Nexen Air Champ WCB120 User manual

(i)
Water Cooled Brakes
Series WCB120 and WCB130
FORM NO. L-20162-B-0601

(ii)
In accordance with Nexen’s established policy of constant product improvement, the specifications contained in this
manual are subject to change without notice. Technical data listed in this manual are based on the latest information
available at the time of printing and are also subject to change without notice.
Technical Support:
800-843-7445
[phone]
www.nexengroup.com
Nexen Group, Inc.
560 Oak Grove Parkway
Vadnais Heights, Minnesota 55127
ISO 9001 Certified
Copyright 2000 Nexen Group, Inc.
Read this manual carefully before installation and operation.
Follow Nexen's instructions and integrate this unit into your system with care.
This unit should be installed, operated and maintained by qualified personnel ONLY.
Improper installation can damage your system or cause injury or death.
Comply with all applicable codes.
WARNING

(iii)
TABLE OF CONTENTS
Introduction---------------------------------------------------------------------------------------------------------------------------------------- 1
Installation ---------------------------------------------------------------------------------------------------------------------------------------- 1
Air Connections---------------------------------------------------------------------------------------------------------------------------------3
Lubrication----------------------------------------------------------------------------------------------------------------------------------------- 4
Cooling Water Connections ---------------------------------------------------------------------------------------------------------------4
Troubleshooting --------------------------------------------------------------------------------------------------------------------------------- 5
Parts Replacement ----------------------------------------------------------------------------------------------------------------------------6
Replacement Parts ----------------------------------------------------------------------------------------------------------------------------8
Parts List -------------------------------------------------------------------------------------------------------------------------------------------8
Warranties-----------------------------------------------------------------------------------------------------------------------------------------9

1FORM NO. L-20162-B-0601
INTRODUCTION
Read this manual carefully, making full use of its explanations and instructions. The “Know How” of safe, continuous,
trouble-free operation depends on the degree of your understanding of the system and your willingness to keep all
components in proper operating condition. Pay particular attention to all NOTES, CAUTIONS, and WARNINGS to avoid
the risk of personal injury or property damage. It is important to understand that these NOTES, CAUTIONS, and
WARNINGS are not exhaustive. Nexen cannot possibly know or evaluate all conceivable methods in which service may
be performed, or the possible hazardous consequences of each method. Accordingly, anyone who uses a procedure
that is not recommended by Nexen must first satisfy themselves that neither their safety or the safety of the product will
be jeopardized by the service method selected.
Nexen’s double piston design WCB Series brakes provide a wide range of precision torque control in an air actuated,
water cooled brake. A special water jacket design with copper alloy disc produces high thermal horsepower.
The special copper alloy disc and friction facing are engineered for constant slip applications, thus providing extended
life and stable slip torque, while the multiple disc feature allows increased torque capacity in a compact unit.
A copper membrane coats the surface of the water path in the water jacket to prevent rust and extend the life of the
brake.
INSTALLATION
WCB PREPARATION
1. Remove two Socket Head Cap Screws from Main
Body (See Fig. 1).
2. Disassemble WCB into the following components;
Water Jacket Flange, Cylinder Assembly, Hub, and
Friction Disc (See Fig. 2).
FIGURE 1
Remove Socket
Head Cap Screw
Remove
Socket
Head Cap
Screw.
FIGURE 2
Cylinder
Assembly
Friction
Disc Hub
Water Jacket
Flange

