Flight Control Actuator
Bearings in Flight Controls
Rexnord® Shafer®, PSI® and Rexlon® bearings are successfully applied on commercial and military aircraft in primary and secondary flight controls.
Primary Flight Controls
Shafer roller bearings are applied on all Boeing commercial aircraft primary flight control systems and all wide-body Airbus primary flight control systems. They are found on the Embraer 170, 190 and 550, Comac C919 and ARJ21, and the Gulfstream G650, F-35, JSF, V-22 and UH-60 Blackhawk because they offer:
• Low system backlash when a preloaded or reduced clearance bearing is used
• Low rolling friction to reduce moment loading
• Predictable long life under complex load motion conditions
• Precessing roller set that eliminates fretting wear due to small angular motions
PSI slotted entry and split ball bearings are found on regional aircraft primary flight controls and a wide range of secondary flight control applications because they offer:
• High-load capability
• Low wear rates under complex loading conditions
• Unique configurations and precise internal fits
• Broad range of materials
• Compact size
Primary Flight Control Actuator Bearings
Shafer roller bearings are chosen for use in primary flight controls due to their proven reliability and quality. The precessing roller set eliminates fretting wear that may be caused by small angular motions present in flight controls. Primary flight control actuator bearings include these features:
• Minimal to zero initial freeplay
• Designed for use in oscillatory motion
• Angular contact angle for high radial and thrust loads
• Corrosion resistance
• Relubricatable
• Internal self alignment
• Minimal to zero wear rate over the life of the aircraft
Examples of applications for Shafer roller bearings are found in:
• Elevators
• Rudders
• Ailerons
• Spoilers
• Airframe structures
The bearings are available in both rod end and annular configurations, and are designed to meet a variety of sizes and loads. Please contact our engineering department to discuss the specifics of your application to ensure optimum cost, performance, and reliability.
Secondary Flight Controls
Rexlon molded liner bearings are found in secondary flight controls on regional and large aircraft because they offer:
• High-load capability
• Maintenance-free operation over the life of the bearing
• No-backlash due to initial bearing preload
• Compact size
Secondary Flight Control Actuator Bearings
PSI bearings are specified by major airframe manufacturers for secondary flight controls.
One of the important reasons for the wide acceptance of PSI control bearings is the broad range of materials and configurations to choose from. Thus, engineers can select an ideal design that accommodates the load/motion/envelop and backlash requirements for a variety of aircrafts or spacecrafts.
Control System Bearings include:
• Slats
• Flaps/spoilers
• Ailerons
• Elevators
• Rudders
PSI annular, rod end, and turnbuckle assemblies are used on internal linkage controls because of their superior durability resulting from excellent ball to race conformity. Superior system maintainability is achieved without costly re-rigging. The PSI bearings advantage is the ball replacement feature. PSI split ball bearings in particular provide long life in a punishing environment.