RINGSPANN REK Series User manual

Schaberweg 30-38
Telephone [phone]
Fax [phone]
www.ringspann.com
[email protected]
61348 Bad Homburg
Germany
Installation and operating instructions for
elastic jaw couplings REK …DGO/…DHO/…DGZ
E 06.700e

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 2
Important
Before installation and commissioning of the product takes place, these installation and operating
instructions must be read carefully. Notes of caution and hazard warnings are to be paid particular
attention to.
These installation and operating instructions apply on condition that the product meets the selection
criteria for its proper use. The selection and dimensioning of the product are not the subject of these
installation and operating instructions.
If these installation and operating instructions are not observed or are interpreted wrongly, this shall
invalidate any product liability and warranty of RINGSPANN GmbH; the same also applies in the case
that our product is taken apart or changed.
These installation and operating instructions are to be kept in a safe place and must, in the event of
onward delivery of our product –be it individually or as part of a machine –be passed on along with
the product so that the user has access to them.
Safety information
The installation and commissioning of our product may only be carried out by trained personnel.
Repair work may only be performed by the manufacturer or by authorised RINGSPANN agencies.
If there is suspected malfunctioning, the product, or the machine into which it is built, must be tak-
en out of operation immediately and RINGSPANN GmbH or an authorised RINGSPANN agency
is to be informed.
The power supply is to be switched off during work on electrical components.
Rotating parts must be secured by the buyer against unintentional touching.
In the case of supplies made to a foreign country, the safety regulations applicable in that country
are to be taken into consideration.
This is a translation of the German original version!
In case of inconsistencies between the German and English version of this
installation and operating instruction, the German version shall prevail.

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 3
Contents
1. General information
1.1. Function
1.2. General safety instructions
1.3. Other applicable provisions, standards etc.
1.4. Classification in accordance with EC Machinery Directive 2006/42/EC
2. Design and function / parts list
2.1. Labelling
2.2. Dimensions
2.3. Parts list
3. Intended use
4. Warning signs / Impermissible use
5. Condition as delivered
6. Storage
7. Technical prerequisite for reliable operation
7.1. Technical specifications
7.2. Permissible misalignments
7.2.1. Inspection of the radial misalignment
7.2.2. Inspection of the angular misalignment
7.3. Manufacturing the hub bore
7.4. Elastomer elements
8. Assembly
8.1. General assembly instructions
8.2. Assembly of the couplings REK…DGO and REK…DHO
8.3. Assembly of the couplings REK…DGZ
9. Start-up
10. Operational disturbances
11. Maintenance and repair
12. Spare part stockpiling
13. Disposal
14. Supplement for operation in areas with potentially explosive atmosphere
14.1. Normal operation
14.1.1. Explosive atmosphere
14.1.2. Instructions for use
14.2. Instructions on occupational health and safety
14.3. Setup and assembly
14.4. Control, inspection and repair
14.5. Testing
15. Declaration of Conformity according to Directive 2014/34/EU

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 4
1. General information
1.1. Function
The main task of the elastic jaw coupling consists in transferring the torque of one shaft
end onto another element. Additionally, the coupling is designed to compensate angular,
radial and axial misalignments and reduce the intensity of vibrations and shocks.
1.2. General safety instructions
Safety takes the highest priority for all works with and on the coupling.
To ensure this, the following safety instructions must be observed:
- During installation and maintenance work, the drive motor must be secured against un-
intended start-up and the load side against turning back.
- Accidental touching of the coupling during operation must be prevented with a suitable
cover or protective device.
- Do not reach into the working area of the coupling during operation.
1.3. Other applicable provisions, standards etc.
The couplings are designed on the basis of DIN 740, part 2 (see RINGSPANN catalogue
“shaft coupling”). If the operating conditions (e.g. output, speed) should change, the original
design of the coupling must be reviewed along with the load-bearing capacity of the shafts
and the used shaft-hub-connections.
The locking screws are in compliance with DIN EN ISO 4029.
1.4. Classification in accordance with EC Machinery Directive 2006/42/EC
The couplings type REK … DGO/…DHO/…DGZ are a machine element. Since machine
elements do not fall under EC Machinery Directive 2006/42/EC, RINGSPANN does not
draw up a declaration of incorporation. All important information with regards to the installa-
tion, commissioning and operation is explained in the following.
2. Design and function / parts list
2.1. Labelling
Depending on the coupling size, the parts are labelled as follows:
Hubs:
- RINGSPANN logo
- Abbreviated designation
Elastomer elements:
- RINGSPANN logo
- Size designation
Spacer and driver
- RINGSPANN logo
- Abbreviated designation
- Marks for mounting position

