JP2009115128A - Retainer for roller bearing, and roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retainer for a roller bearing, which is excellent in durability under high-speed rotation even compared with a conventional resin crown type retainer, and resin combined retainer using a conventional rivet or snap fit, and also to provide a roller bearing equipped with the retainer and excellent in the durability under the high-speed rotation especially. <P>SOLUTION: The retainer for the roller bearing, which constitutes a resin retainer by axially combining a pair of synthetic resin annular body mutually, is characterized in that: in each synthetic resin annular body, an annulus proximal and a pillar section perpendicularly arranged at a constant space in the proximal are molded integrally; the synthetic resin annular bodies are faced with each other so that one side pillar section locates at a middle point between the other side pillars; and they are combined so that a pocket retaining a rolling body is formed between adjacent pillar sections. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing used for various rotating parts, and a resin cage incorporated in the rolling bearing.

  For example, a ball bearing includes a resin-made crown-type cage in order to maintain a plurality of balls arranged between an outer ring and an inner ring at a predetermined interval in the circumferential direction. The crown type cage has, for example, the shape shown in FIG. 3, and holds a ball (not shown) in a cantilever shape.

  In addition, as the resin forming the resin-made crown cage, polyphenylene sulfide (PPS), polyamide (PA), or the like is used particularly when a use temperature exceeding 120 ° C. is required. Further, when a use temperature exceeding 200 ° C. is required, a resin called a super engineering plastic such as polyimide (PI), polyamideimide (PAI), polyetheretherketone (PEEK) is used. For reinforcement, composite materials in which reinforcing fibers such as glass fibers and carbon fibers are blended with these resins are also used.

  However, when used at a high temperature, it is inevitable that mechanical characteristics such as strength and rigidity are lowered. Further, when used at a high speed, a greater force acts on the cantilever portion due to centrifugal force.

  As described above, when the resin crown type cage is used in a high-temperature and high-speed environment, the holding force of the rolling elements is reduced to increase the cage noise, and in some cases, the cage is broken. Against this background, combination cages using rivets and snap fits have been proposed (see, for example, Patent Document 1 and Patent Document 2).

JP 2003-343567 A JP 2006-226448 A

  However, in the structure using rivets and snap fits, not only the bending stress is applied to the joint in the radial direction due to the centrifugal force generated during high-speed rotation, but also the circumferential bending stress generated during sudden acceleration / deceleration is applied. The part to which the snap fit is applied is easily damaged by fatigue.

  In addition, when metal rivets are used as rivets, the specific gravity of the metal is greater than that of the resin, leading to an increase in starting torque, and the stress generated at the joint with the resin during sudden acceleration / deceleration increases, resulting in further damage. It becomes easy.

  The present invention has been made in view of the above-described situation, and is capable of rotating at a higher speed than conventional resin-made crown-type cages, and even conventional resin-made combination cages using rivets and snap-fits. It aims at providing the cage for rolling bearings which is excellent in durability under. It is another object of the present invention to provide a rolling bearing that includes the rolling bearing and has excellent durability particularly under high-speed rotation.

In order to achieve the above object, the present invention provides the following rolling bearing cage and rolling bearing.
(1) In a rolling bearing cage in which a pair of synthetic resin annular bodies are axially coupled to each other to constitute a resin cage,
Each annular body made of synthetic resin is formed integrally with an annular base portion and a pillar portion standing upright from the base portion at equal intervals.
The synthetic resin annular bodies are opposed to each other so that one pillar portion is located at an intermediate point between the other pillar portions, and bonded so as to form a pocket for holding a rolling element between adjacent pillar portions. A cage for a rolling bearing, characterized by being made.
(2) The snap fit coupling female portion is formed on the inner peripheral surface of the intermediate point between the column portions of the base portion, and the snap fit coupling male portion is formed on the upper end surface of the column portion, The rolling bearing retainer according to the above (1), which is snap-fit coupled.
(3) The rolling bearing cage according to (1) or (2) above, comprising at least one resin selected from polyamide, polyimide, polyamideimide, polyphenylene sulfide, and polyetheretherketone.
(4) The rolling bearing retainer according to (3) above, which contains a reinforcing fiber material.
(5) A rolling bearing comprising the rolling bearing cage according to any one of (1) to (4) above.

