Toothed belt axis DGE- -ZR-RF. Repair instructions (en) 7DGE_ZR_RFa_en

Transcription

1 Toothed belt axis DGE- -ZR-RF Repair instructions (en) 7DGE_ZR_RFa_en

2 Imprint Version: 7DGE_ZR_RFa_en (05/2009) Copyright: Festo AG & Co. KG P.O. Box D Esslingen, Germany Editorial staff: SC-S Phone: +49 / 711 / Fax: +49 / 711 / service_international@festo.com Internet: The reproduction, distribution and utilisation of this document as well as the communication of its contents to others without explicit authorisation is prohibited. Violations will give rise to compensation. All rights reserved, in particular the right to file patent, utility model or registered design applications. All product designations and brand names used are the property of the owners and not explicitly identified as such. All technical data subject to change according to technical updates. 2 / 44 Festo 7DGE_ZR_RFa_en

3 Foreword These repair instructions are valid for the toothed belt axes listed on the title page to the exclusion of any liability claims. Deviations compared to the descriptions in these repair instructions may arise depending on the design and/or modification status of the specific toothed belt axis. The user must check this prior to carrying out the repair and take the deviations into consideration if necessary. These repair instructions have been prepared with care. Festo AG & Co. KG does not, however, accept liability for any errors in these repair instructions or their consequences. Likewise, no liability is accepted for direct or consequential damage resulting from improper use of the products. You will find further information on this in Chapter 7 Liability / conditions of use. The relevant regulations on occupational safety, safety engineering and interference suppression as well as the stipulations contained in these repair instructions must be observed when working on the products Festo 7DGE_ZR_RFa_en 3 / 44

4 Table of contents 1 Important information About these repair instructions Pictograms used in this repair instructions General safety information 6 2 General product description Functional description Types and part numbers Overview of variants and mounting directions 7 3 Component overview DGE-25- -ZR-RF DGE-40- -ZR-RF DGE-63- -ZR-RF 12 4 Repair steps Replacing the toothed belt Replacing the toothed belt Testing and setting the toothed belt tension Further information on testing the toothed belt tension Cutting the toothed belt to length Dismantling the toothed belt axis Removing the drive cover Dismantling the drive cover Profile track roller guide Dismantling the slide Adjusting the track roller pretension Measuring the displacement force of the slide Assembling the toothed belt axis Preparing the cylinder barrel Installing the drive covers Assembly and function check No-load torque 37 5 Maintenance Cleaning and lubricating the toothed belt axis Checking and lubricating the roller bearing guide Toothed belt tension 38 6 Tools Standard tools Special tools Devices and meters Devices for in-house assembly 41 7 Liability 41 4 / 44 Festo 7DGE_ZR_RFa_en

5 1 1.1 Important information About these repair instructions This document contains important information about the professional repair of the toothed belt axis type DGE -ZR-RF in the sizes 25, 40 and 63. Before carrying out a repair, the relevant chapter in these instructions must be read in full and followed consistently. For reasons of clarity, this repair manual does not contain complete detailed information. The following documents should therefore also be available during a repair of the toothed belt axis: Operating instructions Contains information about the installation and removal of the motor, motor flange, coupling and coupling housing of the DGE ZR-RF toothed belt axis as well as the function, structure, application, installation, commissioning, care and maintenance, etc. Can be found on the Festo website ( Spare parts documentation Contains an overview of the spare and wearing parts as well as information on their installation. Can be found in the online spare parts catalogue on the Festo website (spareparts.festo.com). Assembly aids Contain an overview of available assembly aids such as lubricating greases, locking agents, maintenance tools, etc. (aids for assembly and maintenance). Can be found in the online spare parts catalogue on the Festo website ( 1.2 Pictograms used in this repair instructions Warning This sign indicates a dangerous situation for persons and / or the product. Failure to observe this warning can result in injury to persons and / or damage to the device. This sign provides important tips and information that can make your work easier. Environment This sign provides information on the steps required for environmentally-friendly use of materials and equipment, as well as the guidelines and regulations that may need to be observed. Documents This sign contains references to other chapters or documents containing additional information. Festo 7DGE_ZR_RFa_en 5 / 44

6 1.3 General safety information Warning The toothed belt axis must only be repaired by authorised and trained persons in accordance with the specifications in the technical documentation and using original spare parts. Installation and repair by unauthorised and untrained persons, repairs using non-original spare parts, as well as without the technical documentation required for installation and/or repair, are dangerous and therefore not permitted. Repairs must only be carried out in conjunction with these repair instructions as well as the respective device-specific operating instructions. Instead of carrying out the repair yourself, your local Festo sales office offers the option of having the repair carried out by Festo. Environment Components and equipment replaced as part of a repair must be disposed of in accordance with the locally valid environmental protection regulations. 2 General product description 2.1 Functional description The DGE- -ZR-RF is a toothed belt axis based on the operational principle of a circulating toothed belt for power transmission. The rotation of a servo or stepper motor produces a linear motion in a toothed belt with a pulley at both ends of the axis that is then transmitted to the roller-bearing slide that is attached to the toothed belt with clamping components. The slot in the cylinder barrel required for this is covered by a toothed belt that protects the roller bearing guide inside the axis against the ingress of dirt. By minimising the moving dead weight, a high dynamic response and shorter cycle times can be achieved. The DGE- -ZR-RF is approved for slide operation and yoke operation (cantilever operation) Drive cover with corner pulley 2 Cylinder barrel aj aa 3 Clamping body for clamping the toothed belt 4 Eccentric screw for adjusting the roller bearing pretension 5 Slide 6 Track rollers 7 Toothed belt pulley with drive trunnion 8 Guide rods 9 Scraper for lubricating the guide rods aj Toothed belt aa Deep-groove ball bearing 6 / 44 Festo 7DGE_ZR_RFa_en

