JP2008019922A - Planetary gear supporting structure for construction machine planetary gear reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planetary gear supporting structure for a construction machine planetary gear reduction gear, with a compact automatic aligning roller bearing having a high load capacity. <P>SOLUTION: The construction machine planetary gear reduction gear 11 has an input shaft 12, an output shaft 14, and first and second planetary gear mechanisms 15, 16. The first and second planetary gear mechanisms 15, 16 are constructed by internal gears 15b, 16b, a plurality of planetary gears 15c, 16c, and planetary carriers 15d, 16d, respectively. The automatic aligning roller bearing 21 for supporting the planetary gears 15c, 16c has an inner ring, an outer ring, a plurality of spherical rollers arranged in double rows, and a cage for holding spaces between adjacent spherical rollers. The cage has a pair of ring portions, a columnar portion, and a spherical roller anti-come-off portion. The anti-come-off portion is located on the upper side of the pitch circles of the spherical rollers for restricting the movement of the longitudinal ends of the spherical rollers to the radial outside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a planetary gear support structure for a planetary gear reducer used in construction machines such as large dump trucks, wheel loaders, hydraulic excavators, and bulldozers.

  Conventionally, a traveling speed reducer, a transmission, or a final speed reducer of a construction machine represented by a large dump truck, a wheel loader, a hydraulic excavator, a bulldozer, or the like is described in, for example, Japanese Patent Application Laid-Open No. 2001-59525 (Patent Document 1). A planetary gear reducer 101 as described above is employed.

  Referring to FIG. 12, a planetary gear reducer 101 described in the publication includes an input shaft 102, an output shaft 103, a sun gear 104 fixed to the input shaft 102, and an internal gear fixed to a housing. (Not shown), a plurality of planetary gears 105 meshing with both the sun gear 104 and the internal gear, and a planet carrier 106 fixed to the output shaft 103 and supporting the planetary gear 105 via a bearing (not shown). Prepare. The planetary gear speed reducer 101 having the above-described configuration can reduce the size of the speed reducer because the input shaft 102 and the output shaft 103 can be coaxially arranged, and has features such as high torque and high efficiency.

  In the planetary gear speed reducer 101 configured as described above, a needle roller bearing is used as a bearing (not shown) for supporting the planetary gear 105 in order to reduce the thickness dimension. However, when used under a large and heavy load at a low speed, a self-aligning roller bearing having a high load capacity may be used.

  Referring to FIG. 13, a self-aligning roller bearing 111 that supports the planetary gear 105 includes an inner ring 112, an outer ring 113, a plurality of spherical rollers 114 arranged in a double row between the inner ring 112 and the outer ring 113, And a cage 115 that holds the spacing between the plurality of spherical rollers 114.

  Referring to FIG. 14, retainer 115 has a ring portion and a column portion 115a protruding from the end surface of the ring portion, and has a pocket 115b for accommodating spherical roller 114 between adjacent column portions 115a. The column portion 115a extends in the radial direction across the pitch circle of the spherical roller 114, and has a function of preventing the spherical roller 114 from coming off in the radial direction and keeping the interval between the adjacent spherical rollers 114 constant.

Since the self-aligning roller bearing 111 having the above configuration has a higher rated load than other bearings and has alignment with respect to shaft deflection caused by the meshing of gears, it is a planetary gear for construction machinery. It is suitable as a bearing for supporting the planetary gear of the reduction gear.
JP 2001-59525 A

  In recent years, there is an increasing demand for higher output and more compact construction machines. When the drive device connected to the planetary gear reducer 101 has a high output, the load applied to the bearing that supports the planetary gear 105 increases. Thereby, in the conventional self-aligning roller bearing 111, a decrease in bearing life due to insufficient load capacity becomes a problem. This problem is not limited to the case where the drive device connected to the planetary gear speed reducer 101 has a high output, but can also occur when the self-aligning roller bearing 111 having the same load condition as that of the prior art is to be made compact.

  The simplest method for handling high loads is to enlarge the spherical roller bearing 111, but it is appropriate to enlarge the spherical roller bearing 111 from the viewpoint of downsizing the planetary gear reducer 101. is not.

