輹: [fù]
1. A wooden block placed between the carriage body and the axle, used for supporting the carriage body. The top part bears the weight of the carriage, while the bottom part is arched and rests on the axle.
2. In ancient times, it refers to something that binds the axle under the carriage, also known as 伏兔 (fútù). The term "輹" is used for larger vehicles. (English: axle sleeve)
引:
1. From "说文": 輹, to bind the axle of a vehicle.