  According to the present invention, a conventional roller bearing cage, and further a rolling bearing cage that is superior in durability under high-speed rotation as compared with a conventional resin cage using a rivet or snap fit. Can be provided. In addition, it is possible to provide a rolling bearing that is particularly excellent in durability under high-speed rotation.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an example of a synthetic resin annular body constituting a rolling bearing retainer according to the present invention, and FIG. 2 is a perspective view showing a state in which the synthetic resin annular bodies are joined together. Here, a cage for ball bearings is shown.

  As shown in FIG. 1, the synthetic resin-made annular body 1 </ b> A (1 </ b> B) is formed by integrally molding a plurality of column parts 20, 20 standing at equal intervals along the circumferential direction of the annular base 10. Half of the pocket 30 is formed on both sides in the circumferential direction of the column portion 20 so as to form pockets 30 for holding balls (not shown) when the synthetic resin annular bodies are joined together as shown in FIG. An arcuate pocket surface 31 constituting the part is formed.

  In order to make a cage for a rolling bearing, as shown in FIG. 2, the above-mentioned synthetic resin annular bodies are made to face each other. Therefore, assembly is extremely easy. Further, in this coupled state, the pocket portion 30 is formed between the one column portion 20 and the other column portion 20. In the pocket portion 30, the rolling elements are constrained by snap fit. In addition, in a rivet-coupled cage, stress generated between the cages is transmitted by rivets (point contact), whereas in the present invention, stress is transmitted through rolling elements (surface contact), so there is a risk of breakage. small.

  The rolling bearing retainer configured as described above has excellent resistance to centrifugal force generated when the bearing rotates because the beam portion 21a of the column portion 20 is on the inside and is supported by the base portion 10 from the outside.

  Further, by forming the snap fit coupling male portion 21 over the entire circumferential width at the upper end portion of the column portion 20, it is possible to improve the axial coupling force. The beam portion 21a of the snap fit coupling male portion 21 is formed by extending the inner peripheral surface of the column portion 20, and an engaging claw 21b protrudes to the outer peripheral surface side. In accordance with this, a snap fit coupling female portion 11 is formed on the inner peripheral surface of the intermediate point between the adjacent column portions 20 in the base portion 10.

  The above embodiment shows a cage for a ball bearing. For example, in order to make a cage for a roller bearing, both sides in the circumferential direction of the column portion 20 are formed in an arc shape so that the pocket 30 is rectangular. Instead, it may be linear. Also for other rolling bearings, the shape of the column portion 20 may be changed in accordance with the shape of the rolling element.

  In addition, the snap fit coupling female portion 11 is formed on the base portion 10 and the snap fit coupling male portion 21 is formed on the column portion 20 so that the snap fit coupling is performed. The upper end surface of the column portion 20 may be a flat surface and may be welded to the thick portion of the base portion 10 without forming the fit coupling female portion 21.

  In the rolling bearing retainer of the present invention, the resin material is not limited, and the resin material for the conventional synthetic resin retainer can be used as it is, but considering the use under high-speed and high-temperature rotation, polyamide having excellent heat resistance , Polyimide, polyamideimide, polyphenylene sulfide, and polyetheretherketone are preferably used alone or in appropriate combination. In particular, polyimide, polyamideimide, and polyetheretherketone are suitable for applications that are used at temperatures exceeding 200 ° C.

  The resin material may contain reinforcing fiber materials such as glass fiber, carbon fiber, metal fiber, aramid fiber, aromatic polyimide fiber, liquid crystal polyester fiber, silicon carbide fiber, alumina fiber, and boron fiber. Of these, glass fiber and carbon fiber are preferable because of their good reinforcement.

  The reinforcing fiber material preferably has an average fiber diameter of 3 to 30 μm, more preferably 5 to 20 μm. When the average fiber diameter is less than 3 μm, fiber aggregation occurs when mixed with a resin, and strength unevenness is likely to occur in the resulting cage. If the fiber diameter is larger than 30 μm, the smoothness of the cage surface will be hindered. Therefore, deformation of the mating material (inner ring, outer ring, rolling element, shield plate, seal member) may occur with the use of the bearing, The characteristic tends to deteriorate. In order to obtain a sufficient reinforcing effect, the aspect ratio is preferably 3 or more. Further, the reinforcing fiber material may be treated with a coupling agent such as a silane coupling agent or a titanate coupling agent or other surface treatment agent according to the purpose in order to have an affinity with the resin. Good.

