Ball bearings shall be of the following types:
22.214.171.124 Ball bearings. -
(a) Single shield, single row, radial, type III class 1 in accordance with Specifica-
tion FF-B-171 or single sealed, single row, radial type III class 6 of Specifica-
tion FF-P-171 having the same envelope dimension as the single shield, single
row, radial, type III class 1 in accordance with Specification FF-B-171.
(b) Radial, single row, both races extended, sealed, cartridge type, type 120 in
accordance with Specification FF-B-171. Where this type of bearing is
utilized, a plate bearing the warning "DO NOT LUBRIGATE" shall be
secured to the end bells.
3. 126.96.36.199 Size and series. - Unless otherwise specified in the contract or order, the bearings shall
oe of the size and series as shown in table B of figure 1 and the applicable table for d. c. motors of Speci -
188.8.131.52.2 Mounting. - The bearings shall be secured on the shaft by means of locknuts and lock-
washers. The pulley end bearing shall be fixed axially in the housing by suitable housing and end cap
shoulders. For gear case motors the front end bearing shall be fixed in the housing. The axial movements
of the shaft shall be not more than 0.010 inch including bearing end play where the application does not
require the end play to be minimized. All fits and tolerance shall be in accordance with Specifica-
tion FF-E-171 (see 184.108.40.206 (b) (l)).
3. 6. 1. 9.3 Heat stabilization. - Bearings operating above 90° C. shall be heat stabilized so that their
dimensions do not increase more than 0.0001 inch per inch of diameter during 2500 hours at 149°C. Where
heat stabilized bearings are used they shall be of the type specified in 3.6,1.9 (b).
3. 6. 1.10 Roller bearing. - When roller bearings are used, they shall conform to Specifica-
tion 42B10 and Specification FF-B-185.
The inside diameter of the oil ring shall be in accordance with table VI.
Table VI - Diameter of oil ring.
220.127.116.11.1 Rings shall have a true circular shape and shall be of uniform cross-sectim. The cross-
section shall preferably be that of a truncated cone with the base on the shaft. Rings shall be machine
all over and shall have all corners rounded. The finish shall be smooth and free from flaws. Split oil,
rings shall not be used.
18.104.22.168 Methods of attaching fans to shaft. - Where fans are not an integral part of the shaft, one
of the following methods shall be used in attaching fans to the shaft.
A key, shaft shoulder and a nut with keyed lockwasher.
A key, shaft shoulders and rings or tubing.
A long key tack welded to the fan and secured in a closed-end key seat.
A Woodruff key with a locked set screw secured on the key. The design shall be
such that the set screw will not produce unbalance.
(e) A split fan with clamping bolts and key.