Selecting Flexible Couplings
6 Huco Dynatork +44 (0) 1992 501900
Note 1: Not recommended in these conditions
Service Factors
2Peak torque values quoted in the coupling performance tables apply to uniform load conditions at constant speed where there is no misalignment
or axial displacement.
2The torque capacity of flexible couplings will reduce when acceleration is present, for example, in stop/start or reversing conditions.
2The more severe the acceleration, the greater reduction in torque capacity.
2Sliding couplings (Oldham and UniLat) are subject to a wear rate dependent on the number of cycles completed.
Load
Steady
State
1.5 2.0 2.0 3.0 4.0 - - - - -
1.5 2.0 2.0 3.0 4.0 - - - - -
1.0 2.0 2.0 3.0 4.0 - - - - -
1.0 1.5 1.5 3.0 4.0 - - - - -
1.0 2.0 4.0 4.0 4.0 - - - - -
1.0 1.5 2.0 (Note 1) (Note 1) - - - - -
1.0 1.5 2.0 (Note 1) (Note 1) - - - - -
1.0 1.5 2.0 (Note 1) (Note 1) - - - - -
- - - - - 1.0 2.0 4.0 6.0 8.0
- - - - - 1.0 1.5 2.0 3.0 4.0
Huco Flex B
1.5 2.0 2.0 3.0 4.0 - - - - -Huco Flex K
Huco Flex M
Huco Flex Ni
Huco Flex P
Huco Flex G
Huco
MultiBeam
Huco S-Beam
Huco TorqLink
Huco Oldham
Huco Flex - B
- - - - - 1.0 1.5 2.0 3.0 4.0Uni-Lat
Stop/Start Reversing Shock Shock &
Reversing <1 1 - 2 3 - 5 6 - 12 >12
Duty (Hours/Day)
In the simplest of terms a coupling’s purpose is
to transfer rotational movement from one shaft
to another. Reality is somewhat more
complicated, though, as flexible shaft
couplings have also to compensate for
misalignment between two shafts. This ability
must be balanced with the need to be pliable
in the planes of misalignment while still
having the torsional strength to carry out the
coupling’s main function. This is known as the
Compliance mechanism where compliance is
the capacity for allowing relative
displacement.
Several factors should always be taken into
consideration when looking to specify flexible
shaft couplings. These are torsional stiffness,
backlash, torque, life and attachment system.
All of these have bearing on coupling
selection.
The choice of couplings available to today’s engineers can be daunting, but
follow our guidelines and you will arrive at the optimum coupling for your
particular application.
2Does the coupling provide adequate misalignment
protection?
2Can it transmit the required torque?
2Do I need axial motion or axial stiffness?
2Can it sustain the required speed of rotation?
2Will it fit within the available space envelope?
2Can it operate at the designated ambient temperature?
2Does it provide torsional stiffness required for positional
accuracy?
2Does it provide electrical isolation
between the shafts?
2Will it have the required life
expectancy?
Introduction to
couplings
Selecting the ideal
coupling
Peak torque must be greater than application torque x service factor
Product Overview
General description
Standard bores
Temperature range
Connection
Electrically isolating
Peak torque largest size
Speeds
Where to use
Vari-Tork, Polyclutch
Basic clutch
Basic clutch + Oldham coupling
Polyclutch
L-Box
T-Box
Small, user-adjustable torque
limiters for concentric or in-line
mounting.
Operate by friction using
interleaved clutch plates.
Friction clutches interrupt
rotation when the load being
transmitted reaches a pre-
determined threshold. Used in
all kinds of small drives to help
protect personnel
and equipment.
Small 90° drives encased in
molded housings providing
electrical isolation between
shafts and mounting surface.
The L-Box is rated for
intermittent use, the
T box for continuous.
1:1 & 2:1 ratios are available
with the T-Box.
L-box offers a compact
means to route drives thru’
90°.
T-box offers 2 & 3 shaft
configurations for multiple
power offtake.
Clamp or Set Screw N/A
Up to 1000 rpm
slipping speed
60 Nm
6 to 32
–10 to +80°C
(when operating)
No
Up to 1500 rpm for
T-box
0.68 Nm
4 & 5 (shafts)
–20 to +60°C
See General Description above
Page 28 - 30 Page 26 - 27 Page 44 Page 42 - 43 Page 45 - 50 Page 51 - 56 Page 57 - 58
Sliding Disc type Universal / Lateral
type Double Loop type Jaw Coupling Universal Joints
& Teleshafts Friction Clutches Bevel Gearboxes
Oldham
Blind bored
Thru’ bored
Thru’ bored
Huco-Pol
Single joints
Double joints
Teleshafts
Encoder, resolver, tacho,
potentiometer drives. Small
positioning slides, dosing
pumps, & light drives generally.
