The present invention relates to a retainer for use in a large roller bearing, particularly in a tapered roller bearing which is utilized to support a main shaft in a wind power-generator, and also for use in a large tapered roller bearing which has an outer diameter in excess of one meter for example, used in industrial equipment.
A tapered roller bearing may include a retainer, a cage usually made from a steel plate. The retainer integrates an inner ring and rolling elements with each other. In an ultra-large tapered roller bearing which is often used as a main bearing in the field of wind power-generation, it is difficult to make a single-piece retainer from a steel plate.
As an alternative, therefore, there is proposed a welded retainer which includes support rods inserted through hollow rollers, and two side plates welded to the support rods. Another alternative is a segmented (divided) retainer which requires special fabrication method using dedicated jigs.
The first alternative has a problem of welding cost while the second alternative has a problem of handling difficulty. The second alternative, which was found to have some cost advantage, was improved further. As found in Patent Literature 1 and Patent Literature 2, in retainers used in large tapered roller bearings, an immobilizing member is arranged with a segmented retainer or a separated retainer on a circumference to prevent separation during assembly, for improved handling and assemblability. Also, Patent Literature 3 discloses an arrangement that a segmented retainer is immobilized by a ring member in order to prevent the segmented retainer from breaking apart during assembly.
Patent Literature 1: JP-A 2009-63102 Gazette
Patent Literature 2: JP-A 2007-064437 Gazette
Patent Literature 3: JP-A 2011-149549 Gazette
A problem, however, with the segmented retainer according to Patent Literature 1 and the separator retainer according to Patent Literature 2 is the ring members which are used to prevent separation. For ultra-large sizes, machining on the ring members requires a substantial cost and also is difficult. Another problem is that since the ring member is fixed to an inner ring, dimension control in fitting areas is difficult, and assembling of the ring members is also difficult.
The alternative disclosed in Patent Literature 3 raises a similar problem that it is difficult to make the ring member for ultra-large sizes.
It is therefore an object of the present invention to prevent separation of a segmented retainer at the time of assembly, without utilizing an ultra-large size ring member which is difficult to make.
As a solution to the problems described above, the present invention provides a roller bearing retainer constituted by two or a greater number of circumferentially disposed segments. Each segment includes: a plurality of columns between mutually opposing long sides of a rectangle; and a plurality of pockets for holding rollers between the columns. At least one of the mutually opposing long sides of the segment is fitted, in a circumferentially slidable fashion, into an arc-shaped connecting member which has a generally U-shaped section. The segments are arranged in the circumferential direction, and then the connecting member of each segment is slid over the long side of the adjacent segment for mutual connection of the segments.
By placing the segments on the outer circumference of the inner ring first, and then sliding the arc-shaped connecting member over the long side of the adjacent segment, the roller bearing retainer according to the present invention can be assembled to an outer circumference of an inner ring without breaking apart.
The arc-shaped connecting member may have a circumferential length equal to a length of the long side of the segment if not longer than that, or the long side of the segment may be divided into a plurality of portions. The arc-shaped connecting member which has the same circumferential length as the long side of the segment gives advantages of decreased number of parts and ease of handling.
Also, the segments which are assembled onto the outer circumference of the inner ring can be easily removed by sliding back so as not to ride on the adjacent segment. This makes it easy to perform inspections.
According to the present invention it is possible to prevent separation of segments during assembly, without utilizing an ultra-large size ring member which is difficult to manufacture.
Also, since segments of an identical design are arranged into an annular shape, only one jig and only one metal mold are enough when responding to demand.
Hereinafter, embodiments of the present invention will be described based on the attached drawings.
On an average, the tapered rollers 15 used in a large tapered roller bearing for supporting, e.g., a main shaft in wind power-generation equipment, has a diameter not smaller than 40 mm, and the bearing has an outer diameter not smaller than 1 m.
The inner ring 11 has a small flange region 17 formed on a small-diameter side of the inner ring track 13, and a large flange region 18 formed on a large-diameter side thereof. These flange regions 17, 18 guide rotating movement of the tapered rollers 15. On an axially outer side of the small flange region 17 and of the large flange region 18, a small-diameter region 19 and a large-diameter region 20 are formed respectively.
