JPH10146005A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which makes it possible to rotate a detachable disc type data storage medium precisely on the axis of rotation and to prevent the deflection of the axis of rotation. SOLUTION: A rotor R which holds a disc type data storage medium D is supported in such a way as to be rotatable in relation to a stator S with a rotation supporting means. This rotation supporting means is provided with four components: a radial bearing 30 which supports the rotor R in such a way as to make it rotatable by receiving the force in the radial direction of the shaft of the rotor R, a thrust bearing 10 which supports the rotor R in such a ways as to make it rotatably by receiving the force in the thrust direction of the shaft of the rotor R, a first dynamic pressure producing means 40 which, provided on the radial bearing 30, produces the dynamic pressure in a lubricating fluid when the rotor R shaft rotates and a second dynamic pressure producing means 60 which, provided on the thrust bearing 10, produces the dynamic pressure in a lubricating fluid when the rotor R shaft rotates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor for continuously rotating a disk-type information recording medium such as a hard disk or an optical disk.

[0002]

2. Description of the Related Art An example of this type of motor is shown in FIG. 14, and the conventional motor shown in FIG.
D is a motor that is fixed to the rotor 1000 and rotates so that it cannot be removed. This motor includes a rotor 1000 and a stator 2000. The stator 2000 has a structure in which a coil 2001 and an iron core 2002 are fixed to a base 2003. This base 2003 has a fixed shaft 2004
Has been fixed. On the other hand, the rotor 1000 is
It is a rotor that can rotate about 04, and includes a rotor yoke 1001, a driving magnet 1002, and the like.

[0003] The fixed shaft 2004 has a thrust fin 2005.
The rotor sleeve 1003 of the rotor 1000 is fitted to the fixed shaft 2004 so as to be rotatable. This rotor sleeve 1003 is fixed shaft 2004
And the thrust fin 2005 is fitted into the groove of the rotor sleeve 1003.
004 is attached to the rotor sleeve 1003 from above the thrust fin 2005. The thrust fin 2005 serves as a bearing for the rotor 1000 in the thrust direction, and the rotor sleeve 1003
0 in the radial direction.

[0004] By energizing the coil 2001 of the stator 2000 in a predetermined pattern, the magnetic force between the coil 2001 and the driving magnet 1002 causes the rotor 1000 to rotate.
Rotates about the fixed shaft 2004, so that the hard disk HD rotates. The hard disk HD is fixed to the rotor yoke 1001 of the rotor 1000 and cannot be removed and replaced with another hard disk D.

[0005]

Therefore, instead of using the fixed type hard disk HD, the rotor 1
000 rotor yoke 1001 to support the removable hard disk D1 and try to rotate,
A member 1004 is provided thereon with respect to the axial direction of the fixed shaft 2004.
The output shaft 1006 integrated with is set. The output shaft 1006 is a protruding portion for centering the removable hard disk D1 to make it removable. The output shaft 1006 can be made of, for example, brass or steel. However, if it is made of brass, the output shaft 1006 is easily processed but is worn. When the output shaft 1006 is made of steel, it is difficult to wear, but processing is troublesome. In addition, the center of the output shaft 1006 and the fixed shaft 2004
If the centers of the two do not coincide, the removable hard disk D1 will be eccentric when rotated, and a signal will be recorded on this removable hard disk D1 or a recorded signal will be read. It will be difficult to put out. Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a motor that can accurately rotate a removable disk-type information recording medium around a rotation center and that can prevent deflection of the rotation shaft. And

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a motor for rotating a disk-type information recording medium set in the rotor by energizing the rotor. Is a shaft, a yoke fixed to the shaft, holding means provided on the yoke for detachably holding a disk-type information recording medium about the shaft, and a rotational drive fixed to the yoke. The rotor holding the disk-shaped information recording medium is rotatably supported by the rotation supporting means with respect to the stator, and the rotation supporting means applies a radial force on the axis of the rotor. A radial bearing for receiving the rotor in a rotatable manner and a thrust bearing for rotatably supporting the rotor by receiving a thrust force of the shaft of the rotor; and a radial bearing. A first dynamic pressure generating means for generating a dynamic pressure of the lubricating fluid when the rotor shaft rotates, and a first dynamic pressure generating means for providing the lubricating fluid when the rotor shaft rotates And a second dynamic pressure generating means for generating dynamic pressure of the working fluid.

