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Bearing housings

Split plummer block housings SNS

Split plummer block housings SNS:

  • are designed in accordance with a modular concept and are highly versatile in application ➤ section
  • are suitable for different bearing types and sizes with bore diameters from 115 mm to 530 mm ➤ section
  • lead, as a result of their design, to optimised load distribution and thereby increase the rating life of the bearing by up to 50% ➤ Figure and ➤ section
  • give a reduction, due to the lower replacement frequency of the bearing fitted, in total costs over the running time

Influence of housing design on the load distribution in the bearing


Conventional plummer block housing with associated load distribution


FAG plummer block housing SNS with associated load distribution

Housing design

Housings for aggressive environmental conditions

Split plummer block housings SNS are highly robust and therefore particularly suitable for aggressive environmental conditions such as those in mining applications ➤ Figure and ➤ Figure.

Split plummer block housings SNS..-H and SNS..-Z

Housing design for labyrinth and Taconite seal

Split plummer block housings SNS..-B

Housing design for Bold-on seal

Modular concept

The decisive factor is the outside diameter of the bearing

The housings are designed in accordance with a modular concept. Each housing can be fitted with rolling bearings of various diameter and width series if they have the correct outside diameter for the housing.

Seals are matched to the shaft diameter

Depending on their design, the bearings can be located either directly on the shaft or by means of an adapter sleeve. This gives different shaft diameters for the same bearing size. The spacings between the shaft and housing body are compensated by means of appropriately matched seals.

Longer bearing life

Bearing rating life up to 50% longer than with conventional plummer block housings

In the case of plummer block housings SNS, the life of the spherical roller bearings fitted is up to 50% longer than in the case of conventional plummer block housings. The increase in life is dependent on the application, the load and the bearing design. Calculation of the bearing life is based on the calculation software BEARINX. The reason for the longer bearing life is the optimised load distribution in the bearing that is achieved as a result of the new housing design ➤ Figure.

Conventional plummer block housings: unfavourable load distribution in the bearing

Conventional plummer block housings are designed such that the bearing load is introduced into the housing locating face by means of a support area directly below the bearing. If loading is in the main load direction, namely with an orientation vertical to the housing locating face, an unfavourable load distribution occurs in the bearing. Due to the narrow load zone, the load is distributed over only a small number of rolling elements, leading to a particularly high load maximum on the roller in the apex position.

Plummer block housings SNS: optimised load distribution

In the case of plummer block housings SNS, a material recess below the bearing distributes the support area over two symmetrically arranged support faces. This leads to a significant improvement in the load distribution in the bearing. The load zone is wider and the load is distributed more uniformly over several rolling elements. The maximum is now present on the two neighbouring rollers of the roller in the apex position and is reduced. This results in a significant increase in the fatigue life of the rolling bearings.

Advantages of detailed design

A large number of details in the housing design that are systematically matched to practical application allows a particularly flexible and economical usage of plummer block housings SNS ➤ Figure.

Advantages of detailed design


Lubrication hole with long axial lubrication groove


Pilot hole at predefined position for condition monitoring


Grease outlet holes


Indentations indicating shaft and bearing centres


Inclined run-off areas


Machined locating faces


Prepared mounting points for condition monitoring


Marking of housing halves


Dismounting notches


Overhang of upper housing section


Lubrication hole with long axial lubrication groove

A lubrication hole with a long axial lubrication groove in the upper housing section ensures supply of lubricant irrespective of bearing position to all bearing series that can be fitted. Suitable lubrication nipples are included in the scope of delivery.

Grease outlet holes

Grease outlet holes in the lower housing section allow the escape of used and superfluous grease during relubrication.

Indentations

Indentations in the lower housing section indicate the shaft and bearing centres in the housing. This allows rapid alignment and reduces mounting time.

Inclined run-off areas

Inclined run-off areas on the upper and lower housing section promote the removal of fluids and reduce deposits of contamination. This leads to reduced cleaning work and a lower risk of corrosion.

Machined locating faces

Machined locating faces on the lower housing section allow precise alignment of the housing. When the housing is painted, the locating faces are also provided with a universal paint coating. Since the locating faces are raised, strips can be used as an alignment aid. One-off alignment is sufficient to allow rapid interchange of the housing when necessary.

Prepared mounting points for condition monitoring

In order to allow the uncomplicated use of condition monitoring, the lower housing section has a connection facility on both sides for condition monitoring systems. Due to the thread M6 and a flattened area of diameter 26 mm, it is possible to directly connect FAG SmartCheck, a modular online measuring system for machine monitoring. Alternatively, other vibration sensors can also be connected.

If neither of the two connection points is accessible as a result of the adjacent construction, a further suitable connection point on the upper section is indicated by a cast-in pilot hole.

FAG SmartCheck must be ordered separately. Detailed information TPI 214 or http://www.schaeffler.de/std/1B6C.

Marking of housing halves

The upper housing section and lower housing section are matched to each other and must not be transposed with other housing halves. The serial numbering on both halves of the housing ensure their correction allocation. Furthermore, the serial numbering allows traceability and simplified documentation.

Dismounting notches

Recessed dismounting notches on the interface of the housing halves make it easier to remove the upper housing section.

Overhang of upper housing section

The overhang of the upper housing section prevents the collection of fluids and contaminants at the interface of the two housing halves. This leads to reduced cleaning work and a lower risk of corrosion.

Suitable bearings

Shaft diameters from 115 mm to 530 mm and from 4 7/16 inch to 19 1/2 inch

Split plummer block housings SNS are suitable for fitting with spherical roller bearings or toroidal roller bearings with a tapered or cylindrical bore ➤ Table. The range of shaft diameters is 115 mm to 530 mm and 4 7/16 inch to 19 1/2 inch.

