F A L K A L I G N M E N T F RE R E E D R IV IV E ™ Gear Drive Technology for Belt Conveyors: Easy Ea sy Installation Combined wi th Lo w Installation Costs and Improved Reliability Reliability Misalignment of connected rotating equipment is one the leading causes of drive system-related failures and downtime in heavy-duty belt conveyor applications. However, that problem may become a thing of the past with the introduction of our new Alignment Free Drive for belt conveyor applications. The Alignment Free Drive eliminates shaft misalignment as a cause of failure and downtime. Simple registered fits and bolt together construction assure quick and proper assembly for trouble-free operation. Heavy-duty belt conveyor systems provide an effective means of moving high volumes of bulk materials in mining, power generation, cement, bulk food processing and other applications. As in every step of the production process, process, companies are continually exploring ways to reduce the cost of material transportation. End users must do everything they can to understand the total costs of conveyor system operations, how that affects cost per ton hauled, and to develop solutions that improve efficiencies, productivity, reliability and reduce costs. Consequently, end users, system designers and component suppliers are working together to understand conveyor system total costs, and create ways to reduce haulage costs. It was with these goals in mind that the Alignment Free Drive was designed. Originally designed designed as part of customized application solutions, Falk Alignment Free Drives are now available as standard product offerings.
Shaft Misalignment Eliminated The alignment-free drive system has been developed to improve reliability, and reduce downtime, installation and maintenance costs. This new drive technology eliminates the leading cause of rotating equipment failure -- shaft misalignment. The new "alignment-free" gear drive technology requires no special shaft alignment or foundation requirements because the gear drive mounts directly to the conveyor pulley shaft. With simple, bolt-on mounting connections, Alignment Free Drive installations are easier and take less time than a conventional drive. Additionally, installation costs are minimized because a foundation isn't required. Unscheduled downtime due to misalignment problems is eliminated, and scheduled maintenance time and costs are reduced. In short, the application of Alignment Free Drive systems offers improved reliability and reduced costs for heavy-duty conveyor belt applications. This article will further explain the new alignmentfree drive technology and offer a comparison to conventional systems.
Conventional Conveyor Belt Drive Configuration Conventional conveyor belt drive configurations consist of a foot-mounted motor, gear drive, and shaft couplings (input and output sides of drive), foundation- mounted on a common bedplate, and aligned with the conveyor pulley shaft. Equipment misalignment is one of the leading causes of conventional drive system failures and maintenance-related problems. By their nature, heavy-duty conveying applications can subject conventional drive system components to operational stresses that can lead to misalignment problems. The movement of earth; heavy loads and shock loads; rough starts and stops; and more can affect drive system components. Conventional foot- mounted/bed-plate foundation installations are especially susceptible to these types of stresses and as a result require periodic realignment of components. Other variables of a conventional drive system are also problematic. For example, the cost of constructing a foundation can account for 10 to 15 percent of the initial cost of a drive system. And, in many applications, this cost will be repeated as operations shift and conveyors are relocated, requiring new foundations. Installation costs can include storage, crane expense, millwright services, equipment alignment and associated labor costs. Installation costs can range from five to eight percent of the initial drive costs. Additionally, the lifetime operating costs for a conventional system will include ongoing preventive maintenance procedures including lubrication, site clean-up, misalignment repairs, parts replacement, oil analysis, temperature checks, and more. Energy, inventory spares, reliability, and other maintenance costs will also affect the lifetime operating costs of a drive system.
The Alignment Free Driv e Solut ion Alignment-free drive technology was first developed for underground coal conveyor applications. Application solutions are currently available for a wide range of heavy-duty belt conveyor applications in many industries. The Alignment Free Drive is a right-angle, shaft-mounted gear drive featuring bolt-together construction. No foundation is required and installation times and costs are dramatically reduced compared to conventional configuration. Scheduled maintenance programs are reduced, and failures due to misalignment are virtually eliminated. The drive is alignment-free in two respects: The drive does not require motor- to-gear drive or gear drive-to-conveyor alignment. An articulating torque arm is the only foundation attachment that is needed. Installation is easy, and installation time and costs are reduced. The ease and speed of installation, compared to a conventional drive, are key Alignment Free Drive gear drive advantages. In some applications, the drive system has been installed in less than half the time of a conventional configuration. The elimination of the foundation reduces engineering, materials and installation costs. The "no foundation" benefit means Alignment Free Drive gear drives are unaffected by ground or foundation movements.
The design uses bolt-together construction and simple, registered fits for fast and error-free gear drive connection to both the drive motor and conveyor. The drive's connection to the motor is a machined and registered flange that mates to the motor flange (NEMA, IEC or others) to create an inherent equipment alignment. The motor connection can be either with a fluid coupling for controlled starting or with a standard flexible shaft coupling.
The gear drive output connection to the conveyor system can be either a flange- moment coupling or a hollow shaft with a shrink disk locking device. With the flange-moment coupling, the gear drive output shaft and the conveyor shaft are brought into alignment as the bolts on the register flanges are tightened. The entire drive assembly is supported by the conveyor pulley-shaft and torque arm reaction point. Two elements are key to the Alignment Free Drive gear drive configuration. First, the system must be properly designed and engineered. Such a system will generate a low bending moment on the conveyor pulley shaft under dynamic loading conditions by virtue of the reaction point location. Second, a non- binding torque arm design is important to avoid inducing shaft deflections.
