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Motor manufacturing technology using a spiral type
core
Akira Hashimoto, Nobuaki Miyake,
Yuji Nakahara, Yasuyuki Nakanishi,
Hideto Nishimura,
Mitsubishi Electric Corp.
1. Abstract
As spindle motors for information devices are
mass-produced in large volumes, high productivity is required and the
parts handling procedures have to be simplified. For instance, when
5 core sheets are stacked by a press at the punching speed of 300 strokes
per minute, the core is finished in 1 second. However, there are
other procedures such as the removal of the cores from the press, forming
the insulation layer and coil winding, and these procedures are carried
out for every stator core fabrication. Therefore, it is required
plural motor stators are fabricated collectively like the flow of a
river.
2. Technology
Motor manufacturing technology using a spiral type
core consists of the following processes as shown in Fig. 1.
1.
Core stacking using press machine (for example, 50 stator cores sets are
stacked)
2. Insulation layer forming (electrical
plating)
3. Development in straight line/separation at
connected area
4. Coil winding (three teeth are wound
simultaneously)
5. Folding cores
cylindrically/assembly
Finally, the stator is fixed on a printed
circuit board, and the coil ends are connected automatically. The
spiral type core can be developed in straight line and separated, and
consists of three kinds of cores a - c which have the slits in different
separation positions as shown in Fig. 2. These cores are stacked and
caulked simultaneously during pressing. Core c is connected to
another stator core via connected portion, that is, core c is located
between two stator cores. Fig. 3 is a photograph of the spiral type
core. This core does not have a simple cylindrical shape, and can be
developed and separated easily.
3. Conclusion
The motor design was reviewed from the viewpoints of
the core structure and coil winding method, and an original manufacturing
technology using a spiral type core was created. Using the proposed
manufacturing process, the working hours required for insulation layer
forming and core attachment for the winding machine were shortened to less
than 1/3 and 1/10 respectively. |