2FORM NO. L-20162-B-0601
MACHINE PREPARATION
Drill mounting holes in machine surface (See Figs. 3 & 4
for mounting hole pattern).
FIGURE 3
WCB120 Mounting Bolt Pattern FIGURE 4
WCB130 Mounting Bolt Pattern
CAUTION
Machine shaft must be perpendicular
to mounting surface to within 0.002"
[0.05mm] and centered within mounting
bolt pattern within 0.004" [0.10 mm].
60
O
30
O
60
O
30
O
11.02" [280 mm]
dia. Bolt circle
(4) 9/16 [14.2 mm]
dia. holes
45
O
14.96" [380 mm]
dia. Bolt circle
(6) 21/32 [16.5 mm]
dia. holes
45
O
45
O
45
O
22
O
'
30
22
O
'
30
MOUNTING WCB120
1. Insert key into machine shaft keyway.
2. Slide Hub onto machine shaft until back of Hub is
approximately 1.34" [34 mm] from machine
mounting surface (See Fig. 5).
3. Tighten customer supplied set screws securing Hub
to machine shaft to torque recommended by set
screw vendor.
NOTE: Set screws must be flush with Hub or
slightly recessed into Hub to avoid damage
to WCB Brake.
4. Apply Never-Seez® or equivalent anti-seize lubricant
to Hub.
5. Slide Water Jacket Flange over Hub and machine
shaft (See Fig. 5).
CAUTION
Water Jacket outlet must be aligned to
the twelve o’clock up position and inlet
must be aligned to the six o’clock down
position. This alignment eliminates air
pockets and/or hot spots
FIGURE 5
Cylinder
Assembly
Friction
Disc
Water Jacket
Flange
Hub
Water
Outlet
6. Position Friction Disc on Hub (See Fig. 5).
7. Slide Cylinder Assembly into position, aligning holes
in Cylinder Assembly with holes in Water Jacket and
machine mounting surface.(See Fig. 5).
8. Tighten Socket Head Cap Screws securing WCB
Brake to mounting surface to 122 ft. lbs.

3FORM NO. L-20162-B-0601
MOUNTING WCB130
1. Insert key into machine shaft keyway.
2. Slide Hub onto machine shaft until back of Hub is
approximately 1.38" [36 mm] from machine
mounting surface. (See Fig. 6).
3. Tighten customer supplied set screws securing Hub
to machine shaft to torque recommended by set
screw vendor.
NOTE: Set Screws must be flush with Hub or
slightly recessed into Hub to avoid damage
to WCB Brake.
4. Apply Never-Seez®or equivalent lubricant to Hub.
5. Slide Water Jacket Flange over Hub and machine
shaft (See Fig. 6).
CAUTION
Water Jacket outlet must be aligned to
the twelve o’clock up position and the
inlet must be aligned to the six o’clock
down position.
6. Insert Cap Screws (Item 25) into counter sunk holes
in Water Jacket Flange, and secure Water Jacket
Flange to machine mounting surface.
FIGURE 6
Cylinder
Assembly
Friction
Disc
Water Jacket
Flange
Hub
Water
Outlet
7. Tighten two Cap Screws to 184 ft. lbs.torque.
8. Position Friction Disc on Hub (See Fig. 6).
9. Slide Cylinder Assembly into position, aligning holes
in Cylinder Assembly with holes in Water Jacket
Assembly and machine mounting surface (See Fig. 6).
10. Tighten four remaining Socket Head Cap Screws
securing Cylinder Assembly to Water Jacket
Assembly and machine to 184 ft. lbs. torque.
TABLE1
WCB120 WCB130 Use Piston
350 ft. lbs. 1042 ft. lbs. “L” + “S”
233 ft. lbs. 692 ft. lbs. “L”
117 ft. lbs. 350ft. lbs. “S"
"S" "L"
FIGURE 7
AIRCONNECTIONS
All Nexen pneumatically actuated devices require clean
lubricatedair for maximum performance andlonglife. Your
local Horton distributor carries filters, regulators, and lubri-
cators specifically designed to operate with Nexen prod-
ucts.
Forquickresponse,shortairlinesbetweenthecontrolvalve
and the WCB Brake are recommended.
NOTE: Do not use rigid pipe or tubing when making air
connections to the WCB Brake.
Air inlets for the WCB Brake’s “S” Piston and “L” Piston
are located in the Air Chamber and are tapped 1/4
NPT (See Fig. 7).
The Dual Piston design of the WCB Brake allows multiple
torque ranges (See Table 1).

