JP3256420B2 - Thrust bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust bearing applicable to a capstan motor such as a digital video recorder or an 8 mm video recorder.

[0002]

2. Description of the Related Art Digital video recorder or 8 mm
FIG. 1 shows an example of a capstan motor such as a video recorder. In FIG. 1, a hole 4a is formed in the substrate 4. On the lower surface side of the substrate 4 and on the concentric circle of the hole 4a, a plurality of air-core coils 6 are attached via an insulating layer 5.

[0003] A bearing holder 3 is attached to the hole 4a from the upper end surface side of the substrate 4. The bearing holder 3 includes an upper bearing holding portion 3a, a lower bearing holding portion 3b, and a side standing portion 3c connecting the bearing holding portion 3a and the bearing holding portion 3b. Among these, the bearing holding portion 3b has a hole in the center on a flat plate, and the outer edge portion below this hole projects and forms a cylindrical portion 3d. This cylindrical portion 3d is a hole 4a of the substrate 4.
The bearing holder 3 is mounted on the substrate 4 by being fitted and fixed therein. The outer peripheral surface of the radial bearing 2 'is press-fitted and fixed to the inner peripheral surface of the cylindrical portion 3d.

On the other hand, the upper bearing holding portion 3a has a cylindrical portion 3e which is partially open on the outer peripheral side. The inner peripheral surface of the cylindrical portion 3e includes a large-diameter portion 3f on the upper opening side and a small-diameter portion 3g on the lower opening side, and the axial dimension of the small-diameter portion 3g is larger than the axial dimension of the large-diameter portion 3f. . The outer peripheral surface of the bearing 2 is press-fitted and fixed to the small diameter portion 3g of the bearing holding portion 3a.

[0005] Naturally, the large-diameter portion 3f, between the small-diameter portion 3g has occurred stepped portion 3 h, the lid member 13 is attached to the stepped portion 3h. The thrust bearing 12 is attached to the lower end surface (the surface on the small-diameter portion 3g side) of the lid member 13.

A rotating shaft 1 is inserted through the inner peripheral surfaces of the radial bearings 2 and 2 ', and the rotating shaft 1 is connected to the radial bearings 2 and 2'.
Are supported in the radial direction. The upper end of the rotating shaft 1 is in contact with a thrust bearing 12, the rotating shaft 1 is supported in the thrust direction by the thrust bearing 12, and the rotating shaft 1 is rotatable with respect to a stator member such as the substrate 5 and the bearing holder 3. ing.

The lower end of the rotating shaft 1 penetrates through the bearing holder 3b and protrudes toward the lower end of the substrate 4, that is, the side where the air-core coil 6 is disposed. The boss member 7 is attached to the lower end of the rotating shaft 1 as described above. Boss member 7
A rotor case 8 is attached by caulking or the like to the outer periphery of the rotor. The rotor case 8 has a peripheral wall on the outer periphery, and a driving magnet 9 is attached to a portion inside the peripheral wall. The upper end surface of the substrate 4
And the air-core coil 6 attached at a certain distance. Therefore, by controlling the energization of the air core coil 6, the driving magnet 9 is biased, and the rotor case 8 and the rotating shaft 9 are driven to rotate. A magnet 10 for frequency power generation is provided on the outer peripheral surface of the peripheral wall of the rotor case 8.
Is attached. Frequency power generation magnet 10
Faces a sensor (not shown) attached to the substrate 4 with a certain gap.

[0008]

The thrust bearing 12 for supporting the rotating shaft 1 in the thrust direction is made of metal or resin. The metal is made of stainless steel or iron, and the resin is made of PPS or nylon. ing. The types of resin and metal used for the thrust bearing 12 and the data of each strength are as follows. Type of resin tensile strength iso Bu Tsu preparative impact strength hardness deformation temperature ^{[kg / cm 2] [kgcm} / cm] Rockwell 4.6kg / cm ² 18.6kg / cm ² nylon 66 830 4.5 R126 M80 230 ℃ 70 ℃ Nylon 6 750 6.0 R120 175 75 ℃ Polyacetal 620 6.5 M80 158 ℃ 110 ℃ PBT 600 3.5 M75 154 ℃ 58 ℃ PPS 850 1.5 173 ℃ 108 ℃ Kind of metal Tensile strength Hardness (Wickers hardness) N / mm ² (kgf / mm ² ) [Hv] Brass 335 or more 80 or more C36404BDS Aluminum 373 (38) or more 10 or more A2011BDS Iron 275 (28) or more 80 to 110 SECC-C20 stainless steel 588 (60) or more 200 or more SUS420J2 (rotary shaft material)

For example, when forming the thrust bearing 12 from stainless steel, iron, nylon, or the like, the thrust bearing 12 is formed by punching out a material member, or from the PPS.
Is formed, the thrust bearing 12 is formed by resin-molding a material member.

If the thrust bearing 12 is formed from a metal such as stainless steel or iron, there is a problem that the weight increases and the processing is troublesome, so that the manufacturing cost is increased. Further, as can be seen from the above-mentioned data, since the thrust bearing 12 and the rotating shaft 1 sliding with the thrust bearing 12 are both made of a metal having high hardness, any one of the thrust bearing 12 and the rotating shaft 1 can be used during sliding. Wear will occur,
There was a problem in durability.

