jbj Techniques Ltd; an excellence in engineering
quality products for mechanical & fluid power

Disc Couplings

jbj Techniques offer a wide variety of superior disc coupling products in models designed to meet the application needs of today’s worldwide power transmission market.

Disc type couplings for mechanical power transmission

Below you will find:
» Attributes of the disc coupling range.
» Steps in selecting a disc coupling.
» Application service factors selection data.
» Technical specification catalogue.

Using advanced design techniques, implementation of Finite Element Analysis, and extensive testing of materials, an innovative disc pack profile design has been developed, revolutionary to traditional disc pack designs found in the market.

This disc pack can accommodate 1/2° to 11/2° of angular misalignment.

ATEX compliance (on request) is yet a further advantage for using these excellent power transmission couplings.
These disc packs are manufactured using high grade stainless steel (AISI-301), ensuring high strength, high endurance to fatigue, and resistance to most environmental conditions.

These disc couplings utilize unitised disc packs with 4, 6 or 8 bolt designs. While the 8 bolt design can transmit greater torque than the 4 or 6 bolt design, it is not able to accommodate as much angular misalignment.

These couplings can also be fitted with overload bushings to protect the disc pack during momentary torsional overloads.

Attributes of the Disc Coupling Range:

»  Eliminates the need for lubrication and coupling maintenance.
»  Coupling can be inspected without disassembly.
»  Condition of disc packs can be inspected with a strobe light while the machine is running.
    (Note: It is not recommended that couplings be operated without coupling guards.)
»  Easy to assess equipment misalignment.
»  Torsionally rigid without any backlash.
»  No wearing parts.
»  Resistance to harsh environments.
»  Long life when properly sized and aligned.
»  High power density (higher torque for a given outside diameter).
»  Lovejoy supports the API-610 Standard up to 3,800 RPM.
»  ATEX Certified for SU, SX, DI, SXC, SXCS, SXCST, DIR, DILR, DIRA and DIRLA product lines.
»  Unitized disc packs ensure repeatability necessary for meeting the balance and piloting requirements as mandated by API-610.

Steps In Selecting A Disc Coupling:

1) Determine coupling type suitable for application. Angular, axial and parallel misalignment properties need to be considered. Size will be determined by the selection torque and shaft diameters.

2) Next, calculate the application torque and apply the service factor to calculate the selection torque. Scroll down this page for service factor table or see or page 7 (link) of the on-line catalogue.

Application torque  Nm = (kW x 9550)
RPM

Application torque x service factor = selection torque

3) Use the relevant table on the relevant page for model of coupling for torque rating and shaft size. Sometimes to have the right bore size it may be necessary to have a coupling with more than sufficient torque capabilities.

4) Ensure selected coupling has sufficient speed rating using tables provided.

5) To determine if the coupling will handle the parallel misalignment, use the trig function of tan 1° = offset allowed for 25.4 mm = 0.0174

Multiply the 0.0174 x the distance between disc packs or ‘S’ dimension from the table on page 13 (link).


Recommended Information Needed to Specify a Disc Coupling from jbj Techniques Limited:

The following information should be provided when placing an order to ensure the proper selection of the disc coupling:
»  Application and type of duty.
»  Type of driver (engine, motor, turbine, etc.)
»  Speed and kW.
»  Type of driven equipment.
»  Shaft sizes and separation.
»  Space limitations for major diameter and length.
» Type of fit (Interference fit default, clearance fit and shaft locking device preparation available upon request).
» Special requirements (vertical mounting, drop out center, flange mount, electrically insulated, API-610 up to 3,800 RPM, shear pins, balancing, etc.)

Application service factors selection data:

1} Select the driving machine service factor SFD(link) from Table 2 (below) or page 7 (link) of the on-line catalogue.
2} Select the driven machine service factor SFA(link) from Table 1 (below) or page 7 (link) of the on-line catalogue.
Care should be taken when the driving machine is other than a standard electric motor or turbine. Some engines will impose extra fluctuations on the drive system and allowance should be made accordingly. Please refer to Table 2 (link).

A torsional coupling may be required for diesel drives.

The two service factors SFA and SFD must be added resulting in the combined service factor SF.
SF = SF
A + SFD

