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Industrial Clutches

ABSSAC Lead Screws, Ball Screws, and Shaft Couplings
Call: 01386 421 005
Email: sales@abssac.co.uk
Web: www.abssac.co.uk
ABSSAC

CLUTCH PRODUCTS

Clutch ProductsSection G1
NLS® - Centrifugal Clutch
(No Load Start)
  • cushion for high inertia starting loads
  • dampens shock starts
  • systems overload protection
Section G2
Roto-Cam® - Mechanical Clutch
  • simple design
  • smooth cam actuated engagements
  • sealed for dirty or dusty applications
  • no lubrication
Section G3
Disc-O-Torque® - Hydraulic Clutch
  • minimum size I maximum torque
  • lubricated and sealed bearing types
  • air or oil activation
  • long life
T: +44 (0)1386 421005F: +44 (0)1386 422441E: sales@abssac.co.ukW: www.abssac.co.uk
ABSSAC

TB Woods ®NLS® CENTRIFUGAL CLUTCH

The NLS centrifugal clutch is a rugged time-proven unit which provides equipment protection and system overload protection. This is done by allowing the motor or other driving source to accelerate to operating speed without load and to slip automatically when overloaded. This clutch is available in a free (type A) and delayed engagement (type AD) model, also in various sizes to handle different horsepower capacities.

TYPE A
Free Engagement

Type A, Free EngagementThe shoes are a free floating part of the driving unit to which the power is applied. As the driver picks up speed, the shoes are forced outward by centrifugal force to make contact with the inside surface of the driven half. The shoes will make smooth contact and slip until the load reaches full speed. Both members then rotate as a unit with no slippage or power loss. Larger units have both inner and outer shoes.

TYPE AD
Delayed Engagement

Type AD, Delayed EngagementOperating under the same principle as the type A unit, the type AD uses springs to hold the shoes out of engagement until the driver reaches a predetermined rpm. At this point centrifugal force, acting on the shoes, overcomes the spring force, allowing smooth engagement of the power source with the load. Because the shoes are out of engagement until the driver is above the predetermined speed, this unit is ideal for dual or stand-by drives as well as idling or warming-up engines.

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ABSSAC

TB Woods ®NLS® SELECTION PROCEDURE

Easy Step by Step Selection Method

Step # 1: Determine HP and minimum driving RPM (also idle RPM if delayed engagement type is required).

Step # 2: Using the service factor chart determine the proper service factor based on the prime mover and driven equipment.

 DRIVEN EQUIPMENT LOAD CLASSIFICATIONS
LIGHT STEADY LOADS
Starting torque is equal to or slightly greater than running torque.
MODERATE LOADS
High starting torque or above average running torque.
MEDIUM LOADS
Starting torque is approximately double running torque.
HEAVY-DUTY LOADS
High starting torque, shock loading, light torque reversals during drive.
LIGHT STEADY LOADSMODERATE LOADSMEDIUM LOADSHEAVY-DUTY LOADS
 Centrifugal pumps, uniformly loaded conveyors, light-duty fans and blowers, liquid mixers and agitators, centrifugal compressors, lobe and vane type blowers, gear pumps, textile machinery, wood-working machinery.Machine tools, hot oil pumps, heavy-duty centrifugal pumps, cooling towers, slurry agitators, boiler feed pumps, hoists, conveyors.Dredge pumps, dynamometer drives, light-duty hammermills, lineshafts, paper converting machinery, rotary kins, rotary or screw-type pumps for high viscosity fluids, paper mill cranes.Mine ventilating fans, reciprocating pumps or compressors, paper making machinery, heavy-duty hammermills, ore crushers, pulverizing mills.
PRIME MOVER
Steam, gas or air turbine1.001.251.501.75
AC electric motor1.251.501.501.75
DC electric motor or DOL start AC electric motor, hydraulic motors1.251.501.752.00
Gasoline, natural gas, propane or other spark ignition engine1.751.752.00CONSULT
ENGINEERING
Diesel*2.002.502.75CONSULT
ENGINEERING

* Consult Wood's applications engineering on all engine drives
Dual drive applications are to be treated as two single drives for service factor purposes.
For conveyor applications consult Wood's applications engineering.
For any application with extremes in inertia, starting torque, or questionable equipment, consult Wood's application engineering.

