Manufacturing Engineering Hydraulic and Pneumatic Systems Copyright © Texas Education Agency, 2012. All rights reserved.

History of Hydraulic and Pneumatic Systems Throughout the history of mankind manual labor has been used to build, develop and advance our societies to a higher standard of living. With the dawn of the industrial revolution, engineers and inventors looked for new and more efficient ways to manage labor. They found their answer in technology. NOTES: Show examples and discuss the efficiency of the waterwheel and windmill Systems - two early uses of hydraulic and pneumatic power. Copyright © Texas Education Agency, 2012. All rights reserved.

History of Hydraulic and Pneumatic Systems The technological advancements of the 21st century have allowed us to understand advance concepts in the design and use of hydraulic and pneumatic systems . NOTES: Show and discuss examples of modern hydraulic and pneumatic equipment. Copyright © Texas Education Agency, 2012. All rights reserved.

Copyright © Texas Education Agency, 2012. All rights reserved. Hydraulic Systems Hydraulic systems operate on the principle of Pascal's Law. This principle states that when pressure is placed on a confined fluid, the pressure (force) is transmitted in all directions equally. Piston -B Piston -A NOTES: Hydraulic Presses, http://www.sme.org/Wiki.aspx?id=61792&terms=hydraulic, (2012) Pascal’s law is based on the principle that liquid can not be compressed. When pressure is applied, equal force (pressure) is transmitted throughout the entire system. A small force can then control a large force. This force can be used to accomplish work in linear, rotational, etc., direction. Heavy tasks like lifting, pressing, pulling, cutting, drilling can be accomplished with minimal human effort. Safety Factors: OSHA Safety Hazard Information Bulletin on Hydraulic Systems Preventive Maintenance, https://www.osha.gov/dts/hib/hib_data/hib19920714.html, (1992)   Safeguarding Equipment and Protecting Workers from Amputations, http://www.osha.gov/Publications/OSHA3170/osha3170.html, (2001) Discuss the safety aspects of working with fluid under pressure. Some hydraulic systems are pressurized up to 5000 pounds per square inch, or more. High pressure leaks are dangerous!!!! High pressure fluid from small openings in the lines can pierce skin and cause serious injuries. It is important to use correct lines and properly tighten all connections during maintenance. Also relieve all system pressure before disconnecting lines. Fluid under Pressure; Equal force throughout system Copyright © Texas Education Agency, 2012. All rights reserved.

Hydraulic Systems Hydraulic Cylinder Hydraulic Motor Reservoir NOTES: A typical hydraulic system is shown above. Discuss the list of components below. Additional components are on the list for added discussion. Actuators: converts the hydraulic pressure (energy) to mechanical energy to operate the load. --cylinder - converts hydraulic energy to linear energy to operate piston rods --hydraulic motor - converts hydraulic energy to rotational energy to rotate a shaft Pump: provides a pressurized fluid supply to the hydraulic system to operate the Actuators; pressure may be 5000 pounds per square inch (psi), or more Gauges: provide an analog or digital indication of system pressure Pressure relief valves: placed in specific locations in a hydraulic system to relieve excess pressure to prevent system overload which would result in leaks, damaged components, etc. Control valve: used to direct fluid to the proper component, like an actuator, gauge, output line, etc. Filter: a critical component used to trap particles (usually metal or dirt) that could clog and damage system components Reservoir: serves as a storage container for hydraulic fluid Hydraulic fluid: liquid used to circulate through a hydraulic system to transfer energy between components and to the load; the fluid provides cooling and transfers particles (contaminants) to the filter Tubes / Hoses: stainless steel or rubber connecting lines that connect system components and are used for fluid transfer Fittings / connections: threaded or clamped connections that are used to connect the tubes and hoses to system components; must be of proper size and orientation to prevent leaks Hydraulic Lines Filter Control Valve Pump Copyright © Texas Education Agency, 2012. All rights reserved. Return Line

Copyright © Texas Education Agency, 2012. All rights reserved. Pneumatic Systems Pneumatic systems convert the energy from compressed gas (usually air) into mechanical energy. Mechanical energy is used to perform work through cylinders or rotary actuators (drilling devices). NOTES: Hydraulic Presses, http://www.sme.org/Wiki.aspx?id=61792&terms=pneumatic, (2012) Discuss the similarities and advantages of both hydraulic and pneumatic systems. Pneumatic systems have many similarities with hydraulic systems. Both systems use a pressurized, liquid medium (hydraulic fluid and air are liquids), lines, control valves, cylinders and actuators. Pneumatic systems have distinct advantages over hydraulic systems: Lower pressure (usually less than 300 psi), no chance of fluid spills or product contamination. Pressurized air can be stored for later use if power is not available from the compressor. Hydraulic systems have distinct advantages over pneumatic systems: Hydraulic systems are very stable under load and can carry very high load capacities. Safety Factors : Construction Safety and Health: Hand and Power Tools, http://www.osha.gov/doc/outreachtraining/htmlfiles/tools.html, (1996) Discuss the safety aspects of working with pressurized. Some pneumatic systems are pressurized up to 5000 pounds per square inch, or more. High pressure leaks are dangerous!!!! High pressure air from small openings in the lines can pierce skin and cause serious injuries. It is important to use correct lines and properly tighten all connections during maintenance. Also relieve all system pressure before disconnecting lines. Copyright © Texas Education Agency, 2012. All rights reserved.

Copyright © Texas Education Agency, 2012. All rights reserved. Air hose connection Pneumatic System Pneumatic Cylinder Compressor Storage Tank Relief Valve NOTES: A typical pneumatic system is shown above. Discuss the list of components below. (remind students that there are close similarities between the components in both hydraulic and pneumatic systems) Pneumatic system terms: Actuators: converts the pneumatic pressure (energy) to mechanical energy to operate the load. --cylinder: converts pneumatic energy to linear energy to operate piston rods --pneumatic motor: converts pneumatic energy to rotational energy to rotate a shaft   Gauges: provide an analog or digital indication of system pressure. Control valve: used to direct air pressure to the proper component, like an actuator, storage tank, output line, etc. Pressure relief valves: placed in specific locations in a pneumatic system to relieve excess pressure to prevent system overload which would result in leaks, damaged components, etc. Compressor: a key component in a pneumatic system and is used to pressurize air and transport it through the system. Gauge Control Valve Control Valve Copyright © Texas Education Agency, 2012. All rights reserved.