Thermo King SB-190 30, Руководство пользователя

Страница: 77 / 119

Refrigeration Service Operations (Rev. 12/03)
67
Compressor Coupling Installation
(Model 30)
In a tapered fit joint the entire twisting load should be han-
dled by the friction fit between the two tapered parts. The
key is only a backup and is used to index the parts correctly.
When a taper fit is machined and assembled properly a key
is not needed. In fact, if the key is not installed correctly it
may be worse than no key at all! If the key does not fit eas-
ily into the keyway, it will push the tapered components
apart and the reduced friction could lead to slippage and
premature failure.
The following procedure requires the key to be fitted after
the tapers are pulled together with 20 ft-lb (27 N•m) torque.
This insures that the key cannot hold the tapers apart when
the final bolt torque is applied.
Use the following procedure to install a compressor cou-
pling on the compressor crankshaft.
1. Clean the compressor shaft taper and coupling bore
taper with a solvent that leaves no oily residue (such as
naphtha, lacquer thinner, brake cleaner or the like).
2. Inspect both mating surfaces for burrs, oxidation and
other surface imperfections. Dress with crocus cloth if
necessary and re-clean as required.
3. Using no lubricants, set the coupling on the crankshaft
and align the keyways using the Keyway Tool (P/N
204-972). Insert the tapered end of the tool into the
keyway and gently move the coupling on the shaft
while pressing the tool into the keyway. This will align
the keyway in the crankshaft with the keyway in the
coupler.
Keyway Tool P/N 204-972
CAUTION: If you are assembling a used
coupler or crankshaft and the tool does not fit
easily there is a problem with one of the
keyways! Do not remove the coupler and place
the key in the crankshaft keyway and then drop
the coupler on. If the tool does not fit, the key
will not fit, and it will hold the taper in the
coupler off the taper on the shaft. Check both
keyways for burrs or corrosion. A key can be
coated with fine lapping compound and used as
a lapping tool to clean the keyways.
4. Remove the Keyway Tool and check the fit of the new
key (P/N 55-9024). It should fit into the keyway with a
light press fit requiring only a minimum of light tap-
ping. If the key does not fit properly, remove the cou-
pler and inspect the keyways and key for burrs or other
problems. Recheck the fit as shown above.
5. When the key fits properly, remove the coupling and
key from the shaft.
6. Re-install the coupling and align the keyways with the
Keyway Tool.
7. Do not install the key at this time. Install the flat
washer and bolt and pre-torque to 20 ft-lb (27 N•m).
Remove the bolt and washer.
AGA333