Patent ID: 8590972

Claim:
A seat recliner, comprising: an inner toothed plate having an inner ring gear and fixedly connected with a seat back, a shaft shoulder being provided at a center of the inner toothed plate; an outer toothed plate having an outer ring gear and fixedly connected with a seat cushion, an axis central hole being provided at a center of the outer toothed plate; the outer ring gear being engaged with the inner ring gear, wherein the shaft shoulder is eccentrically disposed relative to the axis central hole to form a radially eccentric region between the shaft shoulder and the axis central hole; an eccentric wheel provided in the radially eccentric region, and wherein the eccentric wheel, the inner toothed plate and the outer toothed plate forms a planetary gear transmission mechanism with small tooth number difference; a wedge-shaped block provided in the radially eccentric region; wherein the eccentric wheel and the wedge-shaped block are configured to eliminate a clearance between the eccentric wheel and the axis central hole of the outer toothed plate as well as a clearance between engaged teeth under a circumferential force exerted by an elastic member; and a drive component driving the eccentric wheel or the wedge-shaped block so as to rotate the inner toothed plate by an angle relative to the outer toothed plate; wherein the eccentric wheel is of integral eccentric annular shape and fully occupies a first eccentric region between the shaft shoulder of the inner toothed plate and the axis central hole of the outer toothed plate, wherein the first eccentric region is in a direction along which a radial space size becomes largest in the radially eccentric region; the wedge-shaped block is disposed in a recess of the eccentric wheel, wherein the wedge-shaped block includes an inner side surface and an outer side surface, wherein the inner side surface contacts the shaft shoulder in a wedging state and the outer side surface contacts the axis central hole in the wedging state.