In the present invention, the rotor is as follows. The rotor has a shaft, a yoke fixed to the shaft, and a magnet, and the rotor holding the disk-type information recording medium is rotatable with respect to the stator by a rotation support means. This rotation support means has a radial bearing and a thrust bearing. The radial bearing has first dynamic pressure generating means, and the thrust bearing has second dynamic pressure generating means. These first and second dynamic pressure generating means generate a dynamic pressure of a fluid for lubrication when the shaft of the rotor rotates, and stably and reduce friction so that the shaft of the rotor does not run out. It can be rotated with less. Thus, the rotor shaft is rotatably supported by two types of bearings, a radial bearing and a thrust bearing, and they receive the rotor shaft with dynamic pressure due to the generation of dynamic pressure of the lubricating fluid. Therefore, shaft run-out of the rotor shaft during rotation can be prevented. Since the disk-type information recording medium rotates about the axis of the rotor, the center of the disk-type information recording medium is easily aligned with the axis of the rotor, and the rotation of the disk-type information recording medium is rotated about the axis of the rotor. Can be done accurately.

[0008] Further, the object of the present invention is to provide a motor for rotating a disk-type information recording medium set in the rotor by energizing, the rotor comprising a rotor and a stator. A yoke fixed to the shaft, holding means provided on the yoke for detachably holding the disk-type information recording medium about the shaft, and a rotation driving magnet fixed to the yoke. The rotor holding the disk-type information recording medium is rotatably supported by the rotation support means with respect to the stator, and the rotation support means receives the force in the radial direction of the shaft of the rotor to rotate the rotor. A radial bearing made of metal for rotatably supporting, a thrust bearing for rotatably supporting the rotor by receiving a thrust force of the shaft of the rotor, and a thrust Provided receiving, by a motor having a dynamic pressure generating means for generating a dynamic pressure of the lubricating fluid in the shaft of the rotor is rotated, it is achieved.

In the present invention, the rotor is as follows. The rotor has a shaft, a yoke fixed to the shaft, and a magnet, and the rotor holding the disk-type information recording medium is rotatable with respect to the stator by a rotation support means. This rotation support means has a radial bearing and a thrust bearing. The thrust bearing has dynamic pressure generating means. The dynamic pressure generating means generates the dynamic pressure of the lubricating fluid when the shaft of the rotor rotates, and can rotate the shaft of the rotor stably and with less friction. Thus, the rotor shaft is rotatably supported by two types of bearings, a radial bearing and a thrust bearing, and they receive the rotor shaft with dynamic pressure due to the generation of dynamic pressure of the lubricating fluid. Therefore, shaft run-out of the rotor shaft during rotation can be prevented. Since the disk-type information recording medium rotates about the axis of the rotor, the center of the disk-type information recording medium is easily aligned with the axis of the rotor, and the rotation of the disk-type information recording medium is rotated about the axis of the rotor. Can be done accurately.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 shows a perspective view and a disk D showing a preferred embodiment of the motor of the present invention. The disk D is, for example, a hard disk of a type that can be attached to and detached from the shaft 2 of the motor 1. Therefore, this disk D
It can be removed and another similar disk D can be set again by being fitted to the shaft 2 again. FIG.
FIG. 2 shows a cross-sectional view illustrating the structure of the motor 1 of FIG. The motor 1 is a flat spindle motor having a shaft 2. The motor 1 has a rotor R and a stator S, and rotates the rotor R and a disk D (disk-type information recording medium) set in the rotor 3 by energizing the coil 3 of the stator S in a predetermined pattern. Can be.

