Sometimes engineers are confronted with an application that is unique and demanding, that ultimately requires a new approach. There are some famous examples that we all deal with. Technology problems that generate a great deal of revenue get a lot of attention, and sometimes result in great innovation with lasting benefit beyond the immediate solutions.
The hard disk drive spindle motor has been one of the highest volume applications of electric motor technology in history. The industry puts out drives in the 10’s of millions per year. Starting and stopping of the platter takes place in fractions of a second and must be coordinated with the motion of the read head which uses a linear axis to index the track of the disk and a solenoid actuated arm to lower and raise the pickup. The spindle motor has to be very inexpensive, especially when the whole drive is about the memory, an inexpensive drive will not afford more than a few dollars for the spindle motor.
The fact is that the extraordinary success of rotating memory has made it the backbone of the computer industry for decades. That success includes high reliability expressed as 50,000 hours mean time between failures. In spite of the competition from solid state memory, as that technology continues to become more cost effective, the hard drive industry is expected to generate $32 billion in revenue in 2014.
That is some serious big business. It demands a great deal of attention from its manufacturing base to continue to drive the technology forward to insure it’s survival. This means relatively a lot money is spent on R&D both in terms of product and manufacturing technology. Even at 1% for development, which is far below the norms of technology industries, $320 million will go into the ongoing improvements in hard drives.
2 and 3 terabyte “pocket” hard drives are now available at prices between $100 and $200. This kind of capacity was unthinkable in the days of 3.5″ floppy disks. For comparison, a feature length movie in high definition format might require 2-3 gigabytes. So a 2T drive would be able to store around 400 movies and use about half the available memory. There would be plenty of room for you music collection, photos and other data as well.
So the need to develop a specific motor, fully integrated drive electronics and manufacturing processes that help minimize cost are all essential elements of making a successful product. Much high level research was done and many new motor drive chips were developed like the Motorola 33035. The efforts paid off, making the hard disk drive industry the giant it is today and dramatically advancing the motion control industry at the same time.