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ABSSAC

TB Woods ®NLS® SELECTION PROCEDURE (continued)

Step # 3: Calculate the Design HP (HP x service factor). Using the Design HP and the driving RPM select the type and size clutch from the following charts.

TYPE A
Free Engagement Horsepower Tables

In Wood's NLS free engagement clutch the shoes are a free-moving part of the driving half of the twopiece unit to which the power is applied. As the driving half picks up speed the shoes are forced outward by centrifugal force into contact with the inside surface of the driven half which is attached to the load or driven machine. As the shoes make smooth contact, they slip momentarily, or until friction causes the driven half to rotate. When the driven equipment reaches full speed, complete engagement of the shoes with the driven half has taken place, and both members rotate as a unit with no slippage, or power loss.

DescriptionBushingProduct NumberMinimum Dynamic HPShoe Replacement
Minimum Driving RPMOuterInner
40050060072087011601750Product No.Qty.Product No.Qty.
4A-1SHN004-10.020.040.070.110.200.501.60N004-4082NONE 
4A-2SHN004-20.040.070.130.230.400.903.30N004-4084NONE 
4A-3SHN004-30.050.090.150.270.501.103.90N004-4124NONE 
6A-1SDSN006-10.090.200.300.501.002.408.00N006-6132NONE 
6A-2SDSN006-20.150.300.500.901.603.8013.00N006-6133NONE 
6A-3SDSN006-30.200.400.701.202.105.0017.00N006-6134NONE 
6A-4SDSN006-40.290.601.001.803.207.5026.00N006-6136NONE 
7A-1SKN007-10.380.751.302.203.909.4032.00N007-7263NONE 
7A-2SKN007-20.511.001.703.005.2012.0043.00N007-7264NONE 
7A-3SKN007-30.771.502.604.507.9019.0064.00N007-7266NONE 
8A-1SFN008-10.901.803.205.609.8023.0080.00N008-8344NONE 
8A-2SFN008-21.002.003.606.0011.0026.0088.00N008-8424NONE 
8A-3SFN008-31.302.704.908.2014.0035.00120.00N008-8346NONE 
8A-4SFN008-41.503.005.409.1016.0038.00132.00N008-8426NONE 
10A-1EN010-11.503.005.509.0016.0038.00132.00N010-10334N010-1026-I4
10A-2EN010-21.503.506.0010.0018.0043.00149.00N010-10424N010-1026-I4
10A-3EN010-32.004.507.5013.0024.0056.00192.00N010-10336N010-1026-I6
10A-4EN010-42.505.009.0015.0028.0065.00224.00N010-10426N010-1026-I6
12A-1FN012-13.006.5012.0019.0035.0082.00285.00N012-12753N012-1256-I3
12A-2FN012-24.008.5016.0026.0047.00110.00380.00N012-12754N012-1256-I3
12A-3FN012-36.0012.0021.0036.0065.00154.00533.00N012-12606N012-1256-I6
12A-4FN012-46.5013.0023.0039.0070.00165.00570.00N012-12756N012-1256-I6
14A-1FN014-18.5017.0031.0051.0092.00217.00749.00N014-14536N014-1468-I3
14A-2FN014-210.0020.0036.0060.00108.00255.00879.00N014-14706N014-1468-I4
14A-3FN014-313.0027.0048.0081.00144.00340.001170.00N014-14708N014-1468-I6
16A-1JN016-113.0026.0047.0079.00141.00333.001150.00N016-161104N016-16100-I3
16A-2JN016-214.0028.0050.0084.00150.00354.001220.00N016-16856N016-16100-I4
16A-3JN016-320.0039.0070.00118.00212.00499.001720.00N016-161106N016-16100-I4
16A-4JN016-426.0053.0093.00158.00282.00666.002290.00N016-161108N016-16100-I6
19A-1BTSN019-143.0087.00154.00260.00461.001090.00...N019-191506N019-19100-I6
19A-2BTSN019-257.00115.00204.00346.00614.001450.00...N019-191508N019-19100-I8
24A-1BTSN024-177.00156.00276.00468.00828.001967.00...N024-241408N024-24180-I4
24A-2BTSN024-2114.00221.00391.00663.001170.002785.00...N024-242008N024-24180-I6
24A-3BTSN024-3164.00332.00587.00995.001760.004180.00...N024-2420012N024-24180-I8
24A-4BTSN024-4219.00443.00783.001327.002345.005570.00...N024-2420016N024-24220-I8
25A-1BTSN025-1246.00498.00881.001490.002640.006270.00...N024-2420018N024-24180-I8
25A-2BTSN025-2287.00581.001030.001740.003080.007310.00...N024-2420021N024-24220-I8
25A-3BTSN025-3342.00669.001160.002000.003530.008360.00...N024-2420024N024-24180-I8

