Bearing mounting tool with centering function

The invention relates to a bearing mounting tool with a centering function; the bearing mounting tool comprises a pressure head (1), a guide shaft (2) and a spring (3); the guide shaft (2) is installed inside the pressure head and is capable of moving axially inside the pressure head (1); the spring (3) is arranged at one end of the guide shaft (2); the other end of the spring (3) is pressed against the internal wall of the pressure head (1); the other end of the guide shaft (2) is capable of being stretched out of the end part of the pressure head (1); the external diameter of the part of the guide shaft (2) stretched out of the pressure head (1) is equal to the internal diameter of the hollow part of a shaft equipped with a bearing; and the internal diameter of the pressure head (1) matches with the external diameter clearance of the shaft to be mounted with the bearing. The centering function during installation is realized; no deflection of the bearing during installation is guaranteed and the requirement without damaging the bearing, the shaft and the bearing seat is satisfied.