When we formed our corporation we issued voting shares to myself and the other 2 partners. I am at 51% ownership and the other 2 are at 29 and 20%. One partner is going to put in another cash investment but obviously wants more equity for that investment. I am unwilling to give up any of my 51% control as it was my invention, I do 70% of the work and have all the vision. Our share structure is unlimited for both classes so can we simply issue him x amount of non-voting shares to increase his equity? That would bring his equity up to 33% from 20%, the other partners down to 24% and mine down to 43%. However, what I understand based on my numbers, his 'voting' percentage would only be 17% and that combine with the other partner's 24% would only be 41% vs my 43% still leaving me in ultimate control. Am I understanding this right?
You can do whatever you wish with shares as long as the parties agree.
If you have voting and non-voting classes of shares you can issue these for the cash investment.
The question is... why would he? Normally non-voting shares have certain other characteristics like fixed rates of return or preference in the case of company dissolution.
Other things you may consider would be issuing a debenture for the new money. This is a debt instrument so there would be no shares sold.
You could issue a convertible debenture whereby the debt becomes equity at a certain share price in certain events, such as the sale of the company.
It's up to your imagination as long as the other party agrees.
Here are two videos I made that touch on this topic, one about how to use shares in deal making and another about using shares to raise capital.
Just arrange a call if you'd like to discuss your specific situation.