First, the structure of the rotor R will be described. The rotor R has a shaft 2, a magnetic rotor yoke 4, a rotor magnet 5, a chucking magnet 6 for chucking the disk D, and the like. The center of the magnetic rotor yoke 4 has a hole 4a, in which the shaft 2 is fixed by press-fitting or an adhesive. The position where the magnetic rotor yoke 4 is fixed to the shaft 2 is located slightly above the center of the shaft 2. When the disk D is chucked, the disk D
Support portion 7 for supporting the The support 7 is provided on the shaft 2
Is formed to protrude upward in a ring shape with the center as the center. A recess 8 is formed in the center of the magnetic rotor yoke 4. The chucking magnet 6 is fixed in the recess 8. This chucking magnet 6
Has a ring shape, and is fixed to the recess 8 around the shaft 2 by bonding or the like. The chucking magnet 6 is a magnet for detachably fixing a disk D such as a hard disk with a magnetic force. That is, the hole 9 in the center of the disc D
With the upper end 2a of the shaft 2 fitted in, the chucking magnet 6 attracts the metal part of the hard disk D so that the disk D is detachably fixed to the magnetic rotor yoke 4 while being supported by the support portion 7. it can. The chucking magnet 6 and the support part 7 constitute holding means for the disk D.

The rotor magnet 5 is fixed inside the magnetic rotor yoke 4 by bonding or the like. The rotor magnet 5 may be, for example, a plastic magnet or the like.
The poles and S poles are alternately multipolar magnetized. The magnetic rotor yoke 4 is made of a material having magnetism, for example, a metal such as iron. A protrusion 4 is provided on the lower surface side of the concave portion 8 of the magnetic rotor yoke 4.
b is formed in a ring shape. At the lower end of shaft 2,
A thrust bearing 10 is provided. The thrust bearing 10 has a ring shape and is connected to the lower end 2 b of the shaft 2. The thrust bearing 10 is, for example, fixed to the shaft 2.

Next, the stator S will be described. The stator S includes a base 20, an iron core 21, a coil 3, and a thrust receiver 2.
Two. The iron core 21 is fixed to the base 20, and a plurality of slots for arranging the coils are circumferentially arranged around the shaft 2. The coils 3 are wound around iron cores 21, respectively. The plurality of sets of coils 3 are connected to an external power supply control unit through wires arranged on the base 20. The thrust receiver 22 is a disk-shaped member that closes the bearing space 24 of the base 20, and the above-described thrust bearing 10 is disposed in the bearing space 24. Moreover, the thrust bearing 22 rotatably supports the lower surface 10b of the thrust bearing 10. The base 20 has a concave portion 25 into which the protrusion 24b of the magnetic rotor yoke 4 is fitted. The provision of the recess 25 and the projection 4b in this manner is such that when the rotor R rotates, even if oil in the bearing portion scatters, the recess 25 and the projection 24b form a labyrinth structure, and oil leaks to the outer periphery of the labyrinth. Lost.

Next, the bearing structure of the motor 1 will be described. The bearing structure of the motor 1 includes a radial bearing 3
0 and a thrust bearing 10. The radial bearing 30 receives the radial force of the shaft 2 of the rotor R and rotatably supports the rotor. The thrust bearing 10 is a bearing for receiving the force in the thrust direction of the shaft 2 of the rotor R to rotatably support the rotor R. The radial bearing 30 is a bearing composed of the portion 26 of the base 20 and the peripheral surface 2 c of the shaft 2.
Is provided with a first dynamic pressure generating means 40. The first dynamic pressure generating means 40 is a part that generates a dynamic pressure of oil, which is a fluid for lubrication, when the shaft 2 of the rotor R rotates.

In the embodiment shown in FIG. 2, the first dynamic pressure generating means 40 is formed on the inner peripheral surface of the portion 26 of the stator S as shown in FIGS. That is, in the first dynamic pressure generation means 40, a plurality of arrow-shaped oil guide grooves 41 are formed at predetermined intervals on the inner peripheral surface 26a of the portion 26. The apex portions 41a of the oil guide grooves 41 are arranged along the center line 42 of the inner peripheral surface 26a, and each of the oil guide grooves 41 is inclined at a predetermined angle θ with respect to the center line 42, for example, at an inclination of 30 degrees. Is formed.

