Pictorial: DF520 Clutch Assembly W/ Part Numbers

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Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove
Location: Lehigh Valley, PA

Post By: stoker-man » Thu. Dec. 27, 2007 7:16 pm

The Stoker Clutch Assembly

Pictorial: Showing all parts, part numbers and sequence of assembly

Parts and efm part numbers for the clutch assembly. Unless abused, the clutch assembly could last for the life of the unit.

The description and part numbers in order, beginning at the top left of the picture and working across to the bottom left of the picture:

9433944 Ratchet Drum
35426 Retaining Ring
33209 Brass thrust washers
9433922 Clutch Shaft Spacer
9433753 Clutch Shaft Coupling
35659 Retaining Clip
9433767 Shear Collar
35656 Shear Pin
82711 Cotter Pins (3/16 X 1 ½ )
9433763 Bracket Bearing and Bushing assembly
9433721 Feed Control Collar
85002 Thumbscrew (5/16 X 2)
9433725 Steel Guide
83201 Drive screws (2) (Shown under the Steel Guide)
9433720 Feed Lever
9433741 Connecting rod stud
81904 5/8 X 18 Jamb Nut
9433730 Check Pawl Stud
9433731 Check Pawl Stud
82522 Washer
82716 Cotter Pin
9432911 Drive Pawl
9433733 Drive Pawl Stud
81802 5/16 X 18 Nut
These are a combination of more than one part and are sold as kits. Note the K after the part number.

The kit (9433762K) on the left consists of 4 item numbers:

9433721 Feed Control Collar
9433725 Steel Guide
83201 Drive screws (2)
85002 Thumbscrew (5/16 X 2)

The kit (9436271K) on the right consists of 2 item numbers:

9433720 Feed Lever
9433741 Connecting rod stud
The shear collar, shear pin, and retaining clip is attached to the clutch shaft on the left side of the picture. The ratchet drum is held to the feed lever assembly by the retaining ring.

The adjustable feed control collar is installed. Some older model clutch assemblies did not have the feed control collar. It was introduced to reduce the noise of the drive pawl while riding over the top of the drum’s teeth. If an older model stoker has the machined round end on the end of the Bracket Bearing and Bushing assembly, a feed control collar can be added.
The clutch shaft sub-assembly is now placed through the feed lever assembly, thrust washers are added and the rod will be inserted through the Bracket Bearing and Bushing assembly.
The check pawl is adjusted by loosening the large nut and rotating the eccentric check pawl stud to achieve a properly aligned angle between the drum teeth and the pawl.
The addition of the drive pawl is the final step in the assembly.

The complete assembly, showing the clutch shaft spacer and clutch shaft coupling with cotter pins.

EFM Rep.

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