GERWAHcouplings联轴器
The company
Our company was established in 1981.
The GERWAH-Group has been expanding continuously since its establishment and is represented in approximately 25 countries.
We are constantly market-oriented and conformed to the permantent changes in the economic require-ments. Nevertheless, we are able to find the optimum solution and give the most suitable support to our customers for their specific applica-tions.Due to our ideas of innovative pro-
ducts, we have become one of the
significant business partners in the
mechanical engineering industry.
We are a supplier of high-quality
products. Technical competence
and know-how, advice and services
are the pillar of our company and
represent the basis for our success-
ful and professional co-operating
with our customers, who are the
focus of our activities.
The structure of our organisation
enables us to offer highly technical
solutions on the one hand, and a
wide range of standard products
on the other hand.
The ideal location of our company
nearby the Rhein Main Airport in
Frankfurt guarantees our clients
throughout the world that their
deliveries will be dispatched punc-
tually.
Utilise our experience and know-
how in motive power engineering
and do include us in your planning
stage. The special quality and moti-
vation provided by our engineers
will prevent you from wasting a lot
of time and expenses.
We enjoy presenting solutions. Our
aim is nothing but your satisfaction.
Speak to us.
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Product information / Design
? Backlash-free transmission of torque
? High torsional stiffness, precision of transmission of rotational angle ? Different torsional stiffness ? Backlash-free shaft connection ? Small dimensions, low moment of inertia
? Compensation for radial, axial,and angular misalignment ? Free of wear, maintenance-free,no standstill period
? Not sensitive to temperatures bet-ween -30 °C and +100 °C, higher temperature ranges available on demand
? Simple and operationally safe assembly
? Economical and user-friendly due to modular system ? Nominal moments between 0.4-5000 Nm
Backlash-free, torsionally stiff metal bellows couplings are ready to install when delivered. The metal bellows are made of anti-corrosive steel, all other parts are manufac-tured from aluminum or steel and partly have an environmental fri-endly protective coating.
As a standard, the boreholes are equipped with a fitting in accordan-ce with ISO-H7. For the shafts, we recommend an transition, e.g.H7/g6. When selecting other shaft fitting, the fitting should not exceed a maximum of 0.03 mm.
The power transmission between the coupling hub and the shaft occurs through compression and friction between the contact sur-faces. Special attention must be paid to the tightening torque of the re-taining screws as well as the perfect condition of the contact surfaces.
The contact surfaces must be free of oil and grease. Types with a keyway are available. The torques indicated in the lists of Technical Data can only be safely transferred if these points are complied with.Otherwise it would be necessary to make compromises.
Typical characteristics of metal bellows couplings The dimensioning in accordance with the torque
Metal bellows couplings are gene-rally designed according to the
nominal torque stated in the lists of the Technical Data below. The
nominal torque must always be hig-her than the regularly transferred torque. This generally applies to the use of servo motors, whose accele-ration moment in positive and negative directions is much higher than the nominal moment.The use of metal bellows couplings which are put in controlled, high dynamic drives, the following
dimensioning values have proven to be reliable in practice:
K = 1,5for evenly shaped movements K = 2for unevenly shaped movements K = 2,5 – 4
for jerky movements
For Servo drives within tool making machines, the values for K of 1.5-2should be used.
In general, the following relationships apply:
T KN
≥
K x T AS
x
= [Nm]
J Mach J Mot + J Mach
Design
The arithmetic calculation is clearly much higher than the expected resonance frequency.
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To connect two shafts, backlash-
free shaft-hub connection using
collet clamps. For torques between
0.10–10 Nm.
Technical data
and dimensions
To connect two shafts, backlash-
free shaft-hub connection using a
collet clamp and an expanding
clamp.
For torques between 0.40–10 Nm.
Technical data
and dimensions
To connect two shafts, backlash-
free shaft-hub connection using set
screws.
For torques between 0.10–10 Nm.
Technical data
and dimensions
To connect two shafts, backlash-
free shaft-hub connection using
conical hubs. For torques between
30–5000 Nm.
Technical data
and dimensions
To connect two shafts, backlash-
free shaft-hub connection using
collet clamps. For torques between
0.40–10 Nm.
Technical data
and dimensions
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To connect two shafts, backlash
free shaft-hub connection using
outer conical hubs, contracting disc,
no releasing screw required, release
during dismantling. For torques
between 18–5000 Nm.
Technical data
and dimensions
Same as Series AKD but with shor-
ter length and higher torsional
stiffness. For torques between
18–500 Nm.
Technical data
and dimensions
Variable installation element for
mounting of hubs, flanged shafts,
flanges, etc. For torques between
18–5000 Nm.
Technical data
and dimensions
Appropriate coupling for Fanuc AC
motors. Shorter installation models
available. For torques between
18–60 Nm.
Technical data
and dimensions
User-friendly solutions
To connect two shafts, backlash
free shaft-hub connection using
collet clamps. For torques
between 18–500 Nm.
Technical data
and dimensions
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Series DK – miniature (discontinued model)
Angular misalignment:
1.2°to 2°, depending on length
Hub bores:
Standard quality of fitting H7.