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 5
2.2. Dimensions
Figure 2.1: Drawing REK…DGO Figure 2.2: Drawing REK…DHO
Size
REK…DGO
REK…DHO
ØD
mm
ØD1
mm
L1
mm
L2
mm
C
mm
C1
mm
O
mm
ØD
mm
ØD1
mm
ØD2
mm
L1
mm
L2
mm
C
mm
C1
mm
O
mm
0024
68
46
20
8
8
10
2 - 4
-
-
-
-
-
-
-
0028
80
68
30
10
12
18
2 - 4
-
-
-
-
-
-
-
0042
95
76
35
12
15
21
2 - 4
-
-
-
-
-
-
-
0048
110
86
40
14
16
25
2 - 4
110
86
62
40
20
10
25
2 - 4
0055
125
100
50
18
22
33
2 - 4
125
100
75
50
23
14
33
2 - 4
0060
140
100
55
20
20
38
2 - 4
140
100
82
55
28
14
38
2 - 4
0065
160
108
60
20
25
39
2 - 6
160
108
95
60
28
16
39
2 - 6
0075
180
125
70
20
33
48
2 - 6
180
125
108
70
30
20
48
2 - 6
0080
200
140
80
24
38
57
2 - 6
200
140
122
80
32
24
57
2 - 6
0090
225
150
90
18
48
65
2 - 6
225
150
138
90
38
26
65
2 - 6
0100
250
165
100
18
58
70
3 - 8
250
165
155
100
42
29
70
3 - 8
Table 2.1: Dimensions REK…DGO and REK…DHO
Figure 2.3: Drawing REK…DGZ

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 6
Size
REK…DGZ
ØD
mm
ØD1
mm
ØD2
mm
L1
mm
L2
mm
L3
mm
C
mm
C1
mm
O
mm
0028
80
68
55
30
45
100 / 140
12
20
5
0042
95
76
70
35
45
100 / 140
15
20
5
0048
110
86
80
40
50
100 / 140 / 180
16
25
5
0055
125
100
90
50
50
100 / 140 / 180
22
25
5
0060
140
100
100
55
65
140 / 180
20
33
5
0065
160
108
108
60
70
140 / 180
25
35
6
0075
180
125
125
70
80
140 / 180
33
40
6
0080
200
140
140
80
90
180 / 200 / 250
38
45
6
0090
225
150
150
90
100
180 / 200 / 250
48
55
6
0100
250
165
165
100
110
200 / 250
58
61
8
Table 2.2: Dimensions REK…DGZ
2.3. Parts list
Figure 2.4: REK…DGO Table 2.3: Parts list REK…DGO and REK…DHO
Figure 2.5: REK…DHO
Pos.
Quantity
Description
1
1
Hub type 0
2
1
Hub type I / II
3
Size dependent
Elastome relements
4
2
Locking screw
5
1
Driver
6
Size dependent
Screws