Horsepower tables are based on ideal test conditions. As with all friction clutches, the actual horsepower will vary with application conditions.
When using a model with inner shoes:
A) Horsepower ratings prior to shoe lock-up (dynamic horsepower ratings) do not include inner shoe.
B) Horsepower rating after complete shoe lock-up with inner shoe (static horsepower ratings) are approximately double the dynamic rating.
For high speed applications and models above 10", consult TB Wood's application engineering.

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ABSSAC

TB Woods ®NLS® SELECTION PROCEDURE (continued)

TYPE AD
Delayed Engagement Horsepower Tables

In Wood's NLS delayed engagement clutch, shoe engagement is controlled by springs. The springs are fastened to the clutch shoes and inserted in slots in the driving half. Spring action holds the shoes out of engagement with the driven half until the driving half reaches a pre-determined RPM. Above this RPM, centrifugal force acting on the shoes overcomes the spring force allowing smooth engagement of the power source with the driven equipment. Since the shoes do not contact the driven half unless the driving half is started and accelerated, the delayed engagement type A D is ideal for dual or standby drives. The cushioned contact also means no sudden load imposed on motor, electrical, clutch or driven equipment.

DescriptionBushingProduct NumberMinimum Dynamic HPMax Idle RPMShoe Replacement
Minimum Driving RPMOuter
870/300*1160/700*1750/1000*2500/1500*Product No.Qty.
4AD-1SHN104-10.180.311.103.20300-1500N104-90012
4AD-2SHN104-20.370.632.306.40300-1500N104-90014
6AD-1SDSN106-10.801.405.0014.60300-1500N106-90012
6AD-2SDSN106-21.202.108.0021.90300-1500N106-90013
6AD-3SDSN106-31.702.8010.5029.20300-1500N106-90014
6AD-4SDSN106-42.504.3015.5043.80300-1500N106-90016
7AD-1SKN107-13.005.0018.5050.00300-1500N107-90013
7AD-2SKN107-24.006.8024.5067.00300-1500N107-90014
7AD-3SKN107-36.0010.9037.00100.00300-1500N107-90016
8AD-1SFN108-17.5013.0047.00136.00300-1500N108-90014
8AD-2SFN108-211.5019.5071.00204.00300-1500N108-90016
10AD-1SFN110-117.0030.00109.00-300-1000N110-90014
10AD-2SFN110-226.0045.00164.00-300-1000N110-90016
12AD-1FN112-127.0047.00173.00-300-1000N112-90012
12AD-2FN112-241.0071.00259.00-300-1000N112-90013
12AD-3FN112-355.0095.00346.00-300-1000N112-90014
12AD-4FN112-483.00142.00519.00-300-1000N112-90016
14AD-1FN114-173.00125.00--200-700N114-90014
14AD-2FN114-2110.00188.00--200-700N114-90016
14AD-3FN114-3147.00251.00--200-700N114-90018
16AD-1JN116-1100.00172.00--200-700N116-90012
16AD-2JN116-2201.00344.00--200-700N116-90014
16AD-3JN116-3302.00516.00--200-700N116-90016
16AD-4JN116-4402.00689.00--200-700N116-90018
19AD-1BTSN119-1521.00---200-500N119-90016
19AD-2BTSN119-2695.00---200-500N119-90018
24AD-1BTSN124-1701.00---50-300N124-90014
24AD-2BTSN124-21402.00---50-300N124-90018
24AD-3BTSN124-32103.00---50-300N124-900112
24AD-4BTSN124-42805.00---50-300N124-900116

* Horsepower ratings listed are based on idle speed as indicated.
For high speed applications, models above 10", or special idle speeds, consult TB Wood's application engineering.
Horsepower ratings listed are based on ideal test conditions. As with all friction clutches, the actual horsepower will vary with application conditions.

Step # 4: Check high speed applications for dynamic balancing and steel band requirements.

