GB03

04

CatalogueRINGFEDER® Locking Assemblies

RfN 7014

For high torques &axial loads

2

Please note that our guarantee refers to our pro-ducts only. Because of the unlimited number of ap-plications and all different types of machines, it isnot possible for our engineers to know all factorsthat may affect or change the technical data or ourproducts.

This publication may not be reproduced, either part-ly or wholly, without the source being quoted.

We reserve the right to modify design by way oftechnical improvement.

RINGFEDER® Locking Assemblies RfN 7014

Certified by DIN EN ISO 9001 and DIN EN ISO 140001 and ISO/TS 16949

3

RINGFEDER® Locking Assemblies RfN 7014

Due to the narrow cone angles high torques & axial forces canbe transmitted.

RfN 7014 Locking Assemblies are suitable for securing all typesof bosses and hubs onto shafts and axles. Replacing tradition-al shrink fits, key and polygon connections, splined shafts etc.

We guarantee the torque/axial load transmission values as giv-en in this publication, regardless of whether the connection issubjected to static, dynamic or impact loads. However, the val-ues given in this catalogue must not be exceeded.

Locking Assembly connections only require plain shaft andbore diameters, no additional components or machining ofsteps, slots, threaded holes, etc. is necessary. Also due to theRfN 7014 Locking Assembly design, hubs can be manufacturedwith through bores, depending on the centering accuracy re-quired.

Due to the relatively wide design (giving increased guidinglengths) RfN 7014 Locking Assemblies centre better than thestandard series RfN 7012.

Hubs can be located at any point on the shaft and adjusted toprecise angles. The RfN 7014 Locking Assembly uses a fewstandard cap headed screws tightened to a specific torque val-ue.

The RfN 7014 Locking Assembly is released using the lockingscrews in the threaded jacking hole positions. No additionalmeasures or auxiliary devices are required. A small shoulder onthe shaft or in the hub bore is required for releasing (please re-fer to page 7).

As neither the shaft or hub feature grooves the notch effect isminimised giving a higher polar section modulus.

When the admissible load is exceeded the Locking Assemblywill slip. In this way they protect valuable machine componentsagainst damage. However, Locking Assemblies are subject tothe same laws as all other friction connections and are not suit-able for use as slipping clutches.

The Locking Assembly connection can be adjusted at any timeby following removal and fitting instructions.

There is no play or fretting wear with a RfN 7014 Locking As-sembly friction connection.

This catalogue lists all relevant data in the form of quick-refer-ence tables.

For highly stressed shaft-hub connectionsthe shrink fit is unsurpassable. No other shaft-hub connectioncan offer anywhere near the same performance regarding fatiguestress under alternating torsional loads. However, the traditionalshrink fit has drawbacks, as they call for involved calculationsand extremely close machining tolerances. The fitting and re-moval of these connections is difficult, subsequent adjustmentcan be impossible.

UNLIMITED RANGE OF APPLICATIONS

HIGH TRANSMISSION FORCES

OPTIMUM DEPENDABILITY

SIMPLIFIED MANUFACTURING

GOOD CENTERING ABILITY

EASY MOUNTING

EASY REMOVAL

OVERLOAD PROTECTION

EASY ADJUSTABILITY

PERFECT TRUE RUNNING

EASY CALCULATION

HIGH FATIGUE STRENGTH UNDERALTERNATING TORSIONAL STRESSES

CHARACTERISTICS

Fig. 1 · Locking Assembly RINGFEDER® RfN 7014

The connection using a RINGFEDER® RfN 7014 Locking As-sembly is a shrink fit –but a shrink fit of a special kind. With all the advantages andnone of the disadvantages.

4

Locking Assemblies RINGFEDER® RfN 7014Locking Assembly designation for shaft diameter d = 70 mm: Locking Assembly RINGFEDER® 70 x 120 RfN 7014

Mounting of Locking Asembly

The values for T, Fax, p and p´ apply to Locking Assemblies in-stalled in an oiled condition.

for further details see page 6.

Surface finishes

For shaft and hub bores:Ra � 3,2 µm.Corresponds to RMS ≤ 125 micro-inches.

Tolerances

We do not stipulate any particular tolerances. The following maybe taken as guide values:

Shaft: All clearances between h9 and k9.Hub: All clearances between N9 and H9.

In order to avoid impairments of functioning, the clearanceschosen for shaft and hub must permit a correct and symmetricclamping, i.e. if the shaft is smaller than nominal d, the boreshould be accordingly greater than nominal D and vice versa.

