JP2004360738A - Tapered roller bearing filled with lubricant-containing polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tapered roller bearing filled with lubricant-containing polymer, in which a polymer layer is stably formed in a space part between an outer ring and a retainer, and especially which is also applicable as a small-diameter tapered roller bearing. <P>SOLUTION: This device is provided with an inner ring 2, the outer ring 3, a plurality of rolling elements 4 provided between the inner ring 2 and the outer ring 3, the retainer 5 having a plurality of pole parts to retain the rolling elements 4 between two adjoining pole parts, and lubricant-containing polymer 6 filled in the space formed of the inner ring 2, the outer ring 3, the rolling elements 4, and the retainer 5 to cover the retainer. In the pole part of the retainer 5, a through hole 7 is provided for connecting the space on the side of the inner ring 2 to the space on the side of the outer ring 2 to the pole part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a tapered roller bearing in which a polymer layer is stably formed in a space portion between an outer ring and a cage, and in particular, to the space portion that can be applied particularly as a small diameter tapered roller bearing. The present invention relates to a lubricant-containing polymer-filled tapered roller bearing in which a polymer layer is stably formed.
[0002]
[Prior art]
Since the lubricant-filled polymer-filled bearing retains lubricity without being filled with lubricating oil or grease, it is possible to prevent leakage or scattering of the lubricant without using a seal or shield for the lubricating oil or grease. For this reason, lubricant-filled polymer-filled bearings are used in various applications such as robot joints and two-wheeled vehicle steering parts by utilizing the characteristics. However, when this bearing is applied as a small-diameter tapered roller bearing, the space between the outer ring and the cage is thin due to the structure of the tapered roller bearing, and it is difficult to form a stable polymer in the space portion. It was.
[0003]
Conventionally, as a polymer filling method in a lubricant-containing polymer-filled bearing, for example, filling by injection molding as shown in JP-A-2001-248654 has been performed (Technical Document 1). However, in this method, especially in the case of a small-diameter tapered roller bearing, the width (t dimension shown in FIG. 1) between the cage column and the outer ring is small, so that the gap between the cage column and the outer ring is small. There was an example in which the polymer could not be filled sufficiently and the polymer filling was incomplete (the state shown in FIG. 4).
[0004]
Japanese Utility Model Laid-Open No. 6-45116 discloses a rolling bearing in which a through hole is provided in a cage of a ball bearing (Patent Document 2). However, the purpose of this bearing is to improve the strength by integrating the polymers on both sides (inner ring side and outer ring side) of the cage with through holes in order to prevent the solid lubricant from peeling off.
[0005]
[Patent Document 1]
JP 2001-248654 A [Patent Document 2]
Japanese Utility Model Publication No. Hei 6-45116 [0006]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a lubricant-containing polymer-filled tapered roller bearing in which a polymer layer is stably formed in a space portion between an outer ring and a cage.
Another object of the present invention is to provide a lubricant-containing polymer-filled tapered roller bearing that can be applied particularly as a small-diameter tapered roller bearing.
[0007]
[Means for Solving the Problems]
The present invention has an inner ring and an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a plurality of column parts, and holds the rolling elements between two adjacent column parts. A retainer, and a lubricant-containing polymer that fills a space formed by the inner ring, the outer ring, the rolling element, and the retainer and covers the retainer, and the pillar portion of the retainer includes A lubricant-containing polymer-filled tapered roller bearing provided with a through-hole for allowing the inner ring side space and the outer ring side space to pass through a column portion as a reference is provided.
[0008]
The lubricant-containing polymer-filled tapered roller bearing with this structure has a stable polymer layer formed in the space between the outer ring and the cage, and can also be applied as a small-diameter tapered roller bearing. It is.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, the lubricant-containing polymer-filled tapered roller bearing of the present invention will be described in detail based on preferred embodiments with reference to the drawings.
