Hydraulics & Pneumatics - Dec 2013
Mechanical Engg. (Semester 7)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) What are the factors to be considered for selecting a hydraulic pump? Explain in brief(7 marks) 1 (b) Explain the construction and working of a external gear Pump.(7 marks) 1 (c) A vane pump is to have a volumetric displacement of 82.cm3. It has a rotor diameter of 5 cm, a cam ring diameter of 7.5 cm and a vane width of 4cm. What must be the eccentricity?(6 marks) 2 (a) Explain with neat sketch balanced vane motor(6 marks) 2 (b) Explain with sketch liner actuators(4 marks) 2 (c) A hydraulic motor has a displacement of 130cm3>, operators with a pressure of 105 bar and has a speed of 2000 RPM. If the actual flow rate consumed by the motor is 0.05m3/s, and the actual torque delivered by the motor is 200N-m find:
i) Volumetric efficiency
iii) Overall efficiency
iv) Power developed by motor in kW.(10 marks) 3 (a) Classify hydraulic control valves. Explain with neat sketch working of check valve, and give its graphical representation(10 marks) 3 (b) Draw symbolic representation of the following hydraulic control valves
i) simple pressure relief valve.
ii) Pressure reducing valve.
iii) Sequence valve
iv) Counter balance valve.
v) Manually operated spring entered, three position four way valves(10 marks) 4 (a) Explain with neat sketches meter-in and meter-out circuit(10 marks) 4 (b) What are hydraulic accumulators? Classify the accumulators used in hydraulic system and explain spring loaded hydraulic accumulator(10 marks) 5 (a) Explain briefly filters and strainers in hydraulic system.(8 marks) 5 (b) Derive expression for beta efficiency.(5 marks) 5 (c) Discuss about sealing devices(7 marks) 6 (a) What are the advantages using pneumatic system?(10 marks) 6 (b) Explain with neat sketch and cushion arrangement in double acting cylinder(10 marks) 7 (a) (10 marks) 7 (b) (10 marks) 8 (a) (10 marks) 8 (b) (10 marks)