Falk Alignment Free Drive™
Gear Drive Technology for Belt Conveyors:
Easy Installation Combined with Low Installation Costs and
Improved 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, 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 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
alignment-free 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 Drive Solution
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 Costs 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
grease-purged 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 soft- start 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
bell-housing 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.
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