[0017] For example, eight oil guide grooves 41 are formed for 360 degrees corresponding to one circumference of the inner peripheral surface 26a. Therefore, the angle for forming one oil guide groove 41 is 45 degrees. As described above, the plurality of oil guide grooves 41 are sequentially arranged around the center axis CL of the shaft 2. This oil guide groove 4
The forming direction of 1 is along the rotation direction CCW of the shaft 2. Each oil guide groove 41 of the first dynamic pressure generating means is formed to guide oil, which is a fluid for lubrication, between the shaft 2 of the rotor R and the portion 26 of the stator S. Instead of the concave oil guide groove 41 shown in FIG. This first dynamic pressure generating means 40 is a herring bone (herring bone).
Type.

Next, the thrust bearing 10 will be described. The thrust bearing 10 of FIG.
It has a dynamic pressure part 52. The first dynamic pressure portion 51 is arranged between the upper surface 10 a of the thrust bearing 10 and the inner surface 26 b of the portion 26 of the base 20. The second dynamic pressure portion 52 is a portion provided between the lower surface 10 b of the thrust bearing and the upper surface 22 a of the thrust receiver 22. The first dynamic pressure section 51 and the second dynamic pressure section 52 constitute a second dynamic pressure generating means 60. The first dynamic pressure section 5 of the second dynamic pressure generating means 60
As shown in FIGS. 5 and 6, oil guide projections 61 are formed in a spiral shape at predetermined intervals on the upper surface 10a of one thrust bearing 10. These oil guide projections 6
1 is formed so as to face the rotation direction CCW of the shaft 2.

7 and 8 show the second dynamic pressure section 52. FIG. The oil guide projections 62 of the second dynamic pressure portion 52 are arranged at predetermined intervals around a circular central shaft 63 in a direction opposite to the rotation direction CCW of the shaft 2. In other words, these oil guide projections 62 move along the circular
2a coincide with each other, and these oil guide projections 62 are spiral portions 62b, 62 connected to the distal end 62a.
c. The inner spiral part 62b is thinner than the outer spiral part 62c. That is, it has the shape of a herringbone type second dynamic pressure portion 52. The radius of the circular center line 63 is indicated by r2, the outer diameter of the thrust bearing 10 is indicated by R, and the inner diameter of the thrust bearing 10 is indicated by r1. In FIG. 6, the radius inside the oil guide projection 61 is indicated by r3. The shaft 2 includes first dynamic pressure generating means 40 in the radial bearing 30 and two first dynamic pressure parts 51 and second dynamic pressure parts 5 in the second dynamic pressure generating means 60 of the thrust bearing 10.
2, when the shaft 2 rotates in the rotation direction CCW, the center axis CL of the shaft 2
Can be prevented from tilting.

Next, an operation example of the above-described motor 1 will be described. First, the disk D is fitted on the shaft 2, and the disk D is firmly fixed to the support 7 by the magnetic attraction of the chucking magnet 6. Next, a magnetic field is generated in the coil 3 by applying a ball current to the coil 3 of the stator S from the outside in a predetermined energizing pattern.
From the magnetic rotor yoke 4 through the magnetic rotor yoke. As a result, the rotor R is moved around the shaft 2 to the stator S
, The disk D can be continuously rotated integrally with the rotor R. At this time, the shaft 2 is smoothly rotating in the radial bearing 30 and the thrust bearing 10. In the first dynamic pressure generating means 40 of the radial bearing 10, the oil guide groove 41 on the inner peripheral surface 26a of FIG.
Is formed along the rotation direction CCW, so that the oil is guided by the guide groove 41 toward the tip 41a. Thereby, the inner peripheral surface 26a of the portion 26 of the stator S and the shaft 2
A dynamic pressure due to oil is generated between the peripheral surfaces 2c, and the shaft 2 can be smoothly and stably rotated with respect to the base 20 by the dynamic pressure without shaft runout.