Location of several Locking Assemblies RfN 7014

Two Locking Assemblies at most can be installed in series. Inthis case the transmission values of the above table will double.

Change of screw tightening torques

A reduction of the contact pressures and the transmission va-lues by reducing the tightening torque of the screws is possi-ble. The admissible lower limit results from the multiplicationof the TA values of the above table by 0,8.

There is an approximate linear relationship between TA, T,Fax, p and p’ (hub and hollow shaft calculation according tothe equations on page 5)!

Explanations

d x D, L, l, L1 = Basic dimensions, Locking Assemblies nottightend

dG = Clamping/releasing thread

T = Transmissible torque

Fax = Transmissible axial force

p = Maximum surface pressure between LockingAssembly and shaft

p´ = Maximum surface pressure between LockingAssembly and hub

TA = Maximum tightening torque for the screw consideredin order to determine the values T, Fax, p and p´

Fig. 2

70 x 120 62 56 74 6850 197 201 117 8 M 12 x 55 4 145 3,380 x 130 62 56 74 11650 291 263 162 12 M 12 x 55 4 145 3,790 x 140 62 56 74 13000 290 234 150 12 M 12 x 55 4 145 4

100 x 160 80 74 94 19700 389 213 133 12 M 14 x 70 4 230 7,2110 x 170 80 74 94 26600 483 242 157 14 M 14 x 70 4 230 7,7120 x 180 80 74 94 28900 482 222 148 15 M 14 x 70 5 230 8,3130 x 190 80 74 94 31200 480 205 140 15 M 14 x 70 5 230 8,8140 x 200 80 74 94 40200 574 227 159 17 M 14 x 70 5 230 9,3150 x 210 80 74 94 42900 572 212 152 18 M 14 x 70 6 230 10160 x 230 94 88 110 64000 800 227 158 17 M 16 x 80 5 355 14,9170 x 240 94 88 110 67800 795 214 152 18 M 16 x 80 6 355 15,7180 x 250 94 88 110 83000 923 235 170 20 M 16 x 80 5 355 16,4190 x 260 94 88 110 88000 921 223 163 21 M 16 x 80 6 355 17,2200 x 270 94 88 110 105000 1050 242 179 23 M 16 x 80 5 355 18,8220 x 300 116 110 134 123000 1120 189 138 21 M 18 x 100 6 485 27,7240 x 320 116 110 134 153000 1280 198 148 24 M 18 x 100 6 485 29,8260 x 340 116 110 134 186000 1430 205 157 26 M 18 x 100 6 485 32280 x 370 136 130 156 230000 1650 192 145 24 M 20 x 120 6 690 46300 x 390 136 130 156 245000 1650 179 138 24 M 20 x 120 8 690 49

mm mm Nm kN N/mm2 Nm kgd x D L l L1 T or Fax p p´ Qty. dG Qty. TA ≈

TransmissibleLocking Assembly dimensionstorques axial

forces shaft Threadhub Weight

Locking screws DIN 912–12.9

Releasingthreads

Surface Pressurebetween Locking

Assembly and

5

Locking Assemblies RINGFEDER® RfN 7014Hub outside diameter DN as a factor of the yield point (minimum theoretical values)

Explanations

The values apply to:One Locking Assembly RfN 7014, fitted using oilB � b + k; b � L1; k � L1 - L

Calculation according to the following equations:

where Rp0,2N is the yield point of the hub material and p´red thesurface pressure reduced to the zone of stress L1, i. e.:

The following empirically determined relationship applies to theform factor c:

The required yield point of the hub material or the admissiblesurface pressure are to be determined according to the follo-wing formulas (units of meassure see table on pages 4 and 5):

For hubs with B � b + k, but a minimum width B = L, you mustchoose p´ for the preceding formulas instead of p´red .

If two Locking Assemblies are used in series, the values of theabove table also apply if the dimensions b and B are increasedby L1.

Shaft calculation (minimum requirements)

a) Applicable to solid shafts is: Rp0,2W � p

b) The admissible maximum bore diameter of a hollow shaft re-sults from the following formula:

where Rp0,2w is the yield point of the shaft material and pred thesurface pressure reduced to the zone of stress L1.

