Automatic tight pulley rises

The utility model discloses an automatic tight pulley rises, including belt pulley, bearing, bearing frame, pivot, spring and sleeve, the inside bearing frame that is equipped with of belt pulley, install the bearing on the bearing frame, inside the overlapping of bearing frame has the sleeve, the sleeve lower extreme is equipped with the pivot, the pivot upper end is equipped with annular recess in inserting the sleeve on the pivot, be equipped with the spring on the recess, the inside hole of having seted up no. Of sleeve, the inside hole of having seted up no. Two of pivot, a hole and no. Two holes are linked together, the sleeve upper end still is equipped with the end cover, the end cover both ends are equipped with the screw hole, through bolt fixed connection between end cover and the belt pulley. The utility model discloses simple structure, long service life can make the belt to press on the work belt pulley with suitable pressure, can effectually avoid the belt to take place to skid simultaneously to better protection the bearing.