Brake clearance adjuster

The utility model discloses a brake clearance adjuster which comprises a positioning pin, a double-thread screw, a spindle, a spindle gasket, a core seat, an elastic gasket, a shaft check ring, a shifting sleeve, a one-way needle bearing, a bushing, balls, a baffle, a spring, a locking sheet and a clamp spring, wherein a semispherical groove is formed in each of the baffle and the bushing; the balls are placed in the semispherical grooves; the one-way needle bearing is matched with the bushing; an outer ring is in interference fit with the shifting sleeve; the baffle is provided with an inner spline; the spindle is provided with an outer spline; the baffle and the spindle are in spline fit; one end of the spring is propped against the baffle and the other end of the spring is propped against the locking sheet; the clamp spring is clamped in a spindle groove of the spindle; one end of the clamp spring is propped against the locking sheet; the spindle is provided with an inner thread; the double-thread screw is provided with an outer thread; the spindle and the double-thread screw are in thread fit. The brake clearance adjuster can be used for automatically adjusting the braking clearance between the friction piece and the brake disc, and is simple in structure and reliable in performance.