How does the rectifier on my B&D corded mower work to give the proper DC vo?

I own a 120VAC corded electric mower and a 24VDC cordless electric mower. Both motors look the same, so I was wondering if in fact both are 24VDC motors. Therefore, I want to know how the rectifier gives the proper VDC to the motor on the corded 120VAC without a stepdown transformer?? This should be basic electric theory question. I have used my VOM to measure the voltages out of the rectifier but since I don't know the V-rating of the motor, I am unclear how the rectifier gives the motor what it needs.

Thanks, David