26 eccentric mechanism kho tài liệu bách khoa

ME-430 INTRODUCTION TO COMPUTER AIDED DESIGN
ECCENTRIC MECHANISM OF FOUR-BAR LINKAGE
Pro/ENGINEER Wildfire 2.0
Dr. Herli Surjanhata

A component can be placed as a connection within mechanism assembly. The
following six joint types are available:

Pin Joint

1


Cylinder Joint

Planar Joint

2


Slider Joint

Ball Joint

3


Bearing Joint

PREPARE THE PARTS FOR MECHANISM
Download the part files eccentric_mechanism.zip. There are eleven parts that

make up the mechanism:
1
2
3
4
5
6

arm.prt
base.prt
bushing.prt
clip-1.prt
clip-2.prt
link.prt

7
8
9
10
11

eccentric.prt
post.prt
shaft.prt
washer-1.prt
washer-2.prt

4

arm.prt

bushing.prt

base.prt

eccentric.prt

5


post.prt

clip-1.prt

shaft.prt

clip-2.prt

6


washer-1.prt

washer-2.prt

link.prt

CREATE AN SUB-ASSEMBLY eccentric_asm.asm
Sub-assembly called eccentric_asm.asm will be consisted of six component parts –

eccentric, shaft, clip-1, clip-2, washer-1, and washer-2.
Create a new assembly called ECCENTRIC_ASM

7


Bring in eccentric.prt and constrain
it at default location by picking
.

, then Open
Pick
eccentric.prt.

The assembly is shown below.

Next, place shaft.prt to the assembly. Pick

, then Open shaft.prt.

Pick the axis of the shaft, then select the axis of the center hole of the eccentric.

8


Pick the surfaces as shown below.

9

Mate both surfaces

Be sure to enter 0 when prompted with
offset distance.

to flip the
If necessary, click
orientation of the shaft.

The resulted assembly is shown below.

10


Click
below.

. Then open clip-2.prt. Place clip-2 in the groove of the shaft as shown

Place washer-2.prt right behind clip-2 as shown below.

11


Open clip-1.prt and place it in the groove of the pin of eccentric part – see figure
below.

12

Place washer-1.prt right behind clip-1 – see figure below.

13


The resulted assembly is shown below.

14


Perform Global Interference check of the assembly. Make sure there is no
interference in the assembly.

Analysis -> Model Analysis

Choose Global Interference under
Type.
Click

.

There are NO interference parts in the assembly.

Save the assembly.

15


CREATE AN SUB-ASSEMBLY base_asm.asm
Click

,

Enter the name of base_asm.
OK.

Click

. Then open base.prt and assemble it at default location by selecting

.

16


, and open bushing.prt. Place the bushing at the most left hole in the
Click
base – see figure below.

17


Place again the bushing into the hole located on the right of the base.
Hint: Use Repeat option of the assembly.
Edit -> Repeat etc.

, and open post.prt. Place the post at the most left hole in the base – see
Click
figure below.

18


Perform the Global Interference check and make sure there are NO interference.

19


Save the assembly.

CREATE AN SUB-ASSEMBLY arm_asm.asm
Click

,

Enter the name of arm_asm.
OK.

20


Click

. Then open arm.prt and assemble it at default location by selecting

.

Open clip-1.prt and place it in the groove of the pin of arm part – see figure below.

21

Place washer-1.prt right behind clip-1 – see figure below.

22


The resulted assembly is shown below.

23


CREATE AN TOTAL ASSEMBLY eccentric_mechanism.asm
Click

,

Enter the name of
eccentric_mechanism.
OK.

Click

. Then open sub-assembly base_asm.asm and assemble it at default

location by selecting

.

24

Open sub-assembly eccentric_asm.asm and assemble it at lower right hole in the
base where the bushing is.

, then Open
Pick
eccentric_asm.asm.
Pin connection will be created!

Click the Connect tab for
Connections

Be sure to turn on the datum axis only.

25