How to make working gears in an assembly?

Hi Kevin,

If you have toolbox installed in solidworks you can drag gears directly into the assembly and define the tooth profile from a selection box. Once the gear is made, solidworks will automatically save it in the toolbox part folder. Open the gear part in the assembly by right clicking on it and then save it to your desired location.
This method applies to all gears under many international standards which covers a very baud range of tooth profiles( i would recommend ISO). Remember you can always edit the bore and internal features after creating the gear.
If you need b-spoke tooth profile design i would recommend goggling 'gear module' and having a read threw the gear tooth profile definitions. This link will help if that is what you need.
http://www.youtube.com/watch?v=ZaJQvqdSsv8

Assembling gears is made very easy by solidworks. Since the gears will be assembled relative to there pitch circle diameter (PCD) i would recommend drawing a sketch in an assembly marking the centre point of each gear. Use the mates to position the bore as a conical relation to the points on the sketch and mate the gear faces parallel to one another. If the teeth look like they overlap then use the rotate function(in the dropdown menu under move component) to rotate them into the correct position.

With that done you can now define the motion relationships.
Select 'mates' and expand the 'mechanical' mates section. Click on gears and select the bore edges of the two gears you wish to define. You will then have the option to fill in the ratio information. Solidworks does this by default but i have never seen it select the correct values. If you first select a 20mm PCD gear and then a 40mm PCD gear you would make the ratio 1:2. To keep it simple you could always use 20:40 to save confusion.

Now that everything is defined you can use the rotate component option again to check the relationship or run a motion study.

Hope this helps

Rowan