Creating Gear Joints(DMU Kinematics Simulator).pdf

09/08/14 22:07Creating Gear Joints

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Creating Gear JointsThis task shows how to create gear joints in a V5 mechanism.

Open the Create_Gear.CATProduct document.

Automatic switch to Design mode:

If you work with the cache system in visualization mode, you no longer need to use Edit >Representations > Design Mode beforehand as the switch to design mode is automatic (an eyeappears as you point the product in the geometry or specification tree). All you need to do is clickon the object.

1. Click Gear Joint in the Kinematics Joints toolbar or select Insert > New Joint >Gear... from the Menu bar. The Joint Creation: Gear dialog box appears.

The Mechanism is identified in the specification tree.Now you need to select two Revolute joints.

2. Select Revolute.1 either in the specification tree or in the geometry area.

3. Create Revolute.2 within the Gear command. For this: click .The Joint Creation:Revolute dialog box appears automatically:



Select line .1 (green cylinder axis) and line.2 (orange cylinder axis) as shown below in thegeometry area:

Select plane.1 (green cylinder face) and plane.2 (orange cylinder face) either in thespecification tree or in the geometry area:

4. Select the Offset option button and keep the default value. When done, click Ok.



5. Assign a command, select for instance the Angle driven for revolute1 check box.

About Ratio definitionTwo methods are available to define the ratio parameter:

modifying the formula (in this case the ratio is a knowledge parameter)for this, right-click in the ratio field and use the Edit Formula contextual menudisplayed

using the Define option in the joint creation dialog box to calculate the ratioautomatically

6. Click to define the ratio parameter automatically. The Gear Ratio Definitiondialog box is automatically displayed.

7. Select the two circles in the geometry area.



8. Click Ok when done

The calculated ratio appears in the Joint Creation: Gear dialog box

9. Change the rotation direction option if needed.The default is Same (positive)Opposite is negative

Note: simulate your mechanism with commands to check the direction is the one youwant

10. Click Ok when done

Now, if you use the formula editor, (a formula is already defined in our sample), from step 6Right-click in the ratio field and use the Edit Formula contextual menu displayed

The Formula Editor: Ratio is automatically displayed.Click Gear1 product in the specification tree and select the radius as shown below:



The formula is automatically entered in the ratio field, enter a / (division symbol)

Click Gear 2 and select radius.2 as shown below:



11. Click Ok when done. The ratio is updated

The gear joint is created and identified in the specification tree.Now expand the gear joint you have just created, the embedded leaf joints are displayed.Note: the joints involved in a compound joint can be neither edited nor deleted directly.



12. Open the GearV5_Result.CATProduct to check your result

Note: To create a gear joint, the two revolute joints involved in the gear joint must relyon a same support part.See picture below: (P stands for Part, R for Revolute)

Documents

Creating Gear Joints(DMU Kinematics Simulator).pdf