[0010]
The present invention provides, as one embodiment, a lubricant-containing polymer-filled tapered roller bearing shown in FIG. FIG. 1 is a cross-sectional view (a part) showing a general tapered roller bearing filled with a lubricant-containing polymer. FIG. 2 is a cross-sectional view (partial) showing the tapered roller bearing shown in FIG. 1 with the outer ring omitted. FIG. 3 is a sectional view (a part) showing an embodiment of the tapered roller bearing of the present invention with the outer ring omitted.
[0011]
As shown in FIG. 3, the lubricant-containing polymer-filled tapered roller bearing 1 of the present embodiment includes an inner ring 2 and an outer ring 3, and a plurality of tapered rollers that are rolling elements interposed between the inner ring 2 and the outer ring 3. 4 and a retainer 5 having a plurality of pillars and holding the tapered roller 4 between two adjacent pillars, and in a space formed by the inner ring 2, the outer ring 3, the tapered roller 4 and the cage 5. And a lubricant-containing polymer 6 that covers the cage 5 and is a tapered roller bearing.
[0012]
The lubricant-containing polymer 6 of this tapered roller bearing has a through-hole 7 for allowing the space on the inner ring 2 side and the space on the outer ring 3 side to pass through the column portion of the cage 5 with reference to the column portion. Provided.
[0013]
In the conventional tapered roller bearing 1 ′ as shown in FIG. 1 and FIG. 2, a space between the outer ring 3 and the cage 5 ′ such as a failure in filling the lubricant-containing polymer (incomplete filling) occurs. In some cases, the polymer layer is not stably formed on the portion. As shown in FIGS. 4 and 7, this tapered roller bearing 1 ′ has a narrow path (D portion in FIG. 4) between the column portion of the cage 5 ′ and the outer ring 3 in the B direction and the C direction indicated by arrows. Such a filling problem occurs because the filling specification is such that the polymer is filled from only. 4 is a view in the direction of arrow A of the tapered roller bearing 1 ′ shown in FIG. 2, and FIG. 7 is a view in the direction of arrow B (cross section) of the tapered roller bearing 1 ′ shown in FIG. In particular, the smaller the diameter of the bearing, the narrower the width (t dimension shown in FIG. 1) of the bottleneck D portion is, so this filling defect becomes more prominent. In addition, as will be described later, before the polymer is filled, a release agent or grease is generally applied to the inner surface of the outer ring and the surface of the retainer column portion, and the bottle D portion is filled. Making it more difficult.
[0014]
As shown in FIGS. 3, 5 and 8, the tapered roller bearing 1 according to the present embodiment has three cylindrical through holes 7 (hidden lines) in each of the plurality of column portions of the cage 5 at substantially central portions. Part shown). 5 is a view in the direction of arrow A of the tapered roller bearing 1 of the present embodiment shown in FIG. 3, and FIG. 8 is a view in the direction of arrow B of the tapered roller bearing 1 of the present embodiment shown in FIG. Cross section). As described above, the through-hole 7 is a hole that penetrates the space on the inner ring 2 side (inner diameter side) and the space on the outer ring 3 side (outer diameter side) around the column portion of the retainer 5. 5 is a polymer filling path from the inner ring 2 side to the same narrow path D part. Thus, in the tapered roller bearing 1 of the present embodiment, a space different from the B and C directions, that is, the space between the cage 5 and the inner ring 2 is provided in the central portion of the same corridor D portion where the polymer filling is most difficult. In this way, stable polymer formation is realized by filling the polymer.
[0015]
That is, the tapered roller bearing 1 of the present embodiment directly fills the bottleneck D portion with the polymer from the space between the cage 5 and the inner ring 2 having a spatially large filling path, and from the B direction and the C direction. Combined with filling, stable polymer formation is possible (see FIG. 5). Furthermore, in this embodiment, stable polymer formation is possible even if the diameter of the bearing is small.
[0016]
The through holes 7 are not particularly limited by the number and size thereof. The number and size of the through holes 7 are arbitrarily set according to the strength of the cage 5, the polymer filling stability, and the size of the bottleneck D portion.
[0017]
In addition to the example shown in FIG. 5, the through-hole 7 includes a slit-like through-hole 7 whose opening surface is rectangular as shown in FIG. 6. The shape of the through-hole 7 is arbitrary, and any shape can be used as long as the shape and the stability of the column portion of the cage 5 can be realized.
