Swinburne Higher Education Exam Paper SWIN BUR · NE . SWINBURNE UNIVERSITY OF TECHNOLOGY Examination Cover Sheet SEMESTER 1, 2013 EXAMINATION DETAILS Subject Code: HES3350 Subject Title: MACHINE DESIGN Faculty: FEIS Duration: 180 min Reading time: 15 min 30 % of overall assessment covered by this exam CANDIDATE DETAILS Student to complete (please print & do not use pencil) ID: Surname: Given: CANDIDATE DECLARATION · I am the person stated above · I agree to obey the Examination Supervisors instructions for proper conduct of the exam . I have read and understood the Instructions to Candidates provided (see back of this exam paper) · I understand that it is my responsibility to ensure that I have been correctly enrolled for the above subject and that I am fully liable for any outstanding fees and charges . I am aware that I am not allowed to present for any special examination unless approval has been granted by the appropriate Swinburne or external authority STUDENT SIGNATURE: DATE: INSTRUCTIONS TO CANDIDATES Material/equipment that is not on this list is unauthorised material. Where a student is found in possession of any unauthorised material: 1. That material will be removed as soon as it is detected; and 2. The Student Examination Irregularity procedures of the Assessment and Appeals Policy and Procedures - Higher Education will be implemented. Materials Allowed: Open book - anything apart from electronic communication devices Answering Instructions: Answer all questions. State any assumptions made and show all workings. If you complete this exam before the set exam duration time, you may be asked to enter your time of departure. This information will have no bearing on your result.
Question 1 (15 Marks) Consider the spring loaded lock system below. Spring Constant K(N/m) Preload Po(N) Housing Plunger 0 h 0 F d Shaft D The mechanism ensures that the shaft stays in place until a sufficiently large force (F) is applied. This is achieved by the spring pushing the plunger into a groove in the shaft. The force to move the shaft must overcome the resistance provided by the spring (note - it has a preload) pushing the plunger into the shaft groove and the friction (coefficient of u) between the plunger and the shaft. See below. F The Housing is made of a plastic so that it has practically no friction with the shaft or the plunger. This plastic is not hard enough for the plunger or the shaft, and they are both made of metal