Fig. 3

70 x 120 117 197 187 176 171 165 158 154 150 14880 x 130 162 ––– 287 247 231 215 199 189 182 17790 x 140 150 309 274 245 232 219 205 196 190 185

100 x 160 133 311 285 261 250 238 225 216 210 206110 x 170 157 457 381 326 305 283 261 248 238 232120 x 180 148 419 366 323 305 287 267 255 246 240130 x 190 140 395 356 322 307 291 273 262 254 249140 x 200 159 552 455 388 362 336 309 293 281 273150 x 210 152 517 444 388 365 341 316 301 290 283160 x 230 158 ––– 541 455 423 391 359 339 326 316170 x 240 152 617 522 451 423 395 365 347 334 325180 x 250 170 ––– ––– 552 501 455 410 384 367 354190 x 260 163 ––– 658 539 496 455 415 390 374 362200 x 270 179 ––– ––– 662 586 521 462 429 407 392220 x 300 138 654 648 519 495 468 438 417 405 396240 x 320 148 803 685 595 560 522 483 461 445 432260 x 340 157 ––– 830 687 636 588 537 507 486 470280 x 370 145 930 792 688 648 603 559 533 515 500300 x 390 138 878 772 687 652 612 574 546 531 515

chosen Rp0,2N (N/mm2)

200 220 250 270 300 350 400 450 500

d x D p´ DN

mm N/mm2 mm

6

Locking Assemblies RINGFEDER® RfN 7014

Installation and removal instructions

Installation

Since the force is transmitted by contact pressure and frictionbetween the functional surfaces, the condition of the contactsurfaces and correct tightening of the locking screws are ofgreat importance (see point 2).

1. When originally packed, Locking Assemblies are fitted withsmall metal packing pieces located in the slits of the innerand outer rings. These are for shipping purposes only andMUST be removed prior to installation.

2. All contact surfaces, including screw threads and screwhead bearing surface, must be clean and slightly oiled (donot use molybdenum disulphide). In this condition, theshaft, hub, and Locking Assemblies are to be assembled.

3. Tighten locking screws lightly and align hub.

4. Tighten screws evenly in diametrically opposite sequenceand do this in two or three stages up to the indicated finaltightening torque (TA).

5. Re-check tightening torque by applying it to all the screws.When no screw turns any more, the assembly is completed.

Removal

The Locking Assemblies RfN 7014 are to be removed asfollows:

1. Loosen all screws by a few threads.

2. Remove the screws adjacent to each threaded release holeand screw them into these holes. Since the rear thrust ringrests against either shaft or hub shoulder, the jack screwswill automatically push apart both tapers, thus releasing theconnection.

3. The connection can be either re-adjusted or dis-assembled.Remove the jack screws only after the Locking Assemblyhas been taken out of the hub.

Used Locking Assemblies have to be replaced and slightly oi-led prior to reinstallation. Note that the release threads of theof the front thrust ring have to be positioned opposite to un-drilled spaces of the rear thrust ring. These threads are usedfor removal.

Fig. 5 · Locking Assembly with a screw in one of the realease threadsFig. 4 · Locking Assembly not tightened

7

Locking Assemblies RINGFEDER® RfN 7014

Construction hints / Construction examples

Fig. 6 · Arrangement of a Locking Assembly RfN 7014 supported by the hub. Fig. 7 · For hubs with comparatively small outside diameters it is recommendedto step the shaft in order to obtain a sufficient hub section above the LockingAssembly (support by he hub).

Fig. 8 · Arrangement of a Locking Assembly RfN 7014 supported by the shaft. Fig. 9 · In the case of straight through hub bores and shafts without steps orshoulders, it must be possible to push the rear thrust ring of the Locking As-sembly against another construction part in order to release the assembly.

Fig. 10 · Venturi nozzle for the gaspurifying, converter.Flap fastening Locking Asemblies 90 x 140 RfN 7014Messrs. BAUMCO, Essen

Fig. 11 · Rolling crusherFastening of a gearwheel with a Locking Assembly 160 x 230 RfN 7014Messrs . Hazemag, Münster

88

Material standards – selectionHints for material specifications and according values of yield strength

replaced by aproximate rangeDIN DIN EN designation of yield point*

N/mm2

seamless tubes1629 for 215 up to 355

special requirements

cast steel1681 for 200 up to 300

common use

Beibl. 11691 cast iron 98 up to 228

(0,1 – limit of elongation)

1692 malleable cast iron 200 up to 530

1693 spheroidal graphite cast iron 250 up to 500

copper - tin1705 and 90 up to 180

copper - tin - zinc - alloys

1725 575 aluminium alloys 70 up to 380

17100 10025 structural and constructural steels 175 up to 365

17200 10083 heat-treatable steel 300 up to 560

17245 ferritic creep resistant cast steel 125 up to 540

17440 stainless steels 185 up to 600

* dependent on quality, kind of product and intended use

99

ISO-tolerances for shafts and boresAllowances in µm (1 µm = 39.37 µin)

Technical service

Based on your technical drawings and data we are readyto execute installation proposals to solve your specificproblems.Many years of experience and modern calculation me-thods open extraordinary possibilities of assistance.