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 7
Figure 2.6: REK..DGZ
Pos.
Quantity
Description
1
1
Hub type 0
2
1
Hub type I / II / III
3
Size dependent
Elastomer elements
4
2
Locking screw
5
1
Driver
6
Size dependent
Screws
7
1
Spacer
Table 2.4: Parts list REK…DGZ
3. Intended use
The coupling may only be installed, operated and serviced if
- the operating instructions have been read and understood,
- the executing person possesses the necessary qualifications,
- authorisation has been given by the company.
The couplings type REK … DGO / …DHO / …DGZ may only be operated within the operating
limits specified in section “7. Technical prerequisite for reliable operation”.
RINGSPANN shall not assume any liability for damages that result from unauthorised
constructional changes or an unintended use.
4. Warning signs / impermissible use
An impermissible use is given if:
- the shaft-hub-connection was not designed correctly
- the coupling hubs have been thermally overloaded during assembly
- the fit pair for parts to be joined has not been coordinated correctly
- the parameters necessary for the selection of the coupling were not communicated
- the tightening torques of the screw connection do not correspond with the specifications
- the coupling is wrongly fitted
- parts from other manufacturers are used
Mounting position

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
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Pages: 24
Page: 8
- damaged coupling parts are used
The further operation of couplings type Typ REK … DGO / …DHO / …DGZ is not permissible
under the following conditions:
- if the permissible limits of use (torque, speed, permissible misalignments, …) are ex-
ceeded
- exceeding or falling below the permissible temperature limits
- if the wear limit of the parts is reached
- changed running noises or the occurrence of vibrations
If the unit should be operated despite the aforementioned states, it can result in damages to the
coupling and the drivetrain.
5. Condition as delivered
Couplings are generally delivered ready-for-installation in individual parts. Upon customer re-
quest, pre-bored hubs are also available. If the hub bores are manufactured by the customer, the
information in chapter 7.3 must be observed:
6. Storage
The coupling hubs can be stored for 6 - 9 months in a roofed, dry room.
Under the same storage conditions, the properties of the elastomer elements remain unchanged
for up to 5 years.
Storage rooms must: - have a roof and be dry,
- be free of ozone-producing equipment,
- have a relative humidity of less than 65%,
- be free of condensation.
Attention!
RINGSPANN shall not assume any liability for any damages that result in the
event of any impermissible use .

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 9
7. Technical prerequisite for reliable operation
7.1. Technical specifications
Size
REK…DGO
REK…DHO
REK…DGZ
Max. permissible misalignments
REK…DGO / REK…DHO /
REK…DGZ
nmax
[min-1]
Mo-
ment
of
iner-
tia Jk
kgm2
nmax
[min-1]
Mo-
ment
of
inertia
Jk
kgm2
nmax
[min-1]
Mo-
ment
of
inertia
Jk
kgm2
L3
[mm]
Axial
[mm]
Radial
[mm]
Angular
[ ° ]
Indicator
value
[mm]
024
7000
0.0003
-
-
-
-
-
±1.5
0.4
1
1.2
028
6000
0.0012
-
-
6000
0.0014
0.0015
100
140
1.4
042
5500
0.0027
-
-
5500
0.0028
0.0031
100
140
1.66
048
5300
0.0055
5300
0.0047
5300
0.0056
0.0060
0.0064
100
140
180
1.92
055
5100
0.0107
5100
0.0095
5100
0.0099
0.01
0.011
100
140
180
2.18
060
4900
0.0140
4900
0.0150
4900
0.019
0.020
140
180
2.44
065
4250
0.0250
4250
0.0280
4250
0.032
0.034
140
180
2.79
075
3800
0.0450
3800
0.0490
3800
0.054
0.058
140
180
3.14
080
3400
0.0800
3400
0.0850
3400
0.100
0.105
0.110
180
200
250
3.49
090
3000
0.1350
3000
0.1500
3000
0.160
0.170
0.180
180
200
250
3.93
100
2750
0.2300
2750
0.2500
2750
0.280
0.300
200
250
4.36
Table 7.1: Technical specificatiions REK…DGO / …DHO / …DGZ
7.2. Permissible misalignments
The maximum permissible misalignment values (table 7.1) must be adhered to and may not
occur at the same time. In the event of the simultaneous occurrence of radial and angular off-
set, misalignments need to be exploited differently percentage-wise (see figure 7.2). If not ob-
served, damage to the coupling may result.
The misalignment as a percentage is calculated as follows:
Figure 7.1 shows the relationship for radial (Kr) and angular misalignments (Kw) occurring at
the same time:
∆𝐾[%] = ∆𝐾
𝑚𝑎𝑥. 𝑝𝑒𝑟𝑚𝑖𝑠𝑠𝑖𝑏𝑙𝑒 𝑑𝑖𝑠𝑝𝑙𝑎𝑐𝑒𝑚𝑒𝑛𝑡
∗100

