JP5021505B2 - Brushless motor - Google Patents

Description

  The present invention relates to a brushless motor used for information equipment or video / audio equipment.

  In recent years, with the thinning of information devices such as DVDs or video / audio devices, there has been an increasing demand for small, high-efficiency, high-controllability motors. In particular, in spindle motors that drive media, there is an increasing demand for high accuracy in the degree of perpendicularity with respect to the mounting surface of a shaft-mounted motor. The accuracy of verticality can be improved by improving the processing accuracy or assembly accuracy of each part of the motor. However, not only the improvement of the accuracy is limited, but also the cost is increased. For this reason, a configuration for readjusting the verticality after assembly is required.

As a method to cope with this, when adjusting the verticality of the shaft relative to the mounting surface to the equipment on which the motor is mounted by changing the mounting surface, a plurality of holes are formed on the mounting surface to facilitate the deformation. Has been proposed. (For example, see Patent Document 1)
5 (a) and 5 (b) show a motor that facilitates the adjustment of the perpendicularity of the shaft after assembly disclosed in Patent Document 1 described above. In FIG. 5A, a bearing holder 512 is inserted and fixed in a bearing mounting opening 511a formed at the center of a motor base substrate 511, which is a mounting surface to a device on which a motor is mounted. A bearing sleeve 513 is fixed to the inner peripheral side of the bearing holder 512, and a rotating shaft 521 fixed to the center of the rotor assembly 520 is supported by the bearing sleeve 513. As shown in FIG. 5B, a plurality of adjustment holes 511c are provided so as to surround the periphery of the bearing mounting opening 511a of the motor base substrate 511.

Then, the degree of perpendicularity of the central axis CL of the rotating shaft 521 is adjusted by deforming the vicinity of the bearing mounting opening 511a through the adjustment hole 511c. At this time, by forming the adjustment hole 511c, the deformation work in the vicinity of the bearing mounting opening 511a can be facilitated. This makes it possible to easily obtain highly accurate perpendicularity without greatly improving the manufacturing accuracy and assembly accuracy of each component.
JP 2002-218700 A (page 3-5, FIG. 3, FIG. 4)

  However, in the above-described conventional configuration, the adjustment hole 511c is formed so as to surround the bearing mounting opening 511a of the motor base substrate 511, so that the rigidity is lowered.

  Due to the decrease in rigidity, deformation is likely to occur due to impact, and the spring constant around the bearing mounting opening 511a is decreased, and the vertical amplitude due to the load when the disk is rotated increases, leading to deterioration of sound and vibration. It becomes like this. Further, in order to deform the entire bearing holder 512, the thrust receiving member 516 fixed to the bearing holder 512 and the position of the thrust plate 517 in the thrust direction also move simultaneously.

  Therefore, the height of the rotor assembly 520 is changed, and the position of the disk mounted on the rotor assembly 520 is changed in the height direction.

The present invention solves such a conventional problem, and not only has a configuration in which the verticality is easily corrected, but also has high rigidity and no change in the height of the rotor due to the correction of the verticality. An object is to provide an excellent small brushless motor.

  In order to solve the above problems, a brushless motor according to a first aspect of the present invention includes a rotating shaft, a bearing that supports the rotating shaft, a cylindrical portion that holds the bearing inside, and an end of the cylindrical portion. A bearing housing having a flange portion extending in a right-angle direction and integrally formed; and a motor base that holds the bearing housing and is a mounting surface to a device on which the motor is mounted. A plurality of protrusions are formed to protrude from the motor base between the surfaces of the bearing housing where the flanges abut, and a spring material is disposed on the surface of the motor base opposite to the abutting surface of the bearing housing. The spring housing is configured to fix the bearing housing to the motor base while urging the bearing housing in the direction of the motor base, and a portion radially inward of the protrusion of the motor base of the flange portion. A brushless motor which is characterized in that the adjustable perpendicularity relative to the motor base of the rotary shaft by deforming direction.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the brushless motor has an end on the opposite side to the output side of the rotating shaft on the surface opposite to the surface in contact with the bearing housing of the motor base. A thrust plate that abuts against the shaft and supports in the thrust direction, and a thrust cover that holds the thrust plate are disposed to form a protrusion that projects in a counter-output direction from the surface of the bearing housing that contacts the motor base. The thrust cover is formed of a spring material, and the motor base and the thrust cover are formed with holes or notches at positions corresponding to the protrusions, respectively, and the protrusions are formed in the holes of the motor base and the thrust cover. Alternatively, the notch is protruded from the thrust cover through the notch, and the protruding portion is fixed to the thrust cover by welding.

  In the brushless motor according to claim 3 of the present invention, in addition to the structure according to claim 1 or 2, the bearing housing is formed by drawing a material such as iron or SUS by drawing. .

