| 摘要 |
A rotary flow control valve (10) including a valve spool (12) which is rotated back and forth to move a port (12b) in the valve spool (12) into and out of alignment with the main fluid passageway (20a) of the valve (10) to selectively open and close the valve (10). The spool (12) has a pinion gear (12c, 12f) at each end of the spool (12) and each pinion gear (12c, 12f) is engaged by a pair of racks (40a-40e) with the racks (40a-40e) in a pair moving at any given time in opposite directions. Each rack (40a-40e) is constitued by spaced rack teeth (40e) formed in the side wall (40d) of a piston (40) slidably mounted in a cylinder bore (16b, 16c, 18b, 18c) in the valve body (16, 18), and the rotaiton of the valve spool (12) is achieved by selective routing of pressurized fluid to the cylinder bores (16b, 16c, 18b, 18c) containing the pistons (40) defining the racks (40a-40e). |
