Leakproof Structure of Shaft Tube

A leakproof structure of shaft tube, comprising:

• a shaft tube including a center hole with two ends thereof open and sealed respectively, with the shaft tube further including an upper section adjacent to the open end of the center hole and a lower section having an inner diameter smaller than that of the upper section;
• a bearing being received in the lower section of the shaft tube and including a longitudinal hole extending along a longitudinal axis of the bearing;
• a shaft including an annular groove in a neck shape formed in an outer periphery of the shaft to form a neck of the shaft, with one end of the shaft extending through the longitudinal hole of the bearing and the annular groove being adjacent to the other end of the shaft, with the neck of the shaft having an outer diameter smaller than that of two sections of the shaft, with said two sections being adjacent to two end edges of the annular groove;
• and
• a leakproof plate being fixed in the upper section of the shaft tube and including a through-hole with a diameter smaller than the outer diameters of the two sections of the shaft, with an inner edge of the leakproof plate being in the annular groove.