Inner bore grinding device for oil drilling tool

The invention discloses an inner bore grinding device for an oil drilling tool, which comprises an air guide pipe, a middle joint, a motor, a shaft bushing, a shaft and a grinding wheel, which are axially connected in sequence. The middle joint is a pipe joint in a straight-through double-head threaded structure, and one end of the pipe joint is hermetically connected with the air guide pipe while the other end of the pipe joint is hermetically connected with an axial air inlet on a cylindrical motor shell. The motor shell and the shaft bushing are connected with each other and relatively static, the shaft is supported by an inner hole of the shaft bushing, one end of the shaft is rotatably directly connected with a rotor in the motor, the shaft end exposed out of the shaft bushing is a threaded section for axially mounting the grinding wheel, and the grinding wheel is connected with the shaft to form a rotary structure driven by the motor. Pressure air is used as a power source to drive the motor and the grinding wheel to rotate, the inner bore grinding device is simple in structure, small in radial dimension and favorable for miniaturization design, and since no power source is directly used, the inner bore grinding device is safe in operation and free of electric shock when extending into the oil drilling tool for grinding operation.