Monthly Archives: September 2011

Taper Roller Bearings

Tapered roller bearings have two main components: the cup and cone. The cup is comprised of an outer race, while the cone contains a cage, tapered rollers, and an inner race. Both the inner and outer raceway are tapered. Tapered roller bearings support axial and radial loads. The axial and radial load capacity is dependent on the cup angle. A steep cup angle enables the bearing to support large axial load, while a shallow cup angle enables large radial loading. Metric and inch tapered roller bearings have some distinct differences. In general, metric tapered roller bearings maintain a consistent relative cross-section within a series. This is not the case with inch tapered roller bearings. Within a series, inch tapered roller bearings are allowed to mix and match cones and cups. This means that any cone can go with any cup of the same series. Tapered roller bearings are good for applications requiring shock loads, minor misalignment, and high speeds.

  • Cone
  • Cup
  • Inch Assemblies
  • Metric Assemblies
 

Take-up Bearings

Take-up bearings are mounted units that make adjustments to the shaft extension, belt tension, or tracks in a conveyor system. Their structure includes a guide frame, positioning screw, and either plain or roller elements. Agriculture and food processing industries that utilize conveyor systems often require take-up bearings.

  • Ball
  • Frame
  • Plain
  • Roller
 

Sprockets

Sprockets are profiled wheels with teeth. Unlike gears, sprocket never interconnect, but rather interlock with chain to transfer rotational motion. They are commonly used in conveyor systems. Quick-detach sprockets are used in lumber, paper, and agriculture while taperlock sprockets are used in packaging equipment.

  • Plain Bore
  • QD
  • Taperlock
 

Slewing Ring Bearings

Slewing ring bearings, also called plain bearing turntables, are mounted on surfaces rather than shafts. They enable rotational motion parallel to the support surface. Installation is facilitated by mounting holes located along the inner and outer races. Slewing ring bearings are large in size and support high radial, axial, and moment loads at low speeds. The rolling elements are typically balls or rollers. Slewing ring bearings are utilized in cranes, turbines, and engines.

  • Ball
  • Roller
 

Sheaves

Sheaves are grooved wheels used to transmit rotational power and torque. They are used in conjunction with a belt which utilizes friction to turn the sheave. Two common types of sheaves include quick-detaching (QD) and variable pitch. Quick-detaching sheaves facilitate convenient mounting and dismounting. They are ideal for situations where sheaves must be changed frequently. Variable pitch sheaves enable speed adjustment. Other kinds of sheaves include taperlock and plain bore. Sheaves are common in conveyors and fans.

  • Plain Bore
  • QD
  • Taperlock
  • Variable Pitch
 

Seals

Seals block harmful contamination from reaching the inner races and rollers of a bearing as well as prevent the breakdown of lubricant. This protection allows the bearing to perform optimally and elongates service life. Seals are generally located between the rotating shaft and the housing. There are many types of seals including radial, lip, V-ring, and felt.

  • Lip
  • Kit
 

Roller Bearings

Roller bearings utilize either cylindrical, needle, tapered or spherical rollers. Rollers carry load on a line contact and as a result can support large radial loads. Cylindrical roller bearings consist of an inner race, an outer race, and cylindrical rolling elements. A cage allows the bearing to operate at high speeds. Long, thin rolling elements, called needles are well suited for bearings with a small diameter, or where high speeds are desired. Tapered bearings are ideal for combined loads. A tapered roller bearing is comprised of one or two cones and a cup. The cone contains an inner race, cage and tapered rollers which roll on the tapered surface of the cup. Spherical bearings are comprised of a concave outer raceway, convex rollers, and either a tapered or cylindrical bore. Spherical rollers enable high radial loads due to the large contact area between the rollers and raceways. In addition, the concave shape of the raceway allows the bearing to self align. Thrust roller bearings are intended for large magnitude axial loads with very little radial loading. They can contain either cylindrical, spherical, tapered or needle rollers. Applications for roller bearings include machine tool spindles, steel mills, and vibrating equipment.

  • Cylindrical
  • Inserts
  • Needle
  • Spherical
  • Thrust
 

Rod End Bearings

Rod end bearings are used when components must be joined together, such as a shaft or piston head. Two common variations of rod end bearings include solid and ball joint. Solid rod end bearings are one-piece, consisting of a through bore, a solid housing and shank. Ball joint rod ends are perhaps the most common and are available in either two or three pieces. Two-piece rod end bearings include a spherical bushing encased within a single-unit housing and shank. Three-piece rod end bearings are comprised of a single unit housing and shank, spherical bushing, as well as an inner race. The shank may have either male, female, or no threading. A shank with external threading is called male, while internal threading is called female. Materials of the housing, spherical bushing, and inner race vary depending upon the load, friction and rotational requirements. Materials include, steel, stainless steel, nylon and aluminum. Rod end bearings are commonly used in vehicles but are also utilized in machining centers, lift trucks, cranes, and fitness equipment.

  • Female
  • Male
 

Plain Bearings

Plain bearings, also known as “sleeve bearings”, use low-friction contact faces instead of rollers to enable motion. Often they are manufactured out of self lubricating material or require additional lubrication. Three types of plain bearings are plain spherical, thrust washers, and bushings. Plain spherical bearings consist of an inner and outer race with mating spherical curves. A cylindrical through bore allows for shaft mounting. Plain spherical bearings are intended for compensating misalignment under high radial loads. Thrust washers do not have races, but rather consist of a disc with a through bore. Thrust washers support axial loads and prevent movement along a shaft. Bushings are used where minimal cost and low friction coefficients must be obtained. Bushings also serve to locate the shaft. Plain bearings are used for applications such as mining and construction.

  • Bushing
  • Plate
  • Spherical
  • Thrust Washer
 

Pillow Blocks Bearings

Pillow block bearings are utilized when the shaft is parallel to the mount surface. They are a complete assembly consisting of a housing, means of lubrication, and rolling elements. Internal components may be either ball, roller, or plain. Pillow block bearings accommodate light to moderate loads at moderate speeds. General applications for pillow block bearings include machinery, transmission, pharmaceutical packaging, and processing industries.

  • Ball
  • Plain
  • Roller