modeling a sector gear

[billwillett]

Hi,


Could anyone help me with setting this mechanism up? Slowly rotating partial gear drives spring loaded rack. When spring compressed, toothless portion of gear allows spring to quickly drive rack back to a stop. Gear eventuallyre-engages rack and cyclerepeats.


Can't use gear connection asgear is only partial. Tried cam connection (allow liftoff) between teethwhich does not seem to work (skips teeth). I could use custom motor on each, but this would not let me do dynamic analysis (to determine maximum rotation speed that allows rack to fully return before gear re-engagment).


Note: image below does not have rack and gear corectlytimed - but you get the idea.


Thanks for any input.


View attachment 2725

 

[Mloew]

I would just use two "servo motors" to control each DOF separately. An advantage of using the drivers over joints is that they can be turned on and off through the simulation controls during a run.

 

[billwillett]

Thank you Matthew.


If the rack and gear are controlled by motors, how do I run a dynamic analysis?


There is a DC motor on the sector gear, so I want to apply a torque to it. I want to measure the time for the gear to be in place to re-engage the rack once it has released the rack. I want to also measure the time for the rack to spring-return once it is released from the sector gear.


Ultimately, I want to adjust the mechanism to maximize cycles persecond. Spring strong + motor weak= rack is back in time. Spring weak+ motor strong= rack does not get back in time and hits sector gear.


Thanks from anyone that can help me on this

 

[billwillett]

Please, can someone help me set this up?

 

[SRINIVASANIYER1]

Try using slot-follower connection. This being an intermittent motion mechanism.


I had done it long back. I think this should help as far as my memory goes.

 

[SRINIVASANIYER1]

can you post thepinion and rack part files? I would like to give it a try.