EXTERNAL ACTUATOR FOR AN IMPELLER SHROUD OF A VARIABLE WATER PUMP

摘要

An external actuator for a variable water pump is provided having an actuator housing with an outer wall with a plurality of radially inwardly directed projections, and a drive ring rotatably mounted in the housing. The drive ring has an internal thread. The projections contact an outer surface of the drive ring to define a plurality of hydraulic chambers that are divided by vanes extending from the drive ring into first and second chamber portions. A control valve controls a flow of pressurized hydraulic fluid to the chambers to rotate the drive ring in both directions or hold it in position. A drive nut having external threads is located within the drive ring and rotation of the drive ring causes an axial displacement of the drive nut. An actuator pin connected to the drive nut extends into the water pump housing to actuate the variable flow impeller.

主权项

1. An external actuator for a variable water pump which includes a housing and variable flow impeller located in the housing that is connected to a drive shaft, the external actuator comprising:
an actuator housing having an outer wall with a plurality of radially inwardly directed projections; a drive ring rotatably mounted in the housing, the drive ring having an internal thread, the radially inwardly directed projections contact an outer surface of the drive ring to define a plurality of hydraulic chambers, a plurality of radially outwardly extending vanes are located on the drive ring, one of the vanes extending into each of the hydraulic chambers and contacting an inner surface of the outer wall to divide each of the hydraulic chambers into first and second chamber portions; a control valve adapted to control a flow of pressurized hydraulic fluid from a pressurized hydraulic fluid source so that (a) pressurized hydraulic fluid flows to the first chamber portions while hydraulic fluid in the second chamber portions is allowed to drain, causing the drive ring to rotate in a first direction, (b) pressurized hydraulic fluid flows to the second chamber portions while hydraulic fluid in the first chamber portions is allowed to drain, causing the drive ring to rotate in a second direction opposite the first direction, or (c) hydraulic fluid in the first and second chamber portions is held in the chamber portions, fixing the drive ring in position; and a drive nut having external threads located within the drive ring with the external threads engaging the internal threads of the drive ring so that rotation of the drive ring causes an axial displacement of the drive nut, and at least one actuator pin connected to the drive nut that is adapted to extend into the water pump housing to actuate the variable flow impeller.