Festo DHTG User manual

en Operating
instructions
8085860
2018-02e
[8085862]
Rotaring indexing table
DHTG

DHTG
2Festo – DHTG – 2018-02e
Translation of the original instructions
DHTG-EN
Identification of hazards and instructions on how to prevent them:
Danger
Immediate dangers which can lead to death or serious injuries
Warning
Hazards that can cause death or serious injuries
Caution
Hazards that can cause minor injuries
Other symbols:
Note
Material damage or loss of function
Recommendations, tips, references to other documentation
Essential or useful accessories
Information on environmentally sound usage
Text designations:
 Activities that may be carried out in any order
1. Activities that should be carried out in the order stated
– General lists
èResult of an action/References to more detailed information

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English – Rotaring indexing table DHTG
Table of contents
1 Operating elements and connections 4.........................................
2 Function and application 5...................................................
3 Transport and storage 5.....................................................
4 Requirements for product use 5...............................................
5 Installation 6..............................................................
5.1 Mechanical assembly 6......................................................
5.2 Installing the pneumatic system 7..............................................
5.3 Electrical installation 9.......................................................
6 Commissioning 10...........................................................
7 Operation 12...............................................................
8 Maintenance and care 13.....................................................
9 Dismantling and repairs 14...................................................
10 Accessories 16..............................................................
11 Troubleshooting 16..........................................................
12 Technical data 17............................................................
13 Characteristic curves 18......................................................

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1 Operating elements and connections
For all available product documentation èwww.festo.com/pk
123 5
6789
aJ
4
6
1Retaining screw for table bearing
2Threaded and pin hole for adapter
3Through hole for power supply
4Threaded and pin hole for plate
5Centring/through hole and thread for
fastening
6Adjusting screw for setting the cushioning
7Threaded hole for sensor for position sensing
8Supply port A and B for
clockwise/anti-clockwise rotation
9Supply port C and D for reciprocating
operation (sealed on delivery)
aJ One-way flow control valve for speed
regulation
Fig. 1

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2 Function and application
The DHTG rotary indexing table is a double-acting rotary drive
based on the toothed rack and pinion principle with forced locking
(as from size DHTG-140 also with overload protection). When the
compressed air ports are pressurised alternately, two toothed rod
pistons move backwards and forwards. By means of a pinion, the
pistons convert the linear movement into a rotary movement.
A second pair of pistons controls the engagement of the pinion in
the table gearing and the locking of the holding position. The
integrated shock absorber brakes the rotary indexing table in the
direction of rotation.
Fig. 2
The DHTG rotary indexing table is intended for turning the work load by a defined angle into a holding
position.
3 Transport and storage
 Take the weight of the DHTG into consideration. It weighs up to 25 kg.
 Ensure the following storage conditions are met:
– Short storage times and
– Cool, dry, shaded, corrosion-resistant storage locations.
4 Requirements for product use
Note
Improper handling can result in malfunctions.
 Be sure to always comply with the specifications in this chapter.
 Compare the maximum values specified in these operating instructions with those of your actual
application (e. g. forces, torques, temperatures, masses, speeds).
Only compliance with the load limits allows operation of the product in compliance with the relevant
safety regulations.
 Take into consideration the ambient conditions at the location of use.
Corrosive environments reduce the service life of the DHTG.
 Ensure that there is a supply of correctly prepared compressed air.
 Maintain the selected medium for the complete service life of the product.
Example: Always use non-lubricated compressed air.
 Pressurise your entire system slowly.
This will prevent uncontrolled movements from occurring.
For slow start-up pressurisation use safety start-up valve type HEL.
 Comply with the regulations of the trade association, the German Technical Control Board or
relevant national regulations.

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 Remove all transport packing such as foils, caps, cartons (except for any sealing elements in the
pneumatic connections and holes for the proximity switches). The packing is intended for recycling
(except for: oiled paper = other waste).
 Use the product in its original condition without any unauthorised modifications.
 Take the tolerance of the tightening torques into account. Unless otherwise specified, the tolerance
is ±20 %.
5 Installation
5.1 Mechanical assembly
 Make sure there is sufficient space for the pneumatic connections, for conversion or for replacing
the shock absorber.
 Fasten the DHTG with four screws and ZBH centring sleeves.
Tightening torques èTab. 1, Tab. 2.
Direct mounting from above
Size 65 90 140 220
Screw M4 M6 M6 M8
Recess for
centring sleeve
[mm] 7 12 12 15
[mm] 5 8 8 8
Tightening torque [Nm] 2.9 9.9 9.9 24
Tab. 1
Direct mounting from below
Size 65 90 140 220
Screw M5 M8 M8 M10
Recess for
centring sleeve
[mm] 7 12 12 15
Tightening torque [Nm] 5.9 24 24 47
Tab. 2
Fig. 3
Fig. 4

