Shaft seal inner water cooling structure of marine circulating pump

The utility model discloses a shaft seal inner water cooling structure of a marine circulating pump. The shaft seal inner water cooling structure comprises a pump body, an impeller, a sealing ring, aninner cover, a pump cover, an oil injection connector, a pump shaft and a mechanical seal. An impeller arranged in an inner cavity of a pump body is positioned and connected through a pump shaft, aninner cover, a mechanical seal and a pump cover are sleeved on a rear-section pump shaft, two axial counter bores which are sleeved with each other are formed in the end face, provided with a radial outwards-protruding edge, of the pump cover, and the open ends of the axial counter bores of the inner cover are matched with and fixedly connected with the small end face of the inner cover in a sealed mode. A window is formed in the large end face of the inner cover and communicated with an outer axial counter bore of the pump cover and a preset balance hole of the impeller, and an inner water cooling structure for automa