7 2.2 Types and part numbers Type Part number DGE-25- -ZR-RF DGE-40- -ZR-RF DGE-63- -ZR-RF The complete overview of features, accessories, type codes, technical data and dimensions for the DGE- -ZR-RF toothed belt axes can be found in the product catalogue or on the Festo website( 2.3 Overview of variants and mounting directions This diagram provides an overview of the mounting directions and variants for the toothed belt axis. Designs: GK = Standard slide GV = Extended slide Drive shaft, left Drive shaft, right Direction: O U R L V H = Top = Underneath = Right = Left = Front = Rear -H- = Position of the insertion points for slot nuts (DGE-25 only) Drive shafts: LK = No drive shaft on left LV = Drive shaft on left, front LH = Drive shaft on left, rear LB = Drive shaft on left, front and rear RK = No drive shaft on right RV = Drive shaft on right, front RH = Drive shaft on right, rear RB = Drive shaft on right, front and rear Festo 7DGE_ZR_RFa_en 7 / 44

8 3 3.1 Component overview DGE-25- -ZR-RF GK 11 - GV 39 This diagram is intended only to provide an overview of the individual components. To order spare and wearing parts, please use the online spare parts catalogue on the Festo website (spareparts.festo.com). 8 / 44 Festo 7DGE_ZR_RFa_en

9 Position Designation Type 1 Flange screw M5 58 Tightening torque 5.9 Nm, use LOCTITE Sealing cap 3 Sealing disc 4 Retaining ring DIN Drive cover 6-8 Toothed drive shafts With pressed-on deep-groove ball bearings 9 Spring pin DIN Toothed belt 12 Threaded pin DIN 913-M5 6-45H Tightening torque 0.5 Nm 13 Clamping plate 14 Socket head screw DIN 912-M Lubrication nipple 16 Clamping body 17 Retaining ring DIN Only mounted on size Centring screw Tightening torque 9.9 Nm, use LOCTITE Eccentric screw Setting torque 0.5 Nm, use LOCTITE Scraper kit Soaked with oil 21 Track roller 22 Adjusting washer 23 Buffer 24 Slide module 25 Slide 26 Washer DIN 125-A-6.4-A2 27 Hex nut DIN 439 B-M6 Tightening torque 2.9 Nm, use LOCTITE Cover cap 29 Cylinder barrel Aluminium profile with roller-burnished guide rods (surface-hardened) 30 Cover cap 31 Cover cap 32 Socket head screw DIN 912-M Tightening torque 2.9 Nm 33 Sealing cap 34 Coupling housing 35 Centring ring 36 Coupling housing module See operating instructions for assembly 37 Coupling module See operating instructions for assembly 38 Socket head screw DIN 912-M Tightening torque 2.9 Nm 39 Coupling Festo 7DGE_ZR_RFa_en 9 / 44

10 3.2 DGE-40- -ZR-RF GK 11 - GV 39 This diagram is intended only to provide an overview of the individual components. To order spare and wearing parts, please use the online spare parts catalogue on the Festo website (spareparts.festo.com). 10 / 44 Festo 7DGE_ZR_RFa_en

11 Position Designation Type 1 Flange screw M6 80 Tightening torque 11 Nm, use LOCTITE Sealing cap 3 Sealing disc 4 Retaining ring DIN Drive cover 6-8 Toothed drive shafts With pressed-on deep-groove ball bearings 9 Spring pin DIN Toothed belt 12 Threaded pin DIN 913-M8 8-45H Tightening torque 4 Nm 13 Clamping plate 14 Socket head screw DIN 912-M Lubrication nipple 16 Clamping body 17 Retaining ring DIN Only mounted on size Centring screw Tightening torque 24 Nm, use LOCTITE Eccentric screw Setting torque 2 Nm, use LOCTITE Scraper kit Soaked with oil 21 Track roller 22 Adjusting washer 23 Buffer 24 Slide module 25 Slide 26 Washer DIN 125-A-8.4-A2 27 Hex nut DIN 934-M8 Tightening torque 20 Nm, use LOCTITE Cover cap 29 Cylinder barrel Aluminium profile with roller-burnished guide rods (surface-hardened), shown is size Cover cap 31 Cover cap 32 Socket head screw DIN 912-M Tightening torque 5.9 Nm 33 Sealing cap 34 Coupling housing 35 Centring ring 36 Coupling housing module See operating instructions for assembly 37 Coupling module See operating instructions for assembly 38 Socket head screw DIN 912-M Tightening torque 10.5 Nm 39 Coupling Festo 7DGE_ZR_RFa_en 11 / 44

12 3.3 DGE-63- -ZR-RF GK 11 - GV 39 This diagram is intended only to provide an overview of the individual components. To order spare and wearing parts, please use the online spare parts catalogue on the Festo website (spareparts.festo.com). 12 / 44 Festo 7DGE_ZR_RFa_en

13 Position Designation Type 1 Flange screw M8 125 Tightening torque 15 Nm, use LOCTITE Sealing cap 3 Sealing disc 4 Retaining ring DIN Drive cover 6-8 Toothed drive shafts With pressed-on deep-groove ball bearings 9 Spring pin DIN Toothed belt 12 Threaded pin DIN 913-M H Tightening torque 5 Nm 13 Clamping plate 14 Socket head screw DIN 912-M Lubrication nipple 16 Clamping body 17 Retaining ring DIN Centring screw Tightening torque 80 Nm, use LOCTITE Eccentric screw Setting torque 5 Nm, use LOCTITE Scraper kit Soaked with oil 21 Track roller 22 Adjusting washer 23 Buffer 24 Slide module 25 Slide 26 Washer DIN 125-A-13-A2 27 Hex nut DIN 439 B-M12 Tightening torque 40 Nm, use LOCTITE Cover cap 29 Cylinder barrel Aluminium profile with roller-burnished guide rods (surface-hardened), shown is size Cover cap 31 Cover cap 32 Socket head screw DIN 912-M Tightening torque 24 Nm 33 Sealing cap 34 Coupling housing 35 Centring ring 36 Coupling housing module See operating instructions for assembly 37 Coupling module See operating instructions for assembly 38 Socket head screw DIN 912-M Tightening torque 25 Nm 39 Coupling Festo 7DGE_ZR_RFa_en 13 / 44

