Part Number |
FKNN 6208 |
Type |
Ball Bearing Freewheel Clutch Unit |
Spring |
Z (Tension) |
Sealed |
No |
Lubrication1 |
None |
Inner Ring Keyway |
Yes |
Outer Ring Keyway |
Yes |
Integrated Ball Bearing |
Yes |
Integrated Roller Bearing |
No |
Shaft & Housing Tolerances
Shaft Tolerance |
n6 |
Housing Tolerance |
N7 |
Shaft & Housing Chamfer |
1mm × 15° |
Geometrical Data
Bore Diameter |
d [mm] |
40 |
Outer Diameter |
D [mm] |
80 |
Width |
W [mm] |
18 |
Edge Radius |
r [mm] |
1.5 |
Inner Ring Keyway Width |
b [mm] |
12 |
Inner Ring Keyway Depth |
t [mm] |
3.3 |
Outer Ring Keyway Width |
bor [mm] |
10 |
Outer Ring Keyway Depth |
tor [mm] |
3 |
Weight |
[kg] |
0.44 |
Ratings
Nominal Torque |
T [N*m] |
267 |
Nominal Torque |
T [ft*lb] |
196.9 |
Max. Static Radial Load |
Cstat [N] |
7752 |
Max. Dynamic Radial Load |
Cdyn [N] |
8902 |
Max. Indexing Frequency |
[Hz] |
10 |
Max. Speed - Unsealed3 |
n [RPM] |
3700 |
Max. Speed - Sealed |
n [RPM] |
1900 |
Max. Temp. Unsealed4 |
[°C] |
140 |
Max. Temp. Sealed |
[°C] |
110 |
Notes:
1. Standard lubrication is oil for unsealed clutches and grease for sealed clutches. Lubrication requirements are specific for proper sprag clutch function. Please consult catalog and/or GMN USA engineers.
2. The stated speed and torque ratings are contingent on utilizing specified tolerances, correct installation techniques, and operating temperature and load conditions below the specified maximums. If specific applications differ, please consult GMN USA engineers.
3.The stated RPM value is for the maximum freewheel rotational speed for the sprags, not the shaft or housing. High freewheel rotational speeds can produce centrifugal forces that can cause the sprags to lift off from frictional contact, therefore creating an opportunity for improper engagement and potential slip. The sprag RPM must be below the listed value before engagement occurs. The actual sprag freewheel speed is difficult to determine because the sprags are driven by frictional forces from the race(s) and lubrication. Theoretically there is no maximum rotational speed in the driving direction; the inner race, sprags, and outer race rotate as one unit unaffected by centrifugal forces. Please consult GMN USA engineers with high RPM applications that approach or exceed the stated RPM rating.
4. The stated temperature rating is for an injection molded cage. The maximum temperature rating is 170°C for a steel cage.
Applications:
Backstop
A Backstop application is where rotation
is allowed in one direction and stopped in
the opposite.
Application examples:
· Conveyor equipment
· Mixers
· High voltage switches
· Furniture industry
· Turnstiles and revolving doors
· Geared motors
· Winches
· Elevators
· Cranes
· Strap/belt tighteners
· Bucket conveyors
· Belt reversing locks
· Fans
· Automatic doors (subway)
· Fire damper flaps
· Aviation technology
· Roller plants
· Summer skiing
Indexing clutch
A repeated drive then idle motion will
be transferred to the driven side, step by
step, as rotary motion in one direction (the
clamping direction).
Application examples:
·Paper processing (advance)
· Seeding machines
· Staplers (staples)
· Conveyor belts (drive)
· Ratchets
· Ratchet wrenches
· Roller advance
· Installation tools
· Automation technology
Overrunning clutch
If the speed of the driven side exceeds the
speed of the driving side,the freewheel-clutch disengages the driving and driven sides by switching from torque transimit to idle.
Application examples:
·Copier machines
· Printing machines
· Conveyor equipment
· Transport equipment (speed matching)
· Starters for combustion engines
· Ergometers
· E-bikes
· Bicycle hubs
· Starters
· Emergency power aggregates
· Generators
· Hybrid applications (E-mobility)
· Palletizing and storage systems
· Model helicopters
· Hand operated sirens
· Roller coasters
· Washing systems
· Continuous ovens
· Compressors
· Compensating gearboxes
· Gas turbine drives
· Pump drives
· Belt drives
· Wheelchairs