Super precision bearings enable improved optical guidance systems and stabilised camera platforms

In military applications, the latest advanced infrared seeker systems require super precision ball bearings, designed to support the intricate mirror and lens arrangements. To allow the seekers to look through a broad field of vision, the optical elements are mounted in a gimbal system. To ensure optics are perfectly aligned it is necessary to fix one end of each of these axes, typically performed by a duplex pair of bearings clamped to both the shaft and housing. At the free end of the shaft either a similar duplex pair of bearings can be used, clamped only to the shaft, or a spring preload can be applied to a single bearing. In optical guidance systems used in military weapons systems, Barden typically produces ball bearings that provide high stiffness to counteract the high G forces and vibration levels involved. The bearings must hold the optical components in position at all times, often to an accuracy of a few microns. The number and size of balls, curvature of the inner and outer ring and level of preload in a bearing can be altered to optimise overall stiffness. Often the bearings are designed with ball separators (toroids) positioned over every other ball and manufactured from self-lubricating materials, ensuring bearings meet the low torque application requirements. Wet lubrication is not normally an option. If vapours from the oil or grease condense onto the mirror surface, for example, performance of the guidance system could be compromised. Super precision bearings are also used in commercial applications, including stabilised camera/video systems and associated mechanical gimbals and gyros. Bearings may not be directly linked to the camera's optical system, but are still critical in keeping the camera system stable during filming. Vehicle or helicopter-mounted platforms require high performance stabilisation systems to compensate for any erratic movements. The Police, Armed Forces and rescue workers often require these systems during their operations. Barden provides bearings for a range of mechanical gimbal systems and gyros for such stabilised camera platforms. A gyro bearing spin axis system may utilise a cartridge bearing unit, which incorporates a bearing with two rows of balls, a single outer ring and two inner rings. The advantage here is that the customer can mount the bearings quickly and easily into their own assembly. More details can be found on our website