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 Fasten the blank plate with 6 screws and 2 centring pins.
After fitting, the 6 screw recesses can be sealed with the cover caps supplied (press in until flush).
Blank plate mounting
Size 65 90 140 220
Screw M4 M4 M6 M8
Locating hole
for centring pin
[mm] 4 4 5 6
Depth locating hole
for centring pin
[mm] 5 8 8 8
Tightening torque [Nm] 2.9 2.9 9.9 24
Tab. 3
5.2 Installing the pneumatic system
 Connect the pneumatic ports A to D (if applicable remove sealing elements).
Clockwise or anti-clockwise rotation1)
Size 65 90 140 220
Connection A Unlock and turn
Connection B Lock and return stroke
Connecting thread M5 Gx
Tightening torque 1.5 Nm 7 Nm
1) Modification è9 Dismantling and repairs
Tab. 4
Reciprocating operation1)
Size 65 90 140 220
Connection A Unlock
Connection B Lock
Connection C Clockwise rotation2)
Connection D Anti-clockwise rotation
Connecting thread M5 Gx
Tightening torque 1.5 Nm 7 Nm
1) Separate kit required (Accessories èwww.festo.com/catalogue)
2) Use external flow control valve
Tab. 5
Fig. 5
(A)(B)
Fig. 6
(D) (A)(B)(C)
Fig. 7

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As an example 4 interfaces are shown:
Simple interface
Clockwise/anti-clockwise rotation Reciprocating operation/flexible control
(1) (1) (1)
(1) Manual or electrically actuated 5/2-way valve
Tab. 6
Note
If used in safety relevant applications, additional measures are necessary, e. g. in
Europe the standards listed under the EU machine guidelines must be observed.
Without additional measures in accordance with statutory minimum requirements, the
product is not suitable for use in safety-related sections of control systems.
Extended interface
Clockwise/anti-clockwise rotation Reciprocating operation/flexible control
(3)
(2)
(1)
(3)
(2)
(1)
(1) Manual or electrically actuated 3/2-way valve
(2) Single or double-solenoid 5/2-way valve
(3) Non-return valve controlled
The compressed air is interrupted in the basic position of the valve (1). The air in the table is locked in
and the movement stops. The speed at which the table comes to a stand depends on the mass mo
ment of inertia and the angular velocity (division). It may therefore happen that the table moves into
its end position but without additional tightening torque. The table can be moved by hand within a
certain range.
Tab. 7

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5.3 Electrical installation
If proximity switches are used for position sensing:
Note
Faulty switching or damage to the proximity
switches due to being screwed in too far.
 Make sure the proximity switches are
screwed into the thread (U), (V) or (W) up to
the following maximum depth.
Max. screw-in depth
Size 65 90 140 220
Thread (U), (W) [mm] 11.5 11.5 13.5 18.5
Thread (V) [mm] 19.7 14 16 21
Tab. 8
 Screw the proximity switches into the following threaded holes:
Sensing Direction of rotation of plate
Clockwise rotation Anti-clockwise rotation
(reciprocating operation/
flexible control)
Direction of rotation (W) (U)
Locking mechanism (V) (V)
Piston end position (U) (W)
Tab. 9
When the DHTG is used with 3-part split (DHTG-140 and DHTG-220):
Note
Based on the design, the rotating plate can engage in an intermediate position
(corresponding to the 6-index stations).
 After an emergency stop / overload, make sure that the rotating plate is in the
desired position before the system is placed back in operation.
If the rotating plate is engaged in an intermediate position, bring the locked rotating
plate into the desired position by jerking and twisting it against the overload
protection.
Fig. 8
(U)
(V)
(W)

