JP2003074558A - Thrust bearing for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust bearing plate excellent in abrasion resistance and slidability in order to realize high speed rotation function and long life of a motor. SOLUTION: In a thrust bearing of a motor, at least a contiguous part with a rotary shaft is formed of a thrust bearing for a motor made of polyether aromatic keton containing 1-100 pts.wt. of alumina particles in 100 pts.wt. of polyether aromatic keton resin. The polyether aromatic keton is fused and extruded in a sheet and blanked to obtain a flat plate or a curved plate formed in the blanking. The thickness of the plates is as thick as 10-1000 μm and the blanking diameter is as large as 0.5-20 mmϕ.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, information equipment,
The present invention relates to thrust bearing materials used in high-speed micromotors, cooling fan motors, and vibration motors used in office equipment, audio / video equipment, etc.

[0002]

2. Description of the Related Art In recent years, small motors have been continuously used for a long time year after year due to the growing need for light, thin, short, small and long life with the expansion of household and industrial markets for personal computers, information equipment, office equipment, audio / video equipment. It requires a long time and is compact and has a long life.

As the performance of information equipment, office equipment, audio / video equipment is improved, high rotation performance in which the rotation speed of the motors used for these equipment exceeds 10,000 rpm and durability that enables continuous use for a long time are required. Motors that can withstand high rotation speeds and various materials and structures that can be used continuously for a long time have been developed.

A CPU, a hard disk, a CD-ROM drive, a video chip, etc. are mounted in the personal computer. In particular, as the performance of personal computers has increased in recent years, the power consumption of mounted components has increased and the amount of heat generated has tended to increase. If the temperature inside the computer rises, the operation of the mounted components may become unstable and it may not operate properly. A heat sink to prevent the temperature inside the PC from rising and a cooling fan to radiate the air inside the PC to the outside are required. Various materials and structures for cooling fan motors have been developed that can withstand long-term continuous use.

A vibration motor for notifying an incoming call by vibrating as a substitute for a ringing sound is mounted on a mobile phone or the like, which has been rapidly expanding in the market in recent years. It has been promoted to notify an incoming call by vibration as a manner in public places. These vibration motors have been developed into motors with a very small volume as mobile phones have become smaller and lighter. Further, a type in which a carrier tape is automatically mounted like an IC chip component and directly fixed to a printed wiring board through a reflow furnace is being developed.

A radial bearing, which is one of the small motor structures, has a rolling bearing structure and a sliding bearing structure. A ball bearing is a typical example of the former rolling bearing structure, and a representative of the latter is a sliding bearing structure. Typical examples include sintered oil-impregnated bearings.

Recently, a sliding bearing structure called a fluid bearing or a dynamic pressure bearing has a bearing structure which utilizes oil or air for lubrication and holds the rotary shaft and the radial bearing in a non-contact state by the dynamic pressure. Is being developed.

FIG. 1 is a schematic view of a cross section of a rotating shaft portion of a high speed micromotor having a fluid bearing. In FIG. 1, the rotary shaft 1 includes a radial bearing 4 and a thrust bearing 6.
It is rotatably supported by. A groove 2 having a screw shape or the like is machined on the rotary shaft 1, and while the rotary shaft 1 is rotating, the radial bearing 4 and the lubricant 3 between the rotary shaft 1 are uniformly filled to reduce the frictional resistance due to the rotation. However, it is possible to have high-speed rotation performance.

The rotary shaft tip portion 1a in contact with the bearing portion may use the rotary shaft 1 whose tip portion is formed in an arc shape or the like in order to prevent the thrust bearing 6 from being worn.

Further, as for a sintered oil-impregnated bearing which has been conventionally used in the field of low rotation, a bearing capable of supporting high rotation of 10,000 rpm or more has been developed. It has been proposed that the sliding bearing structure is cheaper and has a longer life than rolling bearings represented by ball bearings.

In the rolling bearing structure, a ball bearing, which is a radial bearing, supports the rotating shaft even in the thrust direction, but in the sliding bearing structure, another bearing for receiving the rotating shaft in the thrust direction is required.

For the thrust bearing, a metal or resin having a small amount of wear and excellent sliding characteristics is used on the surface in contact with the rotary shaft.

Regarding the occurrence of wear of the thrust bearing 6,
It is known that the surface smoothness of the thrust bearing 6 is important. If the surface is smooth, the frictional resistance between the rotary shaft 1 and the thrust bearing 6 can be reduced, and the abrasion of the thrust bearing 6 due to the frictional resistance and frictional heat can be prevented.