Certified

Fax enquiry

To make it easier for our technical staff and to avoid errors or mistakes your enquiry should include the following infor-mation:

Information for technical service

Expected maximum loads:

Max. torque Tg max. = ……………………… NmMax. bending moment Mg max. = ……………………… NmMax. axiall load Fg max. = ……………………… kNMax. radial load Fr max. = ……………………… kN

Dimensionens, materials:

shaft diameter dW = ……………………… mmIn case of hollow shaft, internal diameter dB = ……………………… mmSpeed/revolutions n = ……………………… 1/minHub outside diameter DN = ……………………… mmHub width B = ……………………… mmHub material/yield strength Rp0,2N = ……………………… N/mm2

Shaft material/yield strength Rp0,2W = ……………………… N/mm2

Temperature at the connection Temp. = ……………………… °C

Additional information: ....................................................................................................................................................................................................................................................................................................................................

For technical assistance

+49 (0) 2151 835 – 200 or 207

Messrs.: ......................................................................................................................................................................................................................................

contact: ...................................................................

department: ............................................................

address: ....................................................................................................................................................................................................................................

phone: ..................................................................

fax: .........................................................................

Please send a drawing or sketch together with your enquiry!

To: RINGFEDER VBG GMBH, department MVFrom:

RINGFEDER VBG GMBH · Oberschlesienstr. 15 · D-47807 KrefeldP.O.Box 130619 · D-47758 KrefeldPhone +49 (0) 2151- 835-0 · Fax +49 (0) 2151- 835-200/207http://www.ringfeder.de · e-mail: info@ringfeder.de

RINGFLEX Drive Systems LimitedUnit 34, Vauxhall Industrial EstateGreg Street, Reddish · GB Stockport SK5 7BRPhone (0161) 4740464 · Fax (0161) 4290272

RINGFEDER® Locking Assemblies RfN 7012 . . . . . . . . . . . for highly stressed shaft-hub connectionsand big machining tolerances

RINGFEDER® Locking Assemblies RfN 7012-IN . . . . . . . . . for shafts with inch-dimensionsRINGFEDER® Locking Assemblies RfN 7013 . . . . . . . . . . . for higher demands to concentricityRINGFEDER® Locking Assemblies RfN 7013-IN . . . . . . . . . for shafts with inch-dimensionsRINGFEDER® Locking Assemblies RfN 7014 . . . . . . . . . . . for extremely stressed shaft-hub connectionsRINGFEDER® Locking Assemblies RfN 7015 . . . . . . . . . . self-centering, for highest transmission values

as well as for the use in belt drumsRINGFEDER® Locking Assemblies RfN 7110 . . . . . . . . . . compact dimensions, excellent centering ability

RINGFEDER® Locking Elements RfN 8006 . . . . . . . . . . . . adaptable design for special requirements

RINGFEDER® Shrink Discs . . . . . . . . . . . . . . . . . . . . . . . for external ClampingRfN 4071 / 4091 / 4051 / 4073 / 4171RINGFEDER® Shaft Couplings . . . . . . . . . . . . . . . . . . . . . for an absulutly rigid connection of shafts

and high accuracy of alignmentSpecial designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on requestTorque wrenches and accessories . . . . . . . . . . . . . . . . . . for correct tightening

For shaft-hub connections we supply:

Also available from RINGFEDER VBG GMBH:

Damping Elements, such as RINGFEDER® Friction Springs designed to absorb high energies at relati-vely compact dimensions, DEFORM plus ®- non-reusable, “one-hit” shock absorbing elements, made of syn-thetic material or steel, DEFORM plus ®R - reuseable damping elements.Trailer Couplings and accessories for road transport and special vehicles.

2004

-03

· Thi

s pu

blic

atio

n m

ay n

ot b

e re

prod

uced

, eith

er p

artly

or w

holly

, with

out t

he s

ourc

e be

ing

quot

ed.

RINGFEDER products are available from MARYLAND METRICS

Certified in accordance with DIN EN ISO 9001 and DIN EN ISO 140001 and ISO TS 16949