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6 Commissioning
Warning
Risk of injury from rotating masses.
 Make sure nobody can place his/her hand in
the positioning range of the DHTG and that no
objects lie in its path (e. g. by providing a
protective screen).
Note
Incorrect functioning due to inaccurate toothed rod position. When the DHTG is
exhausted, the resetting force of the shock absorber can push the rotary table out of
the end position and into an undefined position.
 Before each commissioning procedure, pressurise the last pressurised connection:
– Connection (B) for clockwise/anti-clockwise rotation
– Connection (C) or (D) for reciprocating operation/flexible control.
Note
Clockwise rotation is controlled internally through the flow control valve aJ.
Reciprocating operation must be controlled externally through an additional one-way
flow control valve GRLA, Connection (C), Fig. 10 (èwww.festo.com/catalogue).
 Screw the flow control screw aJ:
– in completely,
– then loosen one rotation
 Slowly pressurise the complete system with at least 4 bar.
 Start a test run Tab. 10.
 Check in a test run at low pulse frequency whether the following
modifications are necessary:
– Readjustment of the proximity switches
– Increase the speed step-by-step by unscrewing the
flow-control screw aJ
– Set the cushioning. (D) (A)(B)(C)
aJ
Fig. 10
Direction of rotation of plate
Clockwise/anti-clockwise rotation Reciprocating operation/flexible control1)
Basic position: Connection (B) pressurised èsee examples Tab. 11 to Tab. 13
1. Slowly pressurise connection (A)
2. Provide clock pulses for the valve
1) Internal flow control in one direction only (if necessary throttle different direction externally)
Tab. 10
Fig. 9

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Examples for reciprocating operation/flexible control
Clockwise rotation Reaction
Basic position: Connection (B) and (D) pressurised
1. Pressurise connection (A) Unlock
2. Pressurise connection (C) Pulse right
3. Pressurise connection (B) Lock
4. Pressurise connection (D) (continue with 1.) Return stroke
Tab. 11
Anti-clockwise rotation Reaction
Basic position: Connection (B) and (C) pressurised
1. Pressurise connection (A) Unlock
2. Pressurise connection (D) Pulse left
3. Pressurise connection (B) Lock
4. Pressurise connection (C) (continue with 1.) Return stroke
Tab. 12
2 x clockwise and 2 x anti-clockwise rotation Reaction
Basic position: Connection (B) and (D) pressurised
1. Pressurise connection (A) Unlock
2. Pressurise connection (C) Pulse right 1
3. Pressurise connection (B) Lock
4. Pressurise connection (D) Return stroke
5. Pressurise connection (A) Unlock
6. Pressurise connection (C) Pulse right 2
7. Pressurise connection (B) Lock
Direction of rotation change
8. Pressurise connection (A) Unlock
9. Pressurise connection (D) Pulse left
10.Pressurise connection (B) Lock
11.Pressurise connection (C) Return stroke
12.Pressurise connection (A) Unlock
13.Pressurise connection (D) Return stroke
14.Pressurise connection (B) (continue with 1.) Lock
Tab. 13
 Note the maximum permitted frequencies as a factor of the moment of mass inertia (èTechnical
specifications).
The rotary indexing table must not strike hard against the end stops and the overload protection
must not be triggered.
 End the test run.

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For setting the cushioning:
 Loosen the clamping element (K) one rotation.
 Screw in the adjusting screw 6until the desired cushioning
is achieved. The rotary indexing table must not strike hard
against the end stops and the overload protection must not
be triggered. The maximum moment of mass inertia must
not be exceeded.
6(K)
Fig. 11
Adjusting screw direction of rotation 6Reaction
Clockwise1) Cushioning is increased
Anti-clockwise Cushioning is reduced
1) Screw in the adjusting screw until it is flush
Tab. 14
 Tighten the clamping element (K) again.
Tightening torque
Size 65 90 140 220
Width across flats 2.5 2.5 4 4
Tightening torque [Nm] 0.8 0.8 2.5 2.5
Tab. 15
7 Operation
Warning
Risk of injury from rotating masses.
 Make sure nobody can place his/her hand in
the positioning range of the DHTG and that no
objects lie in its path (e. g. by providing a
protective screen).
 Note the moment of mass inertia as a factor of the switching or cycle frequency (èCharacteristic
curves).
– The maximum achievable switching frequency as a factor of the moment of mass inertia can be
read in the diagram Switching frequency. The switching time can be calculated from this
by T = 60/f. The response time comprises: Switching time = unlocking, turning, locking and the
return stroke of the work piston.
Fig. 12

