JP2010139044A - Bearing fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent rotation of a nut member without requiring additional tightening of the nut member after the drag torque reaches a prescribed value and tightening of the nut member is stopped. <P>SOLUTION: The bearing fixing device for fixing bearings 19 and 20 for supporting an turning output shaft 10 to a housing 15 includes the nut member 21 having a screw hole 21C and pressing the bearings 19 and 20 to the housing 15, a lock plate 41 having a spline part 41A fitted with a spline part 10C formed on the turning output shaft 10 and a bolt hole and fixed by the nut member 21, and a bolt 27 inserted into the bolt hole of the lock plate 41 and screwed into the screw hole 21C of the nut member 21 so as to fix the lock plate 41 to the nut member 21. The bolt hole of the lock plate 41 includes two oblong holes 41B extended along the circumferential direction of a circle drawn while having an axis of the turning output shaft 10 as a center. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bearing fixing device that is included in a turning device provided in a construction machine such as a hydraulic excavator or a crane, and fixes a bearing that supports a rotating shaft to a housing in which the bearing is accommodated.

  FIG. 3 is a side view showing a hydraulic excavator exemplified as an example of a construction machine including a turning device including a bearing fixing device.

  The hydraulic excavator shown in FIG. 3 includes a traveling body 2, a revolving body 4 disposed on the traveling body 2 via a revolving wheel 3, and a front work provided on the revolving body 4 so as to be rotatable in the vertical direction. Machine 5. The front work machine 5 includes a boom 5a attached to the revolving structure 4, an arm 5b attached to the tip of the boom 5a, and a bucket 5c attached to the tip of the arm 5b. In addition, a turning device 6 that is interposed between the traveling body 2 and the turning body 4 and turns the turning body 4 is provided. For example, the swivel device 6 includes the bearing fixing device targeted by the present invention.

  FIG. 4 is a front view, partly in section, showing a swivel device including a conventional bearing fixing device, and FIG. 5 is an AA cross-sectional enlarged view of FIG.

  As shown in FIG. 4, the turning device 6 decelerates the rotation of the turning motor 7 and the motor output shaft 8 of the turning motor 7, increases the torque, and transmits it to the rotating shaft, ie, the turning output shaft 10. And a housing 15 in which the turning output shaft 10 is accommodated. The turning motor 7 and the upper surface of the ring gear 11 of the planetary reduction mechanism 9 are fixed by bolts. The flange portion 15 </ b> A of the housing 15 is fixed to the revolving body 4 with bolts.

  The planetary reduction mechanism 9 is configured in two stages, and the rotational force of the turning motor 7 is transmitted to the first stage sun gear 12 by the motor output shaft 8, and the planetary gear 13 rotates between the ring gear 11 and the sun gear 12. While making a revolution. The revolution of the planetary gear 13 is transmitted to the second-stage sun gear 16 through the carrier 14 that supports the planetary gear 13, and the planetary gear 17 revolves while rotating between the ring gear 11 and the sun gear 16. The revolution of the planetary gear 17 is transmitted to the turning output shaft 10 through the carrier 18 that supports the planetary gear 17.

  A gear portion 10A provided at the lower end of the turning output shaft 10 meshes with the inner ring 3A of the turning wheel 3 fixed to the traveling body 2, and the rotational force of the turning output shaft 10 is applied to the inner ring 3A of the turning wheel 3. Reportedly. The outer ring of the turning wheel 3 is fixed to the turning body 4. A grease chamber 25 is provided at a meshing portion between the gear portion 10 </ b> A of the turning output shaft 10 and the inner ring 3 </ b> A of the turning wheel 3 in which grease for lubricating the meshing portion is accommodated. The grease chamber 25 is provided in the traveling body 2.

  The turning output shaft 10 is rotatably supported by a bearing 19 and a bearing 20. The bearing 19 and the bearing 20 are fixed to the housing 15. These bearings 19 and 20 are tapered roller bearings.

  A nut member 21 for pressing the bearing 19 against the housing 15 is provided on the bearing 19 disposed on the upper side. Further, on the nut member 21, as shown in FIG. 5, a lock plate 26 which is a rotation preventing member of the nut member 21 with respect to the turning output shaft 10 is provided. Further, a bolt 27 for fixing the lock plate 26 to the nut member 21 is provided. A conventional bearing fixing device that fixes the bearings 19 and 20 to the housing 15 while applying a pressing force, that is, preload, to the bearings 19 and 20 by the nut member 21, the lock plate 26, and the bolts 27. It is configured.

