cameroon gce intermediate level mechanical drawing 2
cameroon gce intermediate level mechanical drawing 2
HEME: GEAR BOX OF A MODEL LIFT
SET UP
The assembly drawing proposed represents the gear box of a model lift. These include a couple of conic gears 12 and 21.
The rotational motion of the pulley 5 is transmitted to the toothed wheel 5 by the intermediary of the return pinion 21. The
global function of this mechanism is to transmit power between the perpendicular shafts. The left view is the assembly of
the pieces {7, 13, 30, 24, and 26}.
PART I: Technological study (20 marks)
Question 1: Naming and functioning of parts (4 marks)
1. a) Give the names of pieces 1 and 4 (2 marks)
| 1. b) Give the functions of pieces 1 and 4 Question 2: Fits and tolerances (4 marks) |
(2 marks) |
The rotational link between the pinion 21 and the tooth wheel 24 is realized by the rod in the groove with fitting given by
25H8/e9. Use ∅25H8 = 25+0.033
0 and ∅25e9 = 25–00..040 092
2. a) Calculate the maximum and minimum clearances. (2 marks)
2. b) Give your conclusion. (2 marks)
Question 3: Designation of fasteners (4 marks)
3. a) Give the name of the piece 30. (1 mark)
3. b) Normalized designation of the piece 30. (1 mark)
3. c) Give its function on the assembly (2 marks)
Question 4: Lubrication and sealing (4 marks)
