Unit 6 Pneumatics and hydraulics Technology 4

What do we know? Suggested questions and discussion starters: – What is the name of the machine you can see in this picture? – What is it doing? – Do you think this machine uses a hydraulic or a pneumatic circuit? – In what other kinds of machines are pneumatic and hydraulic circuits used in?

Pneumatic and hydraulic circuits Which of these circuits is hydraulic, pneumatic and electric? How are these circuits similar and how do they differ?

Compressors in pneumatic circuits What function do compressors carry out in pneumatic circuits? How are reciprocating and rotary compressors different?

Compressors in pneumatic circuits What function do actuators carry out in pneumatic circuits? Which actuator above is single-acting and which is double-acting?

Control elements in pneumatic circuits What is the function of a valve in a pneumatic circuit? With what type of cylinder do we normally use a 4/2 valve?

Control elements: shut-off valves How do the above shut-off valves work? Which valve carries out the logic function AND and which carries out OR?

Hydraulic circuits: pumps What is the function of the pump in hydraulic circuits? What two types of pumps can you see above?

What have we learned? Pneumatic and hydraulic circuits Elements Energy-generating elements , transport elements, actuators, control elements

What have we learned? Pneumatic circuits are used in can-crushing machines, door open/close systems and pneumatic drills. Provides the circuit with compressed air. There are two types: reciprocating compressors and rotary compressors. Compressor Usually made of steel or brass, soldered together or connected by steel or plastic connectors Pipes Elements of pneumatic circuits Rotary actuators produce the rotating movement of an axle. Actuators Single-acting cylinders move a piston in one direction. Reciprocating actuators Double-acting cylinders move the piston back and forward. Directional control valves: 2/2 valves and 4/2 valves Control elements (valves) Flow control valves Shut-off valves: non-return valves, dual-pressure valves and shuttle valves Protection and maintenance elements Air dryers, filters, lubricators, pressure relief valves, conditioning units, silencers

What have we learned? Hydraulic circuits use a pump instead of a compressor. They can be used in platform lifts, forklift trucks and hydraulic presses. Elements of hydraulic circuits Pump Gear pumps or screw pumps Protection and maintenance elements Filter, relief valve, and reservoir