As shown in
As shown in
Of the six columns 31, four columns 31 at intermediate locations, excluding the two at the ends, have their top ends formed with a Y-shaped arc portion 31a (see
The small-diameter side 33a and the large-diameter side 33b of the segments 21 are respectively formed with a small-diameter-side engager 34a and a large-diameter-side engager 34b each protruding axially outward of the segments 21 and having a tip edge curved in parallel with the axis. As shown in
As shown in
As shown in
In addition, at a circumferentially intermediate position in the re-entrant groove 37 in both surfaces in each of the small-diameter-side engager 34a and the large-diameter-side engager 34b, there is formed an engagement recess 38 as shown in Circle A in
The small-diameter-side connecting member 35a and the large-diameter-side connecting member 35b of the segments 21 can be formed by machining or pressing a copper or a ferrous metal (e.g., SPCC and SUS) . Once the engagement projection 39 is fitted into the engagement recess 38, both ends of the small-diameter-side connecting member 35a and of the large-diameter-side connecting member 35b in the segments 21 are radially swaged to fix the small-diameter-side connecting member 35a and the large-diameter-side connecting member 35b to their predetermined circumferential positions and to prevent the small-diameter-side connecting member 35a and the large-diameter-side connecting member 35b from sliding.
The segments 21 can be formed of a resin material such as PEEK, PPS, PA (66 or 46).
Forming the engagement projection 39 at both ends of the salient 36 in each of the small-diameter-side connecting member 35a and the large-diameter-side connecting member 35b increases fitting with the re-entrant groove 37 which is formed in the small-diameter side engager 34a and the large-diameter-side engager 34b of the segments 21. By setting the gap between the mutually opposed engagement projections 39 in each of the small-diameter-side connecting member 35a and the large-diameter-side connecting member 35b wider than a thickness between two bottom surfaces of the re-entrant grooves 37 which are formed in the upper and the lower surfaces of the small-diameter-side engager 34a and the larger-diameter-side engager 34b of the segments 21, the small-diameter-side connecting member 35a and the large-diameter-side connecting member 35b can slide more smoothly.
The segments 21 in the embodiment described thus far are first placed in an annular pattern as shown in
The segments 21 which are assembled onto the outer circumference of the inner ring 11 can be easily removed: As shown in
In the embodiment described so far, the small-diameter side 33a and the large-diameter side 33b of the segments 21 are respectively formed with an arc-shaped small-diameter-side engager 34a and an arc-shaped large-diameter-side engager 34b, and the small-diameter-side engager 34a and the large-diameter-side engager 34b are respectively fitted into a small-diameter-side connecting member 35a and a large-diameter-side connecting member 35b which have a generally U-shaped section, in a circumferentially slidable fashion. However, there may be an arrangement that only one of the arc-shaped small-diameter-side engager 34a and an arc-shaped large-diameter-side engager 34b is formed correspondingly to the small-diameter-side connecting member 35a or the large-diameter-side connecting member 35b, without forming the other.
In the Embodiment described above, the small-diameter-side connecting member 35a and the large-diameter-side connecting member 35b, each having a generally U-shaped section, have the same circumferential lengths as the circumferential lengths of the small-diameter side 33a and the large-diameter side 33b of the segments 21. However, as shown in
Although the embodiments described thus far cover applications to tapered roller bearings, the invention is applicable also to retainers for cylindrical roller bearings.
Number | Date | Country | Kind |
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2013-046615 | Mar 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2014/055561 | 3/5/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2014/136816 | 9/12/2014 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20090208161 | Jauernig | Aug 2009 | A1 |
20120263408 | Yamada et al. | Oct 2012 | A1 |
Number | Date | Country |
---|---|---|
2602265 | Jul 1976 | DE |
102008011112 | Aug 2009 | DE |
102012206023 | Oct 2013 | DE |
825689 | Dec 1959 | GB |
50-84733 | Jul 1975 | JP |
2007-64437 | Mar 2007 | JP |
2009-63102 | Mar 2009 | JP |
2011-117545 | Jun 2011 | JP |
2011-149549 | Aug 2011 | JP |
2011-208700 | Oct 2011 | JP |
2012-132535 | Jul 2012 | JP |
Entry |
---|
International Search Report issued Jun. 3, 2014 in corresponding International Application No. PCT/JP2014/055561 (with English translation). |
International Preliminary Report on Patentability issued Sep. 8, 2015 in International Application No. PCT/JP2014/055561 (with English Translation). |
Number | Date | Country | |
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20160010690 A1 | Jan 2016 | US |