Joyce CDB3230 - Manual (Page 6)

6
2-3 Disassembly of Ball Screw ComDRIVE® Jacks
First remove the motor and reducer from the Ball Screw ComDRIVE®
Remove the four bolts and washers (item 22 and 23) from the adapter/reducer flange (item
17). The reducer and motor can now be removed from the jack. The motor included with
the ball screw ComDRIVE® is not user serviceable, however, it can be replaced. Loosen
bolts (item 26) to separate the motor from the gear reducer.
Disassembling the ball screw jack portion of the ComDRIVE®
Use the appropriate disassembly procedure. If the ball nut (with the re-circulating ball
bearings) is on the screw outside the sleeve, the jack is a Keyed for Traveling Nut (KFTN)
model. This is also called a “rotating screw” jack. If the ball nut is inside the jack sleeve,
the jack is a translating or keyed model. Handle machined parts with care, and maintain
an “order of disassembly” to aid in re-assembly. Remove all couplings, screw support
bearings, etc. before beginning disassembly.
Disassembly Procedure for KFTN (rotating screw) Models: Sections 3-1 & 3-2
1. Tape or otherwise secure the ball nut (item 35) to the ball screw (item 7). Removal of the
ball nut from the screw would allow all of the ball bearings to be released. If the jack is
equipped with boots, remove the boot clamps, collapse boots, and remove them as
needed.
2. On upright jacks loosen the four set screws (item 5) in the sleeve cap assembly, which
includes the sleeve cap (item 4), bushing, and seal. Loosen the sleeve cap assembly by
rotating counter-clockwise (CCW.)
3. On inverted KFTN models remove the sleeve cap (item 4) by loosening the four set
screws (item 5) and rotating CCW. The inverted model has a solid sleeve cap without a
bushing or seal.
4. On upright KFTN models, the ball screw assembly (with the sleeve cap assembly) can
now be removed from the jack sleeve. The ball screw assembly consists of the ball
screw (item 7), the ball nut (item 35), thrust bearings (item 2), key (item 36) and the
wormgear (item 3). Unthread the wormgear from the ball screw and it will slide off the
end of screw with the upper thrust bearing, then the sleeve cap assembly can be
removed from the ball screw.
5. On inverted KFTN models, the ball screw assembly is removed from the bottom of the
sleeve. First, remove the upper thrust bearing (item 2) and the inverted bushing (not
shown). Push the ball screw (item 7) and the key (item 36), out the bottom of the sleeve.
Remove the wormgear (item 3) and the lower thrust bearing (item 2) from the sleeve.
6. It is not recommended to remove the ball nut (item 35) from the ball screw (item 7)
unless it is being replaced. For instructions on removing the ball nut, see Section 2- 6,
Ball Nut Disassembly and Rebuild.
7. Remove three screws (item 16) from the bearing cap (item 13) on one side and three
screws (item 19) from the adapter cap (item 14) on the other side. Remove the caps
and seals (item 15) carefully to avoid damaging seals. Make sure worm shaft keys (item
21) have been removed first.
8. Carefully remove the shims (item 12) from the jack sleeve, bearing cap, or adapter cap.
NOTE: there will not necessarily be an equal quantity of shims per side. Keep track of
the number of shims on each side of the jack.
9. Remove the worm bearings (item 11). The cup may be press-fit. Use a dead-blow,
plastic or other non-marring mallet to remove the worm (item 10).