14 4 Repair steps This chapter describes how to dismantle, repair and assemble the toothed belt axis DGE- -ZR-RF. This is done by first dismantling the device into individual modules (subsequent chapters deal with the repair of these modules). Depending on the cause of the defect to be remedied it may be necessary to exchange several components. The cause of a defect must therefore always be determined before starting a repair. The repair should preferably be carried out on a stable and flat work surface with storage for small parts. It is also possible to repair the toothed belt axis in its installed condition, if required. 4.1 Replacing the toothed belt If the toothed belt is not torn or if the tear is in the visible area, it can be replaced with the toothed belt axis installed, since the drive covers then do not have to be removed. If the tear is in the drive covers or in the cylinder barrel, the drive covers must be removed (Chapter 4.2.1). Should it be necessary to change the toothed belt, the cause of the failure must be investigated to prevent, for example, repeated and premature failure. A toothed belt axis that has been used as intended will not normally exhibit any premature signs of failure. This is not necessary in the case of non-premature failure (fatigue time). However, the condition of the toothed belt pulley module (wear of the material surface / shape of teeth, radial play of the bearing inner raceway with respect to the drive shaft: when new, it should fit tightly) and the condition of the deep-groove ball bearings (e.g. perceptible bearing clearance, impaired roll-off behaviour and increased operating noise, etc.) should always be checked. If in doubt, it is recommended to replace all the components mentioned so as to rule out reciprocal effects during later operation. Possible visible signs of wear to the toothed belt: Cracks on the back of the toothed belt are signs of wear, for example caused by operation outside the permitted temperature range, impermissible chemical influences or possibly fatigue. Visible individual glass fibre cords in the tooth base are signs of wear caused by fatigue. In this case, the toothed drive shaft must be checked very closely for wear. Replacement of the toothed drive shafts with the associated deep-groove ball bearings is described in Chapter If the toothed belt suffers premature failure, the operating conditions should be observed more closely. The following possibilities should be considered, among others: Overloading Incorrect set values for the braking ramp during STOP conditions (e.g. emergency stop, quick stop) result in overloading of the toothed belt axis and can destroy it or dramatically reduce its service life. Check the settings for all braking ramps on your controller or the higher-order control system (deceleration values and jerking). Make sure that the deceleration values (braking deceleration, deceleration times) for the speed, the load to be moved and the installation position (horizontal / vertical) as well as the specified maximum drive torque or the feed force correspond to the permissible values for the toothed belt axis used. Use the Festo Positioning Drives sizing software, available via the Festo website ( 14 / 44 Festo 7DGE_ZR_RFa_en

15 Block-shaped acceleration profiles (without smoothing) cause high peaks in the motive force that can lead to overloading of the drive. Positions outside of the permissible range can also occur. A smoothed acceleration specification reduces vibrations in the entire system and has a positive effect on the stresses to which the mechanical system is subjected. Check which closed-loop controller settings can be adapted (e.g. smoothing of jerking, smoothing of the acceleration profile). Ambient conditions / material resistance Check whether the ambient temperature is within the permissible range. Check the chemical and physical ambient conditions for hazardous substances, such as dust, abrasive particles, cooling lubricants, solvents, ozone, radiation, water-soluble greases and oils, etc Replacing the toothed belt This description assumes that the toothed belt is not torn, or that the tear is located in a visible area. If the tear is in the drive covers or in the cylinder barrel, the drive covers must be removed (Chapter 4.2.1). Do not pull the old toothed belt out of the axis before you have joined it to the new toothed belt. Otherwise, you will also have to remove the drive covers as well. Place the toothed belt axis on the work surface as shown with the slide facing upwards. Lever the cover caps from the drive covers at both ends. Locking paint is applied to the screw heads of the socket head screws. You can ensure the secure fit of the Allen key by carefully inserting it into the screw head with a hammer. Loosen the socket head screws in the clamping bodies and unscrew them. Move the slide to the left and right to loosen the clamping bodies from the slide. Festo 7DGE_ZR_RFa_en 15 / 44

16 Push the two clamping bodies out of the axis through the recess in the cylinder barrel. Loosen the threaded pins in the clamping bodies at both ends of the toothed belt and unscrew them. Pay attention to the clamping plate in the clamping body as it could fall out. Pull the clamping body sideways from the toothed belt. Remove the clamping plates from the toothed belt. Do not pull the old toothed belt out of the axis before you have joined it to the new toothed belt as otherwise you will need to remove the drive covers. Join the ends of the old and new toothed belts using adhesive tape. Documents The procedure for determining the correct toothed belt length is described in Chapter Pull the old toothed belt carefully out of the axis until the new toothed belt is pulled through. Detach the old toothed belt from the new one. 16 / 44 Festo 7DGE_ZR_RFa_en