Light power drives, pumps and
small generators
Light power drives where
misalignment is small
Intermittent applications in
business machines,
instrumentation, lab equipment,
analytical apparatus, etc.,
where steel joints would be
under-utilised.
Stepper drives for most
applications including
positioning slides, pumps,
actuators, etc.
Uni-Lat Flex-P Jaw coupling
General purpose, robust, easy
to use 3-part couplings with
replaceable wear elements.
Generous radial compensation
and pull-apart / re-engage
facility for blind assemblies.
Unique, general purpose light
duty couplings with generous
angular and radial
misalignment compensation.
Resist axial motion, can anchor
unrestricted shafts and perform
light push/pull duties.
Light duty plastic universal
joints and extensible drive
shafts (teleshafts).
Low mass, corrosion resistant,
ideal where conventional steel
joints would be under-utilised.
Exceptional flexibility in all
three directions, radial, angular
and axial
High torque capacity and high
speed are available from this
naturally balanced coupling
Clamp or Set Screw Clamp or Set Screw Set Screw Clamp or Set Screw Set Screw, Bonding, or
Cross-Pinning
Up to 3000 rpm.
44 Nm
2 to 30
–20 to +60°C
Yes
Up to 3000 rpm. Up to 3000 rpm. Up to 40,000 rpm.
12 Nm 18 Nm 133 Nm
3 to 22 3 to 16 3 to 16
–20 to +60°C –40 to +100°C –40 to +80°C
Yes Yes Yes
Up to 1000 rpm
10.7 Nm
3 to 20
–20 to +60°C
Yes
Material Options:
Aluminium
Stainless Steel
Huco Dynatork +44 (0) 1992 501900 5
Selecting Flexible Couplings
7Huco Dynatork +44 (0) 1992 501900
Round & Keywayed Bore Details & Codes
Metric
mm
Inch
fraction
Inch
decimal
Round
bore
code
Keywayed
bore
code
Key size
w x h
Key size
w x h
KK
Metric keys Inch keys
All shaft mounted products in this catalogue can be
specified with inch and/or metric bore diameters. A
standard range of sizes is listed for each product.
Where physical dimensions permit, keyways may be
specified at extra cost.
For the sake of uniformity and avoidance of errors
when ordering, bore diameters are designated with a
2-digit number which forms part of the order code.
Please note that only the bore diameters listed for
each product in the product pages are standard.
To specify a keywayed bore, prefix the 2-digit
number with a ‘P’ for metric keyways or an ‘R’ for an
inch keyway.
Standard keyways are machined to 2 specifications:
Bore codes prefixed 'P' denote a metric keyway
conforming to ISO 773/774 (BS 4235 Pt. 1).
Bore codes prefixed 'R' denote an inch keyway
conforming to BS 46 Pt. 1.
In most cases, keyways prefixed 'R' are compatible
with AGMA 9002–A86 but can differ in the depth of
the key seat.
All Huco couplings are RoHS compliant.
Combine the COUPLING REF in Main
Product Tables with BORE REFS in
Standard Bores Table.
Please identify both bores e.g.
Order Codes
706.19.1924
Coupling ref.
Ø B1 ref.
Ø B2 ref.
Note that our tooling produces a key seat
classified as ‘nominal’ being a nominal clearance
on standard keys
Shaft Diameter
Key width
K
*Not manufactured. Nearest alternative 4mm.
