GB1120941A - Improvements in and relating to propulsion units for ships - Google Patents

Abstract

1,120,941. Variable-pitch marine propellers. YARROW & CO. 8 July, 1965 [8 April, 1964], No. 14529/64. Heading B7V. In a ship, means are provided for controlling the pitch of at least two variable-pitch propellers 12, 18, Fig. 1, in relation to the angular position of a rudder means in such a manner as to prevent the propellers opposing the steering action of the rudder means. The propellers may be driven by either a main prime-mover 1, e.g. a diesel engine, or a subsidiary primemover 2, e.g. a gas-turbine engine, through a clutch 3 or 5, and a gear train 6-10 and 13-16, the clutches being arranged so as to prevent engagement of both of them simultaneously. Alternatively, the propellers may be driven by either one or both of two main prime-movers (19, 20), Fig. 3 (not shown), or a subsidiary prime-mover 2, through a corresponding clutch, or clutches, 5 (23 and/or 28) and a gear train 10, 16 (20, 21, 22, 24, 25, 30, 32). The ship may be furnished with three prime-movers, e.g. gasturbine engines, which may be identical to one another, clutches associated therewith being arranged such that the propellers can be driven by any combination of the prime-movers through a suitable gear train. The means aforesaid for controlling the pitch of the propellers 12, 18 or that of two similar propellers 33, 34, Fig. 5, may comprise slidable members, or slides, 43, 51 coupled by levers 42, 50 to pitch-control boxes 41, 49 on a pair of propeller-shafts 35, 36, said slides being mounted on plungers 44, 52 that are lodged in cylinders 47, 54 hydraulically or pneumatically connected to a bridge control 48 for regulating the pitch of the propellers independently of each other. When a pair of rudders 40 are angularly displaced from a fore-and-aft position in one direction or the other, one of two cams 56, 57 attached to a rudder-coupling bar or tiller link 55 depresses a plunger 56a or 57a, that is lodged in a cylinder 56b or 57b, hydraulically or pneumatically connected to a plunger 60 or 61, which engages with the lever 42 or 50, adjacent thereto, whereby the pitch of the associated propeller is reduced sufficiently to prevent the propellers opposing the steering action of the rudders. Alternatively, the levers 42, 50 carry slides (62, 64), Fig. 6 (not shown), which are coupled to the plungers 44, 61 and 53, 60, respectively. As shown, the propellers 33, 34 are driven by a single prime-mover 38 through a clutch 39 and a gear-box 37. The connections between the various plungers and the control 48 may be electrical instead of hydraulic or pneumatic. Any of the prime-movers may be constituted by a steam-turbine engine or a reciprocating- piston steam engine, or may be replaced by an electric motor.