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 10
Figure 7.1: Misalignment combination
Size
Max. initial misalignments
REK…
DGO
REK…
DHO
REK…
DGZ
Axial
[mm]
Radial
[mm]
Angular
[ ° ]
Indicator value
[mm]
024
-
-
±0.375
±0.1
0.25°
0.3
028
-
028
0.35
042
-
042
0.42
048
048
048
0.48
055
055
055
0.55
060
060
060
0.61
065
065
065
0.70
075
075
075
0.79
080
080
080
0.87
090
090
090
0.98
100
100
100
1.09
Table 7.2: Maximal initial misalignments
7.2.1 Inspection of the radial misalignment
Figure 7.2: Measurement with a straightedge Figure 7.3: Measurement with a dial gauge
Radial misalignment ΔKr
Angular misalignment ΔKw
Straightedge
Dial gauge

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
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Page: 11
The following measurement methods can be used to check radial/parallel misalignment.
Take a straightedge and place it onto the hub (item 1) as displayed in figure 7.2. With cou-
plings REK…DHO and REK…DGZ, turn the other hub (item 2) until distance R = 0 is
achieved. With coupling REK..DGO, the position where R=0 needs to be found through multi-
ple application of the straightedge. Taking this point as a basis, measure at an approx. 90° off-
set with a feeler gauge distance “R”. To be sure, distance R can be measured again at another
approx. 180°. It can also be carried out in a similar manner with a depth gauge. The largest
measured distance indicates the given radial misalignment.
Alternatively, the radial misalignment can be measured with the help of a dial gauge. The dial
gauge holder is mounted on a hub (item 1). Afterwards, place the volumetric flask on the pro-
cessed outer diameter of the second hub (item 2) (see figure 7.3). With couplings REK…DHO
and REK…DGZ, turn the hub one revolution and read off the full deflection of the dial gauge.
The radial misalignment amounts to half the full deflection.
If the rotation of the second hub (item 2) as with coupling REK…DGO is not possible, the dial
gauge must be placed multiple times at the perimeter. Note the highest and lowest value. The
difference between the values divided by 2 gives you the radial misalignment of the coupling.
Compare the maximum measured value with the permissible value of the initial misalignment
in table 7.1. If the permissible value is exceeded, better alignment needs to be carried out.
7.2.2 Inspection of the angular misalignment
Figure 7.4: Measurement with a feeler gauge Figure 7.5: Measurement with a dial gauge
Calculate the maximum (Xmax.) and minimum (Xmin.) distance between the hubs (see figure 7.4)
using a feeler gauge. With coupling REK…DGZ, the distance can be measured with a caliper.
The difference between both values specifies the indicator value for the angular misalignment
in mm. The respective indicator value for the respective angular misalignment can be found in
table 7.2.
Alternatively, a measurement can be carried out with the dial gauge. To do so, place the dial
gauge holder on a hub (item 1) and the volumetric flask onto the processed plane surface of
Dial gauge
Feeler gauge

