| 摘要 |
828,942. Axial flow pumps; hydraulic turbines. HATCHER, E. C. April 14, 1958 [April 18, 1957; July 16, 1957], Nos. 12757/57 and 22515/57. Classes 110 (1) and 110 (3). [Also in Group XXXIII] In a pump or turbine having variable-pitch blades 2 (Fig. 1), an hydraulic motor for adjusting the pitch of the blades comprises a movable cylinder 13 operatively connected to each of the blades and a piston 10 movable in the cylinder and also operatively connected to each of the blades, the load for controlling the pitch of the blades being shared between the said cylinder and piston. The roots of the blades are bolted at 3 to discs 4 rotatable in bearings 5 secured to the hub 1. Each disc carries two crank-pins 6 (see also Fig. 2), one of which is connected to a crosshead 8 on the piston-rod 9 of the piston 10 and the other to a cross-head 11 carried by an extension 12 of the floating cylinder 13. A tube 17 in the rod 9 extends through the hollow propeller shaft 18 (see also Fig. 3) and is coupled at 27 to a link 42 of a linkage 39-42 through which a control lever 38 actuates a reversing valve 22 for admitting and exhausting pressure fluid through ports 23, 24 in communication with said motor. The port 24 communicates via port 26 in coupling 27, interior of tube 17, and port 30 in rod 9 with the space 7 on one side of the piston 10. Port 23 communicates via a space 21 around the tube 17, ducts 31, pipes 33 and ducts 34, 36, 37 with the space X on the other side. The link 42 serves as a feed-back device which centralizes the valve 22 in a predetermined position after piston 10 and cylinder 13 have moved to adjust the pitch due to movement of the control lever 38. Any tendency to change the established pitch moves tube 17 axially, hence lever 40 is rocked about its pivot 43, thus operating valve 22 to connect said tendency, the lever 40 acting as a differential device. A spring-loaded valve 54 in a duct 31 leading to a pipe 33 co-operates with a bore 57 to maintain the space Z full of oil, at a head determined by a gravity tank 51 when the pump 48 is not operating. |
