FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1918
1918 - 0074.PDF
JANUARY 17, 1918- THE 260 H.P. MERCEDES AERO ENGINE. (Continued from page 37.) Crankshaft —The six-throw crankshaft, which is of sunk in the crankshaft parallel to the taper. The very massive design, weighs no less than 139.5 lb., front flange is fitted on to the boss by six stepped including the propeller boss. The cranks are set serrations or grooves, each 29 mm. wide, and is clamped at 120 degrees, and the diameter of both crankpins to the propeller by six 18-mm. bolts on a 230-mm. and journals is 64 mm. The length of the front diameter circle. The propeller boss and the front journal bearing next to the propeller is 140 mm., and flange are both locked on the shaft by the usual the other crankshaft bearings is 64 mm. The thick- ness and the width of the crank webs increase towards the front end of the crankshaft. The thickness of the front web is 29 mm., that of the second is 28 mm., Mercedes locking device, shown in the drawings of the boss (Fig. 15). Crankcase.—The very clean design of the crankcase casting is evident in the photographic views of the The crankshaft of the 260 h.p. Mercedes engine. whilst the remainder are all 27 mm. in thickness. The crankshaft is bored and the webs drilled with oil passages leading from the hollow journals to the crankpins for lubricating the big end bearings in the usual manner. The holes bored in the journals and crankpins are of decreasing diameters, according to their distance from the oil pump and main delivery, as follows :—• Internal diameter of Hollow Crankshaft JournalsProp. end. i 2 3 4 5 6 35 mm. 35 mm. 35 mm. 38 mm. 40 mm. 41 mm. Oil pump.Internal diameter of Hollow Crankpins Prop. end. 1 2 3 4 s 6 32 mm. 33 mm. 35 mm. 38 mm. 41 mm. 43 mm. Oil pump. engine. It is of very light section considering the size of the engine, the average thickness of the walls of the casing being 6 mm. The top and bottom halves are bolted together in the usual way by 26 10-mm. hollow bolts through the flange on the centre level of the crankshaft. The crankshaft main bearing caps are cast as part of the bottom half of the crank chamber. The long 20-mm. bolts which secure the bearing caps at the bottom pass through the top half of the crankcase and act as the holding-down bolts for the cylinders, which are held in position by tri- angular bridge clamps. The bottom ends of the cylinder barrels extend past the base flanges, and fit into the top of the crankcase; the holding-down m •— 1-3 ••• m " . /^4__Sjm[|_0in£vei Fig. 15.—Arrangement of propeller boss. The ends of the hollow journals and crankpins are plugged with sheet steel caps which are driven into the cranks, and then expanded into an annular groove cut made the holes bored in the cranks. To take the propeller thrust, a single thrust ball race no mm. in diameter is provided on the front end of the front journal bearing, and mounted in a split cage which is held m the housing of the crankcase halves Propeller Boss.—The propeller boss, which is mounted on a taper of the crankshaft, is secured bv a single key 120 mm. long and 13 mm. wide, which is frpn -•cz Ptlumr. Fig. 16.—Diagrammatic section of oil pump.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