  A screw portion 10B is formed on the outer periphery of the upper portion of the turning output shaft 10, and a screw portion 21A that is screwed into the screw portion 10B is formed on the inner periphery of the nut member 21. Therefore, the bearings 19 and 20 are preloaded by screwing the nut member 21 into the turning output shaft 10. The nut member 21 is provided with a screw hole 21C, and the lock plate 26 is provided with a spline portion 26A and a bolt hole 26B. The lock plate 26 is fixed to the nut member 21 by the bolt 27 in a state where the spline portion 10 </ b> C formed on the turning output shaft 10 and the spline portion 26 </ b> A of the lock plate 26 are engaged with each other. Thereby, the nut member 21 is fixed in a state in which the rotation with respect to the turning output shaft 10 is prevented.

The lubrication in the turning device 6 is gear oil lubrication, and the gear oil is sealed by the oil seal 22 at the lower part of the turning device 6 and the sliding member 24 fitted to the turning output shaft 10. The oil seal 22 is held by a cover 23, and the cover 23 is fixed to the housing 15. The oil seal 22 fulfills a sealing function by being in sliding contact with the outer periphery of the sliding member 24. A known technique of this type is disclosed in Patent Document 1.
JP-A-11-351267

  Conventionally, the preload management of the bearings 19 and 20 by the nut member 21 is performed such that the nut member 21 is screwed into the swing output shaft 10 while rotating the housing 15 relative to the swing output shaft 10 to apply the preload to the bearing. It is managed by the drag torque when When the specified drag torque is reached, tightening of the nut member 21 is stopped. Thus, at the position where the nut member 21 is stopped, the screw of the nut member 21 is caused by the meshing relationship between the spline portion 10C of the turning output shaft 10 and the spline portion 26A of the lock plate 26 and various manufacturing errors. The hole 21C and the bolt hole 26B of the lock plate 26 are hardly matched correctly. Therefore, before the bolt 27 is inserted, the nut member 21 is tightened to correctly align the screw hole 21 and the bolt hole 26B. At this time, the rotational angle of the retightening is a maximum of one pitch of the spline. The influence on the life of the bearings 19 and 20 due to such preload at the time of retightening cannot be ignored.

  For this reason, conventionally, the bearings 19 and 20 have a load capacity with a margin for the maximum preload predicted when retightening, that is, a relatively large shape having a load resistance, and strength. A strong bearing must be provided. For this reason, the housing 15 constituting the bearing fixing device is increased in size, and the manufacturing cost of the bearing fixing device is high.

  The present invention has been made from the actual situation in the above-described prior art. The purpose of the present invention is to stop the tightening of the nut member after reaching a specified drag torque, and then to tighten the nut member without requiring additional tightening of the nut member. An object of the present invention is to provide a bearing fixing device capable of realizing rotation prevention.

  In order to achieve this object, a bearing fixing device according to the present invention is a bearing fixing device that fixes a bearing that supports a rotating shaft to a housing, has a screw hole, and presses the bearing against the housing. A lock plate that has a member, a spline portion that engages with the spline portion formed on the rotating shaft, and a bolt hole, and is fixed to the nut member; and the nut member that is inserted into the bolt hole of the lock plate And a bolt for fixing the lock plate to the nut member. The bolt hole of the lock plate is in a state where the lock plate is splined to the rotary shaft. Thus, it is characterized by comprising a long hole extending along the circumferential direction of a circle drawn around the axis of the rotating shaft.

  In the present invention configured as described above, when the bearing preload management for fixing the bearing to the housing is performed, the nut member is screwed into the rotating shaft while the housing is rotated relative to the rotating shaft so as to apply the preload to the bearing. When the drag torque at this time reaches a specified value, the tightening by the nut member is stopped. After that, without tightening the nut member, a bolt is inserted from the elongated hole portion of the lock plate located on the screw hole of the nut member, and this bolt is screwed into the screw hole of the nut member. The lock plate is fixed to the nut member. As a result, the nut member can be prevented from rotating with respect to the rotating shaft. That is, after stopping the tightening of the nut member that has reached the specified drag torque, the bolt is inserted into the screw hole of the nut member from the long hole of the lock plate without requiring additional tightening of the nut member. A detent