  Therefore, it is desired to improve the rated load while maintaining the bearing size of the self-aligning roller bearing 111. As a method for improving the rated load of the self-aligning roller bearing 111, it is conceivable to increase the number of the spherical rollers 114 arranged between the inner ring 112 and the outer ring 113 or to increase the roller diameter.

  However, for example, when increasing the number of rollers, the pillar portions 115a of the retainer 115 are arranged on the left and right of the spherical roller of the self-aligning roller bearing 111, and the pillar portion 115a has a pillar portion 115a from the viewpoint of securing the strength of the pillar portion 115a. The thickness needs to be a certain value or more. As a result, it has been difficult to increase the number of spherical rollers 114 that can be accommodated by reducing the interval between adjacent spherical rollers 114.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a planetary gear support structure for a planetary gear reducer for a construction machine having a compact and high load capacity self-aligning roller bearing.

  A planetary gear support structure for a planetary gear reducer for a construction machine according to the present invention includes a sun gear fixed to an input shaft, an internal gear fixed to a housing, and a plurality of gears disposed between the sun gear and the internal gear. A planetary gear and a planet carrier connected to a plurality of planetary gears via bearings. A bearing that supports the planetary gear includes an inner ring, an outer ring, a plurality of spherical rollers disposed between the inner ring and the outer ring, a pair of ring portions, a column portion positioned between the pair of ring portions, and a spherical roller. It is a self-aligning roller bearing provided with a resin cage having a retaining portion for preventing falling off. The central region of the column portion that faces the central portion in the length direction of the spherical roller is located below the pitch circle of the spherical roller, and the retaining portion is located above the pitch circle of the spherical roller. The spherical roller is brought into contact with the rolling surface to restrict the movement of the spherical roller in the radial direction. Further, the retaining portion is provided in an end region of the column portion facing the longitudinal end portion of the spherical roller.

  Since the spacing between adjacent spherical rollers is the smallest on the pitch circle, the spacing between adjacent spherical rollers can be reduced by placing the column portion in a region outside the pitch circle at the central portion in the length direction where the roller diameter is maximum. Can be small. As a result, more spherical rollers can be accommodated, and the rated load of the self-aligning roller bearing is improved. Then, by adopting such a self-aligning roller bearing as a bearing that supports the planetary gear of the planetary gear reducer, a planetary gear support structure for a planetary gear reducer for a construction machine that is compact and excellent in load resistance is obtained. be able to.

  Preferably, at least one of the pair of ring portions has an outer diameter surface located outside the roller center of the plurality of spherical rollers. Since the inclination of the spherical roller at the time of assembling the bearing can be effectively suppressed, the handling of the bearing becomes easy.

  A planetary gear support structure for a planetary gear reducer for a construction machine according to another aspect of the present invention includes a sun gear fixed to an input shaft, an internal gear fixed to a housing, and the sun gear and the internal gear. A plurality of planetary gears, and a planet carrier coupled to the plurality of planetary gears via bearings. A bearing that supports a planetary gear is a self-aligning roller bearing that includes an inner ring, an outer ring, a plurality of spherical rollers disposed between the inner ring and the outer ring, and a cage that holds a space between the plurality of spherical rollers. . The retainer includes a ring portion that faces the end surfaces of the plurality of spherical rollers, and a protrusion that is positioned between the adjacent spherical rollers and protrudes in the axial direction from the inner surface of the ring portion. When the protruding length is A and the axial length from the inner surface of the ring portion to the maximum diameter portion of the spherical roller is B, the relationship of A <B is established.

  In the cage configured as described above, since the tip of the protruding portion does not reach the position facing the maximum diameter portion where the distance between adjacent spherical rollers is minimum, the distance between adjacent spherical rollers can be reduced. As a result, a larger number of spherical rollers can be accommodated, so that a self-aligning roller bearing having an improved rated load while maintaining the bearing size can be obtained. Then, by adopting such a self-aligning roller bearing as a bearing that supports the planetary gear of the planetary gear reducer, a planetary gear support structure for a planetary gear reducer for construction machinery that is compact and excellent in load resistance is obtained. be able to. In the present specification, the “inner surface of the ring portion” refers to an end surface of the ring portion that faces the spherical roller.

