Transmission device and engineering machinery with same

The invention discloses a transmission device and engineering machinery with the transmission device. The transmission device comprises a main shaft, a transmission part, a box body, an end cover and an oil seal, wherein the transmission part is coaxially and fixedly connected to the main shaft; a mounting space and a through hole are formed in the box body; the end cover is fixedly arranged at one end of the box; the transmission part is connected to a power source; a mounting hole communicated with the mounting space is formed in the end cover; one end of the spindle penetrates through the through hole and is inserted into the mounting hole; the oil seal forms a grease cavity with an open end; the end cover is provided with at least one oil injection channel; the oil seal is positioned between the spindle and the end cover; at least two oil seals are arranged in the mounting hole of the end cover; and the grease cavity in each oil seal is at least communicated with the mounting space or one oil injection ch