Description of Hydraulics

1. What is hydraulics?
Hydraulics 101

2. What is hydraulics?
• Hydraulics – Hydraulikos
• Hydor (water) + aulos (pipe)
• Hydraulics in mechanical engineering is basically transferring
energy using enclosed fluids!

3. Hydraulics vs pneumatics?
• Hydraulics and pneumatics are “sister” sciences
• Hydraulics uses fluids in the liquid state as their “work fluid”
• Pneumatics uses fluids in the gaseous state as their “work fluid”
• Work fluid – enclosed fluid that is used for energy transfer

4. Hydraulics vs pneumatics
• Hydraulics:
1. Works on higher pressures (more force)
2. Work fluids are incompressible (nearly)
• Pneumatics:
1. Work on higher rpms (more speed)
2. Work fluid are compressible (gasses, air)
3. Work fluids are free and available everywhere (air)

5. Energy transfer
1
2

6. Pressure
A
𝐹 = 𝑝 ∙ 𝐴
• The units for pressure are:
1. The Pascal [Pa] = [1
𝑁
𝑚2]
2. Bar [bar] = [100000 Pa]
3. Pound per square inch (PSI) [1 bar = 14.5 PSI]
𝑝 =
𝐹
𝐴

7. Basic parts of a hydraulic cylinder

8. Hydraulic energy transfer
1. Hydrostatic power systems (pressure)
2. Hydrodynamic power systems (fluid speed)
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9. Thank you for listening!