  Preferably, a cage | basket has a recessed part which receives the one side edge part of a spherical roller between adjacent protrusion parts. The cage having the above-described configuration has a function of preventing the spherical rollers from falling off, in addition to a function of maintaining a constant interval between the spherical rollers adjacent to each other by the plurality of concave portions provided on the end surface of the ring portion. Thereby, while maintaining smooth rotation of a spherical roller, drop-off of a spherical roller can be prevented.

  More preferably, the cage is disposed at both ends of the spherical roller. Thus, by arranging the cages at both ends of the spherical roller, it is possible to more effectively maintain the smooth rotation of the spherical roller.

  Preferably, the retainer has an engaging portion that engages with the inside of the small collar portion of the inner ring. Thereby, it is possible to prevent the retainer from dropping off during the rotation of the bearing, particularly when the retainer is disposed independently at both ends of the spherical roller.

  According to the present invention, by increasing the number of spherical rollers that can be accommodated, the rated load of the self-aligning roller bearing can be improved while maintaining the bearing size. By adopting such a self-aligning roller bearing as a bearing that supports the output shaft of the turning mechanism, it is possible to obtain a planetary gear support structure for a planetary gear reducer for construction machinery that is compact and has excellent load resistance. it can.

  With reference to FIGS. 1-6, the planetary gear support structure of the planetary gear reducer for construction machines which concerns on one Embodiment of this invention is demonstrated. FIG. 1 is a view showing a planetary gear reducer for construction machinery according to an embodiment of the present invention, and FIG. 2 is a self-aligning that supports the planetary gear of the planetary gear reducer for construction machinery shown in FIG. The figure which shows a roller bearing, FIGS. 3-6 is a figure which shows the holder | retainer used for the self-aligning roller bearing shown in FIG.

  Referring to FIG. 1, a planetary gear speed reducer 11 includes an input shaft 12, an intermediate shaft 13, an output shaft 14, and two first and second planets arranged between the input shaft 12 and the output shaft 14. The gear mechanisms 15 and 16 are provided and accommodated in the housing 10. The first and second planetary gear mechanisms 15 and 16 include sun gears 15a and 16a, internal gears 15b and 16b, a plurality of planetary gears 15c and 16c, and planet carriers 15d and 16d, respectively. The housing 10 is connected to a tire wheel, a roller (not shown), and the like, and functions as the output shaft 14 of the planetary gear reducer 11.

  Specifically, the first planetary gear mechanism 15 is disposed between the sun gear 15a fixed to the outer peripheral surface of the input shaft 12, the internal gear 15b fixed to the housing 10, and the sun gear 15a and the internal gear 15b. The plurality of planetary gears 15c meshing with each other and a planet carrier 15d having one end connected to the intermediate shaft 13 and the other end connected to the planetary gear 15c via the bearing 21.

  Similarly, the second planetary gear mechanism 16 is disposed between the sun gear 16a fixed to the outer peripheral surface of the hollow intermediate shaft 13, the internal gear 16b fixed to the housing 10, and the sun gear 16a and the internal gear 16b. The plurality of planetary gears 16c meshing with each other and a planet carrier 16d having one end fixed and the other end connected to the planetary gear 16c via the bearing 21.

  The intermediate shaft 13 connects the first and second planetary gear mechanisms 15 and 16 to each other. The intermediate shaft 13 functions as an output shaft when the first planetary gear mechanism 15 is at the center, and the second planetary gear mechanism 16 is at the center. Functions as an input axis. The housing 10 also functions as an output shaft of the second planetary gear mechanism 16. Further, in this embodiment, two double-row self-aligning roller bearings are arranged as the bearings 21 that rotatably support the planetary gears 15c and 16c with respect to the planet carriers 15d and 16d.

  The planetary gear reducer 11 reduces the rotation of the input shaft 12 at a predetermined reduction ratio by the first and second planetary gear mechanisms 15 and 16 and transmits it to the output shaft 14. Specifically, the sun gear 15 a of the first planetary gear mechanism 15 rotates as the input shaft 12 rotates. At this time, the planetary gear 15c rotates between the sun gear 15a and the internal gear 15b in the direction opposite to the rotation of the sun gear 15a, and revolves in the same direction as the rotation of the sun gear 15a. The planet carrier 15d transmits the revolution movement of the planetary gear 15c to the intermediate shaft 13 as an output shaft.

