JP3026117B2 - Rotating machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating machine having a stator, a rotor comprising a rotor hub and a rotor magnet fixed to the rotor hub, and a bearing for rotatably supporting the rotor.

[0002]

2. Description of the Related Art Conventionally, assembling a motor or the like is performed by fitting other parts to a fixed shaft, a motor frame, or the like mainly from both the axial direction. Therefore, when assembling is automated, a certain degree of complication inevitably arises in the handling of fitting each part from both sides.

The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object to facilitate the assembly process and facilitate the automation of assembly. Another object of the present invention is to provide a rotating machine that can reduce manufacturing costs.

[0004]

In order to achieve the above object, a rotating machine according to the present invention comprises a stator comprising a stator core and a stator coil wound on the stator core.
A fixed shaft to which the stator is externally fixed, a rotor composed of a rotor hub and a rotor magnet fixed to the rotor hub, and the rotor is rotatably fitted to the fixed shaft at a position axially separated from the fixed shaft. It has a pair of ball bearings to support, the shape and dimensions of each part are set so that they can be assembled by fitting single or combined parts in order from one side,
The stator is located at an axial position between the pair of ball bearings, and is located at the one side with respect to the stator.
Compared to the outside diameter of the fixed shaft of the part where the one side ball bearing is fitted,
The outer diameter of the fixed shaft at the portion where the stator is externally fitted is formed larger than the outer diameter of the fixed shaft at the portion where the stator is externally fitted.
The other side ball bearing located on the other side with respect to the stator
The outer diameter of the fixed shaft of the part fitted outside is formed to be large,
On the other side of the part where the other-side ball bearing is externally fitted,
From the outer peripheral surface of the fixed shaft where the other ball bearing is fitted
A receiving portion is provided on the outside in the radial direction of the
The other side of the inner ring is received by the receiving portion, and is fixed to the fixed shaft.
And the other side of the part
Between the outer diameter and the portion with the increased outer diameter.
The inner peripheral edge on the other side of the stator is received by the reduced diameter part
It is assumed that it is.

[0005]

According to the shapes and dimensions of the components constituting the rotating machine, such as the stator, rotor, bearings, etc., a single component or a combined component is assembled by fitting them together in an appropriate order from one side. be able to. The stator is located at an axial position between the pair of ball bearings, and the stator has an outer diameter which is smaller than the outer diameter of the fixed shaft in a portion where the one-side ball bearing located on the one side is externally fitted to the stator. The outer diameter of the fixed shaft of the fitted portion is formed large , and the fixed portion of the stator
Others located on the other side of the stator compared to the outside diameter of the shaft
The outer diameter of the fixed shaft at the part where the outer ball bearing is fitted is large.
Has been established. Therefore, the other side ball bearing is connected to the one side
When the ball bearing is externally fitted to the fixed shaft from
Outer periphery of the fixed shaft or the part where the stator is fitted
Since no galling occurs with the outer periphery of the fixed shaft,
Of the outer periphery of the fixed shaft and the inner periphery of the inner ring of the other ball bearing.
Damage is prevented and fitting can proceed smoothly. this
So that the other side ball bearing is fitted to the fixed shaft
When proceeding from the side, the other side of the inner ring of the other side ball bearing is
It is received by its receiving part, whereby positioning is performed.
You. Similarly, the stator is externally fitted to the fixed shaft from the one side.
The one-side ball bearing, the portion of the fixed shaft
Since no galling with the outer periphery occurs, the outer periphery of the fixed shaft
The damage of the portion is prevented, and the fitting can proceed smoothly.
In this way, the fitting of the stator to the fixed shaft is
When proceeding from the side, the inner peripheral edge on the other side of the stator is
It is received by the reduced diameter part, thereby positioning it.
You. Therefore, when assembling the rotating machine, insert the parts in order from one side.
At least the stator and the other side
Position the ball bearing by smoothly fitting it to the fixed shaft.
When both ball bearings are externally fitted to the fixed shaft,
Damage to the outer periphery of the fixed shaft and the inner periphery of the inner ring of the other ball bearing
Prevents the loss of coaxiality with the fixed shaft
Thus, it is possible to achieve sufficient rotation accuracy of the rotor that is supported by the two ball bearings.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a spindle motor for driving a hard disk as one embodiment of the present invention, and FIGS. 2 to 6 are sectional views showing an assembly process of the spindle motor.

