Statically balanced crank-operated packer mechanism for an agricultural baler

A crank-operated packer mechanism includes a crank shaft including crank pins and crank arms. At least some of the crank arms are shaped in a way that deviates from a straight shape to such an extent that the crank shaft is statically balanced. The arms may, for example, be curved or hook-shaped. The crank shaft further includes crank pins and crank arms assembled by a tapered spline connection. The connection includes tapered spline features on outer ends of the crank pins and in openings provided at outer ends of the crank arms, which interlock when the crank pins are inserted in the openings.