Showing my ignorance here (not for the first time 
) but … PTO’s on a truck. like a concrete wagon or a tipper … what RPM do they operate at? Do they have the same 6 spline shaft as you’d find on an agricultural tractor? Presumably you can operate the PTO whilst you are driving (like for a mixer)?
Diggerlot:
Showing my ignorance here (not for the first time
A PTO usually is for static operation like a mixer( not for driving ) etc , a fixed hydraulic pump usually for mobile work from the engine say front of crankshaft or a take off elsewhere at engine speed/variation,its some years since i was involved so not up to date but someone will be along shortly with current information–toshboy
Cant wait till im retired an come on here asking questions to try fool young drivers. Wont be the first time ive drive off with pto engaged but it does fisengage auto. Unless you drive an old foden from the 60s. I know you will get flashbacks.
Hang up your driving boots and forget about it. Take up golfing bowls or some other slow paced game that wont break your bones.
Regards
Diggerlot:
Showing my ignorance here (not for the first time
Almost without exception you do NOT drive with a gearbox driven PTO engaged for anything other than the briefest period necessary, it is capable of causing severe damage to the gearbox and the PTO itself. Vehicles which require a PTO to run while in motion have the PTO driven by the engine.
cav551:
Diggerlot:
Showing my ignorance here (not for the first timeAlmost without exception you do NOT drive with a gearbox driven PTO engaged for anything other than the briefest period necessary, it is capable of causing severe damage to the gearbox and the PTO itself. Vehicles which require a PTO to run while in motion have the PTO driven by the engine.
Generally no benefit from exceeding 1200rpm , some drive underneath the box gear to intermediate gear to pump gear like a 9 piston pump edbro never fail just get slower ,then most gear pumps that can fail drive of the back end of the gearbox via a shaft ,some through a reducer such as 2:1 ect ,mixers drive off the back of the engine and bin lorries used to drive of the front crank pulley.
Every time I’ve used a PTO I’ve set the revs at 800 rpm. Not sure if that’s the question being asked here though.
Ok … so … presumably with a concrete wagon the PTO must be driven directly off the engine, not the gear box and thus can be used in whilst driving … otherwise the concrete would be a solid lump before your arrived at the client?
My RPM question is how fast does the average PTO spin on a truck? On a farm tractor there are only two options 540 & 1000 rpm depending on the task at hand (1000 RPM to run high speed stuff like mowers for 540 RPM for everything else)… with trucks is there a standard PTO output RPM or does it vary from unit to unit?
Diggerlot:
Showing my ignorance here (not for the first time
Usually there’s a plate or sticker in the cab telling you what RPM range to operate it in. Been 15 years since I used one with pumping gear but it was somewhere between 800-1000 RPM and you did it using the cruise control to set the speed. Not quite sure you could use a generic PTO whilst driving but I suppose it depends on what gear its powering.
Diggerlot:
Ok … so … presumably with a concrete wagon the PTO must be driven directly off the engine, not the gear box and thus can be used in whilst driving … otherwise the concrete would be a solid lump before your arrived at the client?My RPM question is how fast does the average PTO spin on a truck? On a farm tractor there are only two options 540 & 1000 rpm depending on the task at hand (1000 RPM to run high speed stuff like mowers for 540 RPM for everything else)… with trucks is there a standard PTO output RPM or does it vary from unit to unit?
You are old. It doesnt really matter. You can vary the revs. I alqays ran them to the max. Bit like digger run them high ir low depending on job needing done. I would however recommend low revs for less hassle but i used to swing scaffold bins at high revs to be able to swing them round.
Diggerlot:
Showing my ignorance here (not for the first time
I’m driving hook lift skips at the moment & our trucks use a PTO to load & de-load bins and also to tip material out of the bins. I don’t know if the PTO is engine or gearbox driven though I suspect it’s gearbox driven as you need to use the clutch & handbrake to engage the PTO.
We can drive only slowly and for short distance, to allow material to be tipped or loading unloading bins, before the PTO will disengage automatically, it will also disengage if you exceed above 1500 rpm. when in use we can use the accelerator, idle or 2 presets (800 &1200 rpm) depending on the task at hand.
cav551:
Diggerlot:
Showing my ignorance here (not for the first timeAlmost without exception you do NOT drive with a gearbox driven PTO engaged for anything other than the briefest period necessary, it is capable of causing severe damage to the gearbox and the PTO itself. Vehicles which require a PTO to run while in motion have the PTO driven by the engine.
… so if I look at a mixer wagon, presumably it’s definitely an engine driven PTO and can be safely used whilst driving? Anyone know what spins the drum on a mixer… hydraulic motor driven by the PTO?
I can’t speak for concrete mixers, but our bulk blowers run at about 1200 rpm at the default setting; driver sets it higher or lower depending on the particular drop, variations being dependent upon what you’re blowing, the length of the blow and the condition of the feed bin.
With something like a cargo compressor 800/850 rpm is generally enough, it has to be enough to stop the blades chattering so you get used to a nice hum
I drove a pto crane truck and only once did I forget to knock it off before driving off. You soon realise what you did.
Although this link is for transmissions no longer fitted in this country it does give an idea about the possible locations and types of PTO which can be gearbox driven. As mentioned engine driven PTOs are common on mixer and dustcart chassis, but these normally need to be specified at the time of vehicle build.
Diggerlot:
cav551:
Diggerlot:
Showing my ignorance here (not for the first timeAlmost without exception you do NOT drive with a gearbox driven PTO engaged for anything other than the briefest period necessary, it is capable of causing severe damage to the gearbox and the PTO itself. Vehicles which require a PTO to run while in motion have the PTO driven by the engine.
… so if I look at a mixer wagon, presumably it’s definitely an engine driven PTO and can be safely used whilst driving? Anyone know what spins the drum on a mixer… hydraulic motor driven by the PTO?
Fairly rare but rechargeable battery powered mixer trucks are about now for emissions purposes. They are usually powered by a hydraulic motor from a pump powered by engine PTO though.
There are different types of PTO depending on application
Clutch dependent - most basic/cheapest only can be used when stationary. Engaged by air valves usually with adjustable revs by cruise stalk or some other method.
Clutch independent - can operate all the time, more expensive but suitable mixer trucks and dustcarts etc. that want hydraulic power on the move. Can also operate like a clutch dependent with increased revs when doing high demand stationary tasks like emptying concrete/refuse.
cav551:
Although this link is for transmissions no longer fitted in this country it does give an idea about the possible locations and types of PTO which can be gearbox driven. As mentioned engine driven PTOs are common on mixer and dustcart chassis, but these normally need to be specified at the time of vehicle build.
They can be retrofitted but can need a shorter prop shaft.
Its difficult to see here but behind the red box is an electric cable and a consumer unit, so the gearbox PTO could drive the pump or compressor, or we could plug into the mains to drive the compressor or hydraulics for the tank.
If you look to the right of the Suzie A frame, for a small green socket, We could also connect the vehicle batteries to the trailer to tip the electric ram on a silo tank, totally flexible and environmentally friendly.
We also carried a tanker heating system operating from the engine, it was all plumbing and pipes but simple to use.
Hiab .
Having (allegedly) destroyed a few over the years I was told that hydraulic pumps run off PTO’s are designed & optimised for 1200-1400rpm.