DE102008004588A1 - Arrangement for yoke and rotor in spindle engine, has flange that extends radially outward in rotor, where rotor is connected with yoke, which has magnet from its inside - Google Patents

Abstract

The arrangement has a flange (14) that extends radially outward in a rotor (5). The rotor is connected with yoke (10), which has a magnet (6) from its inside. The flange is formed on the upper surface of the bearing surface (13) for supporting the L-shaped yoke that stands with each other in the form-fit interference.

Description

Field of the invention

The The invention relates to the arrangement of a yoke with respect to the rotor in a spindle motor, in particular for a spindle motor with a larger electromagnetic design.

State of the art

spindle motors consist essentially of a stator, a rotor and at least an arranged between two storage system. The rotor magnet of the electromagnetic drive is via a yoke, that serves as magnetic inference, with the rotor body connected. As a storage system are often fluid dynamic Stock used.

With the DE 202 18 821 U1 Such a known from the prior art spindle motor, preferably for driving a hard disk drive disclosed which comprises a freely rotatable in a bearing bush shaft which is fixedly connected to a rotor. The rotor has on its radially outwardly directed circumference a yoke, which is connected to a magnet and forms an electromagnetic drive together with the stator.

by virtue of progressive development with higher and higher standards technical requirements with almost constant external dimensions such a spindle motor is the space required Components only conditionally changeable.

So it is for example a spindle motor with high technical Requirements for compliance with the requirements regarding resistance and of the engine torque required that yoke with the arranged on it Arrange magnets as far as possible radially outwards, to make the stator larger in the radial direction and to meet the required requirements.

About that In addition, with the radial expansion in most applications also an extension of the stator in the axial direction of the spindle motor connected, reducing the material thickness of the rotor is.

A Such requirement for an increased space requirement of the stator is also under the concept of an enlarged "electromagnetic Designs "known.

Generally It should be noted that in a current spindle motor with an enlarged "electromagnetic Design "only at the expense of the material thicknesses either to realize the yoke or the rotor.

With The above-mentioned document of the prior art becomes a spindle motor discloses, wherein the yoke with the magnet arranged thereon the bottom of the rotor is connected.

disadvantage in the known arrangement is that the rotor due to the low axial space requirement only a relatively small, flanged surface has, which fixes the yoke in the radial direction. Thus, can the yoke relatively easily detached from the rotor, causing damage or failure of the spindle motor leads.

A Connecting arrangement between yoke and rotor with a sufficient Beading of the rotor, however, has the disadvantage that a radial expansion of the stator is almost impossible.

By process-related inaccuracies in flanging can also an imbalance on the rotor arise.

additionally it is to form a stop surface for the yoke requires that an undercut be placed in the rotor what is the material thickness of the rotor and the associated Strength of the rotor additionally weakens. This is particularly the case when a spindle motor with a to form a relatively large electromagnetic design, however, the axial clearance is relatively low.

It is also known from the prior art that the Yoke is attached to the inner edge of the correspondingly shaped hub. This has the disadvantage that at an enlarged electromagnetic design, the wall thickness of the hub the junction to the yoke must be reduced, resulting in a lower stability of the rotor leads.

Disclosure of the invention

It The object of the invention is a spindle motor with an enlarged Stator space specify while reducing the material thicknesses to avoid the rotor and the yoke.

These Solution of the problem is characterized in that the Rotor a radially outwardly extending flange which has a bearing surface for the yoke forms, wherein the L-shaped yoke in the form-fitting Engages with the bearing surface of the flange and so a loosening of the yoke is avoided.

preferred Embodiments of the invention and other advantageous features arise from the subclaims.

Of the Spindle motor according to the invention comprises a rotatably mounted shaft in a bearing bush, wherein the shaft fluid dynamic is mounted and positively connected to a rotor which is on its outer circumference with a magnet having connected yoke, wherein the magnet in an opposite Position of a stator is arranged and with this the electromagnetic Drive of the spindle motor forms.

According to one preferred embodiment of the invention, the spindle motor a enlarged stator on which in radial and axial direction enlarged dimensions to comply with Specifications regarding resistance and motor torque having.