Bearing types and sizes

Bearing type

Size

Spherical roller bearings
  • with tapered bore and adapter sleeve

22232..-K to 22272..-K

  • with tapered bore and adapter sleeve

22326..-K to 22356..-K

  • with tapered bore and adapter sleeve

23036-K to 230/530..-K

  • with tapered bore and adapter sleeve

23134..-K to 23196..-K

  • with tapered bore and adapter sleeve

23232..-K to 23288..-K

  • with cylindrical bore

22232 to 22272

  • with cylindrical bore

22326 to 22356

  • with cylindrical bore

23036 to 230/530

  • with cylindrical bore

23134 to 23196

  • with cylindrical bore

23232 to 23288

  • with cylindrical bore

24036 to 240/530

  • split

230SM160 to 230SM410

  • split

230S.607 to 230S.1608

  • split

231SM150 to 231SM410

  • split

231S.515 to 231S.1500

  • split

232SM260 to 232SM340

  • split

232S.1200 to 232S.1308

Toroidal roller bearings

  • with tapered bore and adapter sleeve

C2232..-K to C2244..-K

  • with tapered bore and adapter sleeve

C2326..-K to C2356..-K

  • with tapered bore and adapter sleeve

C3036-K to C30/530..-K

  • with tapered bore and adapter sleeve

C3134..-K to C3196..-K

  • with tapered bore and adapter sleeve

C3232..-K to C3288..-K

  • with cylindrical bore

C2232 to C2244

  • with cylindrical bore

C2326 to C2356

  • with cylindrical bore

C3036 to C30/530

  • with cylindrical bore

C3134 to C3196

  • with cylindrical bore

C3232 to C3288

  • with cylindrical bore

C4036 to C40/530


Split spherical roller bearings

Unsplit spherical roller bearings with an adapter sleeve can be replaced by split spherical roller bearings ➤ Table. This gives a considerable reduction in the work associated with bearing replacement in numerous applications.

In order to ensure selection of the correct combination of housing and bearing when using split bearings, please contact Schaeffler.

The range of split spherical roller bearings is described in detail in a separate publication TPI 250.

Allocation of bearing and housing series

On the basis of the modular concept, one or more series of plummer block housings SNS are suitable for each series of spherical roller bearings ➤ Table to ➤ Table.

Plummer block housings SNS for spherical roller bearings with tapered bore and adapter sleeve

Bearing

Plummer block housing

Series

SNS2264

SNS30

SNS31

SNS32

SNS40

Suffixes

H

Z

H

Z

H

Z

B

H

Z

H

Z

222..-K

223..-K

230..-K

231..-K

232..-K

● = suitable

Plummer block housings SNS for spherical roller bearings with cylindrical bore

Bearing

Plummer block housing

Series

SNS2264

SNS30

SNS31

SNS32

SNS40

Suffixes

H

Z

H

Z

H

Z

B

H

Z

H

Z

222

223

230

231

232

240

● = suitable

Plummer block housings SNS for split spherical roller bearings

Bearing

Plummer block housing

Series

SNS2264

SNS30

SNS31

SNS32

SNS40

Suffixes

H

Z

H

Z

H

Z

B

H

Z

H

Z

230S

231S

232S

● = suitable

Materials, corrosion protection

Material

The housing bodies are made from spheroidal graphite cast iron GJS‑400‑15 (suffix D).

Corrosion protection

All outer surfaces not machined by chip-forming methods and the locating surfaces on the lower housing section have a universal paint coating (colour RAL 7016, anthracite grey). The coating can be finished using all synthetic resin, polyurethane, acrylic, epoxy resin, chlorinated rubber, nitrocellulose and acid-hardening hammer tone finishes.

Inner and outer surfaces machined by chip-forming methods are provided with anti-corrosion protection that can be easily removed. It is recommended that only volatile solvents and lint-free cloths should be used.

Locating and non-locating bearings

Locating bearing arrangement by means of locating rings

The bearing seats in the housing are machined such that the bearings are movable and can thus function as non-locating bearings. Locating bearing arrangements can be achieved by the insertion of locating rings NFR on both sides of the bearing outer ring. Depending on the combination of housing and bearing, 2, 4 or 6 locating rings will be required ➤ dimension table. Locating rings must be ordered separately.

Load carrying capacity

Guide values

Guide values are given for the rupture load of plummer block housings SNS and the maximum load carrying capacity of connecting screws for the upper and lower housing sections, ➤ Figure and ➤ Table. The guide values are valid for purely static loading.

The guide values only apply if the flatness of the mounting surface in accordance with DIN EN ISO 1101 corresponds to the tolerance grade IT7 in accordance with DIN EN ISO 286-1 (measured across the diagonal). A precondition for supporting loads is that the housing base surface is completely and rigidly supported.

Safety factors

When determining the permissible static load, safety factors must be applied. For general machine building, the safety factor 6 relative to the housing rupture load is normally applied. Based on the precise calculation of the housing rupture loads using the Finite Element method and the use, as standard, of spheroidal graphite cast iron as the housing material, the safety factor 5 is sufficient for plummer block housings SNS.

A safety factor is not required for the values given for the load carrying capacity of the connecting screws.

If the housing is subjected to axial load, the permissible axial load of the bearing fitted must be taken into consideration. If the bearing is located on the shaft using an adapter sleeve, the axial retaining force of the bearing and adapter sleeve must also be taken into consideration.

