Light large-flow oil pump

The invention provides a light large-flow oil pump which comprises a pump body, a pump cover, an inner rotor, an outer rotor, a pressure-limiting valve, a drive shaft and a transmission gear, wherein the inner rotor and the outer rotor are positioned in a rotor cavity of the pump body; end surfaces of the inner rotor and the outer rotor are provided with weight-reducing holes; one end of the drive shaft is mounted on the transmission gear; the other end of the drive shaft penetrates through a shaft hole of the pump body for being mounted on the inner rotor; the pressure-limiting valve is an inner relief type pressure-limiting valve; the pump body and the pump cover are aluminum die-casting fittings; and the pump cover is mounted on the pump body through a bolt. According to the technical scheme, the inner and outer rotor type structures and the inner relief type pressure-limiting valve are adopted, so that the structure of the whole oil pump is relatively compact; the pump body and the pump cover are aluminum die-casting fittings, and the end surfaces of the inner rotor and the outer rotor are provided with weight-reducing holes, so that weight is reduced; and oil in the inner relief type pressure-limiting valve can be returned into an oil inlet of the oil pump to supplement oil inlet amount, so that flow fluctuation of the oil outlet is reduced.