Transmission system of two-gear pure electric double-clutch transmission

The invention discloses a small-size transmission system of a two-gear pure electric double-clutch transmission. An input shaft assembly comprises an outer input shaft on the periphery of one needle bearing, an inner input shaft in an inner hole of the other needle bearing, a second-gear driving gear fixedly connected to the upper portion, extending out of the outer input shaft, of the inner input shaft, and a first-stage driving gear at the upper end of the outer input shaft. A first-gear clutch and a second-gear clutch of the double clutches are fixedly connected to the lower end of the outer input shaft and the lower portion, extending out of the outer input shaft, of the inner input shaft respectively. A middle shaft assembly comprises a first-gear driven gear, a second-gear driven gear and an output driving gear, wherein the first-gear driven gear and the second-gear driven gear are fixedly connected to a middle shaft from top to bottom. A differential assembly comprises an output driven gear assembled on a differential and meshed with the output driving gear. The second-gear driving gear and the first-gear driving gear are meshed with the second-gear driven gear and the first-gear driven gear respectively.