At the same time, on the upper surface 10a and the lower surface 10b of the thrust bearing 10, the first dynamic pressure portion 51 and the second dynamic pressure portion 5
2 generates dynamic pressure of oil. That is, in the first dynamic pressure portion 51 of FIGS. 5 and 6, the spiral oil guide projection 61 is provided along the rotation direction CCW of the shaft 2, so that the oil is guided to the oil guide projection 61. Thus, a dynamic pressure of oil is generated between the lower surface 26b of the portion 26 of the base 20 and the upper surface 10a. Therefore, the shaft 2 can rotate smoothly and reliably without swinging along the central axis CL. Similarly, in the second dynamic pressure portion 52 shown in FIGS.
Since 0 rotates with the shaft 2 in the rotation direction CCW, the oil is guided inward by the oil guide projection 62. Therefore, the upper surface 22a of the thrust bearing 22 and the lower surface 10b of the thrust bearing 10
Between them, the dynamic pressure of the oil is generated and the thrust bearing 10 floats from the thrust receiver 22, so that the shaft 2 and the thrust bearing 10 can rotate smoothly about the center axis CL. For this reason, the center axis CL of the shaft 2 does not tilt when the disk D is rotated, and the shaft 2 is mounted on the radial bearing 3.
0 and the thrust bearing 10 support at least two places, so that the shaft can be rotated stably without shaft runout.

Since the concave portion 8 of the magnetic rotor yoke 4 is arranged close to the portion 26 of the base 20, the shaft 2
The disk D can be chucked even if the shaft length of the motor 1 is short, and the motor 1 can be made thinner in the axial direction. Since a large coil accommodating portion 77 can be provided between the magnetic rotor yoke 4 and the base 20, the number of turns of the coil 3 can be increased to enhance the driving force of the rotor R.

FIG. 9 shows the first dynamic pressure generating means 40 of FIG. 4, the first dynamic pressure section 51 of FIG. 6, and the second dynamic pressure section 52 of FIG.
2 shows an example of the pressure distribution of the dynamic pressure in each part. The pressure distribution in FIG. 9 shows the pressure distribution along the line CC1 of the first dynamic pressure generating means 40 in FIG. 4, the pressure distribution along the line AA1 in FIG. 6, and the pressure distribution along the line BB1 in FIG. I have. 9 is the center axis CL of the shaft 2, and the thrust fin surface (upper, lower) represents the upper surface 10a or the lower surface 10b of the thrust bearing 10 in FIG. The disk surface indicates the surface on which the disk D is installed.

In the pressure distribution along the line B-B1 in FIG.
The maximum value of the dynamic pressure of the oil occurs in the central part. On the other hand, in the oil pressure distribution along the line A-A1 in FIG. The fact that the dynamic pressure of the oil near A in FIG. 6 is constant means that the oil can supply the oil from the first dynamic pressure portion 51 to the first dynamic pressure generating means 40 side. Therefore, the oil can be supplied from the first dynamic pressure part 51 to the first dynamic pressure generating means 40 side during rotation. In the dynamic pressure distribution along the line C-C1 in FIG. 4, the dynamic pressure is also maximum at the center line. As described above, the motor 1 of FIGS. 1 and 2 chucks the detachable disk D on the shaft 2 and
Rotation can be performed accurately without vibration.

Next, another embodiment of the motor of the present invention will be described with reference to FIGS. Motor 10 of FIG.
1 has basically the same structure as the motor of FIG.
The shape of the lower end surface 2b of the shaft 2 is different. That is, the lower end surface 2b is spherical, and the receiving surface (for example, made of nylon) 22d of the thrust receiver 22 is correspondingly planar. Thus, the lower end surface 2b is spherical,
By forming the thrust receiver 22 as a flat seat, the second dynamic pressure portion 52 of the second dynamic pressure generating means 60 can be omitted. The receiving surface 22d and the pressing plate 22f constitute the thrust receiver 22. The embodiment of FIG. 10 is the same as the embodiment of FIG. 2 except for the points described above, and therefore the same reference numerals are given and the description thereof is omitted.

Next, the motor 201 of the embodiment shown in FIG.
Is characterized in that a small ball 2f is provided on the thrust receiver 22, and the ball 2f supports the lower end surface 2e of the shaft 2. By providing the ball 2f, the second dynamic pressure portion 52 of the second dynamic pressure generating means 60 in FIG. 2 can be omitted. The other points of the motor 201 shown in FIG. 11 are the same as those in the embodiment shown in FIG. The lower end 2 in FIG.
b and the spherical seat 22d constitute a thrust receiver, and similarly, the ball 2f and the lower end 2e of the shaft 2 in FIG. 11 also constitute a thrust receiver.

