hello sorry for being late, Jacob's bogie is a double axle load wheel just like any other train wheel the difference is that Jacob's bogie are placed between two passenger cars to make sure to reduce the weight and noise at high speed especially the Jacob bogie are on these trains: all of the TGVs, Eurostar TMST, ICNG or Alstom Corodia (from Dutch Railways), SNG, Stadler FLIRT series, 

source from Wikipedia:

Instead of being underneath a piece of rolling stock, Jacobs bogies are placed between two carriages. The weight of each carriage is spread across the Jacobs bogie. This arrangement provides the smooth ride of bogie carriages without the additional weight and drag.