Since the thrust bearing portion has a structure in which the thrust bearing 6 receives the load in the thrust direction of the rotary shaft 1 particularly during rotation, wear of the thrust bearing 6 cannot be avoided. In order to solve the wear of the thrust bearing 6, a lubricant 7 is applied to the surface of the thrust bearing 6, or a thrust bearing plate 5 made of a material having excellent wear resistance is designed between the rotary shaft 1 and the thrust bearing 6. There is something.
By selecting the material of the thrust bearing plate 5, the rotary shaft 1
Various studies have been conducted to reduce wear of the metal material used for the sliding.

Generally, a metal having a high hardness is used for the rotating shaft 1. On the other hand, the thrust bearing material is made of metal or resin. When SUS steel, iron or the like, which is a metal having high hardness, is used for the thrust bearing material, there are problems that the weight increases, and that it requires much labor and cost when performing highly accurate machining. Further, abrasion occurs between materials having high hardness due to sliding. Designing a small motor that uses metal for both the rotary shaft and thrust bearing is
There are problems in terms of cost, sliding noise, and durable life.

Conventionally, various resins that replace metallic materials have been studied and used as thrust bearing materials. For example, nylon 4, nylon 6, nylon 11,
Nylon 12, Nylon 66, Nylon 6 ・ 10, Nylon 6 ・ 12 and their copolymers such as Nylon
PET system, PBT system, PAR system, PC system, POM system, P
PS type, PTFE type, ultra high molecular weight PE type resin, ABS
-Based, PI-based thermoplastic resins, PI-based, epoxy-based, D
AP-based and composite resins thereof, and further, for each resin, wood powder, asbestos, graphite, glass fiber, carbon fiber, vitreous ceramic fiber system, aramid fiber,
Solid lubricants of metal sulfides such as molybdenum sulfide and iron sulfide,
It is a material filled with an oil lubricant or the like. When the above material is used as the thrust bearing material of a small motor, wear may occur under severe wear conditions or during long-term use. Further, frictional heat during sliding may cause a problem in durability. The hardness that mixed fluororesin such as PTFE is low,
Even when wear is not caused by using a material having a small coefficient of friction, the bearing of the rotary shaft may not be supported and a dent may be formed in the bearing portion.

Unlike the rolling bearing structure, the fluid bearing is classified into a sliding bearing structure, so that a bearing in the thrust direction is required. However, its rotational speed is extremely high, so that it has excellent sliding suitability and wear resistance. It is excellent and can handle temperature changes depending on the operating environment, and since oil is often used as a lubricant, it required oil resistance, but there was no suitable material. Further, a bearing member made of a material satisfying the above characteristics by compounding each material has been studied, but none of them has been developed to sufficiently satisfy the required characteristics.

A lubricant 7 is applied to the surface of the thrust bearing 6 to solve the wear of the thrust bearing 6, or a thrust bearing plate 5 made of a material having excellent wear resistance.
Is designed in the thrust direction of the rotary shaft 1, but it is difficult to realize a long life due to the effects of wear resistance and heat generation due to friction.

Further, when the number of rotations becomes high (10,000 rpm or more), many problems due to wear occur,
A material that required oil resistance was required because it has excellent sliding suitability and wear resistance, responds to temperature changes due to the operating environment, and because oil is often used as a lubricant, it is suitable. There was no material. Problems due to wear include lateral and vertical runout from the center of rotation of the rotary shaft.

Further, a bearing member made of a material satisfying the above-mentioned characteristics by compounding each material has been researched and developed, but it becomes very expensive and there is a problem in cost.

[0021]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thrust bearing plate which is excellent in wear resistance and slidability in order to realize high-speed rotation performance and long life of a motor.