[0007] Reference numeral 10 shown in FIG. 2 is a fixed shaft. A flange 10a protrudes from the lower end of the fixed shaft 10, and an annular protrusion 10b is provided slightly above the flange 10a.
The reduced diameter portion 10c is further provided above the second reduced diameter portion 10d. A communication hole 12 is provided between the outer peripheral portion of the fixed shaft 10 near the first reduced diameter portion 10c and the lower end of the fixed shaft 10. 14 is a fixed shaft 10
Is a fixing screw hole provided at the upper end of the fixing screw. Annular protrusion 1
0b and the large diameter portion 10e between the first reduced diameter portion 10c, the middle diameter portion 10f between the first reduced diameter portion 10c and the second reduced diameter portion 10d,
A small diameter portion 10g is formed above the second reduced diameter portion 10d.

A lower ball bearing 16 (the other ball) shown in FIG.
And 18 are annular bushes. Annular bush 18
At the intermediate position in the axial direction on the inner peripheral side of
0 is provided in an annular shape. Outer ring 16a of lower ball bearing 16
Is fixed to the inside of the annular bush 18 above the inwardly extending portion 20, and then the joined annular bush 18 and the lower ball bearing 16 are fitted from above the fixed shaft 10.
The lower end surface of the inner ring 16b of the lower ball bearing 16 is received by the upper surface of the annular projection 10b (receiving portion) of the fixed shaft 10, whereby positioning is performed. Therefore, at that position the inner ring 16
b may be adhesively fixed. The inwardly protruding portion 20 of the annular bush 18 and the peripheral wall portion 18a therebelow, and the annular protruding portion 10b and the flange-shaped portion 10 of the fixed shaft 10
a constitutes a labyrinth seal.

In FIG. 4, reference numeral 22 denotes a stator core;
Is a stator coil wound around the stator core 22, and 26 is a lead wire of the stator coil 24. When the stator coil 24 is wound around the stator core 22 and the lead wire 26 is fitted over the fixed shaft 10 while passing the lead wire 26 through the communication hole 12, the inner peripheral edge of the lower end of the stator core 22 becomes the first reduced diameter portion 10 c (reduced). Dia.) , Whereby positioning is achieved. Reference numeral 28 denotes an adhesive extending over the inner peripheral edge of the upper end of the stator core 22 and the vicinity of the second reduced diameter portion 10d of the fixed shaft 10. The lead wire 26 is connected to the communication hole 12.
Through the lower end of the fixed shaft 10.

Reference numeral 30 shown in FIG. 5 is a substantially cylindrical rotor hub. The hard disk (not shown) is fixed to the outer peripheral portion of the rotor hub 30. The lower end of the rotor hub 30 has an outwardly extending portion 30a for supporting the hard disk, and the upper reduced diameter portion 30b of the rotor hub 30 has a hard disk fixing clamp (not shown).
Is provided with a screw hole 32 for attaching the. 34
Is a substantially cylindrical rotor yoke fixed on the inner peripheral side of the rotor hub 30; 36 is a cylindrical rotor magnet fixed on the inner peripheral side of the rotor yoke 34;
Is an upper ball bearing (one-side ball bearing) in which the outer ring 38a is adhesively fixed to the inner peripheral side of the upper reduced diameter portion 30b.

After the rotor hub 30, the rotor yoke, the rotor magnet, and the upper ball bearing 38 have been connected, if they are fitted to the fixed shaft 10 in the state of FIG. 4 from above, it can be positioned at a predetermined position shown in FIG. And the upper ball bearing 38
The inner peripheral surface of the inner ring 38b is bonded to the outer peripheral surface of the fixed shaft 10,
The inner peripheral surface of the lower end portion of the rotor hub 30 is fixed by bonding to the outer peripheral surface of the annular bush 18. Reference numeral 40 shown in FIG. 6 and 42 shown in FIG. 1 are an annular lower piece and an annular upper piece, respectively, for labyrinth seal construction.

