1.Describe, with the aid of sketches, how an axial piston pump can vary the volume of liquid it displaces.(10)
- Describe, with the aid of sketches, the operating principle of an axial variable delivery hydraulic pump.(10)
- Describe, with the aid of a sketch, the operation of a variable delivery axial piston pump.
(10)
- With reference to a pressure compensated variable displacement, swash plate pump, explain FOUR different possible causes of reduction in performance.
Note: The filter has been cleaned, the system is in good condition and there are no visual signs.
(10)
Question
- Although the question clearly states that the system is in good condition, many give low / high viscosity, air etc. Many give worn pistons but no explanation as to why the performance is affected unless they explain I can’t award marks. Few appear to understand what a pressure compensated pump is or how it maintains a constant pressure output hence no faults regarding this are given, whereas many appear to believe that the swash angle is externally set.