160 



HANDBOOK OF MECHANICAL DESIGN 



Composition 

 packing rings 



Oil level wiifi 

 coupling al 

 rest 



Oil level when 

 coupling is 

 running 



Fig. 297. — The Poole Engineering & Machine Com- 

 pany uses a two-piece floating sleeve with the internal 

 gear teeth cut at each end, meshing with gear teeth on 

 hubs. Toothed hubs are mounted at the end of each 

 shaft. The hub teeth have spherically formed 

 crowns. The teeth are in mesh around their entire 

 circumference. Compensates for misalignment in all 

 directions without the use of flexing materials. Bear- 

 ing surfaces are lubricated in a bath of oil. Dust is 

 excluded by packing ring at either end. 



Flexible - 

 member 



4 Jaws '^ 



Chain 

 re la i per 

 slol 



lenl 

 , chain 

 (endless) 



Fig. 298. Fig. 299. 



Fig. 298. — A silent chain is used as the flexible member 

 in the Morse Chain Company coupling, the load being 

 distributed over a number of teeth. A series of retaining 

 Hnks, running in the center of one sprocket, keep the 

 chain in place. Flange covers enclose the chain when 

 necessary. 



Fig. 299. — Convex jaw surfaces that exert a rolling 

 pressure when loaded are used in another Lovejoy Tool 

 Works coupling design. The convex surfaces are so 

 proportioned that the compression is uniform over the 

 entire area of each spider arm. The floating spider is 

 made of a resilient material which gives flexibility in all 

 directions. 



Fig. 300.— This T. L. Smith Company type of 

 coupling has a flexible metal ring engaging projections 

 integral with the outer and inner hubs. A packing 

 ring protects the interior from dirt, yet compensates 

 for angular misalignment. The coupling can drive in 

 either direction. 



Fig. 301. — In this Meriam Company design, the inter- 

 nal and external hub is connected by a series of spring 

 steel rollers fitted into semicircular recesses in each hub. 

 The rollers are made of strip steel, wound spirally and 

 ground on the periphery. Quiet operation is secured by 

 packing the interior of the coupling with grease or ground 

 cork. 



