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 Gear / pinion design Post Reply Forum
 Posted by: boonej ® 04/03/2007, 07:38:51 Author Profile eMail author Edit I'm designing a gear system where I want one drive pinion in contact with two equal size gears (same torque to each one). All the gear design tools I come across only consider a pinion driving one gear. Are there any special considrations in doing this? If the power input into the pinion from the drive motor is 125 hp, and each gear is seeing 62.5 hp, then the pinion tooth only sees the same force as a gear tooth (62.5hp/V), but sees it twice per revolution rather than once per revolution in the gear right? Your thoughts on this would be welcome.

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 Re: Gear / pinion design Re: Gear / pinion design -- boonej Post Reply Top of thread Forum
 Posted by: materialboy ® 04/04/2007, 16:50:21 Author Profile eMail author Edit All the gear design tools I come across only consider a pinion driving one gearCan I know more in details what are you designing for and do you really need to have two gears connecting to pinion - Generally if you have two gears like in watch than one will be giving clockwise and other anti-clockwise which will neutralize the force applied. this type is used in rolling sheet From the look of it you have 2:1 pinion:gear arrangement.- To calculate the tooth thickness of Pinion t = 1.5708/P p = Diametrial Pitch 1.57 = safety facor at partcular alowable stress i have to check at wut stress level is it for - but will let u know soon Modified by materialboy at Wed, Apr 04, 2007, 16:51:26

 Re: Gear / pinion design Re: Gear / pinion design -- boonej Post Reply Top of thread Forum
 Posted by: randykimball ® 04/03/2007, 21:14:19 Author Profile eMail author Edit This is not all that unusual. It is common practice when you have a gear train of several stages such as a roll former and you want to input the power mid gear train to avoid the cascade of torque multiplying through the whole gear train to only one end. So you introduce the powered pinion somewhere later in the gear stack to split the torque loads two directions. But, yes, you should consider the added torque on the pinion when you consider the pitch and gear width. The worst suggestion of your lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them.

 Re: Gear / pinion design Re: Gear / pinion design -- boonej Post Reply Top of thread Forum
 Posted by: jboggs ® 04/03/2007, 09:44:19 Author Profile eMail author Edit I think I understand your question, and yes, each tooth would see the load twice per revolution, but why is that a concern?

 Re: Re: Gear / pinion design Re: Re: Gear / pinion design -- jboggs Post Reply Top of thread Forum
 Posted by: boonej ® 04/03/2007, 10:08:40 Author Profile eMail author Edit It is a concern because of two reasons:1)I want to make sure I specify the correct pinion width - too small and teeth break. Too wide and the cost of manufacture is too high.2) I don't want to add another pinion to my drive shaft for the second gear when one will do the job (assuming I design for an infinite fatigue life).

 Re: Re: Re: Gear / pinion design Re: Re: Re: Gear / pinion design -- boonej Post Reply Top of thread Forum
 Posted by: jboggs ® 04/05/2007, 18:58:32 Author Profile eMail author Edit Is this a high-volume manufacturing process, or low volume? If high volume, then the cost of prototype testing would be easily justifiable, and give you hard data. If low-volume, then design to best practice, and add a very fat safety factor. I would bet that once the setup is made to cut the teeth, the impact of the actual face width is less of a factor.