17 Place the clamping plate on the left-hand end of the new toothed belt. To prevent the toothed belt from getting damaged during operation, the clamping plate must be aligned with the axial centre of the toothed belt. Align the clamping plate axially centred with respect to the toothed belt. X1 X1 Warning The toothed belt must be placed correctly on the clamping plate. It must not protrude and must make contact with four teeth. The tapped holes of the clamping bodies must be recut before the threaded pins are screwed in. Residues from the old locking agent in the tapped holes result in uneven and increased torque in the threaded pins. This means that there is no guarantee of correct tightening. Insert the left-hand end of the toothed belt together with the clamping plate into the clamping body. Align the toothed belt with the axial centre of the clamping body. Apply Loctite 243 to the threaded pin and screw this into the clamping body. Push the clamping plate against the stop (a) on the clamping body. It is imperative that the clamping plate lie against the stop, since otherwise the toothed belt tension will be reduced during operation. Tighten the threaded pin with the corresponding torque (see table). It is crucial to observe the torque as excessive torque will bend the clamping body. Type DGE-25 DGE-40 DGE-63 Torque 0.5 Nm 4.0 Nm 5.0 Nm Festo 7DGE_ZR_RFa_en 17 / 44

18 Warning Do not bend or fold the toothed belt, as this can result in damage to the tensile bodies and shorten its service life by tearing it. Observe the minimum bending radius for assembly and storage (see Chapter 4.1.4). Insert the clamping body into the axis through the recess in the cylinder barrel. Move the clamping body to the left until it is just in front of the recess in the cylinder barrel. Repeat the steps on the other end of the axis to insert the second clamping body. Push the clamping body into the guide in the slide. Warning The clamping bodies must not touch the slide when they are being screwed in, as otherwise the toothed belt could otherwise become overstretched and the service life of the toothed belt would be reduced. Approach the correct toothed belt tension slowly. Screw the socket head screws evenly into the slide through the clamping bodies. Pretension the toothed belt by evenly tightening the socket head screws by feel. If the toothed belt is cut to the correct length, the clamping bodies must be at least flush with the slide. If the clamping bodies protrude, the minimum screw-in depth of the socket head screws is not achieved. This can lead to the screws being pulled out. Adjust the toothed belt tension as described in Chapter / 44 Festo 7DGE_ZR_RFa_en

19 4.1.2 Testing and setting the toothed belt tension The toothed belt tension is determined by measuring the basic oscillation (natural frequency) of the toothed belt with a fixed and freely oscillating span length (L) Since the freely oscillating span length (L) cannot be measured directly, the distance (L1) from the clamping component (a) / clamping body (b) to one of the drive covers is set by shifting the slide. The oscillation measurement is then carried out at this point. Warning The toothed belt tension has a direct influence on the service life of the toothed belt and the performance of the toothed belt axis. The toothed belt tension must therefore be checked with great care. Before the toothed belt tension can be measured, the slide must be moved back and forth several times to allow the toothed belt to fully settle and differences in tension to be equalised. L1 a L L1 L DGE-25/40 b DGE-63 b Documents The easiest way to check the toothed belt tension is using the toothed belt tension test equipment (see Chapter 6.3). The work instructions required for this as well as the setting values can be found in the associated operating instructions in the appendix to this document. Testing the toothed belt tension Place the toothed belt axis on the work surface as shown with the slide facing upwards. Lever the cover caps from the drive covers at both ends. (DGE-25 and DGE-40) For the axes DGE-25 and DGE-40, it is necessary to attach an additional clamping component (see Chapter 6.4) so that the toothed belt can oscillate freely and does not touch the cylinder barrel. Push the appropriate clamping component through the recess in the cylinder barrel between the toothed belt and the cylinder barrel if necessary. It must lie against the clamping body. Festo 7DGE_ZR_RFa_en 19 / 44

20 The larger span length should preferably be set if possible. A longer freely oscillating span length reduces the variation of the measurement results. The clamping component (DGE-25 and DGE-40 only) must lie against the clamping body. Set the distance (L1) between the drive cover and the clamping component (a) / clamping body (b) (see table). Type Distance L1 DGE mm / 50 mm 1) DGE mm / 50 mm 1) DGE mm / 50 mm 1) 1) Alternatives for toothed belt axes with very short strokes. L1 a L1 DGE-25/40 b DGE-63 b Direct the acoustic frequency meter towards the centre of the toothed belt as described in the accompanying operating instructions. Make the toothed belt oscillate by striking it with a narrow and heavy object, for example an Allen key or pin punch. The belt must be able to oscillate freely. To assess the toothed belt tension, several measurements should be made to balance out measurement tolerances. Compare the measurement with the specified value (see table). Type Frequency (f) DGE Hz / Hz 1) DGE Hz / Hz 1) DGE Hz / Hz 1) 1) Alternatives for toothed belt axes with very short strokes. Setting the toothed belt tension Warning The pretension of the toothed belt diminishes during storage and operation. This is normal and must not be changed by increasing the tension of the toothed belt. The reduced pretension, as described above, must not be used for assessing the condition of the toothed belt. 20 / 44 Festo 7DGE_ZR_RFa_en

21 If the measured natural frequency of the toothed belt is outside the specified range, the toothed belt tension must be adjusted as follows. Adjust the toothed belt tension by turning the socket head screws. Before you can measure the toothed belt tension again, the slide must be moved back and forth several times to allow the toothed belt to fully settle and differences in tension to be equalised. Turning the cylinder screw clockwise increases the tension of the toothed belt and thus its ocsillation frequency. Turning the cylinder screw in the counterclockwise direction lowers the tension in the toothed belt, and with this its frequency of oscillation. Place the cover caps in the drive cover at both ends Further information on testing the toothed belt tension The correct toothed belt tension is of critical importance for the service life of the toothed belt as well as the positioning accuracy and performance of the toothed belt axis. The conventional method for measuring the toothed belt tension via the deflection force is too inaccurate and can therefore not be used. Accurate results are achieved by measuring the oscillation frequency. The natural frequency of a belt is based on its tension (span force), mass and span length. The span length is the oscillating length of a belt. Since the span length cannot be determined directly at the toothed belt axis by easy means, the length L1 is used instead for positioning the clamping body / clamping component. A pulse is applied to the toothed belt to start it oscillating. The natural frequency of the toothed belt generated in this way is recorded using a meter and displayed as a frequency value in Hertz. The frequency value is calculated using the specified values for span force (pretension force), belt mass and length of the free belt span according to the following formula: f Natural frequency of the freely oscillating span [Hz] L Span length [m] F V Pretension force [N] m Weight per metre of the toothed belt [kg / m] Festo 7DGE_ZR_RFa_en 21 / 44

