y agoI would guess you will need a long groove and a wheel that slides on it, and it will be prone to breaking if you consider how fast the thing should slide when its heavy rain.
- varjag 7y agoYou would need two separate actuators on top and bottom, making it more expensive and prone to jamming.
- ghaff 7y agoAnd I imagine very prone to jamming in snow and ice when regular windshield wipers can be enough of a problem.
- partialrecall 7y agoLeaves and pollen too (if you ever park your car under an oak tree.) https://0x0.st/zyS9.jpg https://0x0.st/zyS9.jpg
- edh649 7y agoMechanical simplicity and standardisation. The windscreen wiper is very likely to be outsourced to a 3rd party company, and they can reduce costs by having a repeatable design. In terms of a blade going on a straight line, it’s much easier to rotate a wiper blade from a motor than translate that into a linear movement. It’s worth nothing that other systems exist (https://www.a1-windscreens.co.uk/news/windscreen-wiper-movements/ https://www.a1-windscreens.co.uk/news/windscreen-wiper-movem...), but much less common.
- kenhwang 7y agoI actually don't think they're outsourced and they're typically designed in-house. I remember the reason being the windshield wipers are almost always engineered last after almost everything else in the engine compartment. So the wiper engineers are typically given very oddly shaped small spaces that they have to fit the wiper system into, and those differ between cars so it can't just be generically outsourced. Here's a Hyundai engineer talking about wipers: https://www.digitalengineering247.com/article/the-back-and-forth-of-windshield-wiper-design/ https://www.digitalengineering247.com/article/the-back-and-f...
- doersino 7y agoPresumably, it's down to simplicity of implementation: A single servo motor that directly rotates an attached blade vs. a necessarily, due to the curvature of the windshield, curved linear rail (which ought to be more difficult to seal against debris).
- masklinn 7y ago> is there a reason cars don't just have a single blade that goes straight across Some vehicles have pantograph wipers which work horizontally, however that's a more complex design than the usual simple pivot, and you can't "park" the wipers out of view when they're not in use so they're more obstructive. They're sometimes used on car rear windows but mostly seen on commercial vehicle windshields. Some cars (mostly benzes) also have eccentric arc systems where the wiper arm extends and retracts to cover more windshield with a single pivot.
- KaiserPro 7y agoThere are a few reasons: 1) having a single attaching point for the wipers makes designing stuff around it more simple 2) accurate curved tracks that match windscreens are hard to manufacture, secure and keep in shape 3) Keeping constant force for all parts of the windscreen is much harder with a track (high and low spots, change the window screen, the track needs adjusting too) 4) standard bearings are much more simple to seal 5) linear bearing as a pain to seal 6) tracks are much harder to seal against the weather 7) tracks need more lubrication
- clamprecht 7y agoThe Lotus Exige (and the Elise I believe) has a single blade. It might have to do with the unusual curvature of the windshield.
- masklinn 7y agoSingle blade is relatively common, it's tracking across which isn't.
- olivermarks 7y agoFull size cars do often have a single blade, smaller cars like a Honda Fit/Jazz have one huge blade and a mini clean up blade on passenger side