George (or Gogu) Constantinesco is not a well known inventor but he should be.   

George Constantinesco created the branch of physics known as sonics. Sonics are intense vibrations that travel through liquids and solids in a closed system and can transfer a lot of energy efficiently. Sonics share the same principles as electricity. Like most inventors no one believed in his inventions at first but its hard to argue with results. 

Here are some of his most important and interesting inventions.

1. Using reinforced concrete for building bridges.
Imagine where our interstate highway system would be without this development. 

2. C C Gear.
This invention allowed the British to gain air superiority during WWI. The device allowed the machine gun to fire between the blades of the propeller.

3. Mechanical Torque Converter
It's just like what it sounds. George used pendulums and gears to transfer the engines power to the wheels. It had an infinite gear ratio and was very efficient.

4. Sonic Diesel Fuel Injection System for Diesel Engines
A sonic generator replaced the fuel pump and valvetrain. He obtained over 12,000 injection pulses per minute.

Here is some of the technology today.

http://www.zero-max.com/products/drives/drivesmain.asp

Source

http://fluid.power.net/fpn/const/index.html