  According to the first aspect of the present invention, in order to adjust the shaft suspension, it is only necessary to apply a vertical pressing force to the collar portion, so that the adjustment can be performed with a small pressing force. Therefore, there is no need to reduce the rigidity such as providing a hole in the motor base.

  Further, the vertical axis can be adjusted by the applied pressure, and the axial perpendicularity can be easily corrected. Then, by urging the bearing housing toward the motor base with the spring material, the bearing housing follows down even if the convex portion is crushed, so that there is no play and the reliability is not impaired.

  As a result, it is possible to provide a brushless motor having a structure excellent in noise reduction and vibration reduction by easily correcting the axial perpendicularity and maintaining the rigidity.

  According to the invention of claim 2, in addition to the effect of claim 1, by forming the thrust cover with a spring material, the bearing housing can also be used as a spring material for urging the motor base side. Therefore, there is an effect that it is possible to easily apply a force for urging the bearing housing toward the motor base without increasing the number of parts.

Further, since the thrust cover is always in close contact with the motor base and the motor base itself is not deformed, the flatness is not lost, so the axial position of the thrust plate held by the thrust cover does not change. Therefore, the axial height of the rotor supported by the thrust plate does not change. Therefore, it is possible to provide a highly accurate brushless motor that does not cause a change in the axial height of the rotor due to the correction of the axial perpendicularity.

  According to the third aspect of the invention, in addition to the effects of the first and second aspects, not only the rigidity of the bearing can be maintained, but also the productivity can be improved and the cost can be reduced. .

  Hereinafter, a brushless motor according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a longitudinal sectional front view of a brushless motor according to Embodiment 1 of the present invention.

  In FIG. 1, reference numeral 13 denotes a rotor portion, which is attached to the turntable portion 4 for mounting the disc 11, the rotor frame 5, the disc alignment member 12 that supports the disc 11 together with the turntable portion 4, and the rotor frame 5. The rotor magnet 9 and the rotating shaft 3 fixed at the center of the rotor frame 5 are configured. Reference numeral 15 denotes a stator, which is arranged to face the bearing 14 that supports the rotating shaft 3, the bearing housing 2 that holds the bearing 14, the thrust plate 10 that supports the rotating shaft 3 in the axial direction, and the rotor magnet 9. The core 8 is provided with a winding 7 and the motor base 1 holding the bearing housing 2.

  The motor base 1 is a mounting surface for equipment mounted with a motor, and is formed of aluminum or an alloy thereof.

  The bearing housing 2 is formed by integrally forming a cylindrical portion 2a and a flange portion 2b by drawing a material such as iron or SUS, and a bearing 14 is fitted and fixed to the inner peripheral side of the cylindrical portion 2a. On the surface of the motor base 1 that comes into contact with the flange portion 2b of the bearing housing 2, a convex portion 1a is formed so as to protrude, and the bearing housing 2 is attached to the motor base 1 via the convex portion 1a. A thrust cover 6 made of a spring material is disposed on the surface of the motor base 1 opposite to the contact surface with the bearing housing 2 so as to close the motor base hole 1b formed in the center of the motor base 1. In the motor base hole 1b, there is disposed a thrust plate 10 that abuts the end of the rotary shaft 3 on the opposite side to the output side. This thrust plate 10 is held on the thrust cover 6 so that the rotary shaft 3 moves in the thrust direction. I support it. Thus, the brushless motor for rotating the disk is configured.

  2A and 2B show details of the thrust cover 6 according to Embodiment 1 of the present invention.

  In FIG. 2A, the thrust cover 6 is composed of a flat surface portion 6a and a blade portion 6b, and a thrust cover hole portion 6c is formed at a position to be described later on the blade portion 6b. As shown in FIG. 2B, the wing portion 6b has an inclination of a height a at the tip of the flat portion 6a, and the spring force can be adjusted by this inclination.

  FIG. 3 is an exploded perspective view of the motor base 1, the bearing housing 2, and the thrust cover 6 of the stator portion 15 according to Embodiment 1 of the present invention.

  As described above, the bearing housing 2 has the cylindrical portion 2a and the flange portion 2b formed integrally. In the present embodiment, the flange portion 2b is formed to extend from the end portion of the cylindrical portion 2a in a right angle direction. Furthermore, the protrusion part 2c is extended in the axial direction of a cylindrical part, and three places are formed in the collar part 2b.

On the other hand, a notch 1 c is formed in the inner periphery of the motor base hole 1 b of the motor base 1 at a position corresponding to the protrusion 2 c of the bearing housing 2.

  Similarly, the thrust cover hole 6c is formed at a position corresponding to the protrusion 2c of the bearing housing 2.

