Hydrogen cooled generator

The utility model discloses a hydrogen cooled generator which comprises a generator body provided with a hydrogen side oil outlet and an oil return expanded groove, wherein the oil return expanded groove is communicated with the hydrogen side oil outlet through a sealing oil hydrogen side oil return pipeline. In addition, the hydrogen cooled generator further comprises a hydrogen pressure communicating pipe, one end of the hydrogen pressure communicating pipe is communicated with a space of the upper portion in the oil return expanded groove, and the other end of the hydrogen pressure is communicated with a cavity body used for containing hydrogen and arranged in the generator body. According to the hydrogen cooled generator, the hydrogen pressure communicating pipe enables the cavity arranged in the generator and used for containing hydrogen to be communicated with the space of the upper portion in the oil return expanded groove, when pressure of hydrogen is the generator body changes, pressure of hydrogen o