Backlash-free Safety Couplings

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1 Backlashfree Safety Couplings You Can Rely On Us! T h e m o d u l a r s y s t e m s a t i s f i e s a l l y o u r w i s h e s! Edition /00

G E R W A H T h e C o m p a n y GERWAH GmbH was founded in 19. The idea of new, innovative products has made GERWAH a recognized partner in the machine tool industry.

2 G E R W A H T h e C o m p a n y GERWAH GmbH was founded in 19. The idea of new, innovative products has made GERWAH a recognized partner in the machine tool industry. We are a dynamic, spirited and fast growing company with clear goals and open mind that is reflected in the architecture of our new headquarters. Our Goals To add value for our customers by providing innovative product solutions To develop solutions in cooperation with our customers Satisfied customers Our Advantages Knowhow, innovative designs and cutting edge manufacturing plants Customer oriented employees Technical assistance and service, both locally and internationally Qualified sales force Economic stability Worldwide presence with subsidiaries and dealers Our new headquarters in Grosswallstadt, Germany GERWAH You Can Rely On Us! Frankfurt Hamburg Grosswallstadt Munich Berlin Prague Chotesov Pilsen We are certified according to DIN EN ISO 9001 (Cert.No. 003D) info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

after long downtimes Easy handling High dynamics Low mass moment of inertia Specific customer solutions High flexibility through modular design Series DMK/L DMK/M DMK/S Series DMK/B Series DMK/E

3 Guarantee for your success! Machine and system protection Highspeed disengagement within 4 msec. Minimal residial friction Process control Accurate adjustment of disengaging torque Signalling of overloads Process accuracy Backlashfree torque transmission Excellent disengagement repeatability after long downtimes Easy handling High dynamics Low mass moment of inertia Specific customer solutions High flexibility through modular design Series DMK/L DMK/M DMK/S Series DMK/B Series DMK/E Technical data: pages 7 Technical data: pages 89 Technical data: pages 1011 The detent mechanism: rollers as interlocking elements Roller detent system Single position reengagement e.g. after 3 Multy position reengagement T Conventional progressive characteristic System GERWAH degressive characteristic T max. Switching work As = f (x1) x S S S = Spring travel S The details in this catalogue describe the products and do not represent guaranteed qualities. The user is responsible DIST. for checking AUTORIZADO and de fining the technical characteristics of his particular application. We reserve the right to make changes at any time without notice. We cannot be held responsible for any omissions or printing errors. Deliveries are based on individual detailed contractual agreements. Backlashfree safety couplings are dangerous parts and must therefore be protected by the user against unintentional handling during operation. info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt 3

The following pages illustrate technical details of each element.

application. Any questions? Don t hesitate to contact us!

4 Create your own safety coupling! Our new system allows the user to build the requested coupling combining basic coupling elements. The coupling is composed of three parts: the coupling body and the two s. The following pages illustrate technical details of each element. The result is a customer specific coupling tuned to the requirements of your application. Any questions? Don t hesitate to contact us! Example: required shaftconnection required coupling body required shaftconnection required coupling Multiple combinations available! 4 info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

5 Safety Couplings The System Hub 1 Coupling Body Hub Type L Type DMK Type M Type S Type DMK/B Data pages 7 Type Ki Type Kn Type BKi Type BKn/ EKn Type DMK/E Data pages 89 Type Ka Type EKa Data pages 1011 Generally: Keyways acc. DIN 881 on request! Combining desired! info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