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 12
the other hub (item 2) as displayed in figure 7.5. It should hereby be placed as closely to the
outer diameter as possible. With couplings REK…DHO and REK DGZ, turn the hub one full
revolution and record the full deflection. With coupling REK…DGO, the dial gauge must be
placed at the perimeter multiple times until the maximum value has been found. The deflection
provides the indicator value for the angular misalignment in mm.
7.3. Manufacturing the hub bore
Size
Bore d1
Hub type 0
REK…DGO / …DHO
/ …DGZ [mm]
Bore d2
Hub type I
REK…DGO
[mm]
Bore d2
Hub type II
REK…DHO
[mm]
Bore d2
Hub type III
REK…DGZ
[mm]
min.
max.
min.
max.
min.
max.
min.
max.
024
8
24
8
24
-
-
-
-
028
13
30
8
30
-
-
8
32
042
13
42
13
42
-
-
13
42
048
13
48
13
48
13
38
13
48
055
13
55
13
55
13
45
13
55
060
13
60
13
60
13
50
13
60
065
13
65
13
65
13
58
13
65
075
23
75
13
75
23
65
23
75
080
25
85
25
85
25
75
25
85
090
35
90
35
90
35
85
35
90
100
44
100
44
100
44
95
44
100
Table 7.3: Permissible bore diameter
All individual parts are supplied balanced in accordance with DIN ISO 1940 in balance quality G
6.3.
When manufacturing the hub bore, it must be ensured that:
- the hub is precisely aligned,
- the form and positional tolerances in accordance with DIN ISO 286 are adhered to (see
figure 7.3).
If the hub is to be designed with a keyway nut, it is to be brought in between the cams as displayed
in figure 7.3 or between bores for hub types 2 and 3. The design and inspection of the keyway
connection falls to the operator and is his responsibility.
The decision on the necessity of retroactive balancing lies with the operator.
Life-threatening danger!
The max. permissible bore diameters specified in table 7.3 may not be ex-
ceeded. If the permissible values are exceeded, the hub could tear during op-
eration. Here, there is life-threatening danger due to flying parts.

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
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Page: 13
Figure 7.3: Specifications for the form and positional tolerance of the bore and position of the keyway nut
The following fit pair in accordance with DIN 748/1 is recommended:
Bore [mm]
Shaft tolerance
Bore tolerance
≤ 50
k6
H7
> 50
m6
Table 7.4: Fit pairs
Locking screws in accordance with DIN EN ISO 4029 should be used for axial securing.
Here the following applies:
Bore d1/d2
[mm]
from
8
22
38
58
75
to
22
38
58
75
110
Size locking screw G
M5
M6
M10
M12
M16
Tightening torque [Nm]
2
4
17
40
80
Table 7.5: Size and tightening torques of the locking screws
Note!
The operator bears the sole responsibility for damages that may occur
as a result of defective rework on the unbored / pre-bored coupling
parts.
Attention!
RINGSPANN shall not assume any liability for any resulting damages that
arise from work carried out by the operator.

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 14
7.4. Elastomer elements
Figure 7.4: NBR 75 Shore-A
Size
Nominal
torque
TkN
Nm
Max. torque
TKMAX
Nm
Alternat-
ing
torque
TkW
Nm
Torsional stiffness
CT dyn
Nm/rad x 103
1.0
TkN
0.5
TkN
0.25
TkN
0024
34
102
5
3.0
1.1
0.4
0028
60
180
9
8.0
2.7
1.1
0042
100
300
15
12.0
4.1
1.7
0048
160
480
24
19.0
6.8
2.7
0055
240
720
36
28.8
10.4
4.2
0060
360
1 080
54
42.0
15.0
6.0
0065
560
1 680
84
77.0
28.0
11.0
0075
880
2 640
132
145.5
58.1
26.9
0080
1 340
4 020
201
228.0
91.0
42.0
0090
2 000
6 000
300
341.8
122.0
63.0
0100
2 800
8 400
420
472.0
169.0
87.0
Table 7.6: Technical spefications PU 92 Shore-A
Figure 7.5: PU 92 Shore-A
Elastomer element:
NBR 75 Shore-A
Material:
Nitrile rubber
Hardness:
75±5 Shore-A
Temperature range:
-40°C to +100°C
Colour:
black
Elastomer element:
PU 92 Shore-A
Material:
Polyurethane
Hardness:
92±5 Shore-A
Temperature range:
-30°C to +80°C
Colour:
orange