If the load direction is between 55° and 120° or axial load is present, we recommend that the housings should be secured in the load direction by means of stops.

Load directions F for the guide values for the housing rupture load and the maximum load carrying capacity of the connecting screws

Guide values for housing rupture load and maximum load carrying capacity of connecting screws.
Tightening torques

Housing designation

Housing rupture loads1) in load direction F

Housing designation

Connecting screws

Screws to DIN EN ISO 4014

Tightening torque

Maximum load carrying capacity in load direction F2)

SNS22

SNS30

SNS31

SNS32

SNS40

55°

90°

120°

150°

180°

axial

SNS22

SNS30

SNS31

SNS32

SNS40

Grade 8.8

90°

120°

150°

180°

kN

kN

kN

kN

kN

kN

kN

Nm

kN

kN

kN

kN

SNS3036

SNS3134

4  050

4  540

3  040

1  650

1  190

1  220

1  170

SNS3036

SNS3134

M24

559

1  380

760

618

725

SNS3038

SNS3136

4  400

4  940

3  300

1  800

1  300

1  330

1  270

SNS3038

SNS3136

M24

559

1  370

760

615

723

SNS3040

SNS3138

SNS3234

4  880

5  480

3  660

1  990

1  440

1  470

1  410

SNS3040

SNS3138

SNS3234

M24

559

1  500

830

670

790

SNS3236

4  880

5  480

3  660

1  990

1  440

1  470

1  410

SNS3236

M24

559

1  500

830

670

790

SNS3044

SNS3140

SNS3238

5  800

6  500

4  350

2  370

1  700

1  750

1  670

SNS3044

SNS3140

SNS3238

M24

559

1  510

836

677

796

SNS3048

SNS3144

SNS3240

6  240

7  560

5  070

2  880

2  360

2  380

1  880

SNS3048

SNS3144

SNS3240

M24

559

1  484

820

664

781

SNS3052

SNS3148

7  330

8  550

5  720

3  190

2  470

2  510

2  080

SNS3052

SNS3148

M30

1  118

2  380

1  315

1  065

1  252

SNS3244

7  330

8  550

5  720

3  190

2  470

2  510

1  880

SNS3244

M30

1  118

2  380

1  315

1  065

1  252

SNS3056

SNS3152

8  740

9  810

6  550

3  570

2  580

2  640

2  520

SNS3056

SNS3152

M30

1  118

2  372

1  310

1  061

1  250

SNS3248

8  740

9  810

6  550

3  570

2  580

2  640

1  410

SNS3248

M30

1  118

2  372

1  310

1  061

1  250

SNS3060

SNS3156

9  200

10  320

6  900

3  760

2  710

2  780

2  652

SNS3060

SNS3156

M30

1  118

2  330

1  290

1  040

1  230

SNS3064

SNS3160

10  150

11  390

7  620

4  150

3  000

3  070

2  810

SNS3064

SNS3160

M30

1  118

2  220

1  230

990

1  170

SNS3252

10  150

11  390

7  620

4  150

3  000

3  070

2  230

SNS3252

M30

1  118

2  220

1  230

990

1  170

SNS3256

10  150

11  390

7  620

4  150

3  000

3  070

2  230

SNS3256

M30

1  118

2  220

1  230

990

1  170

SNS3068

SNS3164

11  410

12  810

8  560

4  660

3  370

3  450

3  355

SNS3068

SNS3164

M30

1  118

2  220

1  230

1  000

1  170

SNS3072

11  410

12  810

8  560

4  660

3  370

3  450

3  355

SNS3072

M30

1  118

2  200

1  230

1  000

1  170

SNS3260

11  410

12  810

8  560

4  660

3  370

3  450

2  900

SNS3260

M30

1  118

2  200

1  230

1  000

1  170

SNS2264

SNS3076

SNS3168

SNS4076

13  300

14  930

9  980

5  430

3  930

4  020

3  480

SNS2264

SNS3076

SNS3168

SNS4076

M36

1  945

3  260

1  800

1  460

1  720

SNS3264

13  300

14  930

9  980

5  430

3  930

4  020

2  690

SNS3264

M36

1  945

3  260

1  800

1  460

1  720

SNS3080

SNS3172

14  740

16  540

11  060

6  020

4  350

4  450

4  250

SNS3080

SNS3172

M36

1  945

3  100

1  710

1  390

1  630

SNS4080

14  740

16  540

11  060

6  020

4  350

4  450

4  295

SNS4080

M36

1  945

3  100

1  710

1  390

1  630

SNS3084

SNS3176

15  940

17  890

11  960

6  510

4  710

4  820

4  600

SNS3084

SNS3176

M36

1  945

3  100

1  710

1  390

1  630

SNS3268

15  940

17  890

11  960

6  510

4  710

4  820

3  628

SNS3268

M36

1  945

3  100

1  710

1  390

1  630

SNS4084

15  940

17  890

11  960

6  510

4  710

4  820

4  200

SNS4084

M36

1  945

3  100

1  710

1  390

1  630

SNS3088

SNS3180

18  490

20  750

13  870

7  560

5  460

5  590

5  330

SNS3088

SNS3180

M36

1  945

3  200

1  770

1  430

1  690

SNS3272

18  490

20  750

13  870

7  560

5  460

5  590

3  200

SNS3272

M36