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– The maximum achievable cycle frequency as a factor of the moment of mass inertia can be read
in the diagram Cycle frequency. The minimum possible cycle time can be calculated from this
by T = 60/f.
The actual cycle time is then calculated as follows:
Cycle time = switching time + processing time + dwell time.
– The processing time results from the time which the relevant customer application requires
(e. g. time for removing components, press-in time, etc).
– Dwell time may be necessary if the actual cycle time is less than the minimum possible cycle
time (calculation example èCatalogue specifications).
 Note that the viscosity of the shock absorber oil decreases with increasing heat. The shock ab
sorber might therefore strike through if the device is operated for too long a period. If necessary
reduce the moment of mass inertia.
 Avoid the DHTG coming into contact with:
– Aggressive media
– Grinding dust
– Glowing sparks or chips.
These will damage the DHTG.
8 Maintenance and care
 Switch off the power supplies:
– Operating voltage
– Compressed air supply.
Cleaning:
 Only clean the DHTG using a soft cloth.
All non-abrasive cleaning agents are permitted.
Due to its service life lubrication the DHTG does not require any maintenance.
Regular removal of the lubricating grease on the surface of the piston rod will reduce the service
life.
 After a conversion (e. g. to reciprocating operation) lubricate the following components
with LUB-E1:
– piston, piston chamber, seal, lock, toothed rod, pinion, table bearing, dividing disc.
We recommend the mechanical components are lubricated again after every 5 million switching
cycles.
 Check the shock absorbers every 2 million strokes for:
– Oil leakage
– Hard knocking
– Function (shock absorber head must not remain in the retracted end position).
Dismantling the shock absorber (èDismantling and repairs).

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 Replace the shock absorber when it shows one of the following signs of wear, or every 10 million
strokes at the latest.
 Check whether lubrication/testing must be carried out more frequently.
This may be necessary in case of:
– High temperatures
– Excessive dirt
– Fat solvent fluids or fumes in the vicinity.
9 Dismantling and repairs
 Recommendation: Return the product to our repair service for overhaul.
The necessary fine adjustments and tests will then be taken into account.
 Information about spare parts and aids can be found at: www.festo.com/spareparts
 Switch off the power supplies:
– Operating voltage
– Compressed air
 Exhaust the system and the product.
Replacing the integrated shock absorber:
1. Unscrew the flow-control screw aJ.
2. Unscrew the fastening screws (M) on the sub-base.
3. Using pliers, remove the retaining ring on the shock absorber.
4. Replace the shock absorber.
5. Fit the individual parts again in reverse sequence (tightening torque èTab. 16).
(M)
aJ
Fig. 13
Tightening torque
Size 65 90 140 220
Flow control screw aJ [Nm] 1.5 1.5 5.5 5.5
Fastening screws (M) [Nm] 2.9 2.9 9.9 9.9
Tab. 16

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Conversion from clockwise rotation (as supplied) to anti-clockwise rotation:
1. Loosen the clamping element (K) of the adjusting screw one rotation.
2. Unscrew the adjusting screw 6a few rotations.
3. Unscrew flow control screw aJ and the fastening screws (M) from the sub-base.
4. Using pliers, remove the retaining ring (S) on the shock absorber.
5. Fit the following:
– the shock absorber with the retaining ring in the adjacent hole
– the O-ring (P) / buffer (for DHTG-65) in the adjacent groove
– the distance piece (T) in the same hole (distance piece omitted for 2/3 index stations)
– the sub-base with the fastening screws and the flow control screw in reverse sequence
(tightening torque èTab. 17).
6. Unscrew the fastening screws (N) on the stop plate.
7. Unscrew:
– both locking screws (O) on the rear of the stop plate to begin with,
– then screw them in again into the open holes (tightening torque èTab. 17).
The open holes (R) or (L) in Fig. 14 determine the direction of rotation
(Holes (R) open: clockwise rotation).
8. Screw the fastening screws (N) on the stop plate again (tightening torque èTab. 17).
The rotary indexing table remains pneumatically controlled as before.
9. Screw in the adjusting screw 6until the desired cushioning is achieved èFig. 11.
10.Tighten the clamping element (K) of the adjusting screw (tightening torque èTab. 15).
(M) aJ (N)(O)(P)(K) (L) (R)(T)
(S)
6
Fig. 14
Tightening torque
Size 65 90 140 220
Flow control screw aJ [Nm] 1.5 1.5 5.5 5.5
Fastening screws (M) [Nm] 2.9 2.9 9.9 9.9
Plug screw (O) [Nm] 0.5
Fastening screws (N) [Nm] 1.5 2.9 5.9 5.9
Tab. 17

