Postpositional open-type interaxle differential assembly

A postpositional open-type interaxle differential assembly comprises an input axle assembly, a differential lock assembly and an output axle assembly. The input axle assembly comprises an input axle and an input flange, a bearing I, a cylindrical drive gear, a cross axle and a half-rear axle gear which are sequentially arranged on the input axle from front to back, the bearing I is installed in a bearing seat I, and the front end of the bearing seat I is connected with the back end of the input flange; a planet gear is arranged on the cross axle, installed on a planet gear frame and meshed with the cylindrical drive gear and the half-real axle gear, and a bearing II matched with a shell of a main reducer assembly is installed outside the half-rear axle gear; the half-rear axle gear is connected with the differential lock assembly and the output axle assembly. The postpositional open-type interaxle differential assembly has the advantages of being compact in structure, light in weight, low in production cost, long in service life, small in noise and high in transmission efficiency and capable of improving the ride comfort of vehicle driving and reducing the occurrence of the oil leakage phenomenon, and is suitable for the requirements of the high-speed tractor market.