Project: Fluid Machinery

Title: A study on analysis and control of a hydraulic drill machine

1. Introduction

There are three main methods of transmitting power: mechanical, electrical and fluid power. Fluid power systems can transmit power more economically over greater distance. The work is accomplished by a pressurised fluid bearing directly on an operating fluid cylinder. A fluid cylinder produces a force resulting in linear motion. The fluid power systems are well suited in many industries because of their many advantages: ease and accuracy of control, multiplication of force, constant force or torque and simplicity, safety and economy. One example is a hydraulic drill machine for rock drilling.

The machine has two important components: a rotating drill rod with a drill bit at one end and a rotary hydraulic drive motor at the other end. This type of machine is useful for cutting into rock formations. A carriage supports the drill rod and provides linear motion (extension and retraction) to the rotating drill bit into rock formation. The main components of a hydraulic drill machine include a hydraulic striking apparatus with a drill bit, a rotary hydraulic motor, a feed motor, as well as other important components such as pumps and valves along with their operation and controls.

Simulation of a hydraulic circuit in Matlab is a good way to study and analyse the hydraulic circuits you design. In Matlab, you have to use SimScape (Simhydraulic). You have to go to SimScape Fluids, then Hydraulics (isothermal). From the library menu, you can draw the circuit. This menu has various components needed to construct a fluid circuit diagram. By choosing the right components, the hydraulic symbols are assembled for analysis.

2. Aims

The aim of this project is to exercise your theoretical knowledge of fluid power systems and skills in practical applications in the area of mechanical and process engineering using SimScape in Simulink (Matlab).

3. Scope

You are required to study, analyse and assess an existing conventional hydraulic drill machine considering information available (you can assume some reasonable necessary data). Then design a new hydraulic drill machine or modify the existing design to give better performance. This is a team submission and each team must present their findings in week 12 workshop session.

Your submission should have the following items and headings:

(1) Introduction to fluid power systems relating to hydraulic drill machines.

(2) Literature review on conventional hydraulic drill machines using standard papers from journals, conferences, books, patents and reports.

(3) Working principles of existing hydraulic drill machines.

(4) Develop a case based on your research and develop a set of assumptions for your proposed design.

(5) Design and analysis of a new or modified hydraulic drill machine that gives better control: flow control, pressure control and directional control using sufficient minimum controlling devices and valves.

(6) Safety check of pipes and pressure cylinders (thick-walled or thin-walled analysis).

(7) Prepare an Excel calculation sheet to insert input data, standard equations (literature review and scope item (6), creating plots.

(8) Health and safety practices required for maintaining the system.

(9) Use proper drafting tools to show changes in your new design.

(10) Draw necessary fluid circuit diagrams using SimScape Fluid.

(11) Apply SimScape and carry out analysis for constant and variable drill bit motion of your new design: piston positions, velocity and flow rate etc. vs time.

Your report must include executive summary, scope and objectives, methodology, schematic diagrams where necessary, discussions and concluding remarks and references in the Harvard system.

4. Submission: It is a team submission. Due date is Friday midnight, week 12

5. Presentation: It is team presentation during workshop time (dress code - not casual). For distance student teams, pl. send a recording (YouTube) in week 12.