List of Mechanical Engineers - R

R

• Agostino Ramelli (c. 1531-1600) - Inventor of the bookwheel as well as various water-powered inventions (clockwork, treadmill, pump)
• John Ramsbottom (1814–1897) - Inventor of the tamper-proof spring safety valve and the displacement lubricator
• William John Macquorn Rankine (1820–1872) - Major contributor to the science of thermodynamics, known for advancements in heat engine theory and metal fatigue
• George Rennie (1791–1866) - Among other developments, a pioneer in food processing equipment (biscuit, corn, chocolate mills)
• Osbourne Reynolds (1842–1912) - Major contributor to the science of fluid dynamics and heat transfer
• Harry Ricardo (1885–1974) - internal combustion engine designer and researcher
• Richard Roberts (1789–1864) - Developer of high-precision machine tools which helped enable mass production
• Alfred H. Rzeppa (1885–1965) - Developer of the constant-velocity joint