Solid babbitted bearings of babbitted cast iron should be used on slow speed shafting under 4A in. diameter. Lubrication is by grease cup or plain oiling. The split flat box type of babbitted cast iron, furnished with a cap, is employed where moderate powers and speeds are involved, but not on shafting over 3-1-8 in. diameter. Grease or oil is used as a lubricant.
The self-oiling rigid pillow block type of babbitted cast iron is designed to feed the oil to the shaft, by the ring, chain, collar or capillary method. This type should be lubricated by the ring, chain or collar method up to I io r.p.m. Above this speed the capillary system should be used.
The angle self-oiling rigid pillow block type is similar to the self-oiling rigid pillow block except that the split is at an angle of approximately 45°. This bearing should be employed when a severe power pull is directly on the cap.
The ball and socket self-oiling pillow block type is of cast iron construction, is equipped with ring or capillary oiling features, accommodates itself to shaft movement and possesses vertical adjustment. It is made in sizes from in. to 4-14 in. diameter. It is employed for shafting supported from concrete piers or timbers and particularly on line shafting supported from walls of buildings.
The adjustable drop hanger is designed to support line shafting. It can also be used for head, jack or counter shafting. It is con structed of cast iron and equipped with a self-oiling bearing. The ball and socket type has vertical adjustment through threaded plungers and side adjustment through slotted holes in the base. The 4-point suspension type can be adjusted both vertically and horizontally but the bearing is held more rigidly than that of the ball and socket type. These types of hangers are manufactured for shafting 14 in. to 6 in. diameter.
The adjustable ball and socket post hanger type is of cast iron and is equipped with a self-oiling bearing. It is designed for head and line shafting that must be supported from columns. It has vertical adjustment and the bearing can arrange itself to the shaft movement. It is made for shafting i in. to 6 in. diameter. (See BEARINGS.) Transmission by chain has progressed to the extent that there is a type of chain for most any service. The general advan
tages of chain driving are: (I) very high efficiency; (2) relatively high speeds available; (3) reversability; (4) unaffected by heat, cold or moisture; (5) wide power transmitting range; (6) a posi tive velocity ratio; (7) utility on short or long centres; (8) security from slippage.
Steel Roller Chains.—While malleable iron chains have given satisfactory service for the transmission of power in their field, a demand for chains which will operate at higher speeds and carry heavier loads was responsible for the development of a more accurate steel chain. These chains range from a rugged low speed class to machine finished high speed chains.
Finished steel roller chain is intended for general power trans mission purposes and operates on accurately cut sprocket wheels. This chain is manufactured in a number of pitches ranging from to 4 inches. It is constructed with special rolled steel, heat treated side bars. The pins are made from alloy steel hardened and the bushings are steel, case hardened. The rollers are high carbon steel, heat treated and can either be made curled or solid.
It can be had either riveted or detachable and is made in single or multiple widths. It is possible to operate this chain at i,000 f.p.m. and with ratios up to Io to I, but it is more desirable from an economical and long life standpoint to limit its operating speed to approximately 700 r.p.m. and its ratio to 7 to I.