1  945

3  200

1  770

1  430

1  690

SNS4088

18  490

20  750

13  870

7  560

5  460

5  590

4  535

SNS4088

M36

1  945

3  200

1  770

1  430

1  690

SNS3092

SNS3184

SNS4092

20  180

22  650

15  140

8  250

5  960

6  100

5  650

SNS3092

SNS3184

SNS4092

M42

2  794

4  110

2  270

1  840

2  160

SNS3096

SNS4096

20  180

22  650

15  140

8  250

5  960

6  100

5  650

SNS3096

SNS4096

M42

2  794

4  110

2  270

1  840

2  160

SNS3276

20  180

22  650

15  140

8  250

5  960

6  100

4  530

SNS3276

M42

2  794

4  110

2  270

1  840

2  160

SNS30/500

SNS3188

21  940

24  620

16  460

8  970

6  480

6  630

6  320

SNS30/500

SNS3188

M42

2  794

4  110

2  270

1  840

2  160

SNS3280

21  940

24  620

16  460

8  970

6  480

6  630

4  360

SNS3280

M42

2  794

4  110

2  270

1  840

2  160

SNS40/500

21  940

24  620

16  460

8  970

6  480

6  630

6  350

SNS40/500

M42

2  794

4  110

2  270

1  840

2  160

SNS3192

24  150

27  100

18  120

9  870

7  130

7  300

6  962

SNS3192

M42

2  794

4  160

2  300

1  860

2  190

SNS3284

24  150

27  100

18  120

9  870

7  130

7  300

4  747

SNS3284

M42

2  794

4  160

2  300

1  860

2  190

SNS30/530

SNS3196

SNS40/530

26  080

29  270

19  560

10  660

7  700

7  880

7  420

SNS30/530

SNS3196

SNS40/530

M42

2  794

4  160

2  300

1  860

2  190

SNS3288

26  080

29  270

19  560

10  660

7  700

7  880

4  500

SNS3288

M42

2  794

4  160

2  300

1  860

2  190

  1. For housings made from spheroidal graphite cast iron GJS-400-15 (suffix D).
  2. Maximum load carrying capacity in load direction F, where there is still contact at the parting line between the upper and lower housing sections.

Lubrication

Split plummer block housings SNS are principally intended for grease lubrication. However, a design for oil lubrication is also available by agreement.

Lubricating greases

Arcanol rolling bearing greases

In order to achieve a long operating life and high operational security of the bearing arrangement, we recommend the use of rolling bearing greases Arcanol ➤ section. These have been designed and tested for bearing arrangement engineering.

Grease quantity

Basic rule for initial greasing

For initial greasing, the basic rule is that the bearing should be filled with grease to 100% and the free volume of the housing to 60%. The free volume is the space that remains in the housing once the bearing, adapter sleeve, shaft and seals have been fitted.

Recommended grease quantity

The recommended grease quantity can also be stated in grams once the density of the grease has been taken into consideration ➤ Table.

The recommended grease quantity takes account of:

  • filling of the free volume to 60%
  • grease with a density of 0,9 g/cm3

Recommended grease quantity for selected housing/ bearing combinations

Housing

Bearing

Adapter sleeve

Free volume (100%)

Recommended grease quantity

cm3

≈ g

SNS22

SNS2264-H-D

22264..-K

H3064

27 550

14 900

SNS30

SNS3036-H-D

23036..-K

H3036

2 900

1 600

SNS3038-H-D

23038..-K

H3038

3 900

2 250

SNS3040-H-D

23040..-K

H3040

5 020

3 050

SNS3044-H-D

23044..-K

H3044

5 770

4 260

SNS3048-H-D

23048..-K

H3048

7 280

4 550

SNS3052-H-D

23052..-K

H3052

9 930

6 750

SNS3056-H-D

23056..-K

H3056

12 500

6 750

SNS3060-H-D

23060..-K

H3060

14 800

8 000

SNS3064-H-D

23064..-K

H3064

19 400

10 500

SNS3068-H-D

23068..-K

H3068

24 000

13 000

SNS3072-H-D

23072..-K

H3072

30 400

16 450

SNS3076-H-D

23076..-K

H3076

32 000

17 300

SNS3080-H-D

23080..-K

H3080

33 500

18 100

SNS3084-H-D

23084..-K

H3084

35 000

18 900

SNS3088-H-D

23088..-K

H3088

43 400

23 450

SNS3092-H-D

23092..-K

H3092

56 600

30 600

SNS3096-H-D

23096..-K

H3096

55 200

29 850

SNS30/500-H-D

230/500..-K

H30/500

55 200

29 850

SNS30/530-H-D

230/530..-K

H30/530

67 500

36 450

continued ▼

Information on the recommended grease quantity for other housing sizes is available by agreement.

Recommended grease quantity for selected housing/ bearing combinations

Housing

Bearing

Adapter sleeve

Free volume (100%)