22 The frequency to be set can be calculated using the data from the following table: Type Weight per metre m Freely oscillating span length L Pretension force F V DGE kg / m 24 mm + L1 1) N DGE kg / m 33 mm + L N DGE kg / m 51 mm + L N 1) See Chapter on measurement using the acoustic belt tension meter If the toothed belt is excited by means of momentum, the span oscillates with its natural frequency; this dies down reasonably quickly depending on the attenuation. The frequency meter measures the natural frequency generated (transverse oscillation) using the acoustic operating principle. In addition to the basic oscillation (natural frequency), harmonic oscillation can also occur. From experience it is always the first harmonic oscillation. In other words, a further oscillation node is generated, and therefore, in addition to the basic oscillation frequency, values that are twice the natural frequency can also be measured. For this reason, several measurements should always be carried out to differentiate the necessary basic oscillation (natural frequency) from the harmonic oscillation. Only this frequency can be used to extrapolate the force acting along the span Cutting the toothed belt to length The toothed belt is ordered from the online spare parts catalogue (spareparts.festo.com) using the appropriate part number (dependent on the size and design of the toothed belt axis). The part number is a module number which depends on the size of the toothed belt axis. You must specify the stroke of your toothed belt axis in addition to the part number when ordering. The necessary specifications can be determined from the type codes on the name plate of the toothed belt axis (see order example below). Using this information you can calculate the necessary toothed belt length. Cutting the new toothed belt to length The exact length of the toothed belt in mm is the result of the sum of the stroke of the toothed belt axis and a factor (F), which is doubled. The factor depends on the size and type of slide used (see table). The stroke and type of slide can be determined from the type code on the name plate. Check the length of the new toothed belt and shorten it, if necessary, to the calculated length (2 (stroke + factor)). See order example: Type Factor F DGE-25- -GK 330 DGE-25- -GV DGE-40- -GK DGE-40- -GV DGE-63- -GK 834 DGE-63- -GV 949 Example: DGE ZR-RF-LV-RK-GK Stroke: Factor F: 300 mm see table Length of the toothed belt = 2 (stroke + F) = 1260 mm Sturdy general purpose scissors or metal shears are best for cutting the toothed belt. Warning Do not bend or fold the toothed belt, as this can result in damage to the tensile bodies and shorten its service life by tearing it. the minimum bending radius for assembly and storage: DGE-25: R min = 6 mm DGE-40: R min = 10 mm DGE-63: R min = 20 mm 22 / 44 Festo 7DGE_ZR_RFa_en

23 4.2 Dismantling the toothed belt axis The toothed belt axis DGE- -ZR-RF comprises the following modules: Drive cover with toothed-belt pulley and drive. Cylinder barrel with roller-bearing slide on guide rods, driven via clamping bodies on the toothed belt Removing the drive cover Place the toothed belt axis on the work surface as shown with the slide facing upwards. Lever the cover caps from the drive covers at both ends. Locking paint is applied to the screw heads of the socket head screws. You can ensure the secure fit of the Allen key by carefully inserting it into the screw head with a hammer. Loosen the socket head screws in the clamping bodies and unscrew them. Move the slide to the left and right to loosen the clamping bodies from the slide. Push the two clamping bodies out of the axis through the recess in the cylinder barrel. Festo 7DGE_ZR_RFa_en 23 / 44

24 Loosen the threaded pins in the clamping bodies at both ends of the toothed belt and unscrew them. Pay attention to the clamping plate in the clamping body as it could fall out. Pull the clamping body sideways from the toothed belt. Remove the clamping plates from the toothed belt. If the toothed belt is to be replaced, pull it carefully out of the axis. Loosen the socket head screws in the drive cover and unscrew them. Pull the drive cover off the cylinder barrel. The drive covers are connected to the cylinder barrel using spring pins. A certain amount of force is required to pull them off. 24 / 44 Festo 7DGE_ZR_RFa_en

25 Repeat the steps on the other end of the axis to remove the second drive cover Dismantling the drive cover Clamping sleeves The clamping sleeves are inserted into the drive covers. However, they can also be located in the cylinder barrel following the dismantling of the drive covers. Pull out these parts to replace them. Toothed drive shafts The toothed drive shaft sits in a loose fit in the drive cover with two pressed-on deep-groove ball bearings and is axially secured by two retaining rings. Removing the toothed drive shafts Lever the sealing discs out of the drive cover. Remove the retaining ring opposite the drive trunnion. In the case of toothed drive shafts with two or no drive trunnions, you can remove any retaining ring. Festo 7DGE_ZR_RFa_en 25 / 44

26 Push the toothed drive shaft with the two deep-groove ball bearings out of the drive cover. You do not need to pull off the deep-groove ball bearings as the spare part includes the two bearings and the shaft. Check the inner raceways of the deep-groove ball bearings for a secure fit on the toothed drive shaft. If a bearing does not fit securely, replace the module. Installing the toothed drive shaft Apply a light coating of grease to the outside of the deep-groove ball bearings and push the toothed drive shaft into the drive cover with the drive trunnion in front. Use a plastic hammer if necessary to carefully insert the toothed drive shaft into the drive cover. Any installation direction can be chosen for toothed drive shafts with two or no drive trunnions. Insert the retaining ring. Check that the retaining ring is correctly positioned. Press the sealing discs into the drive cover to additionally protect the deepgroove ball bearings from contamination. 26 / 44 Festo 7DGE_ZR_RFa_en

