Sixth wheel?
November 1, 2011 7:20 PM Subscribe
What are the hydraulic centre wheels on dump trucks called and where can I find out more about them?
I've seen trucks with a pair of wheels right in the centre which are down when travelling forward, but lift when the truck goes around corners, and then drop down again afterwards. Do they have a name? Do they work automatically? Looking for more info!
I've seen trucks with a pair of wheels right in the centre which are down when travelling forward, but lift when the truck goes around corners, and then drop down again afterwards. Do they have a name? Do they work automatically? Looking for more info!
Best answer: Apparently they're called "lift axles".
posted by Monday, stony Monday at 7:38 PM on November 1, 2011
posted by Monday, stony Monday at 7:38 PM on November 1, 2011
Best answer: I've always heard them called tag axles. Wikipedia refers to them as Lazy or Dead axles.
They are manually enabled and you need them when fully loaded to reduce the weight per axle.
When they are down the truck is much harder to steer, although some designs are articulated to reduce that effect.
posted by Pogo_Fuzzybutt at 7:43 PM on November 1, 2011
They are manually enabled and you need them when fully loaded to reduce the weight per axle.
When they are down the truck is much harder to steer, although some designs are articulated to reduce that effect.
posted by Pogo_Fuzzybutt at 7:43 PM on November 1, 2011
Response by poster: Apparently they are. Looks like they are also known as dead axles or lazy axles. You've set me on the right path now I think. I'm about to learn way more about axles and dump trucks than I would have ever thought possible. Thanks.
posted by Frasermoo at 7:43 PM on November 1, 2011
posted by Frasermoo at 7:43 PM on November 1, 2011
If the axle is in front of the drive axle, it's a "pusher axle". If it's behind the drive axle, it's a "tag axle". Both pusher and tag axles are known as "dead axles" because they aren't connected to the drivetrain -- they're just there to bear the weight of the load, they can't propel the dump truck by themselves.
The ones that move up and down are called "drop axles" (Wikipedia tells me they're "lift axles", I've never heard that term) and they used to be manually operated by the driver, though I imagine they're automated like everything else is now. But that's a guess.
And pretty soon, when you sate your thirst for knowledge about axles, you'll be deep into reading about power take-offs! Whee. (Power take-offs are actually a really cool piece of clever engineering -- they're how the truck transfers engine power from the drivetrain to the hydraulic lift that raises and lowers the dump body.)
posted by BitterOldPunk at 9:44 PM on November 1, 2011 [1 favorite]
The ones that move up and down are called "drop axles" (Wikipedia tells me they're "lift axles", I've never heard that term) and they used to be manually operated by the driver, though I imagine they're automated like everything else is now. But that's a guess.
And pretty soon, when you sate your thirst for knowledge about axles, you'll be deep into reading about power take-offs! Whee. (Power take-offs are actually a really cool piece of clever engineering -- they're how the truck transfers engine power from the drivetrain to the hydraulic lift that raises and lowers the dump body.)
posted by BitterOldPunk at 9:44 PM on November 1, 2011 [1 favorite]
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posted by Monday, stony Monday at 7:35 PM on November 1, 2011