| 摘要 |
A control valve (80) for a self powered centrifugal separator (15') that is suitable for cleaning engine lubricant comprises a housing (17) having a blind bore (102) of circular cross-section into which open inlet and oulet ducts (40' and 40'') and containing a valve body (84). The valve body consists of a first part (111), which is axially fixed and rotatable between valve-open and valve-closed positions, and a second part (112), axially displaceable but rotatable with the first part by way of axially overlapping coupling parts (161 and 162). A control chamber (120) is defined between the blind end (104) of the bore and an end face (121) of the second part and a bias spring (131) extends between the other end face and the first part. A control passage (140) extends along the second part and flow passage (150) through it. The bias spring normally puts the flow passage out of alignment with the ducts but when the valve-open orientation is selected inlet duct pressure is transmitted by the control passage to the control chamber and the first part (111) deplaced to effect a predetermined degree of alignment between ducts. Under- or over-pressure displaces the part (111) and decreases flow. As the valve-closed orientation is selected the control passage and outlet duct drains the control chamber and permits the part (111) to be biased with the flow passage out of alignment. The control passage (140) senses the liquid pressure and acts on the body part directly, but alternatively, a separate pressure (or flow) sensor could supply control signals to an externally powered actuator. |