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10 Accessories
Note
 Please select the appropriate accessories from our catalogue
èwww.festo.com/catalogue
11 Troubleshooting
Malfunction Possible cause Remedy
Rotating plate does not
move
Overload protection is active Pressurise connection (B) and turn
the plate back against the direction
of rotation as far as possible. Doing
this causes the overload protection
and the locking mechanism, if
applicable, to engage audibly
Audible leakage Send DHTG to Festo
Flow-control screw closed
completely
Open screw
Rotating plate does not
engage
End position not reached Unscrew the adjusting screw for the
shock absorber until the rotating
plate engages
Overload protection is active èsee above
Toothed disc and pinion stand tooth
on tooth
Please contact Festos Technical
Hotline
Hard metal impact at
the end position
Adjusting screw for shock absorber
unscrewed too far
Screw in adjusting screw
Shock absorber defective Replace shock absorber
(è9 Dismantling and repairs)
Hard metallic knocking
in the locking
mechanism
Adjusting screw for shock absorber
screwed in too far (e. g. when
changing the direction of rotation)
Unscrew adjusting screw
Plate position incorrect Overload protection engaged
incorrectly at 180° (plate offset 30°)
Force overload protection and turn
until it re-engages
Tab. 18

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12 Technical data
Size 65 90 140 220
Operating mode Double-acting double piston mode
Mounting position Any
Position sensing For inductive proximity sensors
Cushioning Adjustable shock absorber stroke,
hard characteristic curve
Operating medium Compressed air according to
ISO 8573-1:2010 [7:4:4]
Operating pressure [bar] 4 … 8
Pneumatic connection M5 G1/8
Max. axial force F [N] 1000 2000 4000 5000
Max. radial force R [N] 2000 5000 6000 8000
Max. tilting torque M [Nm] 100 150 300 500
Max. tangential torque T [Nm] 100 150 200 500
Max. mass moment of inertia with flow con
trol screw opened completely (è7 Opera
tion, è13 Characteristic curves)
[kgm2] 0.015 0.03 0.3 2.5
Theor. torque at 6 bar [Nm] 2.1 4.4 18.1 58.9
Parallelism of plate1) [mm] 0.04
Axial eccentricity of plate2) [mm] 0.02
Concentricity of plate3) [mm] 0.02
Repetition accuracy of swivel angle [°] 0.03
Replacement accuracy [mm] 0.2
Ambient temperature [°C] +5 … +60
Storage temperature [°C] –20 … +80
Protection class IP54
Material
Cover, housing Wrought aluminium alloy
Stops, plate Galvanised steel
Seals Nitrile rubber, polyurethane
Note on materials Free of copper and PTFE
Product weight [kg] 1.9 4.5 10 24
1) Parallelism of the plate surface relative to the housing support
2) Measured on the surface of the plate at the edge of the plate in relation to the housing support
3) Measured on the inner diameter of the plate in relation to the housing
Tab. 19

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13 Characteristic curves
Switching frequency f as a function of mass moment of inertia J
Size 65
f [1/min]
J [kgm2]
Size 90
J [kgm2]
f [1/min]
Size 140
f [1/min]
J [kgm2]
2 indexing stations
3 indexing stations
4 indexing stations
6 indexing stations
8 indexing stations
12 indexing stations
24 indexing stations

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Switching frequency f as a function of mass moment of inertia J
Size 220
f [1/min]
J [kgm2]
3 indexing stations
4 indexing stations
6 indexing stations
8 indexing stations
12 indexing stations
24 indexing stations
Max. permissible cycle frequency f as a function of mass moment of inertia J
Size 65
f [1/min]
J [kgm2]
Size 90
f [1/min]
J [kgm2]
2 indexing stations
3 indexing stations
4 indexing stations
6 indexing stations
8 indexing stations
12 indexing stations
24 indexing stations

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Max. permissible cycle frequency f as a function of mass moment of inertia J
Size 140
J [kgm2]
f [1/min]
Size 220
J [kgm2]
f [1/min]
3 indexing stations
4 indexing stations
6 indexing stations
8 indexing stations
12 indexing stations
24 indexing stations