VARIABLE CHOKE ASSEMBLY

摘要

A pressure reducing apparatus for controlling the pressure of oil is provided. The apparatus has ceramic components that resist wear caused by sand and debris in the oil. In one embodiment of the invention, the apparatus has a hollow body having an upstream channel (11), a downstream channel (17), and a pressure reducing chamber between the upstream channel and the downstream channel. The pressure reducing chamber has a longitudinal axis and contains a disk (60) that is rotatable on the longitudinal axis of the pressure reducing chamber. The disk has a sidewall that abuts the upstream channel (11) and a bottom end that abuts the downstream channel (17). The sidewall has a height that varies along the circumference of the disk. The disk (60) is rotatable within the pressure reducing chamber so that the height of the sidewall facing the upstream channel (11) can be varied to throttle the flow of oil from the upstream channel.