GB474790A - Improvements in or relating to reversing gear mechanisms - Google Patents

Abstract

474,790. Hydro-mechanical forward and reverse driving-gearing. SINCLAIR, H. May 8, 1936, No. 13116. [Class 80 (ii)] [Also in Group XXXIII] Forward and reverse torques in a driven member are generated at will by means of the hydraulic drag in an hydraulic coupling acting through two friction clutches to produce the two opposing torques simultaneously, one of the torques being annulled by opening its clutch so as to leave the other torque effective. Thus, a worm shaft 16 is driven in either direction at will to operate a ship's rudder post 21 by opening a clutch 12 or a clutch 12<1> of one or other of two trains which is to be rendered ineffective. A shunt-controlled motor 1, which runs slowly when its control arm 43 is in the mid-position shown, drives the impeller 2 of an hydraulic coupling of the kind having a reservoir 5 between the back of the runner 3 and a dished casing 6 fixed thereto, as described in Specification 385,086, [Group XXIX], the working liquid being in part transferred to this reservoir when the rotor 3 is stalled. A torque is thus constantly transmitted through the runner shaft 4 to a bevel gear 9 which applies torque to two bevel gears 10, 10<1> to rotate them in opposite directions. Thus opposite torques are imparted simultaneously to two shafts 11, 11<1> which are normally connected through the two friction clutches 12, 12<1> to two pinions 14, 14<1> in mesh with wheels 15, 15<1> on the worm shaft 16 which is constantly geared to a quadrant 20 on the rudder post 21. Since the pinions 14, 14<1> tend to turn oppositely, both are held fast while slip goes on in the hydraulic clutch. When the ship's wheel 27 is turned to pull a screwed rod 29, a floating lever 31 pivots downwards about a pivot 37, thrusting downwards a rod 33 with a cam plate 34. This pulls right a clutch rod 24 with a stop 25 which opens the clutch 12 against its spring 23. As the rod 33 is displaced it turns the lever 43 which accelerates the motor 1 and the hydraulic coupling now responds to a magnified torque which is transmitted through the other clutch 121 and the pair 14<1>, 151 and on to the rudder quadrant moving it clockwise so that the right end pivot 37 of the lever 31 is depressed through a linkage 40, 39, 38 so as to raise the rod 33 and so return the hydraulic coupling and the motor to stalled position with the rudder locked. Arrangements are described each with a separate hydraulic coupling in series with each friction clutch. Instead of friction clutches, equivalent epicyclic trains, each with its controllable brake, may be used.