Tractor rear wheel span regulating device

The utility model discloses a wheel gauge adjusting device of the back wheel of a tractor, which comprises a wheel boss surrounding at the outer circumferential surface of a half shaft, the inner hole of the wheel boss is a conical hole, and annular space between the wheel boss and the half shaft is provided with a plurality of wedge-shaped blocks connected with the wheel boss respectively. The wedge-shaped blocks have outer circumferential surfaces matched with the conical hole of the wheel boss respectively and inner circumferential surfaces matched with the outer circumferential surfaces of the half shaft respectively, and at least one wedge-shaped block is in slide key connection with the half shaft. The wedge-shaped blocks also comprise clamping devices which can be used for applying force in an axial direction and can be used for clamping the wedge-shaped blocks at the half shaft in a radial direction. The structure is simple, the non stage continuous adjusting of the back wheel gauge of a tractor can be realized, fastening is reliable, adjusting is convenient, the adaptability of the tractor in different zones is improved, the application range of the tractor is enlarged and the utility model is particularly suitable for requirements of ground laying films of various ground machines for the wheel gauge of a tractor.