JPH04345964A - Outer rotor type motor for magnetic disk drive - Google Patents

Abstract

PURPOSE:To enable to easily pull out a leader of a stator winding wire,etc., and to surely seal a through-shaft part by providing a groove or a chamfer at an outer periphery of a rigid shaft. CONSTITUTION:At the outer periphery of the rigid shaft 14, the groove 18 communicating from one edge surface to an inner room 7 of the stator is provided and the leader 10 of the stator winding wire 9, etc., is pulled out to the outside through the groove 18. At the side where the groove 18 of the shaft 14 is provided, a ring 22 coming in contact with a magnetic fluid seal 21 at the outer periphery is inserted by striding the groove 18 and the gap between the ring 22 and the shaft 14 is filled and sealed with an adhesive or a UV curing resin, etc. Hence the structure is simple and without damaging the leader 10 it can be pulled out easily and also the through-shaft part penetrating the shaft 14 can be surely sealed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer rotor type motor for driving a magnetic disk, in which lead wires such as stator windings can be easily drawn out with a simple structure.

0002

2. Description of the Related Art A conventional example of an outer rotor type motor for driving a magnetic disk will be explained with reference to FIG. In this figure, a cylindrical rotor 2 surrounding a stator 1 is rotatably supported via a bearing 3 by a fixed shaft 4 on which the stator 1 is fitted. The rotor 2 is constructed by fitting a cylindrical permanent magnet 6 to the inner periphery of a cylindrical flanged hub 5 into which a magnetic disk (not shown) is fitted. The fixed shaft 4 is provided with a hole 8 that communicates with the inner chamber 7 of the rotor 2 from the center of one end surface, and a lead wire 10 such as the stator winding 9 is led out through the hole 8.

0003

[Problems to be Solved by the Invention] With the above structure, not only does it take a lot of time to process the hole 8 for drawing out the leader line,
There is a drawback that the drawing out operation of the leader wire 10 is difficult and the leader wire 10 may be damaged during drawing out.

[0004] In order to eliminate the above-mentioned drawbacks, the present invention
It is an object of the present invention to provide an outer rotor type motor for driving a magnetic disk, which has a simple structure and can easily draw out lead wires such as stator windings.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a cylindrical rotor 2 surrounding a stator 1.
is rotatably supported by a fixed shaft 14 on which the stator 1 is fitted, and a groove 18 or a crescent-shaped notch 19 is provided on the outer periphery of the fixed shaft 14 to communicate with the inner chamber 7 of the rotor 2 from one end surface. At the same time, the stator winding 9 and other lead wires 10 are drawn out through this groove 18 or notch 19, and if necessary, a magnetic fluid seal 21 is provided on the outside of the bearing 3 that supports the rotor 2, and a magnetic fluid seal 21 is provided on the outside of the bearing 3 supporting the rotor 2. A ring 22 whose outer periphery contacts the magnetic fluid seal 21 is fitted across the groove 18 or notch 19, and the gap between the ring 22 and the fixed shaft 14 is sealed with an adhesive 23 or the like. .

[0006]

[Operation] Since the lead wires 10 such as the stator windings 9 are drawn out through the groove 18 or notch 19 provided on the outer periphery of the fixed shaft 14, the structure is simple and the lead wires 10
0 can be easily withdrawn. In addition, when sealing the shaft penetrating portion through which the fixed shaft 14 passes, a ring 22 whose outer periphery contacts the magnetic fluid seal 21 is fitted into the fixed shaft 14, and the gap between the groove 18 and the fixed shaft 14 is filled with an adhesive 23, etc. Since the shaft penetrating portion is sealed with , the shaft penetrating portion can be reliably sealed and the ring 22 can be fixed to the fixed shaft 14.