Recommended grease quantity

cm3

≈ g

SNS31

SNS3134-H-D

23134..-K

H3134

2 900

1 600

SNS3136-H-D

23136..-K

H3136

3 810

2 060

SNS3138-H-D

23138..-K

H3138

5 030

2 720

SNS3140-H-D

23140..-K

H3140

6 780

3 660

SNS3144-H-D

23144..-K

H3144

7 520

4 060

SNS3148-H-D

23148..-K

H3148

10 100

5 990

SNS3152-H-D

23152..-K

H3152

11 650

6 300

SNS3156-H-D

23156..-K

H3156

12 550

6 800

SNS3160-H-D

23160..-K

H3160

17 200

9 300

SNS3164-H-D

23164..-K

H3164

21 250

11 500

SNS3168-H-D

23168..-K

H3168

27 550

14 900

SNS3172-H-D

23172..-K

H3172

28 500

15 400

SNS3176-H-D

23176..-K

H3176

28 300

15 300

SNS3180-H-D

23180..-K

H3180

36 450

19 700

SNS3184-H-D

23184..-K

H3184

45 550

24 600

SNS3188-H-D

23188..-K

H3188

48 300

26 100

SNS3192-H-D

23192..-K

H3192

52 000

28 100

SNS3196-H-D

23196..-K

H3196

55 000

29 700

SNS32

SNS3234-H-D

23234..-K

H2334

5 350

2 900

SNS3236-H-D

23236..-K

H2336

5 350

2 900

SNS3238-H-D

23238..-K

H2338

6 500

3 510

SNS3240-H-D

23240..-K

H2340

6 900

3 760

SNS3244-H-D

23244..-K

H2344

10 000

5 400

SNS3248-H-D

23248..-K

H2348

10 200

5 550

SNS3252-H-D

23252..-K

H2352

15 500

8 400

SNS3256-H-D

23256..-K

H2356

15 500

8 400

SNS3260-H-D

23260..-K

H3260

19 000

10 300

SNS3264-H-D

23264..-K

H3264

25 300

13 700

SNS3268-H-D

23268..-K

H3268

25 000

13 500

SNS3272-H-D

23272..-K

H3272

26 800

14 500

SNS3276-H-D

23276..-K

H3276

38 600

20 850

SNS3280-H-D

23280..-K

H3280

44 100

23 850

SNS3284-H-D

23284..-K

H3284

45 000

24 350

SNS3288-H-D

23288..-K

H3288

49 400

26 700

continued ▲

Information on the recommended grease quantity for other housing sizes is available by agreement.

Deviation from basic rule

The recommended degree of filling for the greasing of bearings, as a function of the application and speed, may deviate from 100%.

Relubrication

Bearings with circumferential lubrication groove

Where relubrication is carried out on bearings with a circumferential lubrication groove, the grease is introduced into the housing via the central lubrication hole ➤ Figure. In this type of relubrication, the grease acts directly on the bearing.

Bearings without lubrication groove

For the relubrication of bearings without a lubrication groove, two relubrication points are provided in the upper housing section. One of the two points has a threaded hole, while the other is indicated by a cast-in pilot hole.

Lubrication holes and lubrication nipples

The lubrication holes and lubrication nipples provided for relubrication differ according to the design of the housing ➤ Table. In the case of housings SNS..-H and SNS..-Z, the threaded holes are closed off by a screw plug. This must be removed and permanently replaced by one of the lubrication nipples supplied. In the case of housings SNS..-B, both taper type lubrication nipples are already fitted.

Lubrication holes and lubrication nipples

Housing

Thread

Lubrication nipple

Delivery quantity

SNS..-H

SNS..-Z

M10×1

Button head lubrication nipple
to DIN 3404-M10×1
(with dust cap)

1

SNS..-H

SNS..-Z

M10×1

Taper type lubrication nipple
to DIN 71412-AM10×1
(with dust cap)

1

SNS..-B

ISO 288-G1/4

Button head lubrication nipple
to DIN 3404-A G1/4 St

2


Positions for further lubrication holes

Lubrication holes can be provided at two further points for relubrication of labyrinth seals. These positions are indicated by marks on the housing.

Prevention of overgreasing

In order to prevent overgreasing, the screw plugs must be removed from the two grease outlet holes in the lower housing section for the duration of relubrication. This allows superfluous grease to escape. The grease outlet holes must then be closed off again using the screw plugs.

If unfavourable environmental conditions are present, there is therefore a risk of contaminant ingress into the housing when the grease outlet holes are opened.

Positions for relubrication


Central lubrication hole, for bearings with lubrication groove


Points for relubrication of bearings without lubrication groove


Points for relubrication of labyrinth seals


Grease outlet holes

Sealing

Seals

Standard seals

For sealing of the bearing housings, the following standard seals are available:

  • labyrinth seals and Taconite seals, each in a split and unsplit design. These seals are matched to the rectangular section annular slots on both sides of the housings SNS..-H and SNS..-Z
  • Bold-on seal. This seal is screw mounted to the outside of housings SNS..-B.

Seals must be ordered separately. They are supplied individually. If a continuous shaft is present, two seals are necessary.

Labyrinth seals NTS

Non-contact seal for high circumferential velocities

Labyrinth seals NTS give non-contact sealing. They are therefore suitable for high circumferential velocities. The O ring, which is pressed between the labyrinth ring and shaft, is made from fluoro rubber FKM and is suitable for temperatures of up to +200 °C. The labyrinth seal allows shaft misalignment of up to 0,3° in both directions and is suitable for grease lubrication.

Relubrication

If necessary, the labyrinth can be relubricated. For this purpose, a lubri­cation hole must be made in the upper housing section for each labyrinth seal. The optimum positions are indicated by cast-in pilot holes.

Taconite seals NTC

Seals for extreme contamination impact

Taconite seals NTC are combined seals comprising a labyrinth seal and a V ring. These seals are suitable for extreme operating conditions in relation to contamination and dust. The V ring is made from NBR and is suitable for temperatures of up to +100 °C.

The Taconite seal allows shaft misalignment of up to 0,3° in both directions and is suitable for grease lubrication. For relubrication, the seal is fitted with a lubrication nipple.

Split labyrinth seals NTSG

Split seal reduces mounting work

For plummer block housings SNS, labyrinth seals are also available in a split design. As a result, the work involved in fitting or replacing the seal can be considerably reduced, especially if a split bearing is also fitted.

The characteristics and operating limits correspond to those of the unsplit labyrinth seal NTS.

