Idiom che an pu LUN

Install the pulley [ān chē pú lún]

[Interpretation] Let the applicant sit in the car and wrap the wheels with the leaves of Pu Ye, so that the car body will be more stable when driving. ...

[Source] A Brief History of Emperor Wu of the Han Dynasty by Ban Gu in the Eastern Han Dynasty: "The emissary prepares wheels and silks are attached to the wall.