To provide a mounting structure of a rolling bearing device in which a pressurizing means for supporting a rotary shaft on a shaft box by applying a pressure in an axial direction applies the pressure by converting relative movement in an radial direction to movement in the axial direction using relative movement in the radial direction of two members with different linear expansion coefficients (thermal expansion coefficients).

The pressurizing means 20 is configured such that a first annular member 22 and a second annular member 24 having the different linear expansion coefficients are arranged lining in the axial direction, and both members relatively move in the radial direction by the thermal expansion, and has a mechanism changing the relative positional space in the axial direction of both members with the relative movement in the radial direction.