  Moreover, it is preferable that the compounding quantity of the fiber material for reinforcement shall be 10-40 mass% with respect to the total amount with resin, More preferably, it is 15-40 mass%. If the blending amount is less than 10% by mass, the effect of reinforcing the mechanical properties is small, and if it exceeds 40% by mass, the melt fluidity of the resin is lowered and the moldability is deteriorated, and the dimensional stability is also lowered during the molding or holding. The cage may be damaged when the rolling element is incorporated into the cage.

  Furthermore, various additives may be blended, such as solid lubricants such as graphite, hexagonal boron nitride, fluorine mica, tetrafluoroethylene resin powder, tungsten disulfide, molybdenum disulfide, inorganic powder, organic powder, etc. , Lubricating oil, plasticizer, rubber, resin, antioxidant, heat stabilizer, UV absorber, photoprotective agent, flame retardant, antistatic agent, mold release agent, fluidity improver, heat conductivity improver, non An appropriate amount of a tackifier, a crystallization accelerator, a nucleator, a pigment, a dye or the like can be blended.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is further demonstrated, this invention is not restrict | limited at all by this.

(Production of cage)
Polyamide 46 (“Stanyl TW241F5” manufactured by DSM Co., Ltd.), polyphenylene sulfide (“Fortron T2020” manufactured by Polyplastics Co., Ltd.), polyetheretherketone (“PEEK350CA30” manufactured by Victrex Co., Ltd.) was used. The synthetic resin annular body 1A (1B) having a dimension that can be incorporated into a ball bearing “6909” manufactured by Nippon Seiko Co., Ltd. As shown in FIG. 2, the retainer A was manufactured by snap-fitting the synthetic resin annular body 1 </ b> A and the synthetic resin annular body 1 </ b> B. For comparison, a crown cage equivalent product (Cage B) for ball bearing “6909” manufactured by NSK Ltd. was produced.

(An endurance test)
The durability of the produced cage A and cage B was evaluated using a general-purpose durability rotation test device manufactured by NSK Ltd. As test conditions, the rotational speed was 20000 rpm or 30000 rpm, the ambient temperature was 150 ° C., “Mobile ATF220” was used as the lubricating oil, and the time until the cage was damaged was measured. In addition, when it did not break after 50 hours, the test was terminated. The results are shown in Tables 1-3.

  From the table, it can be seen that the cage A according to the present invention is significantly improved in durability as compared with the conventional crown cage.

(A) It is a perspective view which shows an example of the synthetic resin cyclic | annular body which comprises the cage for rolling bearings which concerns on this invention. It is a perspective view which shows the cage for rolling bearings obtained by couple | bonding the synthetic resin annular body verb shown in FIG. It is a perspective view which shows the conventional crown type holder | retainer.

Explanation of symbols

1A, 1B Synthetic resin annular body 10 Base 11 Snap-fit female part 20 Column 21 Snap-fit male part 30 Pocket 31 Pocket surface

Claims (5)

In a rolling bearing retainer that forms a resin retainer by connecting a pair of synthetic resin annular bodies in the axial direction to each other,
Each annular body made of synthetic resin is formed integrally with an annular base portion and a pillar portion standing upright from the base portion at equal intervals.
The synthetic resin annular bodies are opposed to each other so that one pillar portion is located at an intermediate point between the other pillar portions, and bonded so as to form a pocket for holding a rolling element between adjacent pillar portions. A cage for a rolling bearing, characterized by being made.   A snap fit coupling female portion is formed on the inner peripheral surface of the intermediate point between the column portions of the base portion, and a snap fit coupling male portion is formed on the upper end surface of the column portion. The cage for a rolling bearing according to claim 1, wherein the cage is provided.   The cage for a rolling bearing according to claim 1 or 2, comprising at least one resin selected from polyamide, polyimide, polyamideimide, polyphenylene sulfide, and polyether ether ketone.   The rolling bearing retainer according to claim 3, further comprising a reinforcing fiber material.   A rolling bearing comprising the rolling bearing cage according to claim 1.

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