Hydraulic systems are found in equipment at virtually every manufacturing facility, from operating robots, forging presses and packaging machinery to powering conveyors.
Energy is transferred through hydraulic hoses, tubes, and pipes all connected by hydraulic fittings or flanges. The power within a hydraulic system is regulated by actuators and valves which apply fluid pressure to operate manufacturing equipment.
In most applications a pump pushes hydraulic fluid through the system, passing through fittings, hoses, and control valves to create pressure that operates a cylinder. The cylinder rod then converts hydraulic energy into mechanical energy to create movement of equipment parts or components, such as the arm on a large pick and place robot or ram on a forging press.
Open and Closed Loop Systems
It’s important to understand the distinction between Closed Loop and Open Loop hydraulic systems.
An everyday example of a closed loop system is a heating thermostat which sends a signal to the furnace. The system’s sensor identifies the current air temperature and automatically turns the furnace on and off. In the same respect a closed loop hydraulic system converts hydraulic energy to mechanical power to drive the shaft. In manufacturing and research environments closed loop systems power planers, conveyors, centrifuges in laboratories, refrigerating systems and much more. Many applications incorporate closed loop systems to provide fine motor motion control required by the system.
A common example of an open loop control system is a kitchen toaster. You’ll know when it starts and finishes toasting with control of only the input (one or two slices of bread) and the toasting time and temperature. In an open loop hydraulic system, a series of valves and cylinders rely on a pump to pull fluid flow from the reservoir. An open loop system carries fewer contaminants than a closed loop system because of the constant flow which keeps particles from settling into the filters, where a closed loop system can permit contaminants to keep circulating. Open loop systems are used in gas turbine engines, linear actuation devices, hydraulic presses, heat exchangers and more.
8 Examples of Hydraulics in Manufacturing
- Forging presses use large pistons powered by high pressure hydraulics moving the forge ram down to compress ingots or billets of a solid alloy in creating a part. Closely regulated pressures and speeds control the hydraulic press for creating parts to tight tolerances.
- CNC machines use hydraulics in tool holders which hold cutting tools in machining operations, providing high repeatability and stability.
- Die cast machines use high pressure hydraulics for generating significant force to clamp die molds which are then injected with molten metal to produce parts.
- Material Handling Equipment such as hydraulic conveyors in a closed loop system, along with overhead cranes and forklifts depend on hydraulics to move, lift, and transport materials around a warehouse.
- Metal stampings use hydraulic servo presses to apply a full tonnage of power in evenly placed loads through the entire stroke of the stamping.
- Press Brakes, a.k.a. hydraulic bending machines, use two synchronized hydraulic cylinders which move an upper beam to bend parts into shapes at very tight tolerances.
- Punch presses rely on male and female dies which are placed on opposite sides of the workpiece. Hydraulic power pushes the punch through the die to create a preprogrammed precise hole.
- Robotic arms use hydraulics for power transmission in driving actuators which are wired to electrical circuits for operating electric motors and solenoids. These, along with other system components, leverage mechanical energy to operate a robotic arm.
Conclusion
Hydraulic systems function by using pressurized fluid. Whether it be a simple water system or operating manufacturing equipment with hydraulic fluid power, the principle is basically the same. In other words, pressurized fluid creates work through system components like hydraulic fittings, hoses and valves which send the fluid to cylinders and pistons to operate a machine.
Hydraulic fluid power applies regulated pressure which acts upon a component or components to actuate a piece of machinery for handling heavy loads or operate precise and often repetitive tasks. For example, fluid power works to lift the heavy loads of a gantry crane and compresses a substantial load in creating a forged part. The hydraulic circuit transfers liquid under pressure to a set of discrete interconnected components which can control fluid flow and pressure.
Hydraulic systems which include fittings, valves, hoses, reservoirs, pumps and motors combine to provide significant power and control of machine settings to:
- Stamp or bend metal
- Provide tool holding in CNC machines
- Lift heavy loads
- And much more!
Sources include:
- EVS Tech Co., LTD
- Fluid Solutions Inc.
- fox-ae
- Phoenix Specialty Mfg. Co.
- Rowse Limited
- Scot Forge Company
- Vivian Conveyors
