Week 19, Article 3 : Introduction to the amazing world of Fluid Power – Part 3 (Work)


As presented in Article 1: Introduction to the amazing world of Fluid Power – Part 1 (History lesson) we discuss the concept of using fluid to transfer mechanical energy into fluid power to perform a “Work” function.  We touched on the four key elements Energy, Flow, Pressure and Fluid.

In this article we are going to expand on this principal  –  “Energy”imagesCAQHJ5IU

The fundamental foundation for  designing a fluid power circuit begins with understanding this principal “Work”. Other words what is required to be achieved.  Weights, Mass, Speed, Direction, Time we then can begin to see what sort of Fluid Power Energy is required to complete this Work Function.

In a fluid power operation it is the understanding of converting Input Energy into Output Energy.  Energy is defined as the ability to do work,  by dissecting this concept we find 6 key ingredients:

1. Energy; defined as a source to transfer energy from a Prime Mover (input power source) to an actuator (Output power source).

2. Work; defined as “Work force through a distance” mathematically expressed as a (unit of energy – Joules)

3. Power; defined as the “Rate of doing work” (mathematically expressed as Watts)

4. Hyd Power;  defined as the power requirement to complete the Work. To achieve this task there has to be a required rate of flow at a particular pressure, based on actuator size and pump flow discharge. (mathematically expressed as kw)

5. Heat; defined as wasted hydraulic power, based on the Law of conservation of energy. which states energy cannot be created or destroyed, but can change its Form. Therefore energy is not used in a hydraulic system for will be converted to heat. (mathematically expressed as LPM x Pressure (relief) / 1000 = kw)

6. Torque; defined as the work to generate hydraulic motors . Hydraulic motors are rated on specific torque values, at given pressure. The rotation of motor RPM at a specific torque gives the energy usage power requirement.

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Applying this knowledge helps define how and what components are going to be required to build a Fluid Power System to complete the job successfully.

Anyone who has search Google for a hydraulic pump for example will know that they will be inundated with millions of options and quite often everything seems to become quite contradictory.

By understanding these core concepts of 1. Energy, 2 Work, 3 Power, 4 Hydraulic Power, 5 Heat, and 6 Torque, we can then start sizing the appropriate components and then this will enable concept budgets to be produced with a level of accuracy to progress to the next level of options.

We explore these elements in more detail the coming articles.