The Yoke and the rotor are formed so that their ends in a superposed arrangement non-positively engage each other.

This has the advantage that the rotor with larger External dimensions for an enlarged "electromagnetic Design "is formed, with the material thicknesses of the yoke and the rotor remain virtually unchanged and the engine power is improved.

About that In addition, a material weakening by arranging a Undercut in the rotor also avoided, since the yoke due to the inventive design of the rotor and the yoke sufficient both in the axial direction and in the radial direction is fixed.

Farther forms the inventive design and arrangement the yoke with the rotor a self-assurance, since the yoke in axial Direction to the engine surface by the on the inner surface of the Yoke arranged magnet is not displaceable.

One Another advantage of such an arrangement of the rotor with the yoke is that a plastic deformation of the rotor is not is necessary to make a bead for connecting the yoke form with the rotor.

in the The invention will be described below with reference to one, only one embodiment illustrative drawing explained in more detail. in this connection go from the drawing and its description further essential to the invention Features and advantages of the invention.

Brief description of the drawings

1a shows a section through a known from the prior art spindle motor with a beaded attachment of a yoke to a rotor;

1b shows a section through a known from the prior art spindle motor, wherein the yoke is attached via a press connection to the inner edge of the hub.

2 shows a spindle motor according to the invention with an extended "electromagnetic design";

3 shows an enlarged section of a yoke in a superimposed arrangement with a rotor.

Description of a preferred Embodiment of the invention

The in 1a shown spindle motor 1 has one in a bearing sleeve 3 free rotating shaft 4 on, with its upturned end with a rotor 5 is firmly connected. The rotor 5 has a yoke at its radially outward circumference 10 on which with a magnet 6 is connected and together with the stator assembly 2 forms an electromagnetic drive.

The wave 4 forms with the bearing sleeve 3 a fluid dynamic bearing, wherein the shaft 4 by frontal arrangement of a cover plate 9 is axially mounted, on its surface a thrust washer 8th supports. The rotor 5 forms in a superimposed arrangement with the base plate of the spindle motor 1 a space which is designed for the arrangement of the electromagnetic drive.

The electromagnetic drive has a stator arrangement 2 on which fixed to the base plate of the spindle motor 1 is connected and in an opposite arrangement of a magnet 6 is arranged. The magnet 6 is by means of an adhesive connection with a yoke 10 connected, wherein the yoke in turn by means of a flare connection with the rotor 5 is connected to the outwardly directed periphery with the downwardly facing surface.

Here, the rotor points 5 in the corner region between the crimp necessary for crimping 11 and the down-facing surface an undercut 12 on which a tailor-made connection of the right-angled yoke 10 with the opposite corner region of the rotor 5 allows.

For an axial extension of the dimensions of the stator assembly 2 is a reduction in the material thickness of the radially on the rotor 5 trained flange 14 necessary. In addition, the arrangement of the yoke 10 trained underdog 12 to arrange deeper compared to its conventional position, resulting in reduced strength of the flange 14 on the rotor 5 leads.

A radial extension of the stator assembly 2 with the same dimensions of the space for the stator assembly 2 either forms the yoke 10 with a reduced material thickness or leads to a radially further outward arrangement of the yoke to the undercut 12 must be arranged radially further out, resulting in a reduced material thickness of the flange 14 and thus leads to a reduced stability of the rotor.

At the in 1b Spindle motor shown is the yoke with the inner edge 16 a correspondingly shaped flange 14 via a press connection with the rotor 5 connected.

For an axial and / or radial extension of the dimensions of the stator assembly 2 is a reduction in the material thickness of the rotor in the region of the flange 14 necessary, which leads to a reduced stability of the Roitor and also makes it difficult to press in the yoke.

The in 2 Spindle motor shown in the basic structure corresponds to a in 1a shown spindle motor 1 , wherein the stator assembly 2 is formed in an extended "electromagnetic design", which is an unchanged material thickness of the yoke 10 and the rotor 5 having.

