That is a very pretty mushroom, but I have been unable to identify what it is.  It is not typical of other mushrooms associated with maple trees.  I would be concerned, though, that the mushroom may be a symptom of heartwood rot.  Fungi can enter the tree through wounded areas and over time, attack the heartwood.  If your tree does have rot, then it is at much greater risk of breaking and falling.  It would be worth having an arborist check it out to determine if the tree is still sound or if it should be cut down for safety reasons.  The links below describe heart rot as well as providing information on more typical fungal infections.  Your fungus is not among those described.  Sorry I couldn't be of more assistance in identifying the fungus.  
https://extension.unl.edu/statewide/buffalo/Heart%20Rot%20in%20Trees%20November%2015%202014.pdf
https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/maple/branchesfungi.html

Good luck with your tree!!