A gear coupling for connecting a drive shaft and an output shaft includes a first coupling portion adapted for connection to the drive shaft and a second coupling portion adapted for connection to the output shaft, Each of the first and second coupling portions has a driver toothing with an internal toothing and an external toothing in engagement with the internal toothing. An intermediate tube made of an electrically insulating material connects the first and second coupling portions with one another and electrically insulates the first and second coupling portions from one another. One of the first and second coupling portions surrounds an inner periphery of the intermediate tube and the other one of the first and second coupling portions surrounds an outer periphery of the intermediate tube.