Spline mute device

The invention relates to the field of design and assembly of splines, in particular to a spline muting device which comprises a transmission shaft and a hub, an outer spline shaft is arranged on the transmission shaft, an inner spline is arranged on the hub, the outer spline shaft and the inner spline are matched with each other, and a mounting nut is arranged on the outer spline shaft; a protruding block is arranged on the spline tooth side of the outer spline shaft, and a groove matched with the protruding block is formed in the inner spline. The groove is also positioned on the spline tooth side of the internal spline; an oil injection hole is formed in the hub, and hydraulic oil is filled into the internal spline through the oil injection hole; through cooperation of the protruding blocks and the grooves, the technical problem that abnormal sound is generated at the cooperation position of the inner spline and the outer spline shaft due to the fact that the fit clearance between the outer spline shaft and