6 Backlashfree Safety Couplings Series DMK: Safety Coupling with flange Type L standard Ø B1 Ø C1 ±0,1 Ø F1 g Ø D1 H7 G1 N1 L1 ±1 K1 O1 ØA1 flange side Series DMK side M1 J1 ±1 Ø D4 H7 Type Ki inner cone E1 H1 DIN EN ISO 47 Type M Ø B Ø C ±0,1 Ø F g Ø D H7 N L ±1 K O ØA S pure keyway connection disengaging travel M J ±1 Ø D H7 Type Ka outer cone E G H DIN EN ISO 47 Type S Ø B3 Ø C3 ±0,1 Ø F3 g Ø D3 H7 N3 L3 K3 O3 ØA3 DIN 88 M3 J3 ±1 Ø D H7 Type Kn clamping E3 G3 Lges = L (1//3) + J (1//3) H3 DIN EN ISO 47 L Ki Ordering data example DMK/L 10 Ki/3 H7 Nm/b C flange size inner conical / bore size (mm) disengaging torque / torque adjustment range C = single position reengagement (3 ) standard; (D = multi position reengagement) info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

7 Technical Data Series DMK/L, DMK/M, DMK/S Size Disengaging torque (Nm) Torque adjustment range Moment of inertia (10 3 Kgm 3 ) Weight (appr. kg) Tightening torque of retaining screws (Nm) Max. rotational speed (rpm) Disengaging travel (mm) TKN version a TKN version b J side J flange side m MA MA MA nmax S H1 H H , 0,1 0, 1 9 1, ,4 0, 0,8 8, 8, 8 1, ,1 0, 1,4 / ,8 0,9 1,7 100/ , 1,1, / ,94 1,3 3, ,7, ,7, Flange L Flange M Flange S Hub Ki inner cone Hub Ka outer cone Hub Kn clamping Size Ø A1 Ø B1 Ø C1 Ø D1 min.max Ø F1 G1 x thread/depth (mm) K1 L1 L ges. = L1 + (J1) or (J) or (J3) N1 O1 Ø A Ø B Ø C Ø D min.max Ø F G K L L ges. x thread/depth (mm) = L + (J1) or (J) or (J3) N O Ø A3 Ø B3 Ø C3 Ø D3 min.max Ø F3 G3 K3 L3 L ges. x thread/depth (mm) = L3 + (J1) or (J) or (J3) N3 O3 Ø D4 H1 x DIN EN ISO 47 J1 M1 E1 Ø D H x DIN EN ISO 47 J M E Ø D H3 1 x DIN EN ISO 47 J3 M3 E M/ / M/ / M/ M/ / / / M10 8/ / / / / / / / / / / / M10/ / Couplings for torque ranges different from above also available! info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt 7

8 Backlashfree Safety Couplings Series DMK/B: Safety Coupling with metal bellow as torsionproof misalignment compensating element Type BKn L1 H1(DIN EN ISO 47) Series DMK/B M3 J1 ±1 Ø D4 H7 Type Ki inner cone Ø B1 Ø C1 Ø D1 H7 Type BKi Ø B Ø C Ø D H7 L F M1 M H (DIN EN ISO ) switching ring L1 disengaging travel S L N ØA M J ±1 J3 ±1 H3 (DIN EN ISO ) Ø D H7 Ø D H7 Type Ka outer cone H4 (DIN EN ISO ) Type Kn clamping Lges = L (1/) + J (1//3) H (DIN EN ISO 47) DIST. BKn AUTORIZADO Ki Ordering data example DMK/B /4 BKn/ H7 Ki/0 H7 0Nm/b C type size / bellow 1) on bellow side / Ø on safety element side / Ø disengaging torque / torque adjustment range C = single position reengagement (3 ) standard; (D = multi position reengagement) 1) two metal bellow sizes available: 4 = short bellow, = long bellow 8 info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

