B.E./B.Tech. Degree Examination, April/May 2018

B.E./B.Tech. Degree Examination, April/May 2018

Mechanical Engineering (Regulation 2008)

HYDRAULICS AND PNEUMATICS

Time: Three hours

Maximum: 100 marks

Answer ALL questions. 

Part A - (10 × 2 = 20 marks)

1. Give the advantages of fluid power system.

Ans. Refer Chapter 1, Q. No. 7, Two Marks Q&A, Page No. 1.23.

2. Draw the symbol of pressure relief valve.

Ans. Refer Chapter 6, Q. No. 23, Two Marks Q&A, Page No. 6.50.

3. Write about positive displacement pumps.

Ans. Refer Chapter 4, Q. No. 6, Two Marks Q&A, Page No. 4.45.

4. What is tandem cylinder?

Ans. Refer Chapter 5, Q. No. 15, Two Marks Q&A, Page No, 5.32.

5. Draw the symbol of shuttle valve and write its use.

Ans. Refer Chapter 6, Q. No. 16, Two Marks Q&A, Page No. 6.49.

6. Why flow control valve is essential in hydraulic circuits?

Ans. Refer Chapter 6, Q. No. 29, Two Marks Q&A, Page No. 6.51. 

7. What is the need for mufflers?

Ans. Refer Chapter 11, Q. No. 17, Two Marks Q&A, Page No. 11.22.

8. Name the different types of air motors.

Ans. Refer Chapter 12, Q. No. 13, Two Marks Q&A, Page No. 12.17.

9. What is ladder diagram?

Ans. Refer Chapter 14, Q. No. 12, Two Marks Q&A, Page No. 14.17. 

10. Define low cost automation.

Ans. Refer Chapter 16, Q No. 3, Two Marks Q&A, Page No. 16.39.

Part B - (5 × 16 = 80 marks)

11. (a) (i) List the desired properties of hydraulic fluids.

Ans. Refer Chapter 2, Section 2.5, Page No. 2.12.

 (ii) What are the components required for basic hydraulic systems? Also mention their functions.

Ans. Refer Chapter 1, Section 1.7, Page No. 1.10.

 [OR]

(b) (i) List the applications of fluid power systems employed in industries.

Ans. Refer Chapter 1, Section 1.6, Page No. 1.7.

(ii) How can you measure the frictional losses in laminar flow and turbulent flow. 

Ans. Refer Chapter 3, Section 3.14, Page No. 3.14.

12. (a) Draw a neat sketch of variable discharge axial flow piston pump. Also explain its construction and operation with how to calculate minimum and maximum discharge. Give its graphical symbol.

Ans. Refer Chapter 4, Section 4.17.3, Page No. 4.22.

[OR]

(b) Classify the types of hydraulic cylinders. Describe the working of a double acting tandem cylinder and gear motor. Give its graphical symbols.

Ans. Refer Chapter 5, Sections 5.7 & 5.11, Page Nós. 5.9 & 5.13.

13. (a) (i) Explain the construction of pressure relief valve with neat sketch. 

Ans. Refer Chapter 6, Section 6.14, Page No. 6.20.

 (ii) Design the hydraulic press circuit using unloading valve with sketch. 

Ans. Refer Chapter 8, Section 8.8, Page No. 8.11.

[OR]

(b) (i) Explain any two types of accumulator circuits with sketch.

Ans. Refer Chapter 9, Section 9.10, Page No. 9.10.

 (ii) Design the circuit to speed up the extending speed of a double acting cylinder with suitable circuit.

Ans. Refer Chapter 8, Section 8.5, Page No. 8.6.

14. (a) Draw an pneumatic circuit by cascade method for the following sequence of operation: A+B+B-A- where A and B are the two cylinders and + indicates extension and – indicates retraction of the cylinder.

Ans. Refer Chapter 13, Example 13.3, Page No. 13.22.

 [OR]

(b) Briefly explain FRL unit with neat sketch.

Ans. Refer Chapter 11, Section 11.10,,Page No. 11.15.

15. (a) (i) Explain the working of electro hydraulic servo systems with neat sketch.

Ans. Refer Chapter 6, Section 6.25.8, Page No. 6.37.

(ii) What is meant by fluidics? Name some fluidic devices and its uses?

Ans. Refer Chapter 15, Section 15.2, Page No. 15.1.

 [OR]

(b) (i) Two double-acting pneumatic cylinders A and B, with double-solenoid valves have to work in the following sequences: A+, B+, A−, B–. Draw a ladder diagram and indicate the input and output devices. Both the cylinders have limit switches.

Ans. Refer Chapter 13, Example 13.5, Page No. 13.23.

(ii) Write short notes on failure and trouble shooting in pneumatic circuits. 

Ans. Refer Chapter 17, Section 17.7, Page No. 17.16.