The DBS Pier-Mounted dual concentric drum output drive unit represents state of the art in reliability and performance. Two independent drive units are stacked concentrically together to drive a rake mechanism and a turbine. The rake drive is a low-speed, high-torque, totally enclosed gear drive with positive output torque overload protection. The turbine drive is a heavy-duty, higher speed, totally enclosed gear drive. The specially designed final output precision bearings provide superior life and reliability in excess of 100 years. The forged alloy steel gears and pinions are designed for a minimum life of 20 years.
DBS Pier-Mounted dual concentric drum output drive units are typically used on solids contact and flocculating clarifiers or softeners. The drive unit is supported by a column in the center of the tank. DBS drive units are mounted on tanks that range from 40 to 300 feet (12 to 100 m) in diameter.
DD-Series Industrial Drive Capacity:
- 10-year warranty on main gear-bearing
- Rake drive has accurate torque gauge calibrated in ft-lbf, N-m
- or any units required
- Forged alloy steel main gear-bearing designed for over 20 years of life as calculated per AGMA 2001-C95
- Variable speed turbine drive is standard
- Alarm and cutoff switches and maximum torque-limiting via shear pin or pressure relief valve
- Permanently lubricated rake intermediate gear box, oil bath lubricated main gear housings
- Machine frame
- Drive drum, rake
- Main gear-bearing, rake
- Drive drum, turbine
- Main gear-bearing, turbine
- Pinion support bearing, turbine
- Pinion, turbine
- Primary speed reducer, turbine
- Primary drive, turbine
- Oil drain, turbine
- Oil drain, rake
- Primary speed reducer, rake
- Planetary gearbox, rake
- Pinion, rake
- Pinion support bearing, rake
E-type primary speed reducer
The E-type design uses helical gears for speed reduction. It has alarm and cutoff switches and a shear pin to provide triple protection of the drive unit. This design is used where the output speed is outside the limits of the F-type primary speed reducers or when an electro-mechanical type drive unit is desired.
F-type primary speed reducer
The F-type design uses a hydraulic pump-motor combination for speed reduction. It has alarm and cutoff switches and hydraulic relief (equivalent to a shear pin in the E-type primary speed reducer) to provide triple protection of the drive unit. This design is positive torque-limiting and will operate under stalled and semi-stalled conditions. Optional reversing rotation and variable speed are available. The torque indication and protection system is equally accurate for operation in either direction.
H-type primary speed reducer
The H-type design has all the features of the F-type primary speed reducer. It uses a stand-alone industrial hydraulic power unit. This design is used on higher horsepower and multiple pinion drive applications.
W-type primary speed reducer
The W-type design uses helical gears for speed reduction. It has shear pin and shear pin activated cutoff switch to protect the drive unit. This is simplified E-type design used where a torque gauge and adjustable alarm switch are not required.
Mechanical type variable speed reducer
The mechanical variable speed reducer is a ring-cone or a disc design. The output speed varies as the pitch-line distance between two rotating components decreases or increases. The speed variation is adjusted by turning a hand-wheel on the reducer. These reducers include a standard NEMA C-frame on both the input and output connections for easy installation and removal. The reducers provide a 5:1 variable speed range.
Electrical type variable speed reducer
The electrical type variable speed reducer is a variable frequency drive (VFD) that controls the output speed of the electric motor. The VFD can be mounted near the drive unit or at a remote location. VFDs provide a clean, maintenance- free, and economical way of attaining variable speed. Standard features include forward and reverse, speed indication, motor overload protection, soft-start, 4-20 mA signal, and monitoring of operating conditions. These reducers provide a 5:1 variable speed range or 10:1 when used with an inverter duty motor.
Hydraulic type variable speed reducer
The hydraulic type variable speed reducer is a stand-alone industrial hydraulic power unit with a variable volume piston pump and hydraulic motor combination for speed reduction. This design is used when the rake primary speed reducer is an H-type design. A screw located on the pump is turned to change the stroke of the pump pistons and vary the amount of oil delivered to the hydraulic motor, thus varying the final output speed of the drive unit. These speed reducers provide a 3:1 variable speed range.
Example: Model D30-AF-D3015
D is for a pier-mounted drive unit; 30 is the size of the final rake gear pitch diameter in inches; A is the size of the secondary speed reducer; F is the type of the primary reducer; D is for turbine drive; 30 is the size of the turbine gear pitch diameter in inches; 15 is the turbine horsepower.
- Alarm and cutoff switches
- 3 sets of O&M manuals
- 6″ torque gauge indicating real torque (not available on H-type primary reducer)
- 4-20 mA torque transducer
- Bi-directional operation (available for F and H-type primary reducers)
- Loss motion switch
- 4-20 mA lift position transducer
- Variable speed, turbine
- Variable speed, rake
- Special coating
- Special electric motor
- Oil heater (available for F and H-type primary reducers and main gear housing)
- Oil temperature switch
- Oil level switch
- Explosion proof switches