Clarifier and thickener drive units provide the rotational force necessary to turn the rake arms in a circular basin. The rotating rake arms transport settled solids to the center of the tank for removal.
Customers have been coming to WesTech since the 1970s for precision bearing drives, as part of the company’s high-quality process equipment offerings for liquid-solids separation. Our drive gives you a flexible design, precision components, and strict quality control. WesTech guarantees a long drive life and the best fit for your process equipment needs. We stand behind our equipment, which has proven to meet the toughest requirements.
One of the unique advantages of premium WesTech drives is their great flexibility in design. This flexibility allows the engineer to select a drive that best matches the environmental and mechanical requirements.
Because drive units are applied in water and wastewater treatment plants, as well as industrial facilities, WesTech has developed a premium drive unit for each application. WesTech drive units can be designed for torque requirements from 1,000ft-lbs to 6,000,000ft-lbs.
WesTech's thorough design and meticulous component selection yields a strong, reliable, premium-quality drive that will provide a long service life with minimum maintenance. Your drive unit will be delivered to the job site completely assembled, shop tested, and ready to be installed.
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WesTech offers two main drive types: the Shaft Drive and the Cage Drive. The selection of the drive type depends on how the rotating mechanism will be supported in a given application.
Cage Drive: A cage drive unit rests on a stationary column mounted in the center of the tank. A half or full-span bridge then attaches to the robust housing of the drive unit. This column-mounted drive transmits power to the sludge collection system through a center cage mechanism.
Shaft Drive: A shaft drive works well in smaller-diameter tanks where the entire mechanism is supported by a full-span bridge. This bridge-mounted drive transmits power to the sludge collection system through a center drive shaft.
Concentric Dual Drive: Dual drives are multi-tasking units that provide independent mixing in the feedwell, while the rakes transport settled solids along the floor. Supplied in both shaft and cage designs, dual drives are commonly used in WesTech’s Solids CONTACT CLARIFIERS™ and Flocculating Clarifiers. Two distinct motor/reducer assemblies are combined into one unit, which allows for independent speed control of the mixer/flocculator and the rake arms.
D25 Gearless Shaft Drive: The D25 drive has the motor and speed reducer assembly directly mounted on the precision bearing for low-torque applications. The precision bearing eliminates the need for a submerged bearing that is common with other gearless drives and some strip-liner drives. In these low-torque applications, the main gear-to-pinion reduction is not needed.
Direct Shaft Drive: For light-duty applications, WesTech provides a drive unit that connects the center drive shaft directly to the output of the cycloidal speed reducer.
Peripheral Drive: Rim drives travel along the periphery of a concrete tank and pivot the sludge collection system around the center support column. For large-diameter tanks, rim drives can provide both mechanical and cost advantages.
WesTech offers precision bearings in its drive units, a better choice when compared to the primitive strip-liner bearings of other units.
Precision Manufacturing Tolerances: The precision bearings WesTech uses in its drive units are ideal for high load, high speed applications and are manufactured by recognized bearing companies. The use of these precision bearings is widespread among larger and more heavily-loaded clarifier and thickener mechanisms common to the metallurgical industries, in addition to overhead cranes, gun turrets, and track hoes.
Exceptional Long Life and Load Capacities: Instead of applying the bearing load in four points on the bearing balls as with the old-style strip-lined bearings, the precision bearing utilizes a full band contact race with hardness equal to that of the strip liners. Calculated bearing life is at least five times that for strip liners of the same ball size and diameter. The need for splitting gears and housings is eliminated because of the superior service life.
Overturning Load Capacity: Strip-lined bearings have no inherent overturning load capacity and must rely on the mechanism weight alone to hold the bearing race together. This capacity of the precision bearing makes possible tank settling, misalignment, and lack of precision leveling of the drive during installation and operation a far less determining factor in premature bearing failure.
Even Load Distribution: The rotating turntable of the strip-liner can easily separate from its stationary base and cause a point load on one or two bearing balls. This separation can occur with the simple action of a skimmer riding over a scum box. The locked ring design of the precision bearing eliminates damaging point loads by equally transferring any unbalanced load to the entire group of bearing balls.
Main Bearing Protection: WesTech gear housings protect the bearings from dirt and contamination using designed neoprene seals and gaskets, whereas strip-lined bearings typically only use a loose felt seal. WesTech precision gears also allow the bearing to run in a separate, sealed grease cavity, which achieves additional protection from contamination.