Custom bores on demand.
Standard bores:
DK 1?3H7DK 4-15?6H7
DK 20
?6H7 und 10H7DK 45-100
?10H7
Tooling materials:
Hubs made of anodized aluminum, metal bellows made of stainless steel.Stainless steel version also available.1) Tolerance of keyway: Standard JS9.
9
Technical Data, Dimensions
Angular misalignment:
1.2°to 2°, depending on length
Hub bores:
Standard quality of fitting H7.
Custom bores on demand.
Standard bores:
DKN 4-15?6H7
DKN 20
?6H7 und 10H7DKN 45-100
?10H7
Tooling materials:
Hubs made of anodized aluminum, metal bellows made of stainless steel.Ordering data 1) Tolerance of keyway: Standard JS9.
Angular misalignment: 1.2°to 2°, depending on length Hub bores:
D2: We recommend an H8 fitting for the
share bore.
Standard bores:
DK/S 4-15D1=6H7
DK/S 20D1=6H7 und 10H7
DK/S 45-100D1=10H7
Tooling materials:
Hubs made of anodized aluminum, DK/S 4-9
expanding hubs made of brass, DK/15-100
expanding hubs made of steel, metal bellows
made of stainless steel.
Stainless steel version also available.
1) Tolerance of keyway: Standard JS9
10
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Ordering data Technical Data, Dimensions
Angular misalignment:
1.2°to 2°, depending on length
Hub bores:
Standard quality of fitting H7.
Custom bores on demand.
Standard bores:
EK 1?3H7EK 4-15?6H7
EK 20
?6H7 und 10H7EK 45-100
?10H7
Tooling materials:
Hubs made of anodized aluminum, metal bellows made of stainless steel.Stainless steel version also available.1) Tolerance of keyway: Standard JS9
Series AK with conical hubs
Ordering data
Dimensions (mm) – Series AK
Technical Data – Series AK
1) Keep space for the releasing screws.2) Larger bores on request.3) Stainless steel version also available.
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Series AK/SB with outer conical hubs – release during dismantling
Dimensions (mm) – Series AK/SB
Technical Data – Series AK/SB
1) Keep space for the releasing screws.
2) Stainless steel version also available.
Ordering data
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Series AKD with collet clamp
Technical Data – Series AKD
Ordering data
Dimensions (mm) – Series AKD
Hubs 18 to 60 made of aluminum,Hubs 80 to 500 made of steel, other materials available on request.
1) Tolerance of keyway: Standard JS9.
2) Smaller ?possible for lower torque of transmission.3) Stainless steel version also available.
Series AKN with retaining hub and increased torsional stiffness
Ordering data
Technical Data – Series AKN
Dimensions (mm) – Series AKN
Hubs 18 to 60 made of aluminum,
Hubs 80 to 500 made of steel, other
materials available on request.
1) Tolerance of keyway: Standard JS9.2) Smaller ?possible for lower torque of
transmission.
3) Stainless steel version also available.
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Series CK for flange mounting
Ordering data 1) Other bore diameters available on request.2) Stainless steel version also available.
Technical Data – Series CK
Dimensions (mm) – Series CK
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Series AKD-Fanuc
Ordering data 1) Other motor types on demand.
2) Keyway according to DIN 68851)alternati-vely on demand.
3) Stainless steel version also available.
Technical Data – Series AKD-Fanuc
Selection table – Series AKD-Fanuc
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Sample applications
Variable Series
Series AK/AKD
Model with collet clamp and inner conical hub Series AKN/S
Model with collet and expanding clamps
Series CK
With special flange Series DKN
Application – Linear actuator Series AK
Application – Gantry robot Series AKN
Application – servo-drive /milling machine
Series AKD/AK/SB
Model with collet clamp and outer conical hub
Series AKN-XX
Model with special hub on both sides
Series AKD/CK
Model with collet clamp and flange
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Assembly instructions
Assembly
Clean shaft ends and bores in hubs,degrease and check the tolerances.Insert both shaft trunks into the hubs of the metal bellows coupling,and firmly tighten the screws, after examining the axial installation dimensions.
The tightening torque of the screws and the maximum approved misa-lignment should not be exceeded (refer to list of Technical Data).Alignment
Figure 10 illustrates the individual types of misalignment.
The fitted metal bellows coupling must now be aligned. Please check the values indicated in the lists of Technical Data.
If several types of misalignment
appear simultaneously, then each of the individual values should not be exceeded. Moreover, they should be aligned.
The total of the real misalignments in percentage of the maximum value should not exceed 100%. Figure 9shows how to regulate.
The more precise the alignment, the more reserves are available to handle additional misalignments for opera-tion. This will have an advantageous
effect on the service life, balance quality, and the accuracy of trans-mission.
If several types of misalignment occur at once, then the values must be lower than each of the maxi-mum values. Dismantling
After loosening the backlash-free shaft-hub connections, the drive can be pulled apart and the metal bellows coupling can be removed.Conical bushings for Series AK are forced off with a hexagonal socket screw.
Please ask for our detailed assembly
instructions.
angular
radial axial Figure 9: Compensating for misalignment
Figure 10: Types of misalignment