[Means for Solving the Problems]

According to the present invention, in a thrust bearing of a motor, at least a portion in contact with the rotating shaft contains 1 to 100 parts by weight of alumina particles based on 100 parts by weight of the polyether aromatic ketone resin. A thrust bearing for a motor, which is formed of an aromatic ketone material (hereinafter referred to as a carbon particle-containing polyether aromatic ketone material). As a preferred embodiment, the alumina particle-containing polyether aromatic ketone material is a flat plate punched after being melt extruded into a sheet shape, or a curved plate formed at the time of punching, and has a thickness of 10 μm to
1000 μm, punching diameter φ1 mm to φ20 m
m, and the surface smoothness of the PEEK material is 2 μm or less in the center line average roughness (Ra). The average particle size of the carbon particles used in the present invention is 0.1 μm to 100 μm. It is preferably 1 μm to 50 μm. A further preferred embodiment is the thrust bearing for a motor, in which the radial bearing of the motor has a fluid bearing structure or an oilless metal structure. Further, in the present invention, the motor is a high-speed micromotor, and the rotation speed of the high-speed micromotor is 10,
A thrust bearing for the motor having a speed of 000 rpm or more, which is a high-speed micromotor using the thrust bearing. Further, the present invention is the thrust bearing for a motor, wherein the motor is a cooling fan motor, and a cooling fan motor using the same. The present invention is the thrust bearing for a motor, wherein the motor is a vibration motor, and a vibration motor using the same.

Fiber reinforcement (glass fiber, carbon fiber, potassium titanate fiber, ceramic fiber, aramid fiber, boron fiber, etc.), granular reinforcement (calcium carbonate, calcium carbonate, Clay, talc, silica, mica, carbon particles, etc., conductivity improver (carbon, zinc oxide, titanium oxide etc.), thermal conductivity improver (powdered metal oxide etc.), antioxidant, heat stabilizer, Antistatic agents, UV absorbers, lubricants, release agents, dyes, pigments, other thermoplastic resins (polyamide-based, polycarbonate-based,
Polyacetal type, PET type, PBT type, polyarylate type, polyphenylene sulfide type, polyether sulfone type, polysulfone type, polyarylate type, polyetherimide type, polyimide type, fluorine type, polyether nitrile type, liquid crystal polymer type, etc. ), And a thermosetting resin (phenolic resin, epoxy resin, polyimide resin, silicon resin, polyamideimide resin, etc.) may be used in combination.

The mixing and kneading method of addition is not particularly limited, and various mixing and kneading means can be used. For example, they may be separately fed to a melt extruder and mixed, or only the powder raw material may be previously dry-blended by using a mixer such as a Henschel mixer, a ball mixer, a blender, or a tumbler, and further melted. Any thermoplastic resin can be melt-kneaded by a melt-kneader. As a molding method, an appropriate molding method can be applied to the resin as the base material. For example, various molding methods such as injection molding, melt extrusion molding, cast molding, compression molding, sinter molding, powder coating and the like.

DETAILED DESCRIPTION OF THE INVENTION

The alumina particle-containing polyether aromatic ketone material used in the present invention is preferably formed into a sheet by melt extrusion molding, but its extrusion method and take-up method are not particularly limited. The method for producing a sheet made of the above-mentioned material of the present invention is preferably a method in which it is cooled and solidified by a take-up cooling roll immediately after melt extrusion. By making the surface of the cooling roll smooth, molten P
It is possible to transfer the smoothness of the roll surface to the sheet surface when EEK solidifies. When the PEEK sheet having high smoothness thus obtained is punched and used as a thrust bearing material, abrasion can be prevented.

In the cooling and solidifying step, there is a method of using a belt conveyor type take-up belt in addition to the method of using a cooling roll. By smoothing the surface of the take-up belt, it is possible to transfer the smoothness of the belt surface to the sheet surface when the molten PEEK is solidified. When using a cooling roll, there are a method of cooling the sheet on one side and a method of simultaneously cooling and solidifying both surfaces of the sheet by using two or more rolls. When picking up on a belt conveyor,
There are a method of pulling one side of the sheet by belt conveyance, and a method of cooling and solidifying conveyance while sandwiching both sides of the sheet with two or more belts.

Alumina particle-containing polyether aromatic ketone material used as a thrust bearing material in contact with the rotary shaft is
It is necessary for its wear resistance that its surface be as smooth as possible. Regarding the surface smoothness of the carbon particle-containing polyether aromatic ketone material sheet, the center line average roughness (R
a) is preferably 2 μm or less, more preferably 1 μm or less, still more preferably 0.5 μm or less.

In order to obtain an alumina particle-containing polyether aromatic ketone material sheet having excellent surface smoothness, it is necessary that no foreign matter is mixed into the sheet. When processed into a melt-extruded sheet, it is possible to remove kneaded foreign matters by filtering the melted polyether aromatic ketone material containing carbon particles. The type and conditions of the foreign matter removing filter used for filtration are not particularly limited.

