Automotion Components Flexure Pivot Bearings
What is...
Application
Application
Gimbals
Notes
Free from backlash, friction and wear. Flexure bearings give the extreme accuracy needed for positioning precision optics.
Application
Oscillating mirrors
Notes
Optical scanners using flexure bearings provide for the ultimate in cost-effective design. They allow for easy assembly and, with indefinite life expectancies, perform with undiminished accuracy.
Application
Tensioners
Notes
Belt or chain tensioning can be easily achieved through the use of flexure bearings. Tolerant of hostile environments and not subject to wear, extreme long life can be expected without maintenance.
Application
Linear positioners
Notes
Free of errors due to backlash, friction or wear, flexure bearings mounted in suitable geometric structures can provide accurate linear movement or adjustment.
Application
Lever actuators
Notes
Accurate motion requirements in areas of contamination, temperature extremes, or in a vacuum, can be easily provided through linkages utilising flexure bearings. Used in dynamic conditions, the precision of load sensitive systems can be increased to a much higher level than with ball bearings.
Application
Restrained or dampened oscillating motion
Notes
Eccentric or circular oscillating mechanisms can utilise Flexure bearings to provide centre and dampening actions for a lifetime of maintenance free performance.
Applications
Gauges sensors
Notes
Miniature sizes which are free of error from backlash, friction or wear, make flexure bearings ideal for applications where position must be accurately measured or outside forces sensed.
Application
Vibrating/sorting mechanisms
Notes
A workhorse, capable of supporting heavy loads for years of continuous service without wear or deterioration, Flexure bearings are ideal for equipment such as vibrating hoppers operating in severe environments.
Application
Optical or magnetic disc read/write heads
Notes
With their constant predictable spring rate, Flexure bearings are immune to the problems of starting vs. moving torque requirements of conventional bearings. Also since they operate without backlash errors or wear, a lifetime of accurate performance can be expected.
Technical Specs
The following examples are a few of the possible methods for installing standard flexure bearings. Other techniques may provide satisfactory results. Special options, such as flanged or drilled and tapped sleeves may be provided upon request. Please contact our Technical Department with any questions or for a review of mounting requirements.
Set screw
One or more properly sized cup point set screws may be used to clamp the bearing in place. Hole size should be 0.0005” to 0.0010” larger than the bearing.
Clamp screw
A clamping screw applies suitable pressure to retain the bearing in place. Hole size should be 0.0005” to 0.0010” larger than the bearing.
Radial or axial pins
Pins may be pressed into holes drilled through the mounting bracket and the bearing sleeve. Care must be exercised to orientate the bearing properly so the springs are not damaged. Hole size should be 0.0005” to 0.0010” larger than the bearing.
Locator flats
Locator flats with cup point set screws may be used to orientate and securely clamp the bearing in place. Hole size should be 0.0005” to 0.0010” larger than the bearing.
Radial loading: Spring in tension (Ft)
Radial loading: Spring in compression (Fc)
Axial loading: Springs in shear
The rotation of the bearing sleeve segments is achieved by bending flat spring beams. This causes a slight radial shift in the sleeve segment. For small angle of rotations (eg 2°) the shift is minimal (around 0.2% of the bearing diameter). owever this can increase up to 1% of the bearing diameter at a rotation of 15° (see graph below).
The cycle life of the bearings is based on the fatigue limit of the springs. The graphs below show the life expectancy for Torsional Spring Rates for Series 10, 20 and 30. Max θ shows the angle of deflection. This is the deflection angle from the null position, which can be positive or negative.
Series 10 - Max θ ± 15.0°
Series 20 - Max θ ± 7.5°
Series 30 - Max θ ± 3.7°
The linearity of the bearings (being the rotational defl ection of the pivot v the torque required to induce the deflection) is relatively constant for angles of rotation up to 15°. We define hysteresis as the diff erence between the zero position when the bearing is deflected to a plus angle then relieved and then defl ected to a negative angle then relieved. Comparing these two positions is the angle of hysteresis (see graphs below).
Series 10 - Max. θ ± 15.0°
Series 20 - Max. θ ± 7.5°
Series 30 - Max. θ ± 3.7°