Next, in the motor 301 of the embodiment shown in FIG. 12, a projection 22g is formed on the upper surface of the thrust receiver 22. The projection 22g receives the lower end 2e of the shaft 2.
The projection 22g and the lower end 2e also constitute a thrust receiver. Therefore, in the motor 301 of FIG. 12, the second dynamic pressure portion 52 of the second dynamic pressure generating means 60 of FIG. 2 can be omitted. For other points of the motor 301 in FIG.
Since the motor is the same as that described above, the same reference numerals are given and the description thereof is omitted.

In the motor 401 shown in FIG. 13, a metal bearing 430 is provided instead of the first dynamic pressure generating means 40 shown in FIG. The metal bearing 430 is connected to the portion 26 of the base 20.
, And supports the peripheral surface 2c of the shaft 2.
The other points of the motor 401 shown in FIG. 13 are the same as those of the motor shown in FIG.

The structure of the motor as described above has the following features. The shaft 2 of the rotor R is
Since the radial bearing 30 or the metal bearing 430 and the thrust bearing 10 are firmly rotatably held at a plurality of locations, the center axis CL of the shaft 2 is unlikely to fall down. Therefore, the disk D can be smoothly and continuously rotated without surface deflection. Since the chucking position of the disk D is lowered by providing the concave portion 8 in the central portion of the magnetic rotor yoke 4, the length of the shaft 2 can be reduced. The axial length of the radial bearing 30 is the shaft 2
Can be made shorter than the diameter of Because axis 2
The rotation of the thrust bearing 10 as well as the radial bearing 30
However, it can be supported. The thrust bearing 10 can correct the inclination of the shaft 2 and secure the moment rigidity.

Since the rotation posture of the shaft 2 when the motor is driven can be kept vertical, the disk D can be prevented from oscillating, and even if the portable information reproducing / recording apparatus or the information reproducing apparatus is used, The shaft 2 is firmly supported by the radial bearing 30 and the thrust bearing 10 so that the shaft 2 is not easily affected by the speed and acceleration when the device is moved. The radial bearing is made of, for example, brass, plastic, for example, polycarbonate (PPM) or polyacetal (POM).
Etc. can be adopted. The shaft 2 is made of steel, for example, SUS420.
Etc. can also be adopted. The oil guide projections shown in FIGS. 6 and 7 are spiral fins, and these fins can be formed by a forming method such as etching or pressing. Note that an oil guide projection may be used instead of the oil guide groove 41 in FIG. 6 and 8, an oil guide groove may be used instead of the oil guide projection.

The present invention is not limited to the above embodiment. In the above-described embodiment, a hard disk is used as an example of a disk-type information recording medium, which is detachable from the shaft 2. However, the present invention is not limited to this, and the motor of the present invention can be applied to an optical disk, a magneto-optical disk, and other types of magnetic disks as disk-type information recording media. The oil guide groove or the oil guide projection of the first dynamic pressure generating means 40 may be provided not on the base 20 but on the peripheral surface 2c of the shaft 2. The oil guide projections or oil guide grooves of the first dynamic pressure portion 51 in FIG.
May be provided on the lower surface 26b side of the main body. Similarly, FIG.
The oil guide groove or the oil guide projection of the second dynamic pressure portion 52 may be provided on the upper surface 22 a of the thrust receiver 22 instead of the lower surface of the thrust bearing 10.

[0032]

As described above, according to the present invention,
The removable disk-type information recording medium can be accurately rotated about the center of rotation, and the rotation of the rotation shaft can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a motor and a disk to be set according to the present invention.

FIG. 2 is a sectional view showing the structure of the motor shown in FIG. 1;

FIG. 3 is a perspective view showing an example of a first dynamic pressure generating means of FIG. 2;

FIG. 4 is an expanded view of first dynamic pressure generation means of FIG. 3;

FIG. 5 is a perspective view showing a first dynamic pressure section of a second dynamic pressure generating means of FIG. 2;

FIG. 6 is a plan view showing a first dynamic pressure unit.

FIG. 7 is a perspective view showing a second dynamic pressure section of the second dynamic pressure generating means.

FIG. 8 is a bottom view showing a second dynamic pressure unit.

