37
BXT Series
7.6.1 Sheave Alignment
A set of V-belts transmits rotational power to the rotor. They
must be kept properly tensioned and the sheaves aligned to
obtain the expected performance and life.
For maximum accuracy, have your sheaves aligned with a laser
alignment tool. Contact your dealer for information on laser
alignment.
Alignment may be carried out using a straight edge, to check the
alignment, follow this procedure:
1.
Clear the area of bystanders, especially small children.
2.
Turn machine off, stop engine, remove ignition key and
place in pocket and wait for all moving parts to stop.
3.
Remove the belt guard and upper belt guard.
4.
Have a straight edge at least 50" (127 cm) in length.
5.
Place the straight edge along the face on the back of the
clutch, and place the opposite end along the back face of
the rotor sheave.
6.
Check to see if there is a gap between the straight edge and
the clutch or the sheave, measure the gap (A).
7.
If there is more than 1/32" (.8 mm) offset, adjustment is
required.
8. To adjust alignment:
• Loosen the set screw on the bushing attached to rotor
sheave.
• Remove the 3 hex bolts on the bushing, and thread
them into the tapped holes on the bushing.
• Tighten the hex bolts progressively with 1/4 turns until
bushing is free from the sheave taper.
• Move the sheave to the required position
to align the belt.
• If the offset is 1/32 (.8 mm) or less, then no more
adjustment is necessary.
• Align drilled holes with tapped holes on the sheave,
replace and hand tighten the 3 hex bolts.
• Tighten the set screw and recheck alignment.
• Carefully tighten hex bolts progressively (1/4 turns)
and uniformly until firmly seated.
• Recheck belt tension and assemble belt guards.
Note: movement of the sheave may occur when
tightening the bushing, some allowance for
movement may be required.
Fig. 25 –
BELT DRIVE SYSTEM
Rotor
Sheave
Centrifugal
Clutch
Belt Drive
Straight
Edge
Set Screw
Bushing
Centrifugal
Clutch
Top view of belt drive system
A
Rotor
Sheave
Straight
Edge
A