Maintenance Cost s Reduced Maintenance and other operating costs are greatly reduced with the Alignment Free Drive gear drive system. Periodic maintenance includes checking oil levels, replacement or lubrication of the greasepurged seals and torque- arm bearings, and occasional oil analysis. Other lifetime maintenance costs will be reduced as well. For example, in difficult environments such as underground mining, Alignment Free Drive gear drives are unaffected by ground movement and shifting, reducing the potential for misalignment-related failures. Falk Alignment Free Drive gear drives can be equipped with electronic devices for the remote monitoring of critical drive functions. A symmetrical design allows the unit to be used in either a right- or left-hand configuration. A change in configuration requires only a dipstick and torque-arm repositioning. With its flexible, symmetrical design, one spare unit is generally sufficient for unplanned downtime requirements. Complete units or components can be quickly swapped. Although a rare occurrence, gear sets and other drive components can be replaced on site when required. Stocking fewer spares equates to lower inventory costs.
Lower Total Lifetime Costs with the Alignment Free Drive System A comparison of installed costs for a conventional bedplate-mounted drive versus the Alignment Free Drive system demonstrates lower costs for the latter. The comparison in Figure One indicates lower costs for a Falk Alignment Free Drive based on initial purchase and installation costs. In many applications, the Alignment Free Drive can result in start-up savings of up to 20 percent compared to a conventional configuration. The foundation and installation costs can be up to 90 percent less with an Alignment Free Drive system versus a conventional drive.
Conveyor Drive - Installed Cost Comparison 400 HP/298 KW, 1750 RPM, 75 RPM Output Heavy Duty, 16 Hours/Day Drive Size & Type (Falk)
Alignment-Free Drive 445ABRCM3 Conventional 445AB3C
Exact Ratio
Alignment-Free Drive 22.83:1
Conventional 22.83:1
Mech. Rating
Alignment-Free Drive 651 hp/486 kW
Conventional 651 hp/486 kW
Service Factor
Alignment-Free Drive 1.63
Conventional 1.63
Thermal Rating
lignment-Free Drive 620 hp/463 kw
Conventional 620 hp/463 kW
Suggested Drive $
Alignment-Free Drive $75,072
Conventional $74,658
% Difference
Alignment-Free Drive Base
Conventional -.5%
All selections include the basic drive, cooling fans, bedplate or motor flange, fluid coupling, output coupling, and high-speed backstop Motor $
Alignment-Free Drive $20,120
Conventional $17,063
Motor Mounting $
Alignment-Free Drive $360
Conventional $720
Foundation Cost ** $
Alignment-Free Drive $900
Conventional $11,000
Installation Cost** $
Alignment-Free Drive $750
Conventional $4,300
Total $
Alignment-Free Drive $97,202
Conventional $107,731
% Difference
Alignment-Free Drive Base
Conventional +10.9%
AFD W/Scoop Trim Coupling and Control approx. 1.3 xBase Total AFD W/DC Motor and Control approx. 1.5 x Base Total ** Will vary by plant site Figure One
The combination of lower start-up and lifetime operating costs favors the Alignment Free Drive in comparison to a conventional drive system. An Alignment Free Drive will yield the lowest cost over the life of the installation. The cost savings, coupled with improved operational reliability, ranks the Alignment Free Drive as a true advance in heavy-duty belt conveyor technology.
The Control and Soft Starting of Belt Conveyors Part and parcel with the ongoing process of reducing belt conveyor operating costs and maximizing the advantages of an Alignment Free Drive system is the need to soft start and control heavy-duty conveyor belt systems. Solutions to soft-start and control considerations are dictated by the complexity of the application. Alignment Free Drives can be configured to be compatible with softstart and other control systems. Options include: Fixed-Fill Fluid Couplings: Current fluid coupling technology has reduced the need for complex and elaborate controls in most conveyor applications. Ultra-low starting torques and start times up to 50 seconds are possible with today's fluid couplings. Starting torques as low as 40 percent of full load effectively bridge the gap between empty and loaded starting conditions. For multiple drive systems, a fluid coupling provides effective load-sharing and stagger-start capability to further extend the ramp-up of starting torque. Additionally, the often difficult process of fluid coupling alignment is eliminated because of the bellhousing connection design feature of the Alignment Free Drive. Scoop-Trim Fluid Couplings: For more complex conveyor systems, scoop-trim fluid couplings allow for more responsive control of speed and torque by varying the amount of fluid in the couplings working circuit. These couplings can be used in connection with DC servo-controls for extremely long acceleration ramps, or with a programmable logic controller and load-cell belt- tension monitoring, to adjust for variable loading conditions and changing belt lengths on underground coal tripper booster belt conveyor applications. Electrical Controls: For other complex conveyor systems, the Alignment Free Drive can be used with a DC motor, VFC variable frequency control, or wound rotor motor controls.