FIG. 9 is a diagram showing an example of oil pressure distribution in first dynamic pressure generating means and second dynamic pressure generating means.

FIG. 10 is a sectional view showing another embodiment of the motor of the present invention.

FIG. 11 is a cross-sectional view showing another embodiment of the motor of the present invention.

FIG. 12 is a sectional view showing another embodiment of the motor of the present invention.

FIG. 13 is a sectional view showing another embodiment of the motor of the present invention.

FIG. 14 is a sectional view showing a conventional motor for a hard disk.

[Explanation of symbols]

1, 101, 201, 301, 401 ... motor, 1
0 ... thrust bearing (rotation support means), 30 ... radial bearing (rotation support means), 40 ... first dynamic pressure generation means, 51 ... first dynamic pressure part, 52 ... 2 dynamic pressure part,
60... Second dynamic pressure generating means, R... Rotor, S.
.Stator, D: Disc type information recording medium

Claims (7)

[Claims] 1. A motor having a rotor and a stator, for rotating a disk-type information recording medium set on the rotor by energizing, the rotor comprising: a shaft; a yoke fixed to the shaft; Holding means provided on the yoke for detachably holding a disk-type information recording medium about an axis, and a rotation driving magnet fixed to the yoke, for holding the disk-type information recording medium The rotor is rotatably supported by the rotation support means with respect to the stator, the rotation support means is a radial bearing for rotatably supporting the rotor by receiving a radial force of the rotor shaft, A thrust bearing for rotatably supporting the rotor by receiving a force in the thrust direction of the rotor shaft; and a radial bearing provided for the rotor shaft to rotate. First dynamic pressure generating means for generating a dynamic pressure of the lubricating fluid; and a second dynamic pressure generator provided on the thrust bearing for generating a dynamic pressure of the lubricating fluid when the rotor shaft rotates. And a pressure generating means. 2. The first dynamic pressure generating means has a concave portion or a convex portion having a predetermined angle with respect to the rotation direction of the rotor shaft in order to guide the lubricating fluid between the rotor shaft and the stator. 2. The motor according to 1. 3. The motor according to claim 1, wherein the second dynamic pressure generating means has a concave portion or a convex portion for guiding the lubricating fluid between the shaft of the rotor and the stator. 4. The second dynamic pressure generating means has a dynamic pressure portion formed on a first surface of a thrust bearing set on a shaft of the rotor, and the dynamic pressure portion has a helical portion facing the axis of the rotor. The motor according to claim 1. 5. A thrust bearing formed on a first surface of a thrust bearing set on a shaft of the rotor, and a first surface of the thrust bearing set on a shaft of the rotor. And a second dynamic pressure portion formed on a second surface opposite to the first dynamic pressure portion. The first dynamic pressure portion has a spiral portion facing the axis of the rotor.
The motor according to claim 1, wherein the dynamic pressure portion has a spiral portion directed to a circular center line along a rotation direction of a shaft of the rotor. 6. A motor for rotating a disk-type information recording medium set in the rotor by energization, comprising a rotor and a stator, the rotor comprising: a shaft; a yoke fixed to the shaft; Holding means provided on the yoke for detachably holding a disk-type information recording medium about an axis, and a rotation driving magnet fixed to the yoke, for holding the disk-type information recording medium The rotatable rotor is rotatably supported by the rotatable support means with respect to the stator, and the rotatable support means receives a radial force of the rotor shaft to rotatably support the rotor. A bearing, a thrust bearing for rotatably supporting the rotor by receiving a force in a thrust direction of the rotor shaft, and a thrust bearing provided on the thrust bearing. Motor, characterized in that it comprises a and a dynamic pressure generating means for generating a dynamic pressure of the lubricating fluid at the time of rolling. 7. The dynamic pressure generating means is opposite to a first dynamic pressure portion formed on a first surface of a thrust bearing set on a shaft of the rotor and a first surface of the thrust bearing set on a shaft of the rotor. A second dynamic pressure portion formed on a second surface of the first dynamic pressure portion, and the first dynamic pressure portion has a spiral portion facing the axis of the rotor.
7. The motor according to claim 6, wherein the dynamic pressure portion has a spiral portion directed toward a circular center line along the rotation direction of the rotor shaft.