Pneumatic device for cleaning automobile window and exchanging air in automobile

The invention discloses a pneumatic device for cleaning an automobile window and exchanging air in an automobile. The pneumatic device comprises a machine body, the machine body is a transmission device which is arranged in the automobile and can utilize wind energy, a first fan cavity is formed in the machine body, the pneumatic device is provided with a wind energy transmission device, and the position of a sliding push plate can be changed through centrifugal rotation of a push block; therefore, the meshing center distance between a left variable-speed belt wheel, a right variable-speed belt wheel, a driven variable-speed belt wheel and a stepless variable-speed belt is changed, namely, the transmission ratio is changed, so that a driven shaft keeps a certain unchanged rotating speed under different rotating speeds of a power fan, and a windshield wiper can clean front side glass at a constant speed; therefore, the optimal cleaning effect is achieved, and the sight condition of a driver is not influenced;