Clutch
Size
RPM
Dynamic Balance
Between
Steel Band on Required
Output member above
44700-115005700
63200-76003900
72700-66003300
82400-57002900
101900-46002300
121225-38001900
141400-33001600
161200-29001400
191000-17501200
24900-16001000
25500-16001000
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ABSSAC

TB Woods ®NLS® SELECTION PROCEDURE (continued)

Step # 5: Check bore size and available space envelope.

TYPE A
Free Engagement

Dimensions in Inches

MODElS 4A THRU 16A
MODElS 4A THRU 16A
MODElS 19A & 24A
MODElS 19A & 24A
Clutch SizeSure-Grip BushingAA with
Steel
Band
BCDEFGHXYShaft End CapMB+MApprox.
Wt.
Lbs.
MinMax
4ASH4-7/16-4-13/162-1/41-1/812-3/41/44-3/81-1/161-1/161/16204-13/168
6ASDS6-1/27-7/165-17/323-1/1615/161-1/323-1/81/45-1/321-5/161-5/161/82-13/3213/166-11/3225
7ASK7-5/88-7/167-5/163-5/81-1/21-9/163-7/85/166-11/161-15/161-15/161/82-13/1611/16840
8ASF8-3/49-7/1684-1/41-9/321-25/324-5/811/327-5/162-1/42-1/41/82-13/161-7/89-7/855
10AE10-3/411-3/410-1/24-1/83-1/82-1/461/29-1/2331/83-1/2010-1/2105
12AF131411-3/85-1/23-7/161-5/156-5/89/1610-1/43-15/163-15/161/82-3/8011-3/8225
14AF151611-3/85-1/23-7/161-5/166-5/89/1610-1/43-15/163-15/161/82-3/8011-3/8250
16AJ17-1/418-1/413-5/86-5/84-3/161-9/167-1/45/812-3/84-7/84-7/81/82-5/8013-5/8400
19ABTS20-1/221-1/214-3/166-7/86-1/41-1/1610--771/83/16014-3/16600
24ABTS25-1/226-1/219-1/169-7/881-1/1612-1/2--8-3/4101/83/16019-1/161225
25ABTS-26-1/224-3/1613-7/89-1/41-1/1612-1/2--10101/84-5/64024-3/161400
TYPE AD
Delayed Engagement

Dimensions in Inches

MODElS 4AD THRU 16AD
MODElS 4AD THRU 16AD
MODElS 19AD & 24AD
MODElS 19AD & 24AD
Clutch SizeSure-Grip BushingAA with
Steel
Band
BCDEFGHXYShaft End CapMB+MApprox.
Wt.
Lbs.
MinMax
4ADSH4-7/16-4-13/162-1/41-1/812-3/41/44-3/81-1/161-1/161/16204-13/168
6ADSDS6-1/27-7/165-17/323-1/1615/161-1/323-1/81/45-1/321-5/161-5/161/82-13/3213/166-11/3225
7ADSK7-5/88-7/167-5/163-5/81-1/21-9/163-7/85/166-11/161-15/161-15/161/82-13/1611/16840
8ADSF8-3/49-7/1684-1/41-9/321-25/324-5/811/327-5/162-1/42-1/41/82-13/161-3/89-3/855
10ADSF10-3/411-3/48-9/164-1/821-3/45-1/811/327-7/82-1/42-1/41/83-1/211/169-1/4105
12ADF131411-3/85-1/23-7/161-5/166-5/89/1610-1/43-15/163-15/161/82-3/85/812215
14ADF151611-3/85-1/22-1/81-5/166-5/89/1610-1/43-15/163-15/161/82-3/85/812240
16ADJ17-1/418-1/413-5/86-5/84-3/161-9/167-1/45/812-3/84-7/84-7/81/82-5/85/814-1/4385
19ADBTS20-1/221-1/214-3/166-7/86-1/41-1/1610--771/83/16014-3/16575
24ADBTS25-1/226-1/218-15/169-7/881-1/1612-1/2--8-3/48-3/41/81-7/16018-15/161175
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ABSSAC

TB Woods ®NLS® SELECTION PROCEDURE (continued)