Split labyrinth seals NTSG are available in various sizes ➤ Table. Other sizes are available by agreement.

Sizes

Sizes of split labyrinth seals for

Metric shaft

Inch size shaft

NTSG34

NTSG34×515

NTSG36

NTSG36×607

NTSG38

NTSG40

NTSG44

NTSG48

NTSG52

Split Taconite seals NTCG

Split seal reduces mounting work

For plummer block housings SNS, Taconite seals are also available in a split design. As a result, the work involved in fitting or replacing the seal can be considerably reduced, especially if a split bearing is also fitted.

Split Taconite seals are supplied by agreement.

Bold-on seals BTAC

Seal for extreme contamination impact

Bold-on seals BTAC are combined seals comprising a labyrinth ring and a V ring. They are screw mounted to the outside of the housing and, unlike all other seals for plummer block housings SNS, are not inserted in the annular slots in the housing. The seals are suitable for extreme operating conditions in relation to contamination and dust. The V ring is made from NBR and is suitable for temperatures of up to +100 °C.

The Bold-on seal allows shaft misalignment of up to 0,4° in both directions and is suitable for grease lubrication. For relubrication, the seal is fitted with a lubrication nipple.

The seals are available in the sizes BTAC34 to BTAC68.

Special housing design required

When using Bold-on seals, housings of a special design SNS..-B are required instead of the designs SNS..-H and SNS..-Z suitable for all other seals.

Covers

Covers are used in the case of housings closed on one side. The covers must be ordered separately.

Covers NDK

For housings with annular slot

Covers NDK fit in the rectangular section annular slots of the housings, designed for labyrinth and Taconite seals, SNS..-H and SNS..-Z. They are suitable for temperatures up to +200 °C.

Covers BDK

For housings with Bolt-on seal

Covers BDK are screw mounted to the outside of the housing. They are suitable for the housings SNS..-B designed for the Bolt-on seal.

Characteristics and operating limits

The characteristics and operating limits of the standard seals and covers are compared in an overview ➤ Table.

Standard seals and covers for plummer block housings SNS

Seals and covers

++ highly suitable
+ suitable
(+) suitable with restrictions
– not suitable

Labyrinth seal, unsplit

Taconite seal, unsplit

Labyrinth seal, split

Seal and cover

++ highly suitable
+ suitable
(+) suitable with restrictions
– not suitable

Bold-on seal, unsplit

Covers

Designation

NTS

NTC

NTSG

Designation

BTAC

NDK

BDK

Material

Steel, FKM

Steel, NBR

Steel, FKM

Material

Steel, NBR

Steel, FKM

Steel

Pieces per pack

1

1

1

Pieces per pack

1

1

1

Suitability for sealing against

Suitability for sealing against

dust

(+)

++

(+)

dust

++

++

++

fine, solid particles

+

++

+

fine, solid particles

++

++

++

coarse, solid particles

+

++

+

coarse, solid particles

++

++

++

slivers

++

++

++

slivers

++

++

++

spray liquids

++

spray liquids

++

++

++

Operating limits

Operating limits

Long term temperature

°C

–20 to +200
(due to FKM)

–30 to +100
(due to NBR)

–20 to +200
(due to FKM)

Long term temperature

°C

–30 to +100
(due to NBR)

–20 to +200
(due to FKM)

Not applicable

°F

 –4 to +390
(due to FKM)

–22 to +210
(due to NBR)

–4 to +390
(due to FKM)

°F

–22 to +210
(due to NBR)

 –4 to +390
(due to FKM)

Not applicable

Circumferential velocity

m/s

No restriction

≦12

No restriction

Circumferential velocity

m/s

≦12

Not applicable

Not applicable

Misalignment

°

≦0,3

≦0,3

≦0,3

Misalignment

°

≦0,4

Not applicable

Not applicable

Low friction

++

+

++

Low friction

+

Not applicable

Not applicable

Axial shaft displacement (suitability as non-locating bearing)

+

+

+

Axial shaft displacement (suitability as non-locating bearing)

+

Not applicable

Not applicable

Vertical arrangement

(+)

Vertical arrangement

++

++

Suitability for grease relubrication

+

+

+

Suitability for grease relubrication

++

++

++

Suitability for oil lubrication

(+)

Suitability for oil lubrication

+

Compatibility with sunlight

++

++

++

Compatibility with sunlight

++

++

++

Preconditions

Preconditions

Tolerance class1) of shaft diameter

h8 (h9)

h8 (h9)

h8 (h9)

Tolerance class1) of shaft diameter

h8 (h9)

Not applicable

Not applicable

Shaft roughness

μm

Ra 3,2

Ra 3,2

Ra 3,2

Shaft roughness

μm

Ra 3,2

Not applicable

Not applicable

  1. The envelope requirement Ⓔ applies

Dimensions, tolerances

Dimensions

The dimensions of the housings conform to ISO 113.

Interchangeability

FAG plummer block housings SNS are a further development of the FAG plummer block housings SD31. The design envelope and mounting dimensions of both series of housings are identical and the housings are interchangeable 1:1.

The interchangeability with other series of FAG housings is as follows:

  • All bearing series that can be combined with the plummer block housings SD5 and SD6 can be fitted in plummer block housings SNS
  • Bearing series that can be combined with the plummer block housings S30 can only be fitted in certain cases in plummer block housings SNS

The dimensions of housings SD5, SD6 and S30 are not identical with the dimensions of housings SNS.

Tolerances for the bearing seat

The bearing seat in split plummer block housings SNS is machined to the tolerance class G7 in accordance with DIN EN ISO 286-1.