The shape of the polyether aromatic ketone material containing alumina particles is not particularly limited, but a punched disk-shaped flat plate or a curved plate molded at the time of punching is preferable. The thickness of the polyether aromatic ketone material containing alumina particles is preferably 25 to 1000 μm and is 25 μm.
If it is less than m, the workability such as punching and the stability at the time of assembly are poor, and if it exceeds 1000 μm, it is difficult to punch or the cost becomes expensive.

By the above means, it is possible to prevent wear of the bearing plate that receives a load in the thrust direction from the rotating shaft rotating at high speed, and to realize high-speed rotation performance and long life of the motor.

[0031]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to the examples. As the application example, PEEK450G manufactured by Victrex was used as the polyether aromatic ketone resin used as the substrate, and AO-502 manufactured by Admatex was used as the alumina particles.
The sample used for evaluation was a sheet extruded by melt extrusion under the conditions of a cylinder temperature of 380 ° C. and a die temperature of 400 ° C.

Various evaluations were carried out based on the following. (1) Wear resistance (1): Using a wear wheel wear type wear tester, sliding load 1000 gf, test piece rotation speed 60 rp
m, wear distance 245 m Measure the wear volume of the test piece after operation (JIS K 7204 compliant) (2) Abrasion resistance (2): Sliding load 90 gf, SUS shaft rotation speed using a pin-on-disc type wear tester 1000
Observe the wear mark of the test piece and the wear condition of the shaft tip after operating at 0 rpm for 100 hours. Very little test piece wear and shaft tip wear were evaluated as ◯, test piece or shaft tip wear was confirmed as Δ, and test piece and shaft tip wear were confirmed as x. (3) Moldability: Sheet processing and molding were performed using a single-screw extruder and a T-type die, and the appearance of a sample obtained was visually evaluated.
Good appearances were evaluated as ◯, and those having a large surface roughness or those in which a stable molded product could not be obtained were evaluated as x.

[0033]

[Table 1]

[0034]

According to the present invention, by using the alumina particle-containing polyether aromatic ketone material having excellent slidability in the thrust bearing plate, the wear resistance is improved without impairing the heat resistance of the bearing plate and the motor is improved. High speed rotation performance and long life of

[Brief description of drawings]

FIG. 1 is a schematic view of a cross section of a rotating shaft portion of a motor.

[Explanation of symbols]

1 rotation axis 2 Screw-shaped groove 3 lubricant 4 radial bearing 5 Thrust bearing plate 6 Thrust bearing 7 Lubricants

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 5/167 H02K 5/167 B 7/08 7/08 BF term (reference) 3J011 AA20 BA02 BA08 CA02 DA01 JA02 KA02 KA03 LA04 LA05 MA02 PA10 QA05 SB01 SC20 4F071 AA51 AB09 AE17 AF22 AF28 AH18 BB06 BC04 BC12 4J002 CH091 DE146 GM05 5H605 AA00 BB05 CC04 EB03 EB06 FF06 GG21 5H607 BB01 DD03 GG01 GG03 GG01 GG01 GG03

Claims (10)

[Claims] In a thrust bearing of a motor, at least a portion in contact with the rotating shaft contains 1 to 100 parts by weight of alumina particles with respect to 100 parts by weight of a polyether aromatic ketone resin. A thrust bearing for a motor, which is formed of a group ketone material. 2. The polyether aromatic ketone material is a flat plate punched after being melt extruded into a sheet shape, or a curved plate shaped at the time of punching, and has a thickness of 10 to 1000 μm.
The thrust bearing for a motor according to claim 1, wherein the thrust bearing has a diameter of 0.5 m and a punching diameter of 0.5 mm to 20 mm. 3. The thrust bearing for a motor according to claim 1, wherein the radial bearing of the motor has a fluid bearing structure or an oilless metal structure. 4. The thrust bearing for a motor according to claim 1, 2 or 3, wherein the motor is a high speed micromotor. 5. The number of rotations of the high speed micromotor is 10,
The thrust bearing for a motor according to claim 4, wherein the thrust bearing is 000 rpm or more. 6. A high-speed micromotor using the thrust bearing for a motor according to claim 4. 7. The thrust bearing for a motor according to claim 1, 2 or 3, wherein the motor is a cooling fan motor. 8. A cooling fan motor using the thrust bearing for a motor according to claim 7. 9. The thrust bearing for a motor according to claim 1, 2 or 3, wherein the motor is a vibration motor. 10. A vibration motor using the thrust bearing for a motor according to claim 9.