Is there any way I can get rid of the bees without hurting the birds

If you don't have bee guards on the feeders you are wasting your time. Install guards and very little water will be lost to bees. The Hummingbirds have very long tongues and they can get through the small holes in the guards.

During hot spells, bees need water like any other animal. They will find it wherever they can and a hummingbird feeder filled with sugar water (which by the way is feeding junk food to the birds)is an easy meal. Take the feeders down during the times the bees are showing up. Better yet, take them down and plant flowers that feed the hummers (and the bees) naturally with healthy nectar.

I've had the same problem, and turned to my old friend, Google, for help. Suggestion was to take the feeders down or move them to a different location for a few days, and the bees will 'forget' where they were... sort of worked, but was glad to find a source for lots of hummer information.