27 4.3 Profile track roller guide The track roller guide system consists of two guide rods, also called intermediate shafts, and four profile track rollers (roller bearings). The two guide rods are surface-hardened and roller burnished with positive locking in the cylinder barrel. Thus, it is technically impossible to exchange the guide rods. If there is a defect in the guide rods, the complete toothed belt axis must be replaced. The guide system has negative running clearance, i.e. it is pretensioned and therefore has no mechanical play. This results in a load bearing capacity in all system directions, as well as more precise guiding. Using eccentric trunnions, the guiding system is set and preloaded backlash-free on two of the four roller bearings. The specified pretension is set via a setting torque on the two eccentric trunnions. Felt scrapers fastened to both of the outer roller bearings are used to lubricate the bearing surface of the outer ring of the roller bearings and the guide rods. These are soaked in oil and their semicircular profiles are pressed onto the guide rods. This way, the guide rods are lubricated and contaminants are scraped off Guide rods 2 Non-adjustable track rollers 3 Adjustable track rollers 4 Slide 5 Centric trunnions 6 Eccentric trunnions In general, Festo recommends that the complete drive be exchanged with there is a defect in the profile track roller guide. Exchanging the roller bearings is done at the risk of the user. Replacing the toothed belt axis may be necessary under the following circumstances, for example: The end of the useful life of the profile track roller guide has been reached as a result of material fatigue and wear. Signs of fatigue appear on the material areas of the rolling components. Fine cracks, pores and pits (depending on the wear condition) appear on the bearing surfaces. Pitting on the bearing surfaces of the guide rods and the roller bearings can be seen as the bearing surface is noticeably uneven. This can result in perceptible bearing clearance, impaired roll-off and increased operating noise, etc. The application must be checked for the following causes in the event of premature failure due to increased wear: Lack of lubrication; lubrication interval not adhered to (unlubricated operation). Use of an oil not included in the specification. Dirty and corrosive ambient conditions (dust, etc.). Impact and vibration. Technical limit data exceeded (torques, forces, speed, temperature range, etc.). Festo 7DGE_ZR_RFa_en 27 / 44

28 Incorrect set values for the braking ramp during STOP conditions (e.g. emergency stop, quick stop) result in overloading of the toothed belt axis and can destroy it or dramatically reduce its service life. Check the settings for all braking ramps on your controller or the higher-order control system (deceleration values and jerking). Make sure that the deceleration values (braking deceleration, deceleration times) for the speed, the load to be moved and the installation position (horizontal/vertical) as well as the specified maximum drive torque or the feed force correspond to the permissible values for the toothed belt axis used. Use the Festo Positioning Drives sizing software, available via the Festo website ( to size the toothed belt axis. Block-shaped acceleration profiles (without smoothing) cause high peaks in the motive force that can lead to overloading of the drive. Positions outside of the permissible range can also occur. A smoothed acceleration specification reduces vibrations in the entire system and has a positive effect on the stresses to which the mechanical system is subjected. Check which closed-loop controller settings can be adapted (e.g. smoothing of jerking, smoothing of the acceleration profile) Dismantling the slide Replacing the stop buffer You can replace the stop buffer without dismantling the slide. Lever the stop buffer out of both front sides of the slide and exchange it. Replacing the track rollers The track rollers should at least be replaced in pairs, but it would be best to replace all four track rollers at the same time. Before replacing the track rollers, check the guide rails for damage. Defective guide rails cannot be exchanged. To replace the track rollers, one of the drives cover must be removed. To do this, carry out the steps described in Chapter for removing the drive covers. 28 / 44 Festo 7DGE_ZR_RFa_en

29 Push the slide out of the axis. (DGE-63 only) The scrapers are secured with a retaining ring so that they cannot fall out. DGE-63 only Dismantle the retaining rings from the outer track rollers. All sizes Remove the two scrapers from the outer track rollers. Lever the two covers out of the slide. Loosen the two hex nuts and unscrew them. It might be necessary to counter the eccentric screw underneath. Alternatively, you can use an Allen key insert and a socket spanner insert with milled spanner flat (see Chapter 6.1 and Chapter 6.4) Take the washers out of the hole. Festo 7DGE_ZR_RFa_en 29 / 44

30 Pull the eccentric screw with the track rollers out of the slide holes. Pull the adjusting washers and the track rollers away from the eccentric screws. Loosen the two centring screws and unscrew them. Pull the adjusting washers and the track rollers away from the centring screws. Clean the locating holes in the slide and the eccentric screws. The eccentric screws must insert easily into the locating holes in the slide so that it does not result in a false setting torque when setting the roller pretension. Do not confuse the adjusting washers with the washers. Assembly directions do not have to be observed as the track rollers are symmetrical. Push the new track rollers and then the adjusting washers onto the centring screws. 30 / 44 Festo 7DGE_ZR_RFa_en

31 Apply Loctite 243 to the centring screws and insert these into the slide. Tighten the centring screws with the corresponding torque (see table). Type DGE-25 DGE-40 DGE-63 Torque 9.9 Nm 24 Nm 80 Nm Do not confuse the adjusting washers with the washers. Assembly directions do not have to be observed as the track rollers are symmetrical. Push the new track rollers and then the adjusting washers onto the eccentric screws. Guide the eccentric screws into the locating holes in the slide. Do not apply Loctite 243 to the eccentric screws at this point. This will be done shortly before the roller pretension is adjusted. Place the washer and the hex nut on the eccentric screw and tighten the hex nut by hand. Press the scrapers onto the outer track rollers. The oil-soaked scrapers are important for the running performance of the roller bearing guide and must not be omitted. Without them, the wear of the roller bearing guide increases and the toothed belt axis will fail prematurely. Festo 7DGE_ZR_RFa_en 31 / 44

