There may be several reasons why trolley bearing bushings and wheelchairs are not the same:
Design and use: trolley bearing bushings and wheelchairs have different designs and uses. Trolley bearing bushings are mainly used to support and guide the wheels of a trolley, while wheelchairs are used to support and move a person's body.
Construction and materials: the construction and materials of trolley bearing bushings and wheelchairs may also differ. Trolley bearing sets are usually made of materials such as metal or plastic, while wheelchairs are made up of a variety of materials such as metal, plastic, and wood.
Movement: Trolley bearing bushings and wheelchairs may also move in different ways. Trolley bearing sets usually move the trolley through the rotation of the bearings, while wheelchairs move through the rolling of the wheels.
In summary, trolley bearing bushings and wheelchairs differ in design and purpose, construction and materials, and mode of movement, so they are not the same.