Silverthin thin-section bearings have their origins in defence applications. As equipment manufacturers sought better ways to rotate ever larger heavy-duty equipment with speed and accuracy, so the Silverthin product line of precision thin-section bearings was born. Silverthin thin-section bearings for defence and aerospace applications are specifically designed for the loading, operating temperatures and speed demands made in arduous military applications. They provide great stiffness and excellent torque performance yet remain light in weight and have a thin cross-section which saves valuable space.
Silverthin thin section bearings feature special designs to cater for differing applications, from lightweight airborne versions to others for heavier-duty battlefield platform installations. Thin section bearings have a large bore with a small cross-section to offer many design advantages: for example, the use of a large diameter hollow shaft in place of a smaller diameter solid version can achieve significant weight savings, and also allow designers to route associated components more effectively too. Hydraulic lines, wiring, fibreoptic cables, air lines, and contactor slip rings can all be packaged tightly with a tidier design that is more cost efficient to produce and also less vulnerable to damage in service. Silverthin precision thin-section bearings are widely used in key applications across the aerospace and defence sectors on critical equipment where positional accuracy, compactness and durability count: optical tracking and sighting devices, mobile satellite systems, high accuracy turrets and gimbal mounted ranging units are typical examples.
Precision thin-section bearings from Silverthin are available in a range of sizes to suit most aerospace and defence projects and uses. Materials available include 52100 bearing steel and 440C stainless steel, and all Silverthin thin-section bearings may also be specified with thin-dense chrome plating for extra performance. NTDC – Nodular Thin Dense Chrome Plated bearing rings made from 52100 steel are treated with an electro-deposited chrome plating process which will not chip, crack or peel under the severe stresses experienced in the bearing raceways in arduous applications. Further, the process increases corrosion resistance and improves surface hardness to the Rc70-Rc78 range. This not only assures extended service life: it also reduces friction and helps retain lubrication.
Specifying a coating for large size 52100 steel bearings gives a fast lead time when stainless steel versions are not available. Cages in Silverthin thin-section bearings can be supplied in brass, stainless steel, NYLON, PEEK, phenolic or as full complement construction. Balls can be supplied in 52100 steel, 440C stainless steel, ceramic (silicon nitride), ruby and titanium depending on individual application requirements.
In defence or aerospace applications where axial loads are present in one direction, the Silverthin A-Type, angular contact ball bearings should be used. This bearing also works well in radial or combined radial-thrust applications. The A-Type bearing should never be used alone to support moment loads or reversing axial loading.
The Silverthin C-Type, radial contact ball bearing is specially designed with deep ball grooves to withstand high loads in defence or aerospace use. Although this bearing is used primarily in applications with radial loads, it can also withstand moderate axial loads, reversing axial loads, and moment loads too.
The Silverthin X-Type, or 4-point contact, ball bearing is ideal for moment loading applications. X-Type bearings are designed with ‘Gothic arch’ raceways creating four contact points between the balls and the raceways. This design is excellent for moment loading and reversing axial loading of the type often encountered in defence and aerospace environments. The X-Type bearing can be used for other light loading conditions, but is not recommended in place of the C- or A-Type bearing for pure radial loads.
When specifying this type of bearing for use with axial or moment loads combined with radial loads, the application speed (rpm) should be carefully considered: our specialist aerospace and defence applications team at Oxford can provide all the information likely to be needed on combined load and limiting speeds. Our engineers can also advise on combined radial loads with axial or moment loading and for limiting speeds and separator selection.
In some defence and aerospace applications, two A-Type bearings are used as a duplex pair, and our engineers can advise on the advantages of this. Special non-standard thin-section bearings from Silverthin are engineered and manufactured up to 40 inches in diameter, some from special materials, to serve the needs of a diverse customer base.
Typical applications for Silverthin thin-section bearings include:
- Gun barrel mounts
- Navigation pods
- Target trackers
- Countermeasure systems
- Mast bearings
- Gearbox bearings
- Propulsion systems
- Refuelling booms
- Gun turrets
- Missile defence systems
- Sonar scanners and systems
- Radar and communication mounts
- Aircraft carrier and arrester gear
- Ground combat and security vehicles
- Target acquisition and tracking systems
- Transmissions
- Suspension systems
- Missile launchers
- Ammunition loaders
- Space systems & satellites
- Antenna pedestals