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
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Page: 15
Table 7.6: Technical specifications PU 92 Shore-A
Figure 7.6: HTrans
Table 7.7: Technical spefications HTrans
Size
Nominal
torque
TkN
Nm
Max. torque
TKMAX
Nm
Alternat-
ing
torque
TkW
Nm
Torsional stiffness
CT dyn
Nm/rad x 103
1.0
TkN
0.5
TkN
0.25
TkN
0024
51
153
8
2.0
1.6
1.4
0028
90
270
14
5.0
4.0
3.4
0042
150
450
23
7.0
6.1
5.2
0048
240
720
36
12.0
10.0
8..6
0055
360
1080
54
18.3
15.3
13.2
0060
540
1620
81
27.0
22.0
19.0
0065
840
2520
126
50.0
41.0
35.0
0075
1320
3960
198
99.2
71.5
54.0
0080
2010
6030
302
155
112.0
84.0
0090
3000
9000
450
230.4
182.1
134.4
0100
4200
12600
630
318.0
252.0
186.0
Elastomer element:
HTrans
Material:
Polyurethane
Hardness:
55±5 Shore-D
Temperature range:
-30°C to +120°C
Colour:
white
Size
Nominal
torque
TkN
Nm
Max. torque
TKMAX
Nm
Alternat-
ing
torque
TkW
Nm
Torsional stiffness
CT dyn
Nm/rad x 103
1.0
TkN
0.5
TkN
0.25
TkN
0024
85
255
13
5
7.8
2.676
0028
150
450
23
12
18.9
6.478
0042
250
750
38
19
29.0
9.925
0048
400
1 200
60
31
47.4
16.244
0055
600
1 800
90
47
49.7
45.314
0060
900
2 700
135
69
73.0
25.000
0065
1 400
4 200
210
127
133.6
66.560
0075
2 200
6 600
330
248
167.0
130.000
0080
3 350
10 050
503
388
261.0
203.000
0090
5 000
15 000
750
591
472.0
355.000
0100
7 000
21 000
1050
817
652.0
491.000

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 16
8. Assembly
8.1. General assembly instructions
Before beginning with assembly, check for the completeness of the delivery (see chapter
2.3 Parts list) and the dimensional accuracy of the bores, the shaft, the nut and the keyway
(see 7. Technical prerequisite for reliable operation). The parts are to be cleaned of pre-
servative agents.
8.2. Assembly of the couplings REK…DGO and REK…DHO
1. Mount the hubs onto the input and output shafts
→ the driver (item 5) does not need to be disassembled (REK…DHO)
→ in the event of disassembly, the position of the driver (item 5) on the hub (item 2) is
to be marked and observed during assembly
→ facilitated sliding onto the shaft by heating up the hubs (approx. 80°C)
→ if necessary, the shafts can protrude out of the hub or remain inside. A sufficient
supporting length of the keyway nut must be ensured.
2. Slide the units in axial direction until the O measure is achieved (see chapter 2.2 Di-
mensions)
→ if the units have already been securely installed, the O measure can be adjusted by
sliding the hubs onto the shaft. A sufficient supporting length of the keyway nut must
be ensured.
→ measure O must be adhered to and may deviate within the permissible axial initial
misalignment
→ if the permissible value is exceeded, the coupling may be damaged.
3. Tighten the set screws (item 4) with the respective tightening torque (see table 7.5
Manufacturing the hub bore)
4. Check the alignment, see chapter 7.2
The given misalignments should be measured with suitable measuring equipment, e.g. dial
gauge, straightedge, feeler gauge or depth gauge.
Information
The remaining misalignments should generally be as small as possible. When
commissioning, the actual misalignments should be no more than 25% of the
max. permissible misalignment figures (see chapter 7.2 Permissible misalign-
ments). The remaining 75% of misalignments provide security against external in-
fluences that arise during operation, such as deformation in the machine and
thermal expansion.
8.3. Assembly of the couplings REK…DGZ
1. Mount the hubs (items 1 and 2) onto the input and output shaft
→ facilitated sliding onto the shaft by heating up the hubs (approx. 80°C)
Attention!
Use suitable means of protection when working with the heated hubs. Touch-
ing the heated hubs without safety gloves causes burns.

