Principles of naval engineering - Historic Naval Ships Association

PRINCIPLES OF NAVAL ENGINEERINGDISK CLUTCH-7/-BEARING CAGETOGGLE ASSEMBLY.CONECLUTCHFRONT COVERENGINE SHAFTCOLLAR ANDYOKEREDUCTIONGEAR SHAFTPROPELLERDRIVE SLEEVEENGINE SLEEVEPINION GEAR (LONG)PINION GEAR (SHORT)Figure 22-37.— Cutaway view of Joe's clutch and reverse gear.75.254propeller drive sleeve. In addition, tiie force ofthe plungers on the disk clutch is transmittedto the bearing cage, which is a cylinder containingthe reverse gear pinions. The bearingcage, in turn, is pressed against the cone clutch.Thus, the cone clutch is forced against its seatin the front cover of the gear box, clamping theclutch to the front cover by friction. Since thecone clutch is in mesh on its inner surface withthe engine sleeve, which is in turn keyed to theengine shaft, the front cover is now locked tothe engine shaft. The front cover must rotatewith the engine shaft, in the same direction.Now, since the front cover is bolted to thedrum housing, which is locked to the propellerdrive sleeve by the disk clutch, there is a completelock from the engine shaft to the reductiongear shaft. The entire assembly rotatesas a unit in the same direction as the engineshaft; this motion gives the propeller a forwardrotation.When the operating lever is thrown into thereverse position, the plungers are withdrawn.and both clutches are disengaged. At thesame time the brake band is tightened aroundthe drum, holding the drum stationary. Thebearing cage is locked to the drum. The coneclutch rotates freely out of contact with the frontcover. Then the motion from the engine shaft tothe reduction gear shaft is transmitted throughthe inner gear assembly.The reverse gear pinions are held in thebearing cage, which is stationary for reverserotation. There are three short pinions, eachin mesh with the small inner gear of the enginesleeve. The three short pinions mesh with thethree long pinions, each of which also mesheswith the propeller drive sleeve gear. Enginerotation is transmitted from the engine sleeveto the short pinions, to the long pinions, and tothe propeller drive sleeve. These pinions (geartrain) cause the reduction gear shaft to rotateopposite to the engine rotation (see arrows infig. 22-37), and give the propeller a reverserotation.586