SZL Series Vertical Conical Twin Gearbox for PVC Pipe Extrusion Lines

The SZL series gear units is specially designed as a mechanical transmission device mating for the cone double screw plastic extruder. The gear unit is composed of the transmission case and the distribution case. The device can transmit the power generated by the major motor to the long axis of the distributor case after speed reduction and twist increasing in the transmission case. Then the long axis drives the minor axis through a pair of small-cone-angle spiral gear with a transmission ratio of 1:1. The long axis and the minor axis with the same corner dimension as the screw bolt and in the manner of inverted outward rotation drive the screw bolt to extrude high-quality products.

The SZL series vertical conical twin gearbox is purpose-designed for conical twin screw extruders used in PVC pipe, profile, and sheet production lines. In PVC pipe extrusion, the gearbox's vertical configuration and 1:1 helical gear transmission ensure synchronized rotation of both conical screws, providing the torque balance required for uniform material plasticating and conveying. For PVC window profile extrusion lines, the gearbox's transmission case and distribution case architecture delivers stable power distribution to both screw shafts, maintaining the precise screw timing needed for consistent profile dimensions. Sheet extrusion operations utilize this gearbox to drive screws that deliver uniform melt for sheets used in vacuum forming applications. The 1:1 transmission ratio between the long axis and minor axis ensures that both screws rotate at identical speeds, which is critical for achieving proper intermeshing, self-wiping action, and melt homogeneity in conical twin screw configurations.