SMR SNA Series plummer block housings are an enhanced development of the proven SN Series, offering greater flexibility in bearing selection, mounting, sealing and lubrication. SNA housings are interchangeable with SN Series housings with respect to bearing centre height and foundation bolt-hole distances, while their modular building-block principle allows different bearing, mounting, sealing and lubrication configurations to be combined within the same housing platform. The SNA Series is suitable for self-aligning ball bearings and spherical roller bearings with cylindrical or tapered bores.
SMR SNA Series plummer block housings are an enhanced development of the SN Series, designed to provide greater flexibility in bearing selection, mounting arrangements, sealing and lubrication.
The SNA housing retains the proven horizontally split construction while incorporating an improved housing design with additional configuration options.
SNA housings are designed to be interchangeable with earlier SN type housings in terms of bearing centre height and foundation bolt-hole distances.
The design follows a building-block principle, allowing different combinations of bearings, mounting methods, seals, lubrication arrangements and accessories to be selected according to the required configuration.
SNA housings maintain the established bearing centre height and foundation bolt-hole dimensions of the SN Series, facilitating interchangeability in suitable applications.
The modular design allows different bearing, mounting, sealing and lubrication configurations to be combined within the same housing platform.
Suitable for self-aligning ball bearings and spherical roller bearings with cylindrical or tapered bores.
Cylindrical-bore bearings can be mounted directly on the shaft, while tapered-bore bearings can be mounted using suitable adapter sleeves.
A wider choice of sealing arrangements is available, including felt, V-ring, double-lip, four-lip and labyrinth seals.
The bearing seating allows axial freedom where required. Locating rings can be fitted where a fixed bearing arrangement is required.
SNA housings are primarily configured for grease lubrication, with oil lubrication available for suitable configurations.
An end cover can be provided where the housing is installed at the end of the shaft.
Eye bolts are provided on larger housing sizes for easier handling during installation and maintenance.
SNA Series housings offer a wider choice of sealing arrangements than the standard SN Series.
Felt seal arrangement with felt collar and 'O' cord.
Combination seal comprising a mild steel washer with 'O' cord and rubber V-ring seal. This arrangement is suitable for applications requiring enhanced protection compared with standard felt sealing.
Double-lip seal arrangement providing enhanced sealing protection compared with standard felt sealing.
Four-lip seal arrangement designed to provide enhanced sealing with reduced friction compared with conventional double-lip arrangements.
Labyrinth seal arrangement for applications involving higher speeds or demanding temperature conditions, providing enhanced sealing performance.
The SNA Series follows a modular configuration approach, allowing the housing to be supplied with different combinations of:
This allows the housing configuration to be selected according to the required bearing and installation arrangement.
Grease nipples are provided for convenient bearing relubrication.
For W33-type bearings having an annular groove, the grease nipple can be positioned through the centre of the housing cap.
For other bearing arrangements, the grease nipple is fitted on the sides.
Suitable dimples can be provided on the housing cap as applicable.
For maintenance applications where removal of used or excess grease is required, drain holes with plugs are provided on the bottom pads of the housing.
This facilitates removal of contaminated or excess grease during servicing.
| SNA Series | Bearing Bore | Mounting | Compatible Bearing Series |
|---|---|---|---|
| SNA 200 | Cylindrical | Direct | 1200 · 2200 · 22200 CC · 23200 CC |
| SNA 300 | Cylindrical | Direct | 1300 · 2300 · 21300 CC · 22300 CC |
| SNA 500 | Tapered | Adapter Sleeve | 1200K · 2200K · 22200K · 23200K |
| SNA 600 | Tapered | Adapter Sleeve | 1300K · 2300K · 21300K · 22300K |
The SNA platform also allows the same basic housing to be used across certain 500/600 configurations where bearing outside diameters are equal, by changing the shaft seal arrangement.
The bearing seating width of the SNA housing allows the bearing to accommodate axial movement where required.
Where the bearing needs to be axially located, suitable locating rings can be fitted to establish a fixed bearing arrangement.
For installations where the housing is positioned at the end of the shaft, an end cover can be provided.
The end-cover arrangement is selected according to the sealing configuration.
SNA housings can be supplied with different foundation mounting configurations.
| Configuration | Foundation Arrangement |
|---|---|
| Standard | Two oval foundation slots |
| MS1 | Two drilled foundation slot holes |
| MS2 | Four drilled foundation slot holes |
The alternative foundation arrangements are intended for applications where additional mounting rigidity is required due to heavy vibration or severe loading.
SNA Series housings are available in:
For extremely heavy loading conditions, the SNA range can also be supplied in an SSNAD configuration with a solid base in S.G. / ductile iron material.
The heavy-duty configuration is available with four foundation slots for increased mounting rigidity.
The SNA Series provides a more configurable housing platform than the standard SN Series, with multiple sealing, mounting, lubrication and foundation options.
The appropriate configuration can therefore be selected according to the bearing arrangement, shaft mounting method and required level of sealing and housing support.
For particularly demanding operating conditions, SMR can recommend a suitable housing configuration based on the required bearing and housing arrangement.
The overall fitment dimensions of the SNA Series conform to:
ISO 113:2010
Eye bolts are provided on larger SNA housing sizes to facilitate easier handling during installation and maintenance.
Applicable sizes include:
224 / 320 / 524 / 620
Simply provide:
and the SMR team can help identify the appropriate housing and configuration.
Share your shaft diameter and application details — our team will respond within 24 hours with pricing and availability.