New application possibilities for hard drive motors

MinebeaMitsumi Europe scores with FDB technology

Hard disk motors are special motors with a specific oil consisting bearing technology, which is why experts speak of fluid dynamic bearings. Motors with this technology have established themselves over the past 15 years in the hard disk industry. Currently, there is no better drive solution. Due to the numerous positive characteristics of this drive technology, the hard drive manufacturers have been able to increase their storage capacities ever further in the past years and today provide up to 12 Tera bytes per hard disk.

Since the application manufacturers are particularly fond of the advantages of FDB motors, especially where precision and high accuracy are required, these types of motors are now experiencing new application possibilities. These are found for instance in the areas of laser scanning, virtual reality or LiDAR (light detection and ranging).

The FDB motor of MinebeaMitsumi Technology Center Europe GmbH combines the advantages of a BLDC motor (brushless DC motor) with the FDB bearing technology. It eliminates the limited precision of ball-bearing motors, reduces the non-repeatable run out (NRRO) to an absolute minimum, lowers the acoustic noise level and improves reliability and longevity.

When measuring with a laser scanner, a laser beam is deflected via a deflecting mirror and set in rotation. This process can take several hundred thousandths of a second. The laser light received by the scanner is then evaluated accordingly. Laser scanning is an extremely powerful and cost-effective way of measuring. The measurement is carried out using a laser scanner, which generates a measured scan of landscapes, structures, their facilities and installations. However, laser scanners are also used for 3D surveying or the detection of large components and complex structures.

Volumes, planes, ground plans and cuts and, above all, up-to-date plans and views can be derived from the scan results. Laser scanning is the ideal measurement method for building information modeling (BIM). Laser scanners are also used for measurements in the industry sector, for example in factory planning and plant construction, for the efficient and complete laser measurement of production halls, the technical building equipment (TGA), steel structures, production lines or manufacturing machines. This efficient process for industrial measurements is unique, especially when it comes to modernization, production expansion or production optimization. The measurement of ships and aircrafts is also simplified by the use of laser scanners.

The more efficient the scan process, the more accurate are the images or representations of the objects. The FDB motor delivers outstanding performances. Motors with ball bearings are more likely to show wobble error, the causes of which can be the axial or bearing clearance, the out-of-roundness of the balls and the axle bearing or the axle stud, the deflection of the ball bearing axles or simply an irregular distribution of the lubricating grease. A wobble error has an effect of about 1" on the measured horizontal directions, but also on the vertical angles and distances. During precision measurements, they are minimized in the course of equalization calculus, if the axis errors are randomly irregular. Wobble errors which do not occur at all are, of course, the best ones.

The FDB motor, on the other hand, has a particularly stiff axis stability and considerably reduces the number of wobble errors at different frequencies. The angular changes even almost vanish due to the accuracy of the measurement and evaluation methods.

Motor bearings without preload cause too many wobble error and are difficult to handle during specific applications. Bearings with preload ensure a certain degree of axial stability, but the power consumption is increased by the increased friction in the bearings. The FDB motor achieves a different result: almost no wobble errors occur and there are no significant changes even when using different frequencies. The radial run-out is provided.

The MinebeaMitsumi Technology Center in Europe has decades of experience in the hard-drive industry, which are significant when it comes to the use of FDB motors in the field of laser scanning technologies. If you want to measure precisely, you need the right drive in your application. Decision criteria are the superior characteristics such as extremely quiet running, high speeds, very low vibration, a low non-repeatable run-out below 40 nm, a low wobble error rate, longevity and low power consumption. Laser scanners measure not only objects, but also ensure security in dangerous areas or move gamers into virtual worlds. The FDB motor is customer-specific, it can be adjusted to the application according to the customer requirements.