Bore and keyseat information
Sure Grip BushingBoresKeyseat
SH1/2 - 1-3/8Standard
1-7/16 - 1-5/83/8 x 1/16
1-11/16No K.S.
SDS1/2 - 1-11/16Standard
1-3/43/8 x 1/8
1-13/161/2 x 1/8
1-7/8 - 1-15/161/2 x 1/16
2No K.S.
SK1/2 - 2-1/8Standard
2-3/16 - 2-1/41/2 x 1/8
2-5/16 - 2-1/25/8 x 1/16
2-9/16 - 2-5/8No K.S.
SF1/2 - 2-1/4Standard
2-5/16 - 2-1/25/8 x 3/16
2-9/16 - 2-3/45/8 x 1/16
2-13/16 - 2-15/16No K.S.
Sure Grip BushingBoresKeyseat
E7/8 - 2-7/8Standard
2-15/16 - 3-1/43/4 x 1/8
3-5/16 - 3-1/27/8 x 1/16
F1 - 3-1/4Standard
3-5/16 - 3-3/47/8 x 3/16
3-13/16 - 3-15/161 x 1/8
4No K.S.
J1-7/16 - 3-13/16Standard
3-7/8 - 3-15/161 x 3/8
4 - 4-1/21 x 1/8
BTS NLS Models
ModelBoresKeyseat
19A & 19AD3 - 5-5/8Standard
5-11/16 - 6-5/8Shallow
24A, 25A & 24AD3-1/4 - 7Standard
7-1/16 - 8-3/8Shallow
Standard Keyseat Dimensions
Shaft Dia.WidthDepth
1/2 - 9/161/81/16
5/8 - 7/83/163/32
15/16 - 1-1/41/41/8
1-5/16 - 1-3/85/165/32
1-7/16 - 1-3/43/83/16
1-13116 - 2-1/41/21/4
2-5/16 - 2-3/45/85/16
2-13/16 - 3-1/43/43/8
3-15/16 - 3-3/47/87/16
3-13/16 - 4-1/211/2
4-9/16 - 5-1/21-1/45/8
5-9/16 - 6-1/21-1/23/4
6-9/16 - 7-1/21-3/43/4
7-9/16 - 923/4

NOTE: When installing Sure-Grip bushings follow wrench torque supplied in NLS instructions.

Step # 6: Check clutch capacity for high inertia starts.
If inertia is not known or clutch speed is not listed, see step # 7.

Maximum WR2 (Ibs. ft.2) that may be started at standard motor speeds.
Clutch870 RPM1170 RPM1750 RPMClutch870 RPM1170 RPM1750 RPM
450029013014800047002100
61400800350161500080003700
7200011005101922000130005600
830001700790243800020000-
1038002100880254760026400-
12700040001800 

Step # 7: If inertia is not known or clutch speed is not listed on WR2 chart.

ACCElERATION TABLE
Clutch Model No.Energy Capacity Horsepower-Seconds
4A, 4AD245
6A, 6AD680
7A, 7AD980
8A.8AD1,400
10A, l0AD1,650
12A, 12AD3,400
14A, 14AD4,000
16A, 16AD7,200
19A, 19AD11,000
24A, 24AD17,000
25A25,000
30A38,000

Maximum allowable acceleration time in seconds can be calculated by dividing the energy capacity in horsepower-seconds by the clutch design horsepower.
If actual acceleration time exceeds the maximum allowable time. a larger clutch should be selectled or if the start-up frequency is more than 1 every half-hour.
Example: A 12A-3 is rated at 533 hp @ 1750 with an energy capacity of 3400 Horsepower-seconds

34 00 Horsepower-seconds
533 Horsepower
= 6.4 seconds maximum allowable acceleration time
without a Steel Band

By adding a Steel Band the acceleration time is increased by 35%
6.4 x 1.35 = 8. 6 seconds with a Steel Band

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ABSSAC

TB Woods ®NLS® SELECTION PROCEDURE (continued)

Step # 8: Specify the clutch selected.

Nxxx-x

Basic clutch Product Number
(Chart Step # 3)

- x-x-x

Modification Codes
(Listed in alphabetical order)


Codes
B - Dynamic Balance
L - Limited End Float
S - Steel Band on Output

Sure-Grip bushings are sold separately.

Ordering examples:

N016-2
16A-2 clutch (no modifications)
N016-2-B
16A-2 clutch with dynamic balancing
N016-2-S
16A-2 clutch with steel ring
N016-2-B-S
16A-2 clutch with dynamic balancing and steel ring
N016-B-L-S
16A-2 clutch with dynamic balancing, limited end float, and steel ring
J3316
J Sure-Grip bushing with a 3-3/16 bore

Note: All NLS clutches use non-asbestos shoe linings.

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