Intermediate size available on request
1–0.0394 08 ––– ––
1.588 1/16 0.0625 10 ––– ––
2–0.0787 11 ––– ––
2.286 – 0.0900 12 ––– ––
3–0.1181 14 ––– ––
3.048 – 0.1200 15 ––– ––
3.175 1/8 0.1250 16 ––– ––
*3.969 5/32 0.1563 –––– ––
4–0.1575 18 ––– ––
4.763 3/16 0.1875 19 ––– ––
5–0.1969 20 ––– ––
6–0.2362 22 ––– ––
6.350 1/4 0.2500 24 ––– ––
7–0.2756 25 2 x 2 8.00 ––P25
7.938 5/16 0.3125 27 ––1/8 x 1/8 0.3755 R27
8–0.3150 28 2 x 2 9.00 ––P28
9–0.3543 30 3 x 3 10.40 ––P30
9.525 3/8 0.3750 31 ––1/8 x 1/8 0.4380 R31
10 – 0.3937 32 3 x 3 11.40 ––P32
11 – 0.4331 33 4 x 4 12.80 ––P33
12 – 0.4724 35 4 x 4 13.80 – – P35
12.700 1/2 0.5000 36 ––1/8 x 1/8 0.5630 R36
13 – 0.5118 37 5 x 5 15.30 ––P37
14 – 0.5512 38 5 x 5 16.30 ––P38
15 – 0.5906 40 5 x 5 17.30 ––P40
15.875 5/8 0.6250 41 ––3/16 x 3/16 0.7160 R41
16 – 0.6299 42 5 x 5 18.30 ––P42
17 – 0.6693 43 5 x 5 19.30 ––P43
18 – 0.7087 45 6 x 6 20.80 ––P45
19 – 0.7480 46 6 x 6 21.80 ––P46
19.050 3/4 0.7500 47 ––3/16 x 3/16 0.8410 R47
20 – 0.7874 48 6 x 6 22.80 ––P48
22 – 0.8661 49 6 x 6 24.80 ––P49
22.225 7/8 0.8750 50 ––1/4 x 1/4 0.9930 R50
24 – 0.9449 51 8 x 7 27.30 ––P51
25 – 0.9843 52 8 x 7 28.30 ––P52
25.400 1 1.0000 53 ––1/4 x 1/4 1.1180 R53
28 – 1.1024 54 8 x 7 31.30 ––P54
28.575 1-1/8 1.1250 55 ––5/16 x 1/4 1.2400 R55
30 – 1.1811 56 8 x 7 33.30 ––P56
31.750 1-1/4 1.2500 57 ––5/16 x 1/4 1.3580 R57
32 – 1.2598 58 10 x 8 35.30 ––P58
34.925 1-3/8 1.3750 59 ––3/8 x 1/4 1.4830 R59
35 – 1.3780 60 10 x 8 38.30 ––P60
38 – 1.4961 61 10 x 8 41.30 ––P61
40 – 1.575 63 12 x 8 43.30 ––P63
50 – 1.969 70 14 x 9 53.8 __P70
50.800 2.000 71 ––1/2 x 1/2 2.224 R71
55 – 2.165 73 16 x 10 59.3 ––P73
60 – 2.362 75 18 x 11 64.4 ––P75
63.500 2-1/2 2.500 77 ––5/8 x 5/8 2.778 R77
65 – 2.559 78 18 x 11 69.4 ––P78
Flex-P |Double Loop Flexible Coupling
44 Huco Dynatork +44 (0) 1992 501900
Size Max Diameter Length L
+/- 1.0 Bore length Max Bores Mass kg x 10-3 Size Torque (Nm) A/F
(mm)
Dimensions Fasteners
DIMENSIONS & ORDER CODES
PERFORMANCE
10 047.10
- 049.10
-27 27 7.9 9.53 25 M3 0.32
0.94 1.5
20047.20
- 049.20
-484812.7 12.7 92M42.0
2.27 2.0
30 047.30
- 049.30
-54 55 16.0 16.0 124 M5 2.1
4.62 2.5
40 047.40
- 049.40
-56 56 16.0 16.0 136 M6 3.75
7.61 3.0
40* - 050.40 56 56 16.0 16.0 136 M6 7.61 3.0
Size Max Torque 1
(Nm)
Max Torque 2
(Nm)
max misalignment/displacement
Angular deg Radial mm Axial +/- mm
10 0.5 0.8 10 2.6 4.5
20 1.8 3 15 3.2 7.5
30 5 8 15 3.2 8.5
40 10 18 15 3.2 11
40* 2.5 4.5 15 3.2 11
Torque 1 = torque at maximum displacement
Torque 2 = torque at 1 deg. angular, 2mm axial and 0.5mm radial displacement
* Couplings with dissimilar bores are non-standard
STANDARD BORES*
Size +0.05/-0mm
3 3.175 4 4.763 5 6 6.350 7.938 8 9.525 10 12 12.700 14 15 15.875 16
20
10
30
40
Bore Ref 14 16 18 19 20 22 24 27 28 31 32 35 36 38 40 41 42
Materials & Finishes
Temperature Range
Hubs: Steel 230M07 pb Zn plated + clear passivate
or
Stainless Steel 303 S31 natural finish
Flexing Element: Hytrel
Fastener: Steel Hub: Alloy steel, black oiled
Stainless Steel Hub: stainless steel
–40°C to +100°C
Maximum Rotational Speed
3000 rev/min
steel zinc
plated hubs
stainless steel
hubs
Order Code