32 DGE-63 only Insert the retaining ring. Check that the retaining ring is correctly positioned. All sizes Clean the inside of the cylinder barrel and the guide rods using a cloth and an air gun. Push the slide carefully onto the guide rails in the cylinder barrel Adjusting the track roller pretension The roller bearings must be set via the eccentric screws so that the displacement resistance for the slide is as low as possible and can move without backlash. The track roller pretension is adjusted with the two inner track rollers via eccentric screws. This requires a high degree of mechanical finesse. The adjustment is carried out without the toothed belt screwed on. Unscrew the hex nuts of the eccentric screws and apply Loctite 243 to them. Screw the hex nuts back on the eccentric screws, but do not tighten them yet. 32 / 44 Festo 7DGE_ZR_RFa_en

33 The two track rollers are adjusted one after the other. Place the socket spanner insert with the milled spanner flat (see Chapter 6.4) on the hex nut. Place the Allen key insert through the socket spanner insert onto the eccentric screw. Pretension the eccentric screw using a torque wrench with drag indicator anticlockwise to the specified setting torque (see table). Type DGE-25 DGE-40 DGE-63 Setting torque 0.5 Nm 2.0 Nm 5.0 Nm Tighten the hex nuts slightly so that the pretension of the eccentric screw is maintained. Fastening the hex nuts too tightly will change the pretension. Place a rigid Allen key in the eccentric screw and hold this in its position. Tighten the hex nuts with the specified torque (see table). Type DGE-25 DGE-40 DGE-63 Torque 2.9 Nm 20 Nm 40 Nm Repeat the setting procedure on the second track roller. Check the pretension setting by measuring the displacement force of the slide (Chapter 4.3.3). Festo 7DGE_ZR_RFa_en 33 / 44

34 4.3.3 Measuring the displacement force of the slide The displacement force is measured over the entire stroke when the toothed belt is not screwed on. Check the guide backlash and the displacement force (see table) by moving the slide several times. The slide must move smoothly and jerk-free on the guide rail. Type Min. displacement force Max. displacement force DGE-25 5 N 12 N DGE-40 5 N 35 N DGE-63 5 N 30 N The displacement force can be determined using an electronic hand-held force-measuring device (pressure and tensile force meter). In general, the mechanical awareness of the user is important when adjusting the linear guide. Poor operating behaviour manifests itself through operating noise. Excessive pretensioning manifests itself through harsh, increased operating noise. Adjust the track roller pretension until the running behaviour is flawless (see Chapter 4.3.2). 4.4 Assembling the toothed belt axis Preparing the cylinder barrel Clean the outside of the cylinder barrel using a cloth and an air gun. Blow the toothed belt passage out using an air gun. Before assembling the toothed belt axis, check the guide rails for damage. Defective guide rails cannot be exchanged Installing the drive covers Place the cylinder barrel on the work surface as shown. Guide the toothed belt through the toothed belt guide in the cylinder barrel as shown. The toothed profile must be facing upwards. Warning the minimum bending radii when handling the toothed belt (see Chapter 4.1.4). 34 / 44 Festo 7DGE_ZR_RFa_en

35 Guide the left-hand end of the toothed belt through the prepared drive cover for the left-hand side as shown. Place the clamping plate on the left-hand end of the toothed belt. To prevent the toothed belt from getting damaged during operation, the clamping plate must be aligned with the axial centre of the toothed belt. Align the clamping plate axially centred with respect to the toothed belt. X1 X1 Warning The toothed belt must be placed correctly on the clamping plate. It must not protrude and must make contact with four teeth. The tapped holes of the clamping bodies must be recut before the threaded pins are screwed in. Residues from the old locking agent in the tapped holes result in uneven and increased torque in the threaded pins. This means that there is no guarantee of correct tightening. Insert the left-hand end of the toothed belt together with the clamping plate into the clamping body. Align the toothed belt with the axial centre of the clamping body. Festo 7DGE_ZR_RFa_en 35 / 44

36 Apply Loctite 243 to the threaded pin and screw this into the clamping body. Push the clamping plate against the stop (a) on the clamping body. It is imperative that the clamping plate lie against the stop, since otherwise the toothed belt tension will be reduced during operation. Tighten the threaded pin with the corresponding torque (see table). It is crucial to observe the torque as excessive torque will bend the clamping body. Type DGE-25 DGE-40 DGE-63 Torque 0.5 Nm 4.0 Nm 5.0 Nm The drive cover is centred with respect to the cylinder barrel by means of two clamping sleeves. A certain amount of force may need to be applied for assembly. Place the left-hand drive cover on the cylinder barrel. Apply Loctite 243 to the socket head screws and screw them into the cylinder barrel through the drive cover. Tighten the socket head screws using the appropriate torque (see table). Type EGC-50 EGC-70 EGC-80 EGC-120 EGC-185 Torque 1.2 Nm 2.5 Nm 5 Nm 11 Nm 11 Nm Warning Do not bend or fold the toothed belt, as this can result in damage to the tensile bodies and shorten its service life by tearing it. Observe the minimum bending radius for assembly and storage (see Chapter 4.1.4). Push the clamping body into the axis through the recess of the cylinder barrel. 36 / 44 Festo 7DGE_ZR_RFa_en