  Then, the protrusion 2c of the bearing housing 2 is assembled while passing through the notch 1c of the motor base 1 and the thrust cover hole 6c, the protrusion 2c is protruded from the thrust cover 6, and the flange 2b of the bearing housing 2 is It contacts with the convex part 1a of the motor base 1.

  Subsequently, the jig is pressurized so that the tip of the wing portion 6b of the thrust cover 6 is in contact with the surface opposite to the convex portion 1a of the motor base 1, and in this state, the protruding portion 2c of the bearing housing 2 is welded. Alternatively, it is fixed to the thrust cover 6 by caulking. As a result, the blade portion 6b of the thrust cover 6 is always fixed in a state where the motor base 1 is pressed, so that the bearing housing 2 is urged in the direction of the motor base 1.

  4 (a) and 4 (b) are schematic views of shaft suspension adjustment according to Embodiment 1 of the present invention. When the inclination of the bearing 14 is inclined by θ from the direction of the vertical axis with respect to the motor base 1 as shown in FIG. 4A, the convex portion 1a of the flange portion 2b of the bearing housing 2 that abuts on the convex portion 1a of the motor base 1. By tilting and deforming the more radially inner portion with the jig 22, the inclination of the bearing housing 2 is corrected, and thereby the inclination of the bearing 14 held by the bearing housing 2 is corrected. FIG. 4B shows a state where the inclination of the bearing 14 is corrected. At this time, the spring force of the blade portion 6 b of the thrust cover 6 has an effect of making it difficult for a gap to be generated between the bearing housing 2, the motor base 1, and the thrust cover 6.

  As described above, it is possible to provide a brushless motor having a structure excellent in noise reduction and vibration reduction by easily correcting the axial perpendicularity and maintaining rigidity.

  In addition, it is possible to provide a highly accurate brushless motor that does not cause a change in the axial height of the rotor portion due to the correction of the axial perpendicularity.

  The brushless motor of the present invention is particularly suitable for a thin disk drive device, but is not limited to this, and can be applied to motors that require various types of high axis perpendicularity accuracy.

The longitudinal cross-sectional front view of the brushless motor which concerns on Embodiment 1 of this invention (A) The top view of the thrust cover which concerns on Embodiment 1 of this invention, (b) The longitudinal cross-sectional front view of the thrust cover which concerns on Embodiment 1 of this invention The perspective view of the stator assembly which concerns on Embodiment 1 of this invention (A) Schematic diagram of adjustment according to Embodiment 1 of the present invention, (b) Schematic diagram after adjustment according to Embodiment 1 of the present invention (A) Structural sectional view of a conventional brushless motor, (b) Plan view of a motor base of a conventional brushless motor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,511 Motor base 1a Convex part 1b, 511c Motor base hole part 1c Notch 2, 512 Bearing housing (bearing holder)
2a Cylindrical portion 2b Gutter portion 2c Protruding portion 3, 521 Rotating shaft 4 Turntable portion 5 Rotor frame 6, 516 Thrust cover (thrust receiving member)
6a Plane portion 6b Wing portion 6c Thrust cover hole portion 7 Winding 8 Core 9 Rotor magnet 10, 517 Thrust plate 11 Disc 12 Disc alignment member 13, 520 Rotor portion (rotor assembly)
14,513 Bearing (bearing sleeve)
15 Stator 511a Opening CL Central axis

Claims (3)

A bearing housing having a rotating shaft, a bearing that supports the rotating shaft, a cylindrical portion that holds the bearing inside, and a flange portion that extends integrally from the end portion of the cylindrical portion and is integrally formed; A motor base that holds the bearing housing and is a mounting surface to a device on which the motor is mounted, and a plurality of protrusions protrude from the motor base between the motor base and a surface on which the flange portion of the bearing housing abuts. And a spring material is disposed on the surface of the motor base opposite to the contact surface with the bearing housing, and the spring housing biases the bearing housing in the direction of the motor base. It is a structure to be fixed, and the degree of perpendicularity of the rotating shaft with respect to the motor base can be adjusted by deforming a portion radially inward of the protrusion of the motor base of the flange portion in the axial direction. Brushless motor, characterized in that. On the surface of the motor base opposite to the surface that contacts the bearing housing, a thrust plate that contacts the end of the rotating shaft opposite to the output side and is supported in the thrust direction, and a thrust cover that holds the thrust plate are arranged. A protrusion that protrudes in a counter-output direction from a surface that contacts the motor base of the bearing housing, the thrust cover is formed of a spring material, and the protrusion is formed on the motor base and the thrust cover, respectively. A hole or a notch is formed at a position corresponding to, and the protrusion is protruded from the thrust cover through the hole or notch of the motor base and the thrust cover, and the protrusion is welded to the thrust cover. The brushless motor according to claim 1, which has a fixed configuration. The brushless motor according to claim 1, wherein the bearing housing is formed by drawing a material such as iron or SUS.

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