POWER TRANSMISSION ELEMENTS AND MECHANISMS 187 



Courtesy Gih Bros. 

 Manufacturing Co. 



Fig. 344. — Another type of seal 

 wherein a bronze ring bears against 

 the shoulder of the shaft. The sealing 

 material is in the form of a dia- 

 phragm of heat-resisting fabric which 

 retains oil in the bearing and excludes 

 dirt. In the flanged member that is 

 screwed to the housing is a series of 

 compression springs which hold the 

 ring against the shaft shoulder. 

 These springs not only take up wear 

 but provide for end play of the shaft. 

 To avoid torsional strain on the dia- 

 phragm, guide pins are used between 

 the outer flange and spring bearing 

 washer. 



Courtesy Naiiona/ 

 Motor Bearing 

 Company^ Inc. 



Fig. 345. — When grease is used as a 

 lubricant, it is sometimes desirable to 

 assemble a single seal to keep dirt 

 from reaching the bearing rather than 

 retain the grease in the bearing. The 

 illustration shows an installation 

 wherein a right-hand spiral groove is 

 cut in the bearing bore to lead the 

 lubricant outward. Surplus grease is 

 forced past the seal, thereby keeping 

 the bearing clean. 



Courtesy of the Chicago 

 f^awhide t^anufacturingCo. 



Fig. 346. — Leather flange seal 

 with garter spring mounted in a 

 flanged end plate. Spring ten- 

 sion is such as to give small 

 area of contact between leather 

 and shaft, thereby minimizing 

 friction. A bronze thrust 

 washer is between the bearing 

 and the bearing housing. 



Washe. 



, Bushings 



Washer 



-Dust 

 seal 

 cup 



Fig. 347. — The labj^rinth seal shown does not rely on nonmetallic 

 materials but on the small clearances with the assembly. A steel washer con- 

 tacting a bronze thrust washer is clamped against the shaft shoulder after the 

 formed dust seal cup is pressed into the counterbored hole. 



Courtesy of the 

 Garlocd: t^anufactur- 

 ing Company 



Fig. 348. — When oil seals are to be 

 installed after a mechanism has been as- 

 sembled or to preclude the necessity of 

 disassembling heavy shafts and bearings 

 when making seal renewals, split seals 

 can be used in such installations. The 

 spreader spring and packing ring are 

 split, whereas the retaining cup is made 

 in two halves. The packing is scarf-cut 

 to form an oiltight joint when assembled. 



Fig. 349. — Another mounting of small worm-drive shaft for 

 domestic washing machine and domestic stoker. The composition 

 sealing material is held against the shaft by a V-formed spreader spring 

 having serrated edges which nest into the sealing ring. The angle of 

 the V in the spring is greater than the groove in the seal so that the 

 fingers of the spring exert a light pressure on the sealing lip. An oil 

 return hole is drilled outside the bearing to relieve built-up pressure 

 against the seal. 



