Water turbine compression gap volute structure

The invention relates to a water turbine compression gap volute structure, which comprises a metal volute and concrete on the periphery of the metal volute, wherein the inlet end of the metal volute is a section of straight pipe section, a water introducing steel pipe is connected with the straight pipe section arranged at the inlet end of the metal volute, the tail end of the straight pipe section is a volute direction 0-degree cross section, and a seat ring is arranged at a spiral-shaped structure inner ring part of the metal volute. The water turbine compression gap volute structure is characterized in that soft materials are fixedly arranged between the metal volute and the peripheral concrete, the soft materials generate plastic deformation when being pressed, a compression gap is formed, the force transmission coefficient of the soft materials is not greater than 50MPa/m, the deformation modulus of the soft materials is 0.05MPa to 0.5MPa, and the thickness of the soft materials is not greater than 10mm.