4FORM NO. L-20162-B-0601
LUBRICATION
The most effective and economical way to lubricate the
WCB Brake’s air chamber is with an air line lubricator.
Available from Nexen, the lubricator injects oil into the
pressurized air, forcing a constant oil mist into the air
chamber.
Lubricator drip rate is properly set when an oil drop
starts to form in the sight gage every time the WCB
Brake is cycled or one full drop every twenty cycles.
Locate lubricator above and within ten feet of the WCB
Brake.
For WCB Brakes that are cycled infrequently, apply two
or three drops of oil into the air inlet ports every two
weeks.
Synthetic lubricants are not recommended,
use a low viscosity petroleum base oil such
as SAE-10.
To determine the proper flow of cooling water, use the
following formula:
6.8 (HP)
GPM min = TO- T1
Where: GPM min = Minimum gallons per min required
HP = Thermal horsepower requirement
TO= Outlet water temperature
T1= Inlet water temperature
Insufficient water flow will cause the WCB
Brake to overheat, resulting in excessive
friction facing wear, loss of torque, excessive
friction surface wear and O-ring damage.
Refer to Table 2 for recommended cooling
water flow.
TABLE 2
MAX. RECOMMENDED COOLING WATER FLOW
WCB BRAKE GALLONS PER MIN. LITERS PER MIN.
WCB120 2.6 G.P.M. 10 L.P.M.
WCB130 5.3 G.P.M. 20 L.P.M.
COOLING WATER CONNECTIONS
Water inlet and outlet ports for the WCB Brake are
located in the Pressure Water Jacket and Flange Water
Jacket. To assure that the WCB Brake is filled with
water at all times the water must enter at the bottom and
discharge at the top (See Fig. 8).
NOTE: Use flexible hose for water lines and route water
lines to insure equal flow to inlet and outlet
ports. The use of rigid pipe or tubing will
prevent proper WCB Brake actuation.
Headers installed in the inlet and outlet ports
must be of a type that provide equal flow at
ports.
Water inlet temperature should be approximately 68oF.
[20oC.] or lower and controlled so that the outlet
temperature does not exceed 120oF. [50oC.] (148oF.
[65oC.] Maximum).
Use clean water free from rust, dust, or other corrosive
material.
FIGURE 8 Water Inlet
Water Outlet

5FORM NO. L-20162-B-0601
TROUBLESHOOTING
Air not getting to WCB
Air leak in WCB
Friction Disc binding on Hub
Rigid pipe or tubing used for air lines
Unexhausted air due to faulty control
or restricted air line
Friction Disc binding on Hub
Broken or weak Return Springs
Shortage of cooling water
Water Jacket restricted by scale or
rust
Worn Friction Facing
Measure Gap between
Cylinder and Water Jacket
Pressure Assembly
FIGURE 9
SYMPTOM PROBABLE CAUSE REMEDY
Failure to Engage
Failure to Disengage
Overheating
Loss of torque
Air pressure too low-
Check for control valve malfunction.
Defective or broken O-rings-
Replace O-ring seals.
Lack of lubrication on Hub- Hub must
be lubricated.
Flexible tubing must be used for air
lines.
Check controls and air lines for
restrictions.
Lack of lubrication on Hub-
Hub must be lubricated.
Replace Return Springs.
Inspect water lines. Replace if
defective.
Inspect water flow controls. Replace
if defective.
Flush Water Jacket with automo-
tive radiator cleaner.
Inspect Friction Facing and replace
when space between Cylinder and
Water Jacket Pressure Assembly is
less than 0.55" [14 mm] for WCB120
and 0.63" [16 mm] for WCB130 (See
Fig. 9).

