The wheelset is the part of the rolling stock that is in contact with the rail, and is composed of two left and right wheels firmly pressed on the same axle. The role of the wheelset is to ensure the running and steering of the rolling stock on the rail, to withstand all static and dynamic loads from the rolling stock, to transfer it to the rail, and to transfer the load generated by the uneven line to the parts of the rolling stock. The narrow gauge wheelset normally with the gauge less than 1435mm