[0018]
The lubricant-containing polymer 6 of this tapered roller bearing is not particularly limited by the method of forming (filling and solidifying), but it is preferably formed by injection molding. At this time, the lubricant-containing polymer 6 is formed so as to completely cover the protruding cage 5.
[0019]
In addition, the method for manufacturing the tapered roller bearing 1 of the present embodiment is not particularly limited, but for example, the following method is preferable.
First, a tapered roller bearing is assembled by a normal method, and then subjected to normal degreasing and cleaning. Next, a release agent or grease is applied to the outer peripheral surface of the inner ring 2, the inner peripheral surface of the outer ring 3, the surface of the tapered roller 4, and the surface of the cage 5 of the tapered roller bearing, and the release agent or grease is applied. A film is formed. Next, in the space formed by the outer peripheral surface of the inner ring 2, the inner peripheral surface of the outer ring 3, the surface of the tapered roller 4, the surface of the cage 5 and the through-hole 7 on which a release agent or grease coating is formed. Further, the molten polymer 6 containing a lubricant is filled by injection molding.
[0020]
As the lubricant-containing polymer that can be filled in the tapered roller bearing 1 of the present embodiment, for example, a synthesis selected from the group of polyolefin resins having basically the same chemical structure, such as polyethylene, polypropylene, polybutylene, polymethylpentene, and the like. As a lubricant, any one of paraffinic hydrocarbon oil such as poly α-olefin oil, naphthenic hydrocarbon oil, mineral oil, ether oil such as dialkyldiphenyl ether oil, ester oil such as phthalate, etc. Alternatively, the raw material mixed and adjusted in the form of mixed oil is plasticized by heating above the melting point of the resin, and then cooled to solid form, and in the lubricant in advance antioxidant, rust inhibitor, What added various additives, such as an antiwear agent, an antifoamer, and an extreme pressure agent, may be used.
[0021]
【The invention's effect】
As described above in detail, according to the present invention, there is provided a lubricant-containing polymer-filled tapered roller bearing in which a polymer layer is stably formed in the space between the outer ring and the cage.
Moreover, according to this invention, the lubricant containing polymer filling tapered roller bearing which can be applied also as a small diameter tapered roller bearing is provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view (part) showing a conventional tapered roller bearing filled with a lubricant-containing polymer.
FIG. 2 is a cross-sectional view (a part) showing the tapered roller bearing shown in FIG. 1 with an outer ring omitted.
FIG. 3 is a cross-sectional view (a part) showing an embodiment of the tapered roller bearing of the present invention with the outer ring omitted.
4 is a view in the direction of arrow A of the conventional tapered roller bearing shown in FIG. 2. FIG.
FIG. 5 is a view in the direction of the arrow A of the tapered roller bearing according to the present invention shown in FIG. 3;
FIG. 6 is a view corresponding to FIG. 5 for explaining a through hole 7 of a tapered roller bearing according to another embodiment of the present invention.
7 is a view (cross section) in the B direction of the conventional tapered roller bearing shown in FIG. 2. FIG.
FIG. 8 is a view (cross section) in the B direction of the tapered roller bearing according to the present invention shown in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,1 '... Lubricant containing polymer filled tapered roller bearing, 2 ... Inner ring, 3 ... Outer ring, 4 ... Tapered roller (rolling element), 5, 5' ... Cage, 6 ... Lubricant containing polymer, 7 ... Through-hole

Claims (1)

An inner ring and an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, a retainer having a plurality of pillars and holding the rolling elements between two adjacent pillars; A lubricant-containing polymer-filled tapered roller bearing comprising: a lubricant-containing polymer filled in a space formed by the inner ring, outer ring, rolling element, and cage and covering the cage;
A lubricant-containing polymer-filled tapered roller bearing, wherein a through-hole is provided in a column portion of the retainer so as to penetrate the space on the inner ring side and the space on the outer ring side with respect to the column portion.

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