By agreement, the housings can also be supplied with other tolerance classes for the bearing seat.

Housing configurations

Possible combinations

Modular construction allows numerous combinations

On the basis of the standard components, the following features can be varied in the housing configuration:

  • location of bearings with a tapered bore by means of an adapter sleeve on a shaft of constant diameter or of bearings with a cylindrical bore directly on a stepped shaft
  • sealing of housing by labyrinth seals (unsplit or split), Taconite seals (unsplit or split) or Bold-on seals (in combination with housings of design SNS..-B)
  • with a continuous shaft or a housing closed on one side
  • design of the bearing arrangement as a locating bearing arrangement or a non-locating bearing arrangement
  • spherical roller bearing in a split or unsplit design

The resulting possible housing configurations make it possible to fulfil various requirements on the bearing positions by means of standard components ➤ Figure to ➤ Figure.

Plummer block housing SNS for bearings with tapered bore and adapter sleeve (2 labyrinth seals NTS)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with tapered bore and adapter sleeve (labyrinth seal NTS and cover NDK)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with tapered bore and adapter sleeve (2 Taconite seals NTC)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with tapered bore and adapter sleeve (Taconite seal NTC and cover NDK)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with cylindrical bore (2 labyrinth seals NTS)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with cylindrical bore (labyrinth seal NTS and cover NDK)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with cylindrical bore (2 Taconite seals NTC)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with cylindrical bore (Taconite seal NTC and cover NDK)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with tapered bore and adapter sleeve (2 Bold-on seals BTAC)


Locating bearing


Non-locating bearing

Plummer block housing SNS for bearings with tapered bore and adapter sleeve (Bold-on seal BTAC and cover BDK)


Locating bearing


Non-locating bearing

Mounting of split spherical roller bearings

Simplified bearing replacement by means of split bearing

In the case of plummer block housings SNS, an unsplit spherical roller bearing with a tapered bore and adapter sleeve can be replaced by a split spherical roller bearing ➤ Figure.

Plummer block housing SNS with split and unsplit spherical roller bearing


Locating bearing with unsplit bearing


Non-locating bearing with unsplit bearing


Locating bearing with split bearing


Non-locating bearing with split bearing

In order to ensure selection of the correct combination of housing and bearing when using split bearings, please contact Schaeffler.

The range of split spherical roller bearings is described in detail in a separate publication TPI 250.

Structure of housing designation

The designation of the housings and associated seals, covers and locating rings follows a set model. Description of the designation components ➤ Table to ➤ Table. Structure of designations ➤ Figure to ➤ Figure.

Components of the designations of plummer block housings SNS

Characteristic

Code

Description
Series

SNS

Split plummer block housings SNS
ISO dimension series of bearing

30

ISO dimension series 22, 23, 30 and 40

31

ISO dimension series 22, 23 and 31

32

ISO dimension series 22 and 32

40

ISO dimension series 40
Housing size

36

/530

For bearings of ISO dimension series 30, 31 and 32:

  • Bore code of bearing
Housing design

H

Main design ➤ Table

Z

Additional design ➤ Table

B

Design for Bold-on s
Housing material

D

Spheroidal graphite cast iron

Designation structure of plummer block housings SNS,
example

Plummer block housings SNS with labyrinth and Taconite seals are available in the housing designs H and Z. Spherical roller bearings can be fitted, as a function of the bearing series, in one of the two housing designs ➤ Table.

Allocation of housing designs H and Z to bearing types

Housing design

Bearing series

H

Spherical roller bearings with tapered bore and adapter sleeve

Split spherical roller bearings

Following spherical roller bearings with cylindrical bore:
22232, 22234, 22252, 22272, 22326, 22328, 22330, 22332, 22334, 22338, 22344, 22348, 22352, 22356, 23232, 24036

Z

Spherical roller bearings with cylindrical bore, not allocated to housing design H

Components of the designations of standard seals

Characteristic

Code

Description
Series

NTS

Labyrinth seal, unsplit

NTC

Taconite seal, unsplit

NTSG Taconite seal, unsplit

BTAC

Bold-on seal, unsplit
Dimension series

36

Dimension series 36
Shaft diameter

No further indications

Standard shaft diameter of dimension series

/125

Metric shaft diameter:

  • 125 mm

X415

Inch size shaft diameter:

  • 4 inch + 15 · 1/16 inch = 4 15/16 inch

Designation structure of standard seals,
examples

Components of designations of covers

Characteristic

Code

Description
Series

NDK

Cover for plummer block housings SNS..-H and SNS..-Z

BDK

Cover for plummer block housing SNS..-B
Dimension series

36

Dimension series 36

Designation structure of covers,
example

Components of designations of locating rings

Characteristic

Code

Description

Series

NFR

Locating ring

Outside diameter

280

Outside diameter 280 mm

Width

10

Width 10 mm

Designation structure of locating rings,
example

Ordering examples

Separate ordering of housing body and accessories

When a split plummer block housing SNS is ordered, the housing designation only describes the housing body. The other components such as seals, covers or locating rings must be ordered separately in the specific design required. The rolling bearing and, if necessary, the adapter sleeve must also be ordered separately.

Plummer block housings SNS with a bearing fitted give non-locating bearing arrangements. These can be converted into locating bearing arrangements through the additional insertion of locating rings NFR.

The ordering examples show the construction of orders for selected housing combinations and the appropriate bearings. The allocation of housings, bearings and accessories for all housing sizes is shown in the product tables ➤ link.

Example 1

Plummer block housing SNS made from spheroidal graphite cast iron, closed on one side, spherical roller bearing 23136-E1A-K-M as locating bearing, location by means of adapter sleeve on shaft diameter of 160 mm, labyrinth seal.

