Martin Sprocket & Gear Variable Pitch Sheaves - Manual

Do not operate sheave with flange
projecting beyond the hub end.
Martin
Mounting and Adjusting Procedure
Variable Pitch Sheaves
Single Groove Sheaves Without External Key:
Mounting:
1. Make sure that the shaft, sheave bore, key and keyway are free of burrs and paint.
2. All sheaves should be mounted on the motor or driving shaft with the end containing the
setscrew “R” toward the motor. Be sure setscrew “R” is well over the shaft.
3. Fit shaft key “C” between sheave and shaft. Lock setscrew “R” in place. Wrench torque
110 in.-lb. minimum – 130 in.-lb. maximum.
4. Be sure both driving and driven sheaves are in alignment and that shafts are parallel.
5. Total axial and parallel misalignment must not exceed 1⁄4°.
Adjusting:
1. Loosen setscrew “V” in movable flange of sheave.
2. Adjust sheave pitch diameter for desired speed by opening rotating parts by half or full
turn increments from closed position. Do not open more than five full turns for “A”
belts or six full turns for “B” belts.
3. Tighten setscrew “V” over a flat in the hub to 110 to 130 in.-lb.
4. Put on belts and adjust belt tension. (Do not force belts over grooves.)
5. Future adjustments should be made by loosening the belt tension and increasing or decreasing the pitch diameter of the
sheave by half or full turns as required. Readjust belt tension before starting drive.
6. Be sure that key is in place and that all setscrews are torqued properly before starting drive. Check setscrews and belt tension
after 24 hours of service.
Single Groove Sheaves With External Key:
Mounting:
1. Make sure that the shaft, sheave bore, keys and keyways are free of burrs and paint.
2. All sheaves should be mounted on the motor or driving shaft with the end containing the
setscrew “R” toward the motor. Be sure setscrew “R“ is well over the shaft.
3. Fit shaft key “C” between sheave and shaft. Lock setscrew “R” in place. Wrench torque
110 in.-lb. minimum - 130 in.-lb. maximum.
4. Be sure both driving and driven sheaves are in alignment and that shafts are parallel.
5. Total axial and parallel misalignment must not exceed 1⁄4°.
Adjusting:
1. Loosen setscrew “V” in movable flange of sheave and pull out external key “H”. (This key
projects a small amount to provide a grip for removal.)
2. Adjust sheave pitch diameter for desired speed by opening rotating parts by half or full
turn increments from closed position. Do not open more that five full turns for “A”
belts or six full turns for “B” belts. (Except 1VP34 - 5 turns.)
3. Replace key “H” and tighten setscrew “V” to 110 to 130 in.-lb.
4. Put on belts and adjust belt tension. (Do not force belts over grooves.)
5. Future adjustments should be made by loosening the belt tension and increasing or decreasing the pitch diameter of the
sheave by half or full turns as required. Readjust belt tension before starting drive.
6. Be sure that all keys are in place and that all setscrews are torqued properly before starting drive. Check setscrews and belt
tension after 24 hours service.
SINGLE GROOVE WITH FLAT
R
V
C
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WARNING: Because of the possible danger to person(s) or property from accidents which may result from
the improper use of products, it is important that correct procedures be followed: Products must be used in
accordance with the engineering information specified in the catalog. Proper installation, maintenance and
operation procedures must be observed. The instructions given above must be followed. Inspections should
be made as necessary to assure safe operation under prevailing conditions. All rotating power transmission
products when used in a drive are potentially dangerous and must be guarded by the user as required by
applicable laws, regulations, standards, and good safety practice. (Refer to ANSI Standard B15.1.)
Key “H” projects to provide a grip for
removal.
Do not operate sheave with flange
projecting beyond the hub end.