  Next, the sun gear 16a of the second planetary gear mechanism 16 rotates as the intermediate shaft 13 serving as the input shaft rotates. At this time, since the planet carrier 16d is fixed, the planetary gear 16c does not revolve and rotates in the direction opposite to the sun gear 16a. The internal gear 16b that meshes with the planetary gear 16c rotates in the same direction as the planetary gear 16c together with the housing 10 as the output shaft 14. Thereby, the rotation of the input shaft 12 is decelerated and transmitted to a tire wheel or a roller connected to the housing 10 as the output shaft 14.

  Next, referring to FIG. 2, a bearing 21 that supports the planetary gears 15 c and 16 c includes an inner ring 22, an outer ring 23, and a plurality of spherical rollers 24 arranged in a double row between the inner ring 22 and the outer ring 23. A self-aligning roller bearing provided with a retainer 25 that holds the interval between adjacent spherical rollers 24. A double row raceway surface is formed on the outer diameter surface of the inner ring 22, and a spherical raceway surface having a center of curvature as the center of curvature is formed on the inner diameter surface of the outer ring 23.

  Referring to FIG. 3, cage 25 includes a pair of ring portions 25a and 25b, a column portion 25c positioned between the pair of ring portions 25a and 25b, and an end region on the ring portion 25a side of column portion 25c. And a retainer portion 25d that restricts the movement of the end of the spherical roller 24 in the lengthwise direction to the outside in the radial direction, and is a resin cage manufactured by injection molding. By using a resin material having a high elastic deformability as the material of the cage 25, the assemblability is improved and the breakage of the cage 25 can be suppressed. Further, by manufacturing by injection molding, even a complicated shape can be manufactured relatively easily.

Next, FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. Referring to FIG. 4, the column portion 25 c in the vicinity of the ring portion 25 a extends in the radial direction across the pitch circle of the spherical roller 24, and the wall surface facing the spherical roller 24 follows the rolling surface of the spherical roller 24. Curved shape. The opening width w ₁ of the opening end above the pitch circle of the spherical roller 24 is set smaller than the roller diameter w _{2 of} the spherical roller 24 and restricts the movement of the spherical roller 24 outward in the radial direction.

  Next, FIG. 5 is a cross-sectional view taken along line V-V in FIG. Referring to FIG. 5, the column portion 25 c located at the center in the longitudinal direction of the pocket is located below the pitch circle of the spherical roller 24, and the end surface facing the spherical roller 24 is the rolling surface of the spherical roller 24. It is a curved shape along.

  Next, FIG. 6 is a sectional view taken along line VI-VI in FIG. Referring to FIG. 6, the outer diameter surface of ring portion 25 a is located outside the roller center of spherical roller 24, and the outer diameter surface of ring portion 25 b is located inside the roller center of spherical roller 24. positioned.

  In the self-aligning roller bearing 21 configured as described above, the interval between adjacent spherical rollers 24 is minimized on the pitch circle. Therefore, the interval between the adjacent spherical rollers 24 can be reduced by disposing the column portion 25c in a region outside the pitch circle. As a result, a larger number of spherical rollers 24 can be accommodated, so that the self-aligning roller bearing 21 having an improved rated load can be obtained while maintaining the bearing size.

  Further, the cage 25 having the above configuration does not have a means for restricting the radial movement of the spherical roller 24 on the ring portion 25b side, so that the outer diameter surfaces of the spherical roller 24 and the ring portion 25a at the time of assembling the bearings. There is a possibility that the spherical roller 24 tilts with the contact portion as a base point. Therefore, as shown in FIG. 6, by disposing the outer diameter surface of the ring portion 25b near the center of the roller of the spherical roller 24, the inclination of the spherical roller at the time of assembling the bearing can be effectively suppressed, so that the roller drop is suppressed. be able to.

  In the above-described embodiment, the example in which the retaining portion 25d is provided only on the ring portion 25a side is shown. However, the present invention is not limited to this, and the retaining portion may also be provided on the ring portion 25b side.

  In addition, although the example in which the retaining portion 25d is a part of the column portion 25c has been shown, the present invention is not limited to this, and the position of the ring portions 25a and 25b facing the end surface of the spherical roller 24 is not limited to this. It may be a convex portion protruding from the wall surface and abutting against the rolling surface of the spherical roller 24 to restrict the radial movement of the spherical roller 24.

