Helical gear speed reducer with parallel shafts

The utility model provides a parallel shaft helical gear speed reducer, and belongs to the technical field of speed reducers. Comprising a speed reducer body and an oil supply structure installed on the speed reducer body. The oil supply structure comprises an oil outlet connector, a filter box, a filter supporting plate, a filter element block, an impurity removal filter box, an abutting assembly, a sealing cover plate, an oil pump assembly and an oil inlet connector, the oil outlet connector is connected to the speed reducer body in a threaded mode, the filter box is installed on the oil outlet connector, the filter supporting plate is welded in the filter box, and the filter element block is installed on the oil pump assembly. The filter element block is inserted into the filter box and located on the upper surface of the filter supporting plate, lubricating oil is preliminarily filtered through an impurity removal filter box of the filter box, and large-size metal scraps in the lubricating oil are filtere