How to drive gear to articulate mechanism

[ScaleyZVFC5]

In the assembly (AS-01-test.zip) I attempt to Drive the angle of the 15 tooth spur gear from 0 - 45 deg. However I receive the error: 

Cannot solve at (or near) this point. Check drive parameters and adaptivity settings.

My goal is:

• Rotational motion of spur gear (Angle:4) and the pinion shaft to be driven from 0 - 45 degrees (for starters)
• Spur gear to mesh with ring gear (Rotation constraint set to Ratio of 0.150). Ring gear is constrained in all DOF to grounded bearing block, so spur gear is expected to rotate and revolve within the ring gear
• Lower arm to rotate about the bearing block's pivot point, being articulated by the orbital motion of the pinion shaft 

The mechanism articulates as I expect if Angle:4 is suppressed and the 15 tooth spur gear is dragged live with the cursor. However the error occurs when I attempt to Drive Angle:4.

Thanks in advance!

Scott

Autodesk Inventor 2024.3

Windows 10 Enterprise ver. 22H2

Dell 12th Gen Intel Core i7-12800H 2.4 GHz

RAM: 32 GB

[johnsonshiue]

Hi! Suppress Angle:4. You need to add another Rotational constraint between the Lower Arm and the Spring Gear. Then drive Angle:3.

Many thanks!

[ScaleyZVFC5]

Thank you @johnsonshiue for your reply.

However, the ring gear is fixed (fully constrained to bearing block). Only the 15 tooth spur gear can rotate and revolve. I can drag the spur gear live with the cursor as shown in the video below, but I need help to get the spur gear to be a driven motion (i.e. rotating 0-45 deg).

Do you have any thoughts to get around the error I listed in the original post?

Many thanks for your reply!

Scott

[johnsonshiue · Accepted solution]

Hi! In that case, you need to ground the Ring gear and suppress Angle:3. Edit Rotation:1 change the Rotational constraint to be between the Lower arm and Spur gear.

Many thanks!

[ScaleyZVFC5 · Accepted solution]

@johnsonshiue you solved it! Thank you very much.

I learned from your solution that the Rotation constraint must be applied to two moveable components, with neither of them being grounded (or otherwise fully constrained to ground). Without your help I would not have thought to apply the Rotation constraint to anything but the two gears!

The result is shown in the video below. Interestingly, there are two things to be aware of with this solution:

1. The ring gear becomes nothing more than an ornament in this mechanism
2. The expected ratio (22 teeth / 100 teeth = 0.22) results in an incorrect rotation. I had to change the ratio of the Rotation constraint to 0.2823 (28.3% higher) to achieve the intended rotation for this gear ratio

Thanks again Johnson!!

Scott