Worm Gears

[Switchblade]

Hello everyone, I am fairly experienced with Solid Works, but would like some advice on how to create both of the gears in this picture. Mainly the worm gear, but just some background advice on how to make these better, faster, etc.

 

http://static.howstuffworks.com/gif/gear-worm.jpg

 

Thanks a lot. I will be on here periodically to try and help you guys help me. I have Solid Works 2011.

 

Here is one that I made real quick, but it does not have the proper angle to fit into the worm. Any ideas on how to add that? Thanks.

 

[Switchblade]

Bump. This is ultimately what I would be needing to make:

 

http://www.cadtutor.net/forum/showthread.php?39384-Worm-Gear-Reducer-In-Exploded-View

 

Any ideas on how to make those sorts of gears? Thanks.

[Switchblade]

I just watched this video very closely, and am definitely a LOT better than where I started. I found this thru some of the related threads:

 

 

Anyway, I will check back in a while for further questions.

[shift1313]

Switchblade, check the post above this one one designing a gear. I put a lot of links in there for suresh about gear design and a few how to links in there.

 

The worm gear is just a sweep operation. The tooth profile will depend on your design but the pitch of your helix needs to match the pitch of your gear. The picture you posted is a little more complicated but because it is an enveloping style worm gear setup but you just need to draw your profile of the gear and a sweep path. More than likely you will need a straight line for the centerline. Ill try to draw an example when i get a moment. What version of Solidworks are you using?

[shift1313]

here is an example of that type of gear for you. Let me know if you have questions on how it was created.

Gear1.zip

[Switchblade]

I am using Solid Works 2011.

[Switchblade]

For some reason I can't open that picture you attached, maybe I will be able to at work once I start up there. Anyway, the company I will be working for makes both types of gears, inveloped and 'standard' gears. They do that for both the worm and helical gears, so that will be something I need to learn how to make.

 

The first gear I made (pictured in my first post) all I did was made a circle, then made a sketch on the front face, drew the tooth and extruded it. The way I made it inveloped was by making a sketch on the right side plane I believe, and revolving that around the gear. Is that the correct way to go about making an inveloped gear? Also, what will I have to do to make the gear teeth pitched so that it is a helical gear? Thanks a lot!

[Switchblade]

Very nice! I just looked into that other thread. Basically, as long as the company has the design library, I can go to the toolbox and create gears through that correct?

[shift1313]

the zip file i attached is a SW2011 part file. Its a gear. I ended up using a loft between two teeth profiles that were 10degrees off from each other. I also used a split line on the surface to give them an arced path to follow.

[shift1313]

Very nice! I just looked into that other thread. Basically, as long as the company has the design library, I can go to the toolbox and create gears through that correct?

 

 

the design library is inside solidworks. If the people at the company have a standard gear then hopefully they created some components or some way to catalog that. It would be silly for them to re-draw it over and over again. I think drawing it is the easy part, designing it is the tough part. If someone hands you a drawing with specs the modeling of the gear shouldnt be too difficult.

[endlasuresh]

yeah thats correct

using your own sketch is for you only and you wont find that type in market.if you want to make then use wirecut method.best option is use from toolbox even you find them in gear companies too.

i previously used as you have did but now i am doing with toolbox and learning those all things.

[Switchblade]

the design library is inside solidworks. If the people at the company have a standard gear then hopefully they created some components or some way to catalog that. It would be silly for them to re-draw it over and over again. I think drawing it is the easy part, designing it is the tough part. If someone hands you a drawing with specs the modeling of the gear shouldnt be too difficult.

 

Well they have a PhD Mathematician on staff, so I am pretty sure the actual specs he would be creating, along with me doing some designing/FEA/Testing. That would lead me to my next question, how do you do FEA in Solid Works?

[Switchblade]

Okay, so I understand how to create the gear with straight teeth, but I am lost on how you 'used a split line on the surface' to create the curved path. In Autodesk Inventor you could just make a sketch plane and offset it so that it was tangent to the surface, but I have no idea how to do that in Solid Works, or if that is even the way I should be going about this? Thanks for any help man.

[Switchblade]

This is where I am at before cutting the teeth:

 

[shift1313]

Well there are two ways. You can use the Split Line like I did. This will take a 2d sketch and split the face of a solid or a surface. You could also use the Project Curve(both can be found in the curves menu on Features or Surfaces). So in your case I did a sketch on the back face of your cylinder for the second part of the cut(if you want to use loft-cut). If you want to use a sweep-cut you can just create a path(split line or project curve).

 

This isnt what you are looking for but its a video i did on using the split line. Maybe it will answer a few questions for you.

 

The solidworks Help file does a great job of explaining all of these features as well.

 

FEA is a big bag of worms. What version of Solidworks do you have? Premium, pro, or basic. You need to turn simulation on for starters if you have it. Go to Tools>Add-ins and turn on simulation. Then start a new topic in here for your specific question so others can find it later

[Switchblade]

The main issue I am having is trying to get the curved line itself on this face:

 

 

When I used the split line tool, the best I can possibly get is this:

 

EDIT: I have the same problem when trying to use the project curve tool as well.

[Switchblade]

A little more success:

 

[shift1313]

Here are a few screen shots. Were you able to open my file?

 

So the first pic is the sketch I used for my split line. It goes between two gear profile sketches and is just an arc.

 

The second pic is just for representation. I extruded a surface using that same sketch so you can see how it intersects my model. The split line is splitting the face of my boss where that surface is essentially.

 

The third pic shows the loft between the two sketches using the split line as a path. From there i did a linear pattern for the number of teeth.

[Switchblade]

Were you able to open my file?

 

Just did now. Not sure if that helped or made it worse, that is not what I was doing/expecting lol.

[Switchblade]

The issue I am having now is I cannot get the second sketch of the tooth to line up with curved line I have made. The centerline of the tooth will not match the gear, and when I try and do so, it says I am overdefining the sketch.