  Next, another embodiment of the self-aligning roller bearing for supporting the planetary gear of the construction machine planetary gear reducer 11 shown in FIG. 1 will be described with reference to FIGS. 7 is a self-aligning roller bearing according to another embodiment of the present invention, and FIGS. 8 to 11 are views showing a cage used in the self-aligning roller bearing shown in FIG. .

  Referring to FIG. 7, the self-aligning roller bearing 31 includes an inner ring 32 having small flange portions 32 a at both ends, an outer ring 33, and a plurality of spherical rollers 34 arranged in a double row between the inner ring 32 and the outer ring 33. And cages 35 and 36 for holding the spacing between the plurality of spherical rollers 34. Since the cages 35 and 36 rotate independently of each other, the cage 36 disposed at both ends of the self-aligning roller bearing 31 has a small flange portion 32a of the inner ring 32 to prevent the cage from falling off. An engaging portion 36a that engages inside is provided.

  Referring to FIGS. 8 and 9, the retainer 35 is located between the ring portion 35a facing the end surfaces of the plurality of spherical rollers 34 and the adjacent spherical roller 34, and axially extends from the inner surface of the ring portion 35a. And a recess 35b for receiving one end of the spherical roller 34 between the adjacent protrusions 35c. When the protruding length of the protruding portion 35c is A and the axial length from the inner surface of the ring portion 35a to the maximum diameter portion of the spherical roller 34 is B, the relationship of A <B is established. Is set to The cage 35 is a squeezed cage that forms a recess 35b by cutting on the end surface of a cylindrical material made of a copper alloy or the like. The retainer 36 has a similar structure.

  Further, referring to FIG. 10, the protruding portion 35 b of the cage 35 extends in the radial direction across the pitch circle of the spherical roller 34, and the wall surface facing the rolling surface of the spherical roller 34 is the spherical roller 34. The curved surface shape along the rolling surface. The protrusion 35b abuts on the rolling surface of the spherical roller 34 to guide its rotation, and prevents the spherical roller 34 from coming out radially outward. The same applies to the cage 36 shown in FIG.

  Since the self-aligning roller bearing 31 having the above-described configuration includes a pair of cages 35 and 36, and the tips of the protruding portions of the cages 35 and 36 do not reach a position where the maximum diameter portion of the spherical roller 34 faces. The interval between the adjacent spherical rollers 34 can be reduced. As a result, a larger number of spherical rollers 34 can be accommodated, so that a self-aligning roller bearing 31 with an improved rated load can be obtained while maintaining the bearing size.

  Although the example of the squeezing retainer has been shown as the retainer shown in FIGS. 8 to 11, the present invention is not limited to this and can be applied to a resin retainer by injection molding.

The self-aligning roller bearings 21 and 31 according to the above embodiments are supported on the planetary gears 15c and 16c of the planetary gear reducer 11 that is employed in construction machines represented by large dump trucks, wheel loaders, hydraulic excavators, bulldozers, and the like. By using it as a bearing, the durability of the reducer can be improved, and a reduction in maintenance costs can be expected. In addition, since the bearing size can be reduced if the load applied to the bearing is approximately the same as the conventional load, the planetary gear speed reducer 11 can be made compact. Furthermore, it is possible to obtain a construction machine capable of reducing friction and heat generation during rotation of the bearing and reducing CO ₂ emission to the atmosphere.

  In the planetary gear speed reducer 11 shown in FIG. 1, an example in which two double row spherical roller bearings 21 are arranged to support the planetary gears 15 c and 16 c is shown. And three or more may be arranged. Furthermore, the self-aligning roller bearings 21 and 31 according to the embodiment of the present invention may be combined with other bearings such as a tapered roller bearing.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention is advantageously used for a planetary gear support structure of a planetary gear reducer for construction machinery.

