Parker Hannifin series hydraulic hybrid garbage trucks

[Herm]

I was just standing outside my house in Miami watching one of these trucks, very nice looking, dark green, square and sleek.. very quiet also. This one uses an articulated claw on the side to pick up a special square trash can.. a couple of interesting things:

1. Manpower: the thing is operated by one driver, in a large enclosed glass cabin.. the older classic rear loading trucks had the driver and a couple other guys to pick up the cans

2. Diesel Economy: there was none, the driver was slinging this thing around like a sports car.. I have never seen such a large truck move so quickly. I believe it accelerated much faster than the previous claw trucks, also those trucks would bellow loudly when accelerated, MUCH louder and god know what emissions the diesels were pouring out under that extreme load.

3. I dont know the numbers but it must have substantial savings from the speed and reduction in manpower. The diesel never shut off, it was not given any time for that. The truck cleared a whole block of trashcans in under 30 seconds. I have never seen anything like it before.

4. Expect to see these things in your hometown soon, yes it was that impressive. Invest in this company if you can.

More details here:

http://www.greencarcongress.com/2011/03/parker-20110321.html

http://showtimesdaily.com/news-articles/autocar-parker-e3-hybrids-for-hialeah-and-for-miami-dade

 

[LTLFTcomposite]

If I understand correctly the PH runwise unit is a sort of black box that mounts in the drive line between the engine (transmission?) and rear axle. It's still a conventional diesel engine, but during stop and go driving picking up trash, the engine can run at constant/idle speed. At higher speeds it shunts, maybe with a clutch, eliminating the hydrostatic loss, although it still provides recapture of braking energy. Very clever.

 

[Herm]

I believe its a series configuration, there is no transmission.. the engine drives a hydraulic pump that drives the hydraulic motors, plus they use a pressure accumulator to store energy.. In operation the diesel runs at a constant power level, perhaps a bit of throttle but not the roar it used to be. I dont know how much garbage was in the truck but it takes quite a bit of power to get it moving.

 

[AndyH]

I think you're correct, Herm. I recall reading about this a number of years ago with a Freightliner connection but didn't remember the details. This article says it's series hybrid.

http://www.greencarcongress.com/2009/10/parker-20091018.html

http://freightlinerchassis.com/documents/FCCC0323_HHV Flyer 02-24-11-20110228124643000000.pdf

Check out this doc starting on page 23:
http://www.c-5.org/C5 Hybrid Presentation.pdf

Thanks for this Herm - I think my earlier awareness was the more limited 'hydraulic boost' system not the full series hybrid. Excellent progress!

 

[LTLFTcomposite]

I believe its a series configuration, there is no transmission.. the engine drives a hydraulic pump that drives the hydraulic motors, plus they use a pressure accumulator to store energy.. In operation the diesel runs at a constant power level, perhaps a bit of throttle but not the roar it used to be. I dont know how much garbage was in the truck but it takes quite a bit of power to get it moving.

http://www.parker.com/portal/site/Market-Tech/menuitem.4f2d948a76574676de92b210237ad1ca/?vgnextoid=763cf84ab14ba210VgnVCM10000048021dacRCRD&vgnextfmt=default&catalog=&vgnextcat=How%20Does%20Runwise%20Work&vgnextcatid=8788409&vgnextdiv=null&propercase=Y&partshow=yes

The Runwise® hybrid drive system is built around the company’s proprietary Power Drive Unit (PDU), C24 Variable Displacement Bent-Axis Hydraulic Pump/Motors, and Composite Bladder Accumulators – all designed specifically for high power, high start-and-stop applications. An onboard controller coordinates pumps, hydrostatic motors and accumulators to power the vehicle when in hydrostatic mode during start-and-stop operation while collecting refuse. Instead of solely using power from the engine, accumulated energy from the vehicle’s braking system is stored and used to power the truck each time it accelerates. As the truck reaches highway speed, the PDU transfers from hydrostatic drive to mechanical drive to maximize operational efficiency.

Sounds like they took a page from the Chevy Volt playbook!

Seriously, that last sentence suggests the system gets bypassed at highway speed. I suppose it's possible the input shaft to the Runwise system could be coupled directly to the crankshaft, but I was thinking there still might be some type of tranny bolted to the back of the engine.

 

[LTLFTcomposite]

Some other interesting links including a video from that PH page.

This clears things up some:

http://www.parker.com/literature/Hydraulics%20Group%20US/2401%20Runwise%20Broch%20FINAL%20%28LR%29.pdf

Looks like it is driven directly by the engine apparently without any gearing/reduction (although there still has to be some sort of coupling, you can't put a U-joint directly onto a crankshaft can you?)

 

[turbo2ltr]

The company I consult for is in pretty much direct competition with these guys. Our specialty is class 3 to 8 hybrid propulsion systems. Except we do only electric systems, no hydraulic. But it's a battle to win approval of fleet managers everywhere.

Hydraulic hybrids are very efficient. The downside is the hydraulic system is very expensive to add to a truck. Oh, and ask any garbarge truck fleet manager about hydraulic leaks..

 

[LTLFTcomposite]

...ask any garbarge truck fleet manager about hydraulic leaks..

Did you ever meet Dick Barone?

 

[Coffee_Slurry]

I dunno.. if they got rid of that insanely loud "hooooonk" sound with each stop (air brakes?), how would I know to put my cans out when they're two blocks away?