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 17
2. Slide the units in axial direction until the L3 measure is achieved (see chapter 2.2 Di-
mensions)
→ if the units have already been securely installed, the L3 measure can be adjusted by
sliding the hubs onto the shaft. A sufficient supporting length of the keyway nut must
be ensured.
→ Measure L3 must be adhered to and may deviate within the permissible axial initial
misalignment
→ If the permissible value is exceeded, the coupling may be damaged.
3. Take apart the transmission group consisting of items 7 + 5.
4. Slide the cams from the driver (item 5) between the elastomer elements of the hub
(item 1) until stop
5. Mount the spacer (item 7) between hub (item 2) and driver (item 5).
→ Observe the marks for the mounting position of the spacer (items 7 and 5)
6. Tighten the screws (item 6) with the specified tightening torque in table 8.1.
7. Check measure O according to table 2.2
8. Tighten the set screws (item 4) with the respective tightening torque (see table 7.5)
9. Check the alignment, see chapter 7.2
Size
Thread
Tightening torque
Nm
0028
M6
12.8
0042
M6
12.8
0048
M8
31.2
0055
M8
31.2
0060
M10
61.6
0065
M10
61.6
0075
M10
61.6
0080
M12
150
0090
M12
150
0100
M16
250
Table 8.1: Tightening torques of the screws
9. Start-up
Before start-up, the following parameters need to be checked:
- the tightening torque of all screws,
- the tightness of the set screws,
- the alignment of the coupling,
- the clearance O.
The operator has the task of attaching a suitable coupling protection to prevent the unintended
touching of the coupling during operation. It may only be removed when the machine is at a
standstill.
During commissioning, attention must be paid to vibrations and running noises. If any vibra-
tions or unusual running noises should occur, the drive unit must be immediately switched off.
Attention!
Use suitable means of protection when working with the heated hubs. Touch-
ing the heated hubs without safety gloves causes burns .

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 18
10. Operational disturbances
The possible operational disturbances are listed in the following table. In order to remedy them,
first bring the unit to a standstill and then follow the further instructions in the column “Reme-
dy”. This table only provides a starting point for the search for the cause. All neighbouring com-
ponents should also be subjected to an examination.
Disturbances
Causes
Remedy
Danger notice for
areas with poten-
tially explosive at-
mosphere
Changes in
sounds or vi-
brations
Alignment error
1) Eliminate the cause of the
alignment error
2) Carry out wear inspection
Increased tempera-
ture on the elasto-
mer surface, ignition
risk as a result
Wear of elasto-
mer elements →
transfer torque
via metal contact
1) Disassemble coupling, re-
move residues of elastomer
elements
2) Check coupling parts, re-
place damaged parts
3) Insert elastomer elements,
install coupling parts
4) Check alignment, correct if
necessary
Ignition risk due to
formation of sparks
Screws for axial
hub securing are
loose
1) Check alignment
2) Tighten screws for axial hub
securing, secure against re-
peated loosening
3) Carry out wear inspection
Ignition risk due to
hot surfaces and
spark formation
Cam break
Wear of elasto-
mer elements →
transfer torque
via metal contact
1) Replace entire coupling
2) Check alignment
Ignition risk due to
spark formation
Overload
1) Replace entire coupling
2) Check alignment
3) Determine reason for over-
load
Operating pa-
rameters do not
correspond to the
coupling output
1) Check operating parame-
ters, select larger coupling if
necessary
2) Install new coupling
3) Check alignment
Operating error
1) Replace entire coupling
2) Check alignment
3) Instruct and train operating
staff
Premature
wear of the
elastomer ele-
ments
Alignment error
1) Eliminate the reason for the
alignment error
2) Carry out wear inspection
Increased tempera-
ture on the elasto-
mer surface, ignition
risk as a result
Physical changes
due e.g. to too
low/high ambient
1) Disassemble coupling, re-
move residues of elastomer
elements