Order

1 plummer block housing SNS3136-H-D
1 spherical roller bearing 23136-E1A-K-M
1 adapter sleeve H3136-HG
2 locating rings NFR300/10
1 cover NDK36
1 labyrinth seal NTS36

Example 2

Plummer block housing SNS made from spheroidal graphite cast iron, continuous shaft, spherical roller bearing 23136-E1A-K-M as non-locating bearing, location by means of adapter sleeve on shaft diameter of 160 mm, Taconite seal.

Order

1 plummer block housing SNS3136-H-D
1 spherical roller bearing 23136-E1A-K-M
1 adapter sleeve H3136-HG
2 Taconite seals NTC36

Example 3

Plummer block housing SNS made from spheroidal graphite cast iron, closed on one side, spherical roller bearing 23136-E1A-K-M as non-locating bearing, location by means of adapter sleeve on shaft diameter of 160 mm, Bold-on seal.

Order

1 plummer block housing SNS3136-B-D
1 spherical roller bearing 23136-E1A-K-M
1 adapter sleeve H3136-HG
1 cover BDK36
1 Bolt-on seal BTAC36

Mounting and dismounting

Eye bolts

The upper housing section has 2 eye bolts in accordance with DIN 580. These are intended as locating points for mounting and dismounting of the housing. The load carrying capacity of the eye bolts allows lifting of the housing including a bearing fitted in the housing.

Eye bolts must always be screwed fully into the housing.

Eye bolts must not be subjected to a mass greater than that of the housing together with the bearing fitted in the housing.

Foot screws

Foot screws are used for screw mounting of the housing to the mounting surface. They are not included in the scope of delivery of the housings.

The appropriate screw size for each housing is given in the product tables ➤ link.

Tightening torques for foot screws

The following table contains tightening torques for metric coarse pitch threads in accordance with DIN 13, DIN 962 and DIN ISO 965-2.

The maximum tightening torques are valid when utilising 90% of the yield stress of the screw material 8.8 and with a friction factor of 0,14. We recommend that foot screws should be tightened to approx. 70% of these values ➤ Table.

Tightening torques for foot screws with metric thread in accordance with DIN 13, DIN 962 and DIN ISO 965-2

Nominal
screw diameter

Maximum
tightening torque

Recommended
tightening torque

Nm

Nm

M24

798

550

M30

1 597

1 100

M36

2 778

1 950

M42

3 991

2 750

M48

6 021

4 250

Permissible shaft end designs

No contact between shaft and cover

In the case of a housing closed on one side, the length of the shaft in the housing must be restricted such that no contact occurs between the shaft and the cover. In this case, the displacement facility of the bearing in a non-locating bearing arrangement must be taken into consideration. The basis for determining the permissible length of the shaft is the spacing between the centre of the bearing seat and the cover ➤ Figure and ➤ Table.

Spacing between centre of bearing seat and cover

ad = spacing between centre of bearing seat and cover

Spacing between centre of bearing seat and cover

Housing

Spacing

SNS22

SNS30

SNS31

SNS32

SNS40

ad

mm

SNS3036

SNS3134

107,5

SNS3038

SNS3136

113,5

SNS3040

SNS3138

SNS3234

117,5

SNS3236

117,5

SNS3044

SNS3140

SNS3238

127,5

SNS3048

SNS3144

SNS3240

133,5

SNS3052

SNS3148

SNS3244

141,5

SNS3056

SNS3152

SNS3248

151,5

SNS3060

SNS3156

154,5

SNS3064

SNS3160

SNS3252

175,5

SNS3256

175,5

SNS3068

SNS3164

SNS3260

186,5

SNS3072

186,5

SNS2264

SNS3076

SNS3168

SNS3264

SNS4076

202,5

SNS3080

SNS3172

SNS3268

SNS4080

208,5

SNS3084

SNS3176

SNS4084

208,5

SNS3088

SNS3180

SNS3272

SNS4088

223,5

SNS3092

SNS3184

SNS3276

SNS4092

243,5

SNS3096

SNS3188

SNS3280

SNS4096

243,5

SNS30/500

SNS40/500

243,5

SNS30/530

SNS3192

SNS3284

SNS40/530

248,5

SNS3196

SNS3288

248,5

Detailed information on mounting

Careful and correct mounting of the bearing housing, including the correct mounting of the rolling bearing in the housing, is fundamental to reliable operation. Detailed information is given in the publication MON 84 http://www.schaeffler.de/std/1B6B.

Legal notice regarding data freshness

The further development of products may also result in technical changes to catalogue products

Of central interest to Schaeffler is the further development and optimisation of its products and the satisfaction of its customers. In order that you, as the customer, can keep yourself optimally informed about the progress that is being made here and with regard to the current technical status of the products, we publish any product changes which differ from the printed version in our electronic product catalogue.

We therefore reserve the right to make changes to the data and illus­trations in this catalogue. This catalogue reflects the status at the time of printing. More recent publications released by us (as printed or digital media) will automatically precede this catalogue if they involve the same subject. Therefore, please always use our electronic product catalogue to check whether more up-to-date information or modification notices exist for your desired product.

Further information

In addition to the data in this chapter, the following chapters must also be observed in the selection of a housing:

Further information:

  • Product tables on split plummer block housings SNS for inch size shaft diameters GK 1
  • Product tables on split plummer block housings SNS in combination with Bold-on seals GK 1
  • Electronic housing selection wizard http://www.schaeffler.de/std/1B6A