Driven Machine Service Factor SFA Table

Driven equipment SFA
BLOWERS, FANS . . . .
Centrifugal 1.0
Lobe / Vane / Turboblowers 1.25
Forced draught fans 1.5
Induc.draught with damper 1.5
Induc.draught without control 2.0
Cooling towers 2.0
CHEMICAL INDUSTRY . . . .
Agitators (thin liquid) 1.0
Agitators (viscous liquid) 1.5
Centrifuges (light) 1.25
Centrifuges (heavy) 1.75
Mixers 1.75
COMPRESSORS . . . .
Centrifugal 1.0
Lobe/Rotary 1.25
Turbocompressors 1.75
Reciprocating:
1 to 3 cylinders 3.0
4 or more cylinders 1.75
CONVEYOR, HOISTS1, ELEVATORS1 . . . .
Conveyors:
Screw / Apron / Belt / Chain 1.25
Bucket / Rotary / Lifts 1.5
Reciprocating 3.0
Hoists:
Medium duty 2.5
Heavy duty 3.0
Elevators:
Centrifugal and gravity disch 1.25
DREDGERS 2.0 . . . .
FOOD INDUSTRY . . . .
Packaging machines and fillers 1.25
Kneading machines 1.5
Cane crushers 1.5
Cane cutters 1.5
Cane mills 2.0
Sugar beet cutters 1.5
Sugar beet washing machines 1.5
GENERATORS . . . .
Even load 1.0
Frequency converters 1.5
Welding generators 2.0
MACHINE TOOLS . . . .
Main Drives 2.0
Auxiliary and transverse drives 1.5
METAL WORKING . . . .
Presses/Hammers 2.0
Straighteners 2.0
Bending machines / Shears 1.5
Punching machines 2.0
MARINE APPLICATIONS 2.5 . . . .
MINING AND STONES . . . .
Crushers 2.5
Mills 2.5
Mine ventilators 2.0
Vibrators 1.5
OIL INDUSTRY . . . .
Pipeline pumps 1.5
Rotary drilling equipment 2.0
PAPER INDUSTRY . . . .
Calenders 2.0
Couches 2.0
Drying cylinders 2.25
Pulpers 2.0
Pulp grinders 2.0
Suction rolls 2.0
Wet presses 2.0
Reels 2.0
Agitators 2.0
PLASTIC INDUSTRY . . . .
Calenders, Crushers, Mixers 1.75
PUMPS
Centrifugal,General Feed or Boiler Feed 1.0
Centrifugal, Slurry 1.5
Centrifugal, Dredge 2.0
Rotary / Gear / Lobe or Vane 1.5
Reciprocating:
1 cylinder 3.0
2 cylinders, single acting 2.0
2 cylinders, double acting 1.75
3 cylinders or more 1.5
ROLLING MILLS . . . .
Billet shears 2.5
Chain transfers 1.5
Cold rolling mills 2.0
Continuous casting plants 2.5
Cooling beds 1.5
Cropping shears 2.0
Cross transfers 1.5
Descaling machines 2.0
Heavy and medium duty mills 3.0
Ingot and blooming mills 2.5
Ingot handling machinery 2.5
Ingot pushers 2.5
Manipulators 2.0
Plate shears 2.0
Roller adjustment drives 1.5
Roller straighteners 1.5
Roller tables (heavy) 2.5
Roller tables (light) 1.5
Sheet mills 2.5
Trimming shears 1.5
Tube and welding machines 2.0
Winding machines 1.5
Wire drawing benches 1.5
RUBBER INDUSTRY . . . .
Extruder 1.75
Calender 2.0
Mixing mill / Refiner / Crusher 2.5
STEEL PLANTS . . . .
Blast furnace blowers 1.5
Converters 2.5
Inclined blast furnace elev. 2.0
Crushers 2.0
TEXTILE MACHINES . . . .
Printing and drying machines 1.5
Tanning vats 1.5
Calenders 1.5
Looms 1.5
WATER AND WASTE INDUSTRY . . . .
Aerators, Screw pumps, Screens 1.5
WOOD WORKING MACHINERY . . . .
Trimmers, Barkers, Saws, Planes 2.0


Note: n 1 indicates: If people are transported,
Lovejoy does not recommend and will
not warranty the use of the coupling.

The factors in Table 1 are for general guidance
and can be modified by customers´ specialist
knowledge of their own equipment.

Driving Machine Service Factor SFD Table 2
Driving equipment SFD
Multi-cylinder engine
8 or more 0.5
6 1.0
4 or 5 1.5
Less than 4 Refer to Lovejoy
Variable speed motors 0.8
Electric motors1 and turbines 0

1 Except variable speed motors
Please consult our Application Engineering
Department if axial excitations are foreseeable
either on the driving or driven side.

jbj Techniques provide:

»  An extensive range of couplings for mechanical power transmission.
»  Many standard types and sizes held in stock for quick despatch.
»  Technical expertise and in-house machining facilities for minor customisation or full bespoke couplings.
»  A wide range of coupling types to fulfill the requirements of a vast range of applications.

Ranging from miniature couplings, all steel gear couplings, flexible spider couplings, shaft couplings, torque limiting couplings, disc and grid type couplings, ATEX compliant and shaft locking devices. Magnetic couplings for power transmission between hermetically sealed areas.

There are a range of criteria in specifying the most suitable coupling for your application but the jbj Techniques technical department will guide you all the way to specify the right coupling for power transmission.
Questions?

Contact
jbj Techniques Limited
for friendly help and advice
telephone: +44 (0)1737 767493
email:
happy to help at jbj Techniques Limited, quality products for mechanical and fluid power
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