It is a figure which shows the planetary gear support structure of the planetary gear reducer for construction machines which concerns on one Embodiment of this invention. It is a figure which shows an example of the self-aligning roller bearing which supports the planetary gear shown in FIG. It is the figure which looked at the retainer used for the self-aligning roller bearing shown in FIG. 2 from radial direction. It is sectional drawing in IV-IV of the holder | retainer shown in FIG. It is sectional drawing in VV of the holder | retainer shown in FIG. It is sectional drawing in VI-VI of the holder | retainer shown in FIG. It is a figure which shows the other example of the self-aligning roller bearing which supports the planetary gear shown in FIG. It is the figure which looked at the retainer used for the self-aligning roller bearing shown in FIG. 7 from the axial direction. It is the figure which looked at the retainer used for the self-aligning roller bearing shown in FIG. 7 from radial direction. It is sectional drawing in XX of FIG. It is sectional drawing in XI-XI of FIG. It is a figure which shows the planetary gear support structure of the conventional planetary gear reducer for construction machines. It is a figure which shows the conventional self-aligning roller bearing which supports the planetary gear shown in FIG. It is sectional drawing in XIV-XIV of the self-aligning roller bearing shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Housing, 11, 101 Planetary gear reducer for construction machines, 12, 102 Input shaft, 13, 103 Intermediate shaft, 14 Output shaft, 15, 16 Planetary gear mechanism, 15a, 16a, 104 Sun gear, 15b, 16b Internal gear , 15c, 16c, 105 planetary gear, 15d, 16d, 106 planet carrier, 21, 31, 111 spherical roller bearing, 22, 32, 112 inner ring, 32a small collar part, 23, 33, 113 outer ring, 24, 34 , 114 Spherical roller, 25, 35, 36, 115 Cage, 25a, 25b, 35a Ring part, 25c, 115a Pillar part, 25d Retaining part, 35b Recessed part, 35c Protruding part, 36a Interlocking part, 115b Pocket.

Claims (7)

A sun gear fixed to the input shaft;
An internal gear fixed to the housing;
A plurality of planetary gears disposed between the sun gear and the internal gear;
A planetary gear support structure for a planetary gear speed reducer for a construction machine, comprising a planetary carrier coupled to the plurality of planetary gears via a bearing,
The bearing that supports the planetary gear includes an inner ring, an outer ring, a plurality of spherical rollers disposed between the inner ring and the outer ring, a pair of ring portions, and a column portion positioned between the pair of ring portions, And a resin cage having a retaining portion that prevents the spherical roller from falling off, and the central region of the column portion that faces the central portion in the longitudinal direction of the spherical roller is below the pitch circle of the spherical roller. The self-aligning roller that is located on the side of the spherical roller and that is positioned above the pitch circle of the spherical roller and abuts against the rolling surface of the spherical roller to regulate the radial movement of the spherical roller. A planetary gear support structure for a planetary gear reducer for construction machinery, which is a bearing.   The planetary gear support structure for a planetary gear reducer for a construction machine according to claim 1, wherein the retaining portion is provided in an end region of the column portion facing a longitudinal end portion of the spherical roller.   The planetary gear support of the planetary gear reducer for a construction machine according to claim 1 or 2, wherein an outer diameter surface of at least one of the pair of ring portions is located outside a roller center of the plurality of spherical rollers. Construction. A sun gear fixed to the input shaft;
An internal gear fixed to the housing;
A plurality of planetary gears disposed between the sun gear and the internal gear;
A planetary gear support structure for a planetary gear speed reducer for a construction machine, comprising a planetary carrier coupled to the plurality of planetary gears via a bearing,
The bearing that supports the planetary gear includes an inner ring, an outer ring, a plurality of spherical rollers arranged between the inner ring and the outer ring, and a cage that holds a space between the plurality of spherical rollers, and the holding The vessel has a ring portion facing the end faces of the plurality of spherical rollers, and a protrusion portion that is located between the adjacent spherical rollers and protrudes in an axial direction from the inner surface of the ring portion. A self-aligning roller bearing in which the relationship of A <B is established, where A is the protruding length and B is the axial length from the inner surface of the ring portion to the maximum diameter portion of the spherical roller. Planetary gear support structure for planetary gear reducers for construction machinery.   The planetary gear support structure for a planetary gear reducer for a construction machine according to claim 4, wherein the retainer has a concave portion that receives one end portion of the spherical roller between the adjacent projecting portions.   The planetary gear support structure for a planetary gear reducer for a construction machine according to claim 4 or 5, wherein the cage is disposed at both ends of the spherical roller.   The planetary gear support structure for a planetary gear reducer for a construction machine according to any one of claims 4 to 6, wherein the retainer has an engaging portion that engages with an inside of a small flange portion of the inner ring.

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