GB975436A - Steering means for ships - Google Patents

Abstract

975,436. Differential gear. INSTITUT FUR SCHIFFBAU. June 29, 1962, No. 25069/62. Heading F2D. [Also in Division B7] In a ship's propulsion unit (see Division B7) having its propeller shaft 21 driven by two oppositely rotating concentric vertical shafts 12, 14 obtaining their drive from a horizontal driving shaft 2 through a bevel gearing, the driving bevel gears 13, 15 on the vertical shafts engage in bevel gears 6, 4 arranged on the driving shaft and adjustable angularly relatively to one another to cause swivelling of the propeller about a vertical axis. The bevel gear 4 on the end 3 of the shaft and the bevel gear 6 on the flange 5 thereof have external and internal teeth 7 and 8 respectively in mesh with intermediate gears 9 on axle pins 10 in the flange 5. The axle-pin 10 of one of the gears 9 has a worm gear 22 which meshes with a worm 23 carrying a bevel gear 26 in mesh with a bevel gear 27 surrounding the shaft 2 like a sleeve and with a bevel gear 28 mounted thereon. The bevel gears 27, 28 have spur gears 29 and 30 respectively with the same number of teeth, and these mesh with two pairs of gear wheels, each pair consisting of a gear 31 and a gear 32 having one more tooth and accommodating a magnetic winding 33. The housing 1 carries magnetic windings 35, 36 opposite gears 31. Normally the gear 9 is held by the worm and worm gear so that the bevel gears 4, 6 rotate with the shaft 2. If the bevel gear 28 is held stationary by its meshing gear 31 due to energising the winding 35, the gear 26 will roll on gear 28, thereby rotating the worm 23 and gear 22 and bevel gear 9, this latter causing angular movement of the gears 4 and 6 relative to each other, thus producing swivelling of the propeller. The swivelling will be in the opposite direction if the gear 27 is stopped instead of the gear 28, this being done by energising the winding 36. This swivelling action is rapid. A slower one is obtained by energising a winding 33 to lock two wheels 31, 32 together. Since one wheel has one tooth more than the other, a slow relative rotation of the bevel gears 27 and 28 relatively to one another (and hence a slow swivelling of the propeller) takes place.