Here, the rotor points 5 on its radially outward circumference a flange 14 on which on its upwardly facing surface a bearing surface 13 for the arrangement of the yoke 10 forming

The right-angled yoke 10 stands with its inwardly directed, right-angled surface in a superimposed engagement with the surface 13 of the rotor 5 trained flange 14 , whereby a radial extension of the stator assembly 2 without a reduction in the material thickness of the yoke 10 and / or the rotor 5 is possible.

In addition, the forms at the yoke 10 adhesive magnet 6 a self-fixing connection of the yoke 10 with the rotor 5 because of an axial displacement of the yoke 10 through the magnet 6 is prevented and vice versa.

Also a plastic deformation of the rotor 5 By flanging is avoided because the attachment of the yoke 10 due to the engaged surfaces of the inner surface of the yoke 10 and the upward contact surface 13 of the rotor 5 form an at least partially positive and non-positive connection.

In addition, the arrangement of a strength-reducing undercut 12 in the arranged flange 14 of the rotor 5 omitted, since a connection technique by means of beading is not required.

In the 3 shown magnification for the arrangement of a yoke 10 on a rotor 5 clearly shows that due to the adhesive bond of the magnet 6 with the inward, vertical surface of the yoke 10 the upward facing surface 13 ' of the magnet 6 with the inwardly facing surface of the right angle angled yoke 10 a play-free clamping connection on the support surface 13 of the rotor 5 which forms an axial displacement of the yoke 10 avermeidet.

Thus, no additional structural safety measures for the arrangement of a yoke 10 on a rotor 5 required, which in an expansion of the stator assembly in the radial and / or axial direction, the material thicknesses of the rotor 5 and the yoke 10 reduce it further.

Of the Subject of the present invention does not arise only from the subject matter of the individual claims, but also from the combination of the individual claims among themselves.

All in the documents, including the abstract Information and features, in particular the spatial shown in the drawings Training, are claimed as essential to the invention, as far as individually or in combination with the state of the art Technology is new.

1

spindle motor

2

stator

3

bearing sleeve

4

wave

5

rotor (Stroke)

6

magnet

7

connection cable

8th

printing plate

9

cover

10

yoke (Yoke)

11

flare

12

Freeway

13

bearing surface

13 '

bearing surface

14

flange

16

palm

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 20218821 U1 [0003]

Claims (4)

Arrangement of a yoke ( 10 ) and a rotor ( 5 ) in a spindle motor ( 1 ), wherein the spindle motor ( 1 ) is preferably designed for driving hard disk drives, with a base plate or flange, a shaft and a bearing system for pivotally mounting a rotationally driven rotor, wherein the rotor is connected to a yoke, which has a magnet from its inside and with a stator assembly opposite the magnet forms an electromagnetic drive, characterized in that the rotor ( 5 ) a radially outwardly extending flange ( 14 ), which on its upwardly facing surface a bearing surface ( 13 ) for supporting the inwardly directed surface of the L-shaped yoke ( 10 ) forms, which are in positive engagement with each other and so releasing the yoke ( 10 ). Arrangement of a yoke ( 10 ) and a rotor ( 5 ) according to claim 1, characterized in that the yoke ( 10 ) has on its inwardly directed, vertical surface a magnet ( 6 ), which with its upwardly directed end face a bearing surface ( 13 ' ) for supporting the downwardly directed surface of the flange ( 14 ) trains. Arrangement of a yoke ( 10 ) and a rotor ( 5 ) according to one of the preceding claims 1 to 2, characterized in that the flange ( 14 ) with its upwardly and downwardly directed surface between the yoke ( 10 ) and the magnet ( 6 ) is arranged and a shift-free arrangement of the rotor ( 5 ) is formed in the radial and axial directions. Arrangement of a yoke ( 10 ) and a rotor ( 5 ) according to one of the preceding claims 1 to 3, characterized in that the engaging surfaces of the rotor ( 5 ) and the yoke ( 10 ) a self-assurance of the yoke ( 10 ) with the magnet ( 6 ) forms against displacement in the axial direction.