6FORM NO. L-20162-B-0601
Cylinder
Assembly
FIGURE 11
FIGURE 10
17
22
16
Remove Socket Head
Cap Screws (Item 24).
PARTS REPLACEMENT
FRICTION DISC
1. Remove four Socket Head Cap Screws (Item 24)
(See Fig. 10)
2. Separate Cylinder Assembly from Water Jacket
Flange (Item 22) (See Fig. 11).
3. Slide Friction Disc (Item 17) off Hub (Item 16) (See
Fig. 11).
4. Clean and lubricate Hub (Item 16) spline with
Never-Seez® or equivalent (See Fig. 11).
5. Install new Friction Disc.
6. Reverse above procedure to reassemble
WCB120.
7. Tighten four Socket Head Cap Screws (Item 24)
removed in Step 1 to 122 ft. lbs. torque on
WCB120 and 184 ft. lbs. torque on WCB130.
O-RING SEAL REPLACEMENT
1. Remove two Shoulder Screws (Item 15) and
Springs (Item 14) securing Pressure Water Jacket
(Item 10) to Cylinder assembly (See Fig. 12).
2. Remove Pressure Water Jacket Assembly (Item 10)
from Cylinder assembly (See Fig. 12).
3. Separate Large and Small Pistons (Items 4 & 5) from
Cylinder Assembly (See Fig. 12).
4. Remove O-rings (Items 6 & 7) from Large Piston
(Item 4) and O-rings (Items 8 & 9) from Small Piston
(Item 5) (See Fig. 12).
5. Lubricate O-ring grooves of both Pistons and new
O-rings with O-ring lubricant and install new O-rings
into respective grooves of both Pistons (See Fig. 12).
15
5
4
10
14
9
8
67
FIGURE 12

7FORM NO. L-20162-B-0601
6. Install Large and Small Pistons (Items 4 & 5) back
into Cylinder Assembly.
7. Secure Pressure Water Jacket (Item 10) to Cylinder
Assembly.
NOTE: Inspect Springs (Item 14) for signs of
fatigue and replace Springs if required.
8. Tighten Shoulder Screws (Item 15) to 9 ft. lbs.
torque.
WATER JACKET (Pressure) O-RING REPLACEMENT
1. Disassemble WCB Brake and remove Water Jacket
(Pressure) (Item 10) from machine.
2. Remove Button Head Cap Screws (Item 26) and
Hex. Nuts (Item 27) securing Copper Plate (Item 13)
to Water Jacket (Item 10) (See Fig. (13).
3. Remove O-rings (Items 11 & 12).
4. Clean surface of Water Jacket (Item (10).
NOTE: Water Jacket coolant path is coated with a
special waterproof paint, if paint is
damaged, repaint coolant path with fresh
waterproof paint.
5. Coat new O-rings with gasket sealant and install
new O-rings.
6. Replace Copper Plate (Item 13) and secure with
Button Head Cap Screws (Item 26) and Nuts
(Item 27).
10
26
12
11
14 15 13
FIGURE 13
7. Tighten Button Head Cap Screws to 2 ft. lbs.
torque.
8. Pressure test Water Jacket for leaks.
9. Reassemble WCB Brake.
WATER JACKET (Flange) O-RING REPLACEMENT
1. Disassemble WCB Brake and remove Water Jacket
(Flange) (Item 22) from machine.
2. Remove Button Head Cap Screws (Item 26) and
Hex. Nuts (Item 27) securing Copper Plate (Item 19)
to Water Jacket (Item 22) (See Fig. (14).
3. Remove O-rings (Items 19 & 20).
4. Clean surface of Water Jacket (Item (22).
NOTE: Water Jacket coolant path is coated with a
special waterproof paint, if paint is
damaged, repaint coolant path with fresh
waterproof paint.
5. Coat new O-rings gasket sealant and install new
O-rings.
6. Replace Copper Plate (Item 21) and secure with
Button Head Cap Screws (Item 26) and Nuts
(Item 27).
26
21 19
20 22
FIGURE 14
7. Tighten Button Head Cap Screws to 2 ft. lbs.
torque.
8. Pressure test Water Jacket for leaks.
9. Reassemble WCB Brake.