Assembly Drawings 329
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d:\N-Design\Des18-4.pm5
18.5.8 Swivel Bearing
It is used to support shafts where there are possibilities of misalignment. These, like plummer
blocks, may be placed at any desired location.
Figure 18.46 shows the details of a swivelling or self-aligning bearing. If consists of the
fork 3 which is fitted into the body 1 by means of the spindle 4, and by adjusting the spindle
position, the fork may be elevated to any required height. It is then free to swivel in a horizontal
plane. The bearing is then supported in the fork by means of two set screws 8. The connection
between the fork and the screws is such that, the bearing is free to swivel in a vertical plane. The
flexibility in both the planes is thus made available.
Accurate alignment may be obtained by screw height and slide adjustments. After the
required adjustments are made to suit the shaft position, these are then locked. The lock-nut 5
with the set screw 7 passing through it, and another set screw 6 passing through the body are
used to lock the height adjustment. The tips of these set screws tighten upon the brass disks 9
and 10, thus preventing damage to the threads on the spindle. Hexagonal nuts 11 are used with
the side adjustment set screws to lock them in position. The gun metal bush 12 is used inside the
bearing.
Exercise
Assemble the parts of the swivel bearing shown in Fig. 18.46 and draw, (i) half sectional view
from the front, with left half in section, (ii) view from the left and (iii) view from above.
18.5.9 Foot-step Bearing
This consists of two bearings, one in the form of a disc and the other in the form of a bush. It is
intended to support a vertical shaft under axial load. The axial load is resisted by the disc shaped
bearing provided at the bottom of the shaft, whereas the bush bearing resists radial load on the
shaft.
The details of a foot-step bearing are shown in Fig. 18.47. The disc 3 is located in the body
1 after placing the pin 5 in the corresponding hole in the body. This prevents the rotation of the
disc, due to rotation of the vartical shaft. Bush 2 is now placed in the body such that, the snug on
the bush rests in the recess provided in the body. This assembly is now ready to support the
vertical shaft 4. Figure 12.9 shows the assembly drawing.
Exercise
Assemble the parts of a foot-step bearing, shown in Fig. 18.47 and draw, (i) sectional view from
the front and (ii) view from above.
