Shuttle hoist, and belt drive motor bushing

THE BUSHING PART NUMBER 54STB603
 

GEAR BOX HOIST WITH #80 ROLLER CHAIN

On Milnor shuttles and elevators using a motor and gearbox with #80 chain for the hoist, the motor to hoist bushing was problematic.  
In normal service the bushing may wear between the motor and gearbox.  The gearbox has a 7/8" bore and the normal motor has a 5/8" shaft.  The original coupling/bushing was brass and PN 54STB601.  This coupling was split and required a separate key.  The fit of these parts was somewhat loose and wallowing of the shaft was common in heavy use.  
The replacement bushing (mid 1998) is steel casting (PN 54STB603) and has an integral internal and external key.  
Later designs called for a slightly larger motor with a 7/8" shaft, thus eliminating the bushing.  The larger motor part number is 39T015DAU.  
Using the smaller shaft and motor is possible.  The bushing can be loctited to the shaft (use 272) to help the loose fit of the parts and may help wear issues.  
GLL 2018 derived from knowledge and notes from 1999. 

GEAR REDUCERS ON SOME CONVEY40/42/44/46/48/50/60 BELT DRIVES 

Milnor has a series of gear reducers used on conveyors that have a .875" (7/8") bore.  As some of the assemblies use corresponding motors that have a .625" (5/8") shaft diameter, we use bushing 54STB603 to complete the power transfer. 

Hower, after much use the bushing key can sheer off.
Or, after a lot of stress, the bushing can break in pieces.

here is a list of the gear reducers that have the .875" bore with kits that include the 54STB603 bushing. 

GEAR REDUCERS	GEAR REDUCERS IN KITS
54STB33230 REDUCER 30:1 SF732-30T-B7-G	54STB3323A REDUCER + 7/8-5/8 IN-ADAPTER CONTAINS BUSHING AND KEY 15E229 PICTURED BELOW
54STB33240 REDUCER 40:1 SF732-40T-B7-G	54STB3324A REDUCER + 7/8-5/8 IN-ADAPTER CONTAINS BUSHING AND KEY 15E229 PICTURED BELOW
54STB33250 REDUCER 50:1 SF732-50T-B7-G	54STB3325A REDUCER + 7/8-5/8 IN-ADAPTER CONTAINS BUSHING AND KEY 15E229 PICTURED BELOW
54STB33260 REDUCER 60:1 SF732-60T-B7-G	54STB3326A REDUCER + 7/8-5/8 IN-ADAPTER CONTAINS BUSHING AND KEY 15E229 PICTURED BELOW