Internal gear grinding equipment

The utility model discloses internal gear grinding equipment which comprises a gear fixing seat and a grinding device. The gear fixing seat is arranged below a grinding head of the grinding device; the gear fixing base comprises a base table, a four-point clamping assembly and a transmission assembly. The four-point clamping assembly comprises four sliding tables arranged on the upper portion of the base table in a sliding mode. A square clamping area is defined by the four sliding tables. The transmission assembly drives the four sliding tables to slide synchronously, so that the clamping area is reduced or expanded under the condition that the center line is not changed. The gear grinding device is ingenious in structure, the gear outer ring is effectively positioned through the gear fixing seat, the gear inner ring is ground through the grinding device, the four-point clamping assembly of the gear fixing seat clamps and positions the gear outer ring in a four-point mode through thefour sliding tables, posi