Hi everyone.....in my pneumatics class I need to write a one page report of a pneumatic system giving a complete description on the role of the hydraulic or pneumatic system including the control mechanisms and any advantages or disadvantages you see in the system when compared against some other system (say a mechanical system).

The W140 popped into my head with their pneumatic door assists but I cant seem to find any detailed info on the net.

Can anyone fill me in as much as they can?

Much Appreciated!

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99 C43
98 S420
99 C230K
01 C240

Try something simpler like MB door locks. Lots of info on those. Or convertible top mechanisms.

If you have access to an entomologist (is that right?), compare the hydraulics in some bug legs vs muscles in mamalian legs.

You might pose the same question to your dentist. Or does your dentist use a Dremel?

I'd like to see a purely mechanical backhoe.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Vacume brakes versus hydraulic boost. Diesels and Vacume pumps (and brake booster). Turbocharged engines that change from vacume to pressure during boost (that kept engineers working for a while), Hydraulic brakes v air brakes on trucks. Vacume windshield wipers v electric or air in trucks ( boy, did I just show my age.) Air horns v electric horns. Need I go on?

quoted by Benzonline
I have always considered hydraulic or pneumatic systems "mechanical".

You can move a lot of BIG stuff with a properly designed hydraulic system. Way back before all the electronics were established in industrial control everything was done using pneumatic control systems. A 3-15 psi (in some applications 3-27) signal equaled 0-100% signal. The signals were used to position pneumatic damper drives, control valves, steam drum water level and turbine speed controllers in addition to providing the 0-100% "signal" to indicate anything from feedwater flow to steam flow (as applied to a utilities boiler). Like the old Benz with the vacuum leaks the issues that usually came up with these old robust systems were - you guessed it - leaks. As long as you kept the compressor running you could run the boiler. With the way boilers and plants are run today you would not be able to stand the "inaccuracies" associated with a pneumatic control system.

I use the attached site from time to time and you can probably find some pretty good info in there.
good luck

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Jim

here is the link

http://www.eng-tips.com/

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Jim

were all we had in the late 50s & early 60s. They worked real good using only two cables out to the boom, but running one was like rubbing your stomach while patting your head with both hands at the same time. Shield Bantum was one of the moet popular brand names.

In the 1970's I operated a 1937 Northwest diesel crane at a granite quarry. While I never operated it, sitting in the corner of the quarry was another piece of old Northwest equipment, a diesel powered 'steam shovel' , which was essentially a mechanical backhoe.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13