Rotor structure of pneumatic tool

A rotor structure of pneumatic grinder, comprising a rotor main body formed with a central shaft hole for a rotary shaft to pass through, several radial projecting sections being formed on outer circumference of the rotor main body at equal intervals, a split being defined between each two adjacent projecting sections, a vane being inserted in each split, at least one reinforcing plate being coaxially embedded in the rotor main body, the reinforcing plate outward radially expanding from an axis of the rotor main body for increasing the strength of the rotor main body;

• wherein the reinforcing plate is a hollow plate, the reinforcing plate having several protruding sections respectively corresponding to the projecting sections of the rotor main body, each protruding section having two straight sides, an arc section being connected between each two adjacent protruding sections, the reinforcing plate being cut alone inner sides of the protruding sections, straight sides and arc sections, whereby each protruding section has a notch corresponding to the projecting section of the rotor main body for facilitating assembly of the reinforcing plate and enhancing bonding between the reinforcing plate and the rotor main body.