Making a Gear with Involute Teeth in Solidworks Tutorial
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- Опубликовано: 10 июл 2024
- GearParameters.txt contains the following text
"DiametralPitch"= 32
"NumTeeth"= 16
"PressureAngle"= 20deg
"Addendum"= 1 / "DiametralPitch"
"Dedendum"= 1.25 / "DiametralPitch"
"WorkingDepth"= 2 / "DiametralPitch"
"WholeDepth"= 2.25 / "DiametralPitch"
"Clearance"= 0.25 / "DiametralPitch"
"ToothThickness"= 1.5708 / "DiametralPitch"
"CircularPitch"= pi / "DiametralPitch"
"PitchCircle"= "NumTeeth" / "DiametralPitch"
"OutsideDiameter"= ( "NumTeeth" + 2 ) / "DiametralPitch"
"Fillet"= "Clearance" * cos ( "PressureAngle" ) * tan ( ( 90 + "PressureAngle" ) / 2 )
"AddendumCircle"= "PitchCircle" + ( 2 * "Addendum" )
"DedendumCircle"= "PitchCircle" - ( 2 * "Dedendum" )
"BaseCircle"= "PitchCircle" * cos ( "PressureAngle" )
"PitchAngle"= 360deg / "NumTeeth"
"Alpha"= sqr ( "PitchCircle" ^ 2 - "BaseCircle" ^ 2 ) / "BaseCircle" * 180 / PI - "PressureAngle"
"Beta"= ( "PitchAngle" / 4 - "Alpha" )
"Phi"= sqr ( ( "AddendumCircle" / 2 ) ^ 2 - ( "BaseCircle" / 2 ) ^ 2 ) / ( "BaseCircle" / 2 )
ParametricEquations.txt contains the following text
Top x
"BaseCircle"/2*(cos(t+"Beta"*pi/180)+t*sin(t+"Beta"*pi/180))
Top y
"BaseCircle"/2*(sin(t+"Beta"*pi/180)-t*cos(t+"Beta"*pi/180))
Bot x
"BaseCircle"/2*(cos(-t-"Beta"*pi/180)-t*sin(-t-"Beta"*pi/180))
Bot y
"BaseCircle"/2*(sin(-t-"Beta"*pi/180)+t*cos(-t-"Beta"*pi/180))
Range
All 0-"phi"
I've been struggling with the larger gears all weekend. This is the first video I've found that went over how to modify the sketches to make it work. I really appreciate it.
same
So far the best video on the subject I've seen. Great Job! Btw, your comment at 14:00 has made my day :)
Thankyou so much ,this is video is a life saver
Have you ever done an internal spine gear with this?
I found that I was able to increase the limit on the number of teeth by defining an ellipse segment in the tooth profile sketch with a center on the midpoint line between the ends of the involutes, endpoints coincident to the involute ends and minor radii colinear with the midpoint line. I chose to define the major radius as half of the Dedendum, but that was arbitrary. This allows spurs with over 100 teeth, but seems to cap out between there and 128, at the point when the upper and lower involute curves start to intersect. I don't know if there's a way to fork the geometry based on whether those curves intersect, but I chose to build a separate part which used the perimeter formed by the intersecting involutes and the Addendum Circle as the tooth profile with a fillet on the inside corner with the radius defined by the Fillet parameter from earlier. I'm writing this at 1am and haven't had a chance to test these gear profiles, but they seem reasonable from a visual inspection and I checked the second profile up through 500 teeth without issue (and I'm pretty sure there aren't many good reasons to build a 500 tooth gear" even with a modest 1mm pitch, that means the pitch diameter is half a meter, which is an absurdly large gear to be using that pitch. I'm pretty sure a sane engineer would build a planetary set into the middle before using a gear like that in a final design).
I've also been looking onto what you can and can't define in solidworks, and I think if you use if statements, you might be able to define the whole tooth profile with one equation curve, by using if statements to conjoin equations for the involutes. Assuming SW doesn't throw a fit about discontinuity, this would also allow you to build in conditional equations for very large and very small gears, though this would come with a drawback: SW evaluates the whole equation before checking the if statements, so the system would be doing the calculations for all gear types at once. Thankfully, all that would be happening in the sketch before the resulting curves get turned into geometry, so only potato workstations, if those, will notice any difference.
Good Tutorial on making spur gears from scratch via with an equation assist. I'm surprised no is questioning you if this method creates true involute gears. I've watched a few other videos about creating spur gears in Solidworks and there's some whacky methodology out there and people are quick to point out that it resembles an involute spur gear but actually isn't. Your method is straight forward and easy to understand! I didn't mind grabbing a gear from the toolbox but adding anything onto the gear was difficult and break some references which is annoying. This is the tutorial I was looking for, thank you! Do you have a tutorial for making Helical Gears?
I can confirm the method creates true involutes, the parametric equation used is that of an involute. I modeled and 3D printed straight, helical and bevel gears using essentially the same method (I used the module and other names instead) and got very good results (although sometimes the gear model who need tweaks depending if the teeth number was >20 or not).
You can model helical gears by using a swept cut with an helix instead of an extruded cut and replacing the following formulas to take into account the helix angle "Helix":
"DiametralPitch"= 32/cos( "Helix" )
"PressureAngle"= atn( tan( 20deg ) / cos( "Helix" ) )
The other equations shouldn't be modified. That way, you'll project the tooth profile into the side view depending on the Helix angle.
Good video, much helpful, but how to model involute teeth profile if there is a "profile shift", where X is different form 0?
What would my gear parameters be if I wanted to make a gear with 60 teeth and i want the thickness of the gear to be .125 inches. With a Dedendum circle being 4.75 inches. For some reason when I solve for the other variables my Base Circle is smaller in diameter than my Dedendum circle. Would you be able to help me fix this?
nvm i figured it out
Glad you got it. The second half of the video shows how to make larger gears with more teeth.
Gears tooth interfere when try to assemble them, please help.
I dont know is this because I use metric values or because my module is only 0.8 but dimensions are working wonky with those calculations on textfile. My Diametral Pitch is 118.4mm and gear has 148 teeths. So outer diameter is showing 1.26mm :D
Besides this little inconvenience this tutorial was really helpful!
And now I can answer to myself that i used wrong value on Diametral pitch. I ment to use 1.25 and not the 118.4.
@@ZziKaT Thanks for putting that bit about the Diametral pitch in the comments! I was breaking my head on that one for a bit until I decided to read the comments. (Making a 0.8module gear too lol) Converting units is why we lost spacecraft in the past and I can see why lol