When the lower piece 40 is fitted onto the fixed shaft 10 in the state shown in FIG. 5 from above, the lower end surface of the lower piece 40 on the inner peripheral side is received by the upper surface of the inner ring 38 b of the upper ball bearing 38. The adhesive is fixed in that state. Then fixed shaft 10
The upper piece 42 from above the upper reduced diameter portion 3 of the rotor hub 30.
0b, the lower end surface on the outer peripheral side of the upper piece 42 is received and positioned on the upper surface of the outer ring 38a of the upper ball bearing 38, and a labyrinth seal is formed by bonding and fixing in this state. You.

As described above, the spindle motor can be assembled by fitting a single component or a combined component in an appropriate order from above the fixed shaft 10. Large diameter part 10e, medium diameter part 10f and small diameter part 1
Each outer diameter of 0 g and each inner diameter of the inner ring 16b of the lower ball bearing 16, the stator core 22, and the inner ring 38b of the upper ball bearing 38 are set so that their respective clearances are several μm or less in the radial direction. . Therefore, until the lower ball bearing 16, the stator core 22, and the upper ball bearing 38 reach their respective fixed positions in the axial direction of the fixed shaft 10, the fixed shaft 10
The fitting can be smoothly advanced without any galling, and by reaching the home position, positioning of each component in the radial direction is also performed.

[0014]

Rotating machine of the present invention exhibits, necessary to fit the parts from two or more directions <br/> phrase as in the conventional motor during assembly, securing at least the stator and the other side ball bearing To axis
Since the outer fitting can be smoothly performed and the positioning can be performed, the assembling process can be smoothly performed, the automation of the assembling is easy, and the effect of reducing the manufacturing cost can be exhibited. In the process of externally fitting the other-side ball bearing and the stator to the fixed shaft from one side , the one-side ball bearing is externally fitted.
Of the fixed shaft outer part or the part where the stator is fitted
Since no galling occurs with the outer periphery of the fixed shaft,
Damage to the outer periphery of the fixed shaft and the inner periphery of the inner ring of the other ball bearing
Is prevented , and sufficient rotation accuracy of the rotor can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a spindle motor for driving a hard disk.

FIG. 2 is a sectional view showing an assembling process of a hard disk drive spindle motor.

FIG. 3 is a sectional view showing an assembling process of a hard disk drive spindle motor.

FIG. 4 is a sectional view showing an assembling process of a spindle motor for driving a hard disk.

FIG. 5 is a sectional view showing an assembling process of a spindle motor for driving a hard disk.

FIG. 6 is a sectional view showing an assembling process of a spindle motor for driving a hard disk.

[Description of sign]

 10 Fixed shaft 16 Lower ball bearing 18 Annular bush 22 Stator core 24 Stator coil 30 Rotor hub 34 Rotor yoke 36 Rotor magnet 38 Upper ball bearing

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 21/22 H02K 29/00

Claims (1)

(57) [Claims] A stator comprising a stator core and a stator coil wound on the stator core; a fixed shaft to which the stator is fitted and fixed; a rotor comprising a rotor hub and a rotor magnet fixed to the rotor hub; A pair of ball bearings which are fitted externally at positions axially separated from each other with respect to the shaft and rotatably support the rotor, wherein single or coupled parts are fitted in order from one side. The shape and dimensions of each component are set so that they can be assembled by the following. The stator is located at an axial position between the pair of ball bearings, and is located at the one side with respect to the stator.
Compared to the outside diameter of the fixed shaft of the part where the one side ball bearing is fitted,
The outer diameter of the fixed shaft at the portion where the stator is externally fitted is formed larger than the outer diameter of the fixed shaft at the portion where the stator is externally fitted.
The other side ball bearing located on the other side with respect to the stator
The outer diameter of the fixed shaft in the part fitted outside is formed to be large, and the other side of the part in which the other-side ball bearing is fitted outside is provided on the other side.
Of the fixed shaft at the part where the other side ball bearing is fitted
A receiving portion is provided radially outward from the surface, and the other side ball shaft is provided.
The other side of the inner ring of the bearing is received by the receiving portion, and a portion of the fixed shaft on which the stator is externally fitted;
A reduced diameter portion is provided between the other side of the
And the inner peripheral edge on the other side of the stator by the reduced diameter portion.
A rotating machine characterized in that a part is received .