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 19
temperature, con-
tact with aggres-
sive liquids
2) Check coupling parts, re-
place damaged parts
3) Insert elastomer elements,
install coupling parts
4) Check alignment, correct if
necessary
5) Ensure that all triggers for
the physical changes have
been eliminated
Impermissible
ambient, contact
temperatures
1) Disassemble coupling, re-
move residues of elastomer
elements
2) Check coupling parts, re-
place damaged parts
3) Insert elastomer elements,
install coupling parts
4) Check alignment, correct if
necessary
5) Check and regulate temper-
ature, select elastomer ele-
ments from other material if
necessary
Premature
wear of the
elastomer ele-
ments due to
liquefaction on
the inside
Drive vibrations
1) Disassemble coupling, re-
move residues of elastomer
elements
2) Check coupling parts, re-
place damaged parts
3) Insert elastomer elements,
install coupling parts
4) Check alignment, correct if
necessary
5) Determine cause of vibra-
tions, select elastomer ele-
ments with smaller/higher
shore hardness if necessary
Ignition danger due
to spark formation
for metallic contact
of the cams
Table 10.1: Operational disturbances
To ensure that the coupling can be operated safely, the specified wear values may not be exceed-
ed. The wear of the coupling is detected by the measurement of the torsional backlash.
Size
0024
0028
0042
0048
0055
0060
0065
0075
0080
0090
0100
Wear limit
Smax [mm]
5.5
5.0
6.0
7.0
8.0
8.0
8.0
8.0
8.5
9.0
10.0
Tabelle 10.2: Wear limits
To measure the torsional backlash, one of the hubs must be clamped so that it can no longer be
turned. Turn the second hub without torque in one direction until stop. Make markings on both
hubs in this position as shown in figure 10.1 a). Then turn the same hub without torque in the op-
posite direction until stop. The markings move apart. The distance Xmax. (figure 10.1 b) and c)) be-
tween the markings indicates the given torsional backlash. Compare the measured value with the
threshold value in table 10.2. If the value of maximum permissible play is exceeded, all bushings,
bolts and nuts must be replaced.

Installation and operating instructions for
elastic jaw couplings
REK…DGO / …DHO / …DGZ
E 06.700e
Issue: 17.12.2019
Version: 03
Drawn: SCHW
Checked: EISF
Pages: 24
Page: 20
Figure 10.1: Check the wear limit
11. Maintenance and repair
Even if REK …DGO/ …DHO/ …DGZ ranks among the more low-maintenance couplings, it
should be subject to a visual inspection at least once a year. This includes:
- examining the coupling alignment,
- examining the coupling for damages,
- examining the screw connections,
- Check the wear limit of the elastomer elements.
The tightening torques of the screws must be examined at regular intervals.
12. Spare part stockpiling
In order to keep disturbances in operation to a minimum, it is advisable to keep a stock of spare
parts directly at the deployment site in order to be able to guarantee optimal operational capabil-
ity.
13. Disposal
At the end of its operating life:
- plastics must be disposed of via a disposal company,
- metals must be cleaned and disposed of properly with other scrap
metal.
Please also properly dispose of the packaging.
14. Supplement for operation in areas with potentially explosive atmosphere
If the elastic shaft couplings REK …DGO / …DHO / …DGZ are operated in or in connection with
potentially explosive atmosphere, the following supplemental information must also be observed.
Attention!
RINGSPANN shall not assume any liability for any occurring damages if
spare parts from other manufacturers are used.