THRUST BEARINGS
SEm12
Self equalising thrust bearings
8 pads · metric dimensions
GEOMETRY & FITS
Dimensions & technical data
Selection data
| Symbol / field | Value | Unit |
|---|---|---|
| ShaftMaximum standard shaft diameter | 140 | mm |
| SpecialMaximum special shaft diameter · separate rating scope | 152.4 | mm |
| AreaThrust surface area | 46211 | mm² |
| MPDMean pitch diameter | 240.97 | mm |
Ring / housing dimensions
| Symbol / field | Value | Unit |
|---|---|---|
| aPad outside diameter | 304.8 | mm |
| bPad inside diameter | 152.4 | mm |
| cRing inside diameter | 165 | mm |
| dDimension d | 294 | mm |
| eRing outside diameter · nominal and deviations | 317.5 (-0.05 / -0.1)Nominal (upper / lower signed deviation) | mm |
| fOverall thickness · symmetric tolerance | 95.25 ± 0.13 | mm |
| gDimension g | 30.2 | mm |
| hDimension h | 47.59 | mm |
| HousingHousing bore · nominal and deviations | 317.5 (+0.05 / +0)Nominal (upper / lower signed deviation) | mm |
Condition-specific ratings
| Symbol / field | Value | Unit |
|---|---|---|
| OffsetOffset pivot maximum normal operating thrust load | 195.03 | kN |
| CentreCentre pivot maximum normal operating thrust load | 180.62 | kN |
Stops & oil slots
| Symbol / field | Value | Unit |
|---|---|---|
| jRing stop j | 14.3 | mm |
| kRing stop k | 5.6 | mm |
| lRing stop l | 67.290 | mm |
| xOil slot depth | 12.7 | mm |
| yOil slot width | 32 | mm |
Shaft & collar dimensions
| Symbol / field | Value | Unit |
|---|---|---|
| mShaft and collar m | 309.600 | mm |
| nShaft and collar n | 50.8 | mm |
| pShaft and collar p maximum | 149.200 | mm |
| rShaft and collar r maximum | 0.75 | mm |
Adjusting liner dimensions
| Symbol / field | Value | Unit |
|---|---|---|
| sAdjusting liner outside diameter | 282.58 | mm |
| vAdjusting liner inside diameter | 200.02 | mm |
| t finishedNominal finished liner thickness | 6.35 | mm |
| t suppliedAs-supplied liner thickness | 9.53 | mm |
Dimensions use the units shown. Read absolute limits and signed deviations with their stated nominal dimensions. Contact our engineers for manufacturing drawings and application-specific details.
THE BEARING DESIGN
Self equalising thrust bearings
The SE bearing combines retained tilting pads with a closed ring of mechanical equalising segments. The linkage transfers the thrust from the pad faces to the machine seating and evens the pressure around the thrust surface. Each half assembly can be handled with its pads retained in position. Explore separate metric SEm and English SE dimensional ranges, each with its stated units.
Flooded or directed oil supply
In a flooded arrangement, oil circulates around the collar and pads. In the low-loss arrangement, oil enters an annulus and is directed through angled jet holes towards the leading edges of the pads. Oil leaving the trailing edges drains away. Reduced collar churning lowers power loss; the actual benefit depends on the operating duty.
ENGINEERING GUIDANCE
Technical guide
Explore the materials, operating requirements and arrangement details for SE / SEm bearings.
Preliminary selection and operating conditions
Select the thrust ring against both the required thrust load and collar speed, then check the available shaft diameter and installation space. Centre and offset pivots have separate operating limits.
The preliminary selection curves use ISO VG 46 oil, with a viscosity of 46 cSt at 40°C. Duties outside the indicated operating limits, including the low-speed region, require an engineering assessment and may require a different oil viscosity.
- State the normal, starting and peak thrust loads, shaft speed and direction, oil grade, inlet temperature and inlet pressure. Identify a special large-shaft arrangement explicitly.
Power loss and cooling oil
Oil-film shear and collar-rim churning are separate contributions to power loss. The following relationships are approximate guides for the stated lubrication arrangement.
HP₁ is the shear-loss contribution, HP₂ is the collar-rim contribution and K₃ is the oil-viscosity correction factor. The collar-rim relationship uses ISO VG 46 oil at 40°C as its reference condition.
- Flooded double thrust bearing
- Total power loss = HP₁ + 2 × (HP₂ × K₃).
- Flooded single thrust bearing
- Total power loss = 0.95 × HP₁ + 1.5 × (HP₂ × K₃).
- Low-loss double thrust bearing
- Total power loss = HP₁.
- Low-loss single thrust bearing
- Total power loss = 0.95 × HP₁.
- The approximate cooling-oil quantity assumes 40°C inlet oil and a 17°C rise between inlet and outlet.
- A low-loss double thrust bearing requires twice the oil quantity of a low-loss single thrust bearing because each thrust face has a separate oil feed.
- Ask our engineers to establish oil-film thickness, temperature, power loss and oil quantity for the actual duty.
Axial adjustment and liners
Optional steel adjusting liners are secured behind the retaining ring by countersunk screws. They provide a means of setting the axial position of the thrust face relative to the machine housing.
Liners are supplied with machining allowance for finishing during machine assembly. The supplied thickness, nominal finished thickness and bearing thickness f are separate dimensions; use the selected size and unit range when checking the axial stack.
Materials used in standard manufacture
The ASTM and DIN designations are near equivalents to the British materials; composition and properties can differ.
- Retaining ring and adjusting liners
- Steel: BS 970-070 M20 / ASTM A576 AISI C1022 / Werkstoff No. 1,0724; or BS 4360 GR43A / ASTM A284 GR B.
- Thrust-pad steel
- BS 4360 GR43A / ASTM A284 GR B; or BS 3146 CL A13 / AISI 4615.
- Thrust-pad whitemetal
- BS 3332/2 / ASTM B23 GR2 / DIN 1703 Lg Sn 89.
- Retaining-ring stops
- Steel: BS 970-080 M40 / AISI 1039 or 1040 / Werkstoff No. 1,5038.
- Equalising segments
- Steel: BS 3146 CL A13 / AISI 4615.
Understanding the bearing code
- SE / SEm
- The type and size identify the English or metric range; m denotes the metric version.
- F / D
- F: flooded housing. D: directed, low-loss lubrication.
- L / R / C
- L: left-hand rotation. R: right-hand rotation. C: centre-pivoted pads.
- H / W
- H: retaining ring in halves. W: whole retaining ring.
- A / B
- A: without adjusting liners. B: with adjusting liners.
- Give the number of thrust rings required and the duty for each face. Code meanings describe the requested arrangement; our engineers confirm the complete bearing specification.
APPLICATION GUIDANCE
Technical notes
- 01
Standard and special shaft limits are distinct. A special pad bore changes the thrust surface area and load capacity; request a rating for the selected shaft arrangement.
- 02
Normal operating thrust ratings distinguish centre and offset pivots. Check speed, temperature, oil supply, start-up and reverse duty as well as the tabulated load.
- 03
English SE dimensions use inches, square inches and pounds-force. Select the required range and units before comparing dimensions.
- 04
Overall thickness f carries its own symmetric tolerance: ±0.13 mm in the metric table and ±0.005 in in the English table. Ring and housing deviations remain signed deviations about their nominal diameter.