Typically, there is a small sensor embedded in the windings somewhere. When it senses a particular temperature it trips out, as you have noticed. It has an internal (to the sensor) timer which resets when the time is up. This timer could be as simple as waiting for the something to cool down, or it could be electrical in nature. I’ve never seen one of these which could be altered since it is probably just a small encapsulated device.
Usually if you repeatedly trip one of these sensors, it is for good reason. My suggestion would to be to replace the motor with something heavier.