Further, when the thrust bearing 12 is formed of PPS, nylon, or the like, there is no problem that the weight increases and the manufacturing cost increases. However, as can be seen from the above-mentioned data, since the metal rotating shaft 1 having high hardness slides against the thrust bearing 12 made of resin having low hardness, there is no wear. As shown, the sliding of the rotating shaft 1 causes a depression A on the thrust bearing 12 side having a low hardness, and also in this case, there is a problem in durability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a thrust bearing which suppresses an increase in weight and a rise in manufacturing cost, and is excellent in slidability and durability. The purpose is to provide.

[0013]

According to the first aspect of the present invention,
A thrust bearing for supporting a rotary shaft in a thrust direction by contacting one end of a metal rotary shaft supported by a radial bearing , wherein the thrust bearing has a tensile strength of 900 kg / c.
m ^2, characterized in that it is formed by punching Izod impact strength 9.0kgcm / cm and <br/> polyetheretherketone material Rockwell hardness M98. The invention according to claim 2 is characterized in that the thrust bearing according to claim 1 is used for a capstan motor of a video recorder.

One end of the rotating shaft abuts the thrust bearing and is supported in the thrust direction. When the rotating shaft is driven to rotate, the rotating shaft slides on the thrust bearing.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a thrust bearing according to the present invention.
Since the basic configuration of a capstan motor using a thrust bearing is the same as that of the conventional art, the same drawing is used and the description is omitted.

In FIG. 1, a thrust bearing 12 for supporting the rotating shaft 1 in a thrust direction is formed from a PEEK (polyether ether ketone) material. The respective strength data of the PEEK material are shown below. Tensile strength iso Bu Tsu preparative impact strength hardness heat distortion temperature ^{[kg / cm 2] [kgcm} / cm] Rockwell ^{4.6kg / cm 2 18.6kg / cm 2} PEEK 990 9.0 M98 152 ℃ above 152 ° C.

As can be seen from the above data, the PEEK material has a higher hardness, lighter weight and a very smooth surface as compared with the above-mentioned resins such as nylon. Therefore, by forming the thrust bearing 12 from a PEEK material, an increase in weight can be suppressed, and the slidability of the rotating shaft 1 can be improved.

The hardness of the PEEK material is lower and softer than that of a metal such as stainless steel or iron. Therefore, by using the PEEK material for the thrust bearing 12, even if the metal rotary shaft 1 slides, no abrasion occurs. Further, the PEEK material has a lower hardness than metals such as stainless steel and iron, but has a higher hardness than, for example, PSS or nylon. Therefore, when the PEEK material is used for the thrust bearing 12, no depression occurs even when the metal rotary shaft 1 slides. For this reason, by forming the thrust bearing 12 from the PEEK material as in the above-described embodiment, the thrust bearing 12 is excellent in durability and can extend the life.

Further, since PEEK material has high hardness,
Even when the thrust bearing 12 using the EEK material is formed thin, sufficient hardness can be obtained, which can contribute to a reduction in the thickness of the device.

It should be noted that the thrust bearing 12 only needs to be formed of a PEEK material, and the shape is not particularly limited. As shown in FIG. 3, it may be disk-shaped. Or,
When the rotating shaft 1 slides and the thrust bearing 12 rotates due to the frictional force of the rotating shaft 1, as shown in FIG. It may be configured not to.

[0021] Incidentally, PEEK material Ri resin der, that form a thrust bearing 12 by punching <br/> Chi must be unplugged it.

[0022]

According to the present invention, one end of the rotating shaft is abutted.
Pull the thrust bearing that supports the rotating shaft in the thrust direction.
8. Tensile strength 900 kg / cm ² , Izod impact strength 9.
Since it is formed of a polyetheretherketone material having 0 kgcm / cm and Rockwell hardness of M98, it is possible to improve the slidability of the metal rotary shaft with respect to the thrust bearing. The polyetheretherketone material used for the thrust bearing is light and has a lower hardness than metals such as stainless steel and iron, but has a higher hardness and is harder than PSS and nylon. For this reason, an increase in weight due to the attachment of the thrust bearing can be suppressed, and when the rotating shaft slides, wear and dents of the thrust bearing are prevented from occurring, and durability can be improved. Further, since the polyetheretherketone material is a kind of resin, it is easy to handle, and it is possible to suppress an increase in production cost due to processing or the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a capstan motor to which a conventional thrust bearing is applied.

FIG. 2 is an enlarged sectional view of a main part of the same.

FIG. 3 is a sectional view showing an embodiment of a thrust bearing according to the present invention.

FIG. 4 is a cross-sectional view showing another embodiment of the thrust bearing according to the present invention.

[Explanation of symbols]

 12 Thrust bearing

────────────────────────────────────────────────── ─── Continued on the front page (56) References JP-A-61-262221 (JP, A) JP-A-7-228883 (JP, A) JP-A-8-23656 (JP, A) JP-A-5-228 68355 (JP, A) JP-A-60-18614 (JP, A) JP-A-6-9888 (JP, A) JP-A-4-308484 (JP, A) JP-A-2-44856 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16C 17/00-17/26 F16C 33/00-33/28

Claims (2)

(57) [Claims] 1. A thrust bearing for supporting a rotary shaft in a thrust direction by contacting one end of a metal rotary shaft supported by a radial bearing, wherein the thrust bearing has a tensile strength of 9 mm.
00 kg / cm ² , Izod impact strength 9.0 kgcm
A thrust bearing formed by punching a polyetheretherketone material having a hardness of / cm and a Rockwell hardness of M98. 2. The thrust bearing according to claim 1, which is used for a capstan motor of a video recorder.