EATON Airflex WSB 11210 WCSB3 Installation Operation and Maintenance E-CLCL-11001-E October 2013
8
WCSB3 Brakes
1.1.2 WCSB3 tensioner is available in multiple designs.
The model number identifies the multiple of discs and
the nominal disc diameter. For example, 436WCSB3
indicates there are four total discs in the assembly
and the nominal diameter of the water-cooled discs is
36” diameter. Note that the air-cooled disc is typically
larger in diameter by 2” when compared to the
water-cooled disc; therefore, the model number will
refer to the total number of Water cooled plus Air
Cooled discs. Additional notations may be made in
describing the model number to indicate the number
of water-cooled (WC) disc assemblies and number of
air cooled (AC) discs. For example, a 436WCSB3
(3WC/1AC) would indicate three water-cooled discs
and one air-cooled disc.
1.1.3 When size, such as 36WCSB3, is referred to in this
manual, it means that the information given applies
to all models using the 36” diameter water-cooled
disc assembly; i.e., 236WCSB3, 336WCSB3.
1.1.4 Tensioners can be used with either closed loop or
open loop fresh water systems. Tensioners can be
used with closed loop 50/50 ethylene glycol systems.
1.1.5 This manual includes metric equivalents usually
shown in (#) following the U.S. measurement system
value. Be sure to use the correct value.
1.1.6 All Airflex WCSB3 tensioners are supplied with long
wearing, non-asbestos friction material .
1.2
How It Works
1.2.1 Referring to Figure 1 and Table 1, the gear (28)
is mounted on the shaft which is to be stopped and
the tensioner assembly is attached to the machine
frame.
The Airflex WCSB3 has a dual chambered piston/
cylinder on the air-applied, water-cooled tensioner.
Air pressure is first applied through the ports in the
mounting flange/cylinder (112) causing the piston (33)
to apply force to the pressure plate assembly (116).
As air pressure is applied through the ports in the
cylinder (19) on the spring set section of the unit,
the cylinder and pressure plate (13), which are
attached to each other with screws (20), flat washers
(17) and spacer tubes (27), move away from the
mounting flange (112), which is connected to the
machine frame. The pressure plate compresses the
springs (22) and (53) against the stationary spring
housing (16). As the pressure plate moves, the end
plate subassembly (117) also moves away from the
mounting flange/cylinder until it rests against the
stop plates (125) which are axially fixed. The pressure
plate (13) then continues to move away from the
end plate subassembly and the clamp force is
removed from the disc (119) that rides on the gear.
As the end plate subassembly (117) moves towards
the stop plates, the piston (33) and friction disc
subassembly move by means of the air pressure
initially applied. Relieving the air pressure within the
mounting flange/cylinder reduces the clamp force
applied to the friction discs, allowing the shaft to be
free to rotate. Modulation of the air pressure controls
the applied torque of tensioner.
As air pressure is exhausted from both the mounting
flange/cylinder (112) and the cylinder (19), the springs
force the pressure plate (13) toward the mounting
flange, clamping the disc (119) between the pressure
plate and the end plate subassembly (117). As the
piston (33) retracts, the endplate subassembly
continues to move towards the mounting flange/
cylinder, pressing against the friction disc assemblies
(7), reaction plate (30) and pressure plate
subassembly (116). As the pressure plate (116)
comes to rest against the mounting flange, the spring
force clamps all discs between adjacent surfaces,
applying stopping torque to the shaft.
High heat dissipation within the tensioner section
in the WCSB3 is accomplished by passing water
through a cavity behind copper alloy wear plates.
Caution
The tensioner is never to be operated without the
coolant supply attached and coolant running
through the pressure plate (116), reaction plates (30)
and end plate (117).
1.3
Dual Piston Design Advantages
The air applied pistons in the tensioner are available in
either single or dual piston designs. The WCSB3 dual
piston/cylinder (112) power head offers precise
tensioning control by dividing the piston/cylinder into
inner and outer sections (See Figure 1). This provides
the ability to improve fine modulation of clamping
pressure on the tensioner discs and improved control
over our standard single chamber design. For very
light tensioning loads, the outer piston can be used
solely, with no pressure applied to the inner piston.
For the largest tensioning loads, both pistons can be
used together. If it is desirable to operate the
tensioner at maximum tensioning load and not utilize
the precise tensioning feature, the tensioner can be
ordered without the intermediate piston seal (114).
Danger
Prior to installation of the WCSB3 tensioner, make
sure that the machinery will remain in a secured
position. Failure to do so could result in serious
personal injury or possibly death.
Warning
Only qualified maintenance personnel should install,
adjust or repair these units. Faulty workmanship will
result in unreasonable exposure to hazardous
conditions or personal injury.