9 Technical Data Series DMK/B Size Disengaging torque (Nm) TKN version a torque adjustment range TKN version b Moment of inertia BKn (10 3 Kgm )J side J metal bellow side Moment of inertia BKi (10 3 Kgm ) J side J metal bellow side Weight BKn (appr. kg) m Weight BKi (appr. kg) m Tightening torque of retaining screw H1(Nm) Ma Tightening torque of retaining screw H(Nm) Ma Tightening torque of retaining screw H3(Nm) Ma Tightening torque of retaining screw H4(Nm) Ma Tightening torque of clamp screw H (Nm) Ma Dynamic torsional stiffness (10 3 Nm/rad) CTdyn 4/ 1) Radial spring stiffness (N/mm) Cr 4/ 1) Axial spring stiffness (N/mm) Ca 4/ 1) Max. rotation speed (rpm) nmax Disengaging travel (mm) S Max. allowable misalignment: see page 1 BKn clamping BKi inner cone Size Ø A Ø B1 Ø C1 Ø D1 H7 min. max. H1 DIN EN ISO 47 L1 ) L ges. = L1 + (J1) or (J) or (J3) N M1 Ø A Ø B Ø C ,1 0,1 0,1 0,11 0,7 0,7 1/1 1 3/ 7/ 48/7 9 1, 47/ 10/0 0/ 70/ / ,4 0,4 0,3 0,7 1,4 1, / 8, 8, 8, 73/49 11/333 91/3 83 1, Ø D min. max. F H DIN EN ISO L ) L ges. = L + (J1) or (J) or (J3) N M Hub Ki inner cone Ø D H3 x DIN EN ISO J M Hub Ka outer cone Ø D H4 x DIN EN ISO J Hub Kn clamping Ø D H 1 x DIN EN ISO 47 M10 J M ) Two metal bellow dimensions featuring different degrees of torsional stiffness are available: 4= short bellow, = long bellow. Consequently, length dimensions L1 and L vary 7 7/ /3 3/3 8/ / , 1, 1,3 0,7,4, /70/0 / 11/101 0/1 7/ //84 0/8/3 /3/ M10 10/ / , 1,,1 1,1 3 3, 100/ 100/ 3/11 131/0 7/ /90 /3 3/4 113/ / , 3, 4,3,,3, /90 /90 499/ 38/70 84/ /9 3/ / / / ,8 3,8 11,3,7, 7,1 /310 80/97 10/ / 11/ / Couplings for torque ranges different from above also available! info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt 9

10 Backlashfree Safety Couplings Series DMK/E: Safety Coupling with elastomer spider as torsionally elastic misalignment compensating element Type EKa C1 H1(DIN EN ISO 47) Series DMK/E M3 J1 ±1 Ø D4 H7 Type Ki inner cone Ø B1 Ø D1 H7 M1 Type EKn Ø B Ø D H7 M L L1 C H(DIN EN ISO 47) E L1 disengaging travel S L ØA Lges = L (1/) + J (1//3) N M H3 (DIN EN ISO ) J ±1 Ø D H7 Typ Ka outer cone H4 (DIN EN ISO ) J3 ±1 Ø D H7 Type Kn clamping H (DIN EN ISO 47) DIST. EKn AUTORIZADO Ki Ordering data example DMK/E EKn/ H7 Ki/0 H7 Nm/b C type size on elastomer side / bore size inner conical on safety element side / bore size disengaging torque / torque adjustment range C = single position reengagement (3 ) standard; (D = multi position reengagement) 10 info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

11 Technical Data Series DMK/E Size Disengaging torque (Nm) TKN version a torque adjustment range TKN version b Moment of inertia (10 3 Kgm ) J side J elastomer spider side Weight (appr. Kg) m Tightening torque of retaining screw H1 (Nm) Ma Tightening torque of clamping screw H (Nm) Ma Tightening torque of retaining screw H3 (Nm) Ma Tightening torque of retaining screw H4 (Nm) Ma Tightening torque of clamping screw H (Nm) Ma Max. rotational speed (rpm) nmax Disengaging travel (mm) S Standard shore hardness of spider Max. allowable misalignment: see page ,1 0,03 0, , ,3 0,1 1,4 8, 8, , ,8 0,33,8 / / ,04 4, 10 / / ,1 7, SH A (red) (spider with different shore hardness available!) EKa outer cone EKn clamping Bore size range D1/D and applicable transmissible torque values (Nm) Hub Ki inner cone Hub Ka outer cone Hub Kn clamping Typ Ø Ø11 Ø13 37 Ø 4 Size Ø A Ø B1 C1 D1 H7 min. max. E H1 DIN EN ISO 47 L1 L ges. = L1 + (J1) or (J) or (J3) M1 N A Ø B C D H7 min. max. E H DIN EN ISO 47 L L ges. = L + (J1) or (J) or (J3) M N Ø D4 H3 x DIN EN ISO J1 M3 Ø D H4 x DIN EN ISO J Ø D H J3 M Ø1 Ø 8 Ø19 1 Ø Ø4 Ø Ø7 Ø Ø3 Ø3 Ø38 Ø41 Ø4 Ø44 Ø48 Ø0 Ø Ø M M Couplings for torque ranges different from above also available! info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt 11