37 Move the clamping body to the left-hand end of the cylinder barrel. Repeat the steps on the other end of the axis to install the second drive cover. Push the clamping body into the guide in the slide. Warning The clamping bodies must not touch the slide when they are being screwed in, as otherwise the toothed belt could otherwise become overstretched and the service life of the toothed belt would be reduced. Approach the correct toothed belt tension slowly. Screw the socket head screws evenly into the slide through the clamping bodies. Pretension the toothed belt by evenly tightening the socket head screws by feel. If the toothed belt is cut to the correct length, the clamping bodies must be at least flush with the slide. If the clamping bodies protrude, the minimum screw-in depth of the socket head screws is not achieved. This can lead to the screws being pulled out. Adjust the toothed belt tension as described in Chapter Assembly and function check After completing the assembly work on the toothed belt axis, the correct function must be checked as follows No-load torque It must be possible to move the slide without much resistance or jerking when idle without a drive attached or load connected. This check is based on the technician's instinct and experience. It is not possible to specify precise test values. Festo 7DGE_ZR_RFa_en 37 / 44

38 5 Maintenance This chapter contains key technical information about how to carry out maintenance work on the toothed belt axis. A detailed description of the steps for care and maintenance can be found in the operating instructions. Further information on the assembly aids and lubricants can be found on the Festo website ( 5.1 Cleaning and lubricating the toothed belt axis During the repair of the toothed belt axis, no machine elements have to be lubricated. 5.2 Checking and lubricating the roller bearing guide During maintenance work, check if the roller bearing guide is set so it is backlash and tension-free. The track rollers are equipped with a filling to last its entire service life. They do not have to be relubricated. The guide rods of the roller bearings are lubricated during operation by the oil-soaked felt scrapers. The scrapers must be relubricated after every km. If the environment is dusty and dirty, or if the working strokes are very short, the relubricating interval must be shortened. The maximum volume the scraper can accommodate is about 5 ml. Recommended oil Manufacturer / source Comment Constant OY 390 Klüber ( Can be purchased as 200 ml package via Festo, purchasing details on request Oils from other manufacturers which have the same specifications can also be used. The press-fitted lubrication nipples on both sides for relubricating the scrapers are miniature funnel-type lubrication nipples based on DIN 3405 (they do not fully comply with it). Relubricating must always be done on both lubrication nipples. Festo offers a one-hand high-pressure grease gun with a matching pinpoint nozzle for reoiling via these lubrication nipples (see Chapter 6.2). It is not possible to use a grease or oil press with a pointed nozzle connection (C5) for funnel-type lubrication nipples in accordance with DIN 3405, since the smallest outlet diameter of the tapered nozzle is too large and the resilient pressure ball of the funnel-type lubrication nipple cannot press against the nozzle. lubrication nipple 5.3 Toothed belt tension Warning The toothed belt is set to the specified value in the factory and is thus maintenance-free over its entire service life. The pretension of the toothed belt diminishes during storage and operation. This is normal and must not be changed by increasing the tension of the toothed belt. The reduced pretension, as described above, must not be used for assessing the condition of the toothed belt. 38 / 44 Festo 7DGE_ZR_RFa_en

39 6 Tools This chapter provides an overview of the tools and aids required to repair and maintain the toothed belt axis. 6.1 Standard tools The following standard tools are required for repair and maintenance of the toothed belt axis: Designation Additional information Plastic hammer Screwdriver inserts with ¼ drive square, for 3, 4 and 6 mm Allen screws, min. hexagon length 30 mm (long version) Pliers for retaining rings mm (interior protection for hole) Pliers for retaining rings mm (outer protection for pins) Ruler Allen key 2 10 mm Torque wrench 1 80 Nm Torque wrench with dial gauge with ¼ drive square, Ncm and / or drag indicator Tensile and pressure force Electronic hand-held force meter, measuring range: 0 50 N meter Screwdriver inserts Internal hexagon (Allen): 2 10 mm Flat pliers Sturdy general purpose For cutting the toothed belt to length scissors or metal shears 6.2 Special tools The following special tools are required for repair and maintenance of the toothed belt axis: Designation One-hand high-pressure grease gun Additional information Pinpoint nozzle for miniature funnel-type lubrication nipple Festo order no ) Illustration 1) See Assembly aids in the online spare parts catalogue on the Festo website ( Festo 7DGE_ZR_RFa_en 39 / 44

40 6.3 Devices and meters The following meters are required for repair and maintenance of the toothed belt axis: Designation Device for testing the toothed belt tension Additional information Holds the measuring probe, excites the toothed belt by means of a plunger Manufacturer / source Festo (purchasing details on request, reference BMK ) Illustration O-ring 10 1 mm Acoustic belt tension meter Measurement with or without test device Secures the acoustic measurement head in the test equipment Optibelt TT mini S plus with swan neck plus: Special bonding of the measurement head for use with the test equipment Festo part number Optibelt GmbH Purchase via Schaefer Technik GmbH or Festo Acoustic belt tension meter Measurement without test equipment Optibelt TT mini S with swan neck Optibelt GmbH or any comparable measuring device from other manufacturers 40 / 44 Festo 7DGE_ZR_RFa_en

41 6.4 Devices for in-house assembly Designation DGE-25 dimensions DGE-40 dimensions DGE-63 dimensions Illustration Socket spanner insert with milled spanner flat For tightening the hex nuts of the eccentric screws SW 10 Max. outer diameter 14.5 mm SW 13 Max. outer diameter 18.6 mm SW 19 Max. outer diameter 31.4 mm Spanner flat 14 mm Spanner flat 14 mm Spanner flat 14 mm Hole dimensions of the slide for manufacturing the socket spanner insert d = 14.7 mm t = 16 mm d = 18.8 mm t = 20 mm d = 31.6 mm t = 20 mm d t Clamping component for toothed belt tensioning (included in the device for checking the toothed belt tension) a=10 mm b= mm c=r 5 mm d=1.85 mm e=11 mm a=15 mm b= mm c=r 6 mm d=2.6 mm e=14 mm Clamping component not required e f d c b a f= mm f= mm g g=20 mm g=30 mm 7 Liability The General Terms and Conditions of Festo AG & Co. KG apply, which can be viewed on the Festo website ( Festo 7DGE_ZR_RFa_en 41 / 44