[0007]

[Example] Figure 1 shows an example of this invention, and Figure 4
Items with the same reference numerals are the same parts. In this figure, a cylindrical rotor 2 surrounding a stator 1 is rotatably supported via a bearing 3 by a fixed shaft 14 on which the stator 1 is fitted. The rotor 2 is constructed by fitting a cylindrical permanent magnet 6 into the inner periphery of a cylindrical flanged hub 5 into which a magnetic disk (not shown) is fitted, and bearings 3 are fitted into the inner periphery of both ends of the hub 5 for support. The cylindrical bearing housings 5a and 24 are integrally formed or fitted together. As shown in an enlarged view in FIG. 2, a groove 18 is provided on the outer periphery of the fixed shaft 14, and the groove 18 communicates with the inner chamber 7 of the rotor 2 from one end surface. is pulled out to the outside. In place of the groove 18, a crescent-shaped notch 19 shown by a chain line in FIG. 3 may be provided. According to this embodiment, the structure is simple and the lead wire 10 can be easily drawn out without being damaged.

The motor is further provided with a magnetic fluid seal 21 on the outside of the bearing 3. This magnetic fluid seal 21 is used when it is necessary to prevent, for example, the base oil of the lubricating grease of the bearing 3 from gasifying and leaking out of the machine as the motor operates. It is constructed by filling a magnetic fluid sealing material between a pair of disc-shaped magnetic poles that are fitted together. This magnetic fluid seal material is
Magnetic fine particles are uniformly mixed into a colloidal solution such as oil to prevent sedimentation due to gravity and aggregation due to magnetic attraction, and are attracted and held by the magnetic attraction of the magnetic poles. A ring 22 whose outer periphery contacts the magnetic fluid seal 21 is fitted across the groove 18 or the notch 19 on the side of the fixed shaft 14 where the groove 18 or the notch 19 is provided, and this ring 22 and the fixed shaft 14 The gaps are filled with an adhesive 23 or a resin that hardens when exposed to ultraviolet light to fix them and seal them. According to this embodiment, the shaft penetrating portion through which the fixed shaft 14 passes can be reliably sealed.

[0009]

According to the present invention, in an outer rotor type motor for driving a magnetic disk, a groove or a crescent-shaped groove is formed on the outer periphery of a fixed shaft that supports an outer rotor through a bearing and communicates with the inner chamber of the rotor from one end surface. Since a notch is provided and the lead wires such as stator windings are drawn out through this groove or notch, the lead wires can be easily pulled out without damaging them with a simple structure. If a magnetic fluid seal is provided on the fixed shaft, a ring whose outer periphery is in contact with the magnetic fluid seal is fitted on the fixed shaft across the groove or notch, and the gap between this ring and the fixed shaft is sealed with adhesive or the like. This provides the effect that the shaft penetrating portion through which the fixed shaft passes can be reliably sealed and the ring can be fixed to the fixed shaft.

[Brief explanation of drawings]

[Fig. 1] Longitudinal cross-sectional view of an embodiment of this invention

[Figure 2] Enlarged vertical cross-sectional view of the main part of Figure 1

[Figure 3] Side view of main parts in Figure 2

[Figure 4] Longitudinal cross-sectional view of conventional example

[Explanation of symbols]

1 Stator 2 Rotor 3 Bearing 7 Inner room 9 Stator winding 10 Lead line 14 Fixed axis 18 Groove 19 Notch part 21 Magnetic fluid seal 22 Ring 23 Adhesive

Claims (2)

[Claims] 1. A cylindrical rotor surrounding a stator is rotatably supported by a fixed shaft into which the stator is fitted, and a groove on the outer periphery of the fixed shaft communicates with an inner chamber of the rotor from one end surface. Alternatively, an outer rotor type motor for driving a magnetic disk, characterized in that a crescent-shaped notch is provided and a lead wire such as a stator winding is drawn out through the groove or the notch. 2. The outer rotor type motor for driving a magnetic disk according to claim 1, wherein a magnetic fluid seal is provided on the outside of the bearing that supports the rotor, and the outer periphery of the magnetic fluid seal extends over a groove or a notch in the fixed shaft. An outer rotor type motor for driving a magnetic disk, characterized in that a ring that contacts a seal is fitted, and a gap between this ring and a fixed shaft is sealed with an adhesive or the like.