12 Safety Couplings Product Information T Conventional progressive characteristic System GERWAH degressive characteristic Figure 1: advantage of the GERWAH system S switching work As = f (x1) x S T max. S S = spring travel GERWAH backlashfree safety couplings work as springloaded positive couplings. The special roller or ball guides guarantee a totally backlashfree transmission of the torque in both directions of rotation (patented). The couplings are therefore especially suitable for use in speed and direction controlled drives. Uniform loading of the rollers and balls guarantees high system stiffness, which is important especially for modern servo drives. The roller guides simultaneously guarantee high reliability and switching frequencies when used with dynamic servo drives. In the event of an overload the rollers move out of the guides (fig. and fig. 3). This results in an axial movement (S), which activates a proximity switch that immediately makes contact to switch off drive (fig. page 13). To avoid damage to the safety coupling, the drive must be switched off immediately after an overload. In order to reengage the safety coupling, the drive needs to be turned off. Then, the motor will be rotated at very low speed or manually. The coupling reengages on its own in its original angular position (Csynchronous engagement) or in the next position (Dcontinuous engagement). The reengaging of the coupling is clearly audible and is displayed through the switch contact. After reengaging, the safety coupling features its original disengaging torque. The drive can be switched on again after the cause of the torque overload has been removed. GERWAH backlashfree safety couplings have been developed especially for dynamic drives. The safety couplings work exclusively with specially selected disc springs with a pronounced degressive characteristic (see figures 1 and 4). This advantage guarantees shortest switching times and a low residual torque. The coupling disengages immediately when the predetermined amount of torque is exceeded. The torque drops immediately to a small residual value, typically to %. The switching work required of our couplings corresponds to only a fraction of that of conventional safety couplings with progressive characteristics (see fig. 1). This is a crucial advantage because even ultrashort surges in speed are rendered harmless by the safety coupling. Figure 3: disengaged S = disengaging travel T T max T min { degressive characteristic Figure : engaged F = spring force STmax remaining spring force Figure 4: Spring characteristic disengaging travel STmin 1 info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

Limit Switches Application examples Proximity sensor as mechanical limit switch Application examples of GERWAH

the ring in the event of an overload (see figure).

13 Limit Switches Application examples Proximity sensor as mechanical limit switch Application examples of GERWAH Safety Couplings in a plastic injection molding machine im special machinery opening function switch direction disengaging travel S = ca. 1, mm GERWAH backlashfree safety couplings produce an axial movement (disengaging travel) of the outer cover or the ring in the event of an overload (see figure). This disengaging motion allows a proximity sensor or a mechanical limit switch to switch off the drive and simultaneously emit an acoustical or optical signal. in a machine tool info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt 13

