Electric Hoist- Motor Modification & Upgrade
Motors are single phase, 120 Vac/ 60Hz, permanent -split phase- capacitor types, with forward and reverse rotation.
The motor gear boxes have an output speed of 60 RPM @ the drive shaft, providing a roof motion of 20 ft / min.
Motors are available in 5/8 hp and 1-1/8 hp, producing 400 in lbs and 800 in lbs of torque respectively. This provides enough power for most roll off roof designs in the range of 100 to 800 sq ft. (500 - 5,000 lbs).
The heaviest roof to date, with an MVO system, uses a 1-1/8 hp motor, driving a 4,000 lb roof. (see this link)
To use the motors with a pinion gear or chain sprocket requires machine work on the gear box and output drive shaft.
The motor modification outlined below is fot the Heavy Duty 1-1/8 HP Motor. The same steps are required for the Standard 5/8 HP Motor with a slightly smaller Bearing Assembly. The following shows the progression of dis-assembly, re-assembly and precision machine work required:
(2) The Gear Box must be completely disassmebled........................................... All grease needs to be removed
(3) Gear Box disassembled and a one ton arbor press used to remove the drive shaft from gear.
(4) Disassembly, often leaves scoring to be polished out........Shaft machined to fit extra bearing + pinion drive gear.
(5) New Bearing Plate machined for the new support bearing...........Casting is machined flat for new bearing plate.
(6) Mounting holes for new bearing assembly are drilled and tapped.......Bearing assy machined on back side to fit.
(7) All parts are cleaned and ready to reassemble
(8) Re-pack new grease and reassembled with new bearing plate, pinion drive gear + New Steel mounting plate.
With the extra (2nd) bearing support, the motor shaft will remain ridged without any deflection. This will provide precise engagement with the rack, less wear and increased life of the gear box..
(1) Motor with hoist is disassembled from its housing.