Non-power bogie with built-in axle box and for high-speed motor train unit

The invention discloses a non-power bogie with a built-in axle box and for a high-speed motor train unit, and belongs to the field of railway vehicle bogie mechanisms. The non-power bogie comprises combined side beams each composed of a box type welding side beam and a forged side beam forged cross beams, a lightweight integrated mounting seat, a transverse straight baffle, a side beam brake cylinder hanging seat, a rotating arm positioning seat, two cross beam brake cylinder hanging seats and a traction pull rod seat. And the two combined side beams and the two forged cross beams form a framework. The cross section of the box type welding side beam with the middle protruding outwards is gradually increased from the two ends to the middle, the variable cross section design can not only enhance the overall diamond load resisting capacity of the framework, but also effectively increase the distance value of air springs on the two combined side beams, the mass between the springs extends outwards in the transver