14 Safety Couplings Dimensioning A good concept offers many possibilities Even large destructive forces have no chance! When determining the disengaging torque of the safety coupling, brief peaks of torque in the drive assembly as well as the machine need to be taken into account. GERWAH safety couplings have been developed for rapid interruption. We recommend paying special attention to the motor characteristic regarding the maximal acceleration torque. When using dynamic drives (servo motors), e.g. machine tools, we suggest to consider the influence of the moments of inertia. Since the acceleration torque in both positive and negative direction is usually much higher than T (torque) the nominal moment, the sizing of the safety coupling and the disengaging torque level needs to be based on the maximum acceleration torque. highest torque, high demolition forces will become ineffective adjusted torque of disengagement normal operating sector remaining torque (disengaged) t (time) The following values have been determined for a correct dimensioning of couplings on highly dynamic drives. Generally, the following equation applies: TA = K x Tmax x Jmach Jmot + Jmach = [Nm] Jmot Jmach Tmax TA K K K K = moment of inertia of motor = moment of inertia of machine = max. acceleration torque = cutoff (disengaging torque) of coupling = load or impact factor = 1, (regular movements) = (irregular movements) =, 4 (shock loads) A load/impact factor of K=1. should be applied to servo drives in machine tools. A higher load factor should be used for extreme applications. info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt

15 Safety Couplings Installation Instructions Types of misalignment (figure 1) axial radial = parallel angular Shaft alignment: Figure 1 shows the types of misalignment. Prior to mounting the coupling, both the coupling and the shafts must be aligned. The precision in aligning the shafts will determine the amount of reserves the coupling offers for compensation of misalignment occurring during operation. Well aligned shafts prolongue the life cycle of the coupling and help reducing the noise level of the drive. When more than one type of misalignment are present at once, each single type of misalignment must not reach the maximal value. Instead, they have to be balanced (see figure 3). Assembly: Clean and degrease shaft ends and coupling bores and check tolerances. The max. clearance between shaft and s must not exceed 0.03 mm. Slide coupling s onto shaft ends, check axial installation dimensions and tighten locking screws according to the tightening torque values shown in the technical data pages. Removal: Loosen locking screws. When necessary, use the pushoff threads to loosen the backlash free connection. Should the shaft/ connection not come loose, use a rubber hammer, applying light taps. Please ask us for a detailed installation instruction or download from our website! Misalignment DMK/B Misalignment DMK/E size 10 0 elastomer spider shorescale A A Misalignment mm radial Kr mm axial Ka 1) 0, 0, 0,7 0,7 0,0 0,10 0,11 0,1 degree angular Kw 0,9 0,9 0,9 0, A 1,0 0, 0,9 1) The Ka values need to be added to the length dimension L of the selected coupling type Kr radial misalignment (%) size bellow short / long 4 / 4 / 4 / 4 / 4 / 4 / 7% Compensation of misalignment (figure 3) Kw excessive angular misalignment misalignment (%) will cause accelerated wear and premature failure 0% % mm axial Ka 1) 0,4 / 0, 0,4 / 0, 0,4 / 0, 0,4 / 0, 0,4 / 0, 0,4 / 0, 0, 0, 0% Misalignment mm radial Kr 0,1 / 0, 0,1 / 0, 0, / 0, 0, / 0, 0, / 0, 0, / 0, 0, 0, Ka axial misalignment (%) degree angular Kw 1,0 /1, 1,0 /1, 1,0 /1, 1,0 /1, 1,0 /1, 1,0 /1, 1,0 1,0 info@gerwah.com Phone You Can Rely On Us! Fax D388 Grosswallstadt 1

16 Log on to for: Complete catalogue info 3DCAD product drawings Calculation software Product and corporate news And much more You Can Rely On Us! 8/01/0.0/SBL/4c Your GERWAH Partner GERWAH GmbH Phone (49)0/040 Fax (49)0/0411 Luetzeltaler Strasse a D388 Grosswallstadt Germany DIN EN ISO 9001 PETER is a registered trade mark of GERWAH GmbH

Backlash-free Safety Couplings. pioneer in innovation

Backlash-free Safety Couplings. pioneer in innovation Backlashfree Safety Couplings pioneer in innovation T h e m o d u l a r s y s t e m s a t i s f i e s a l l y o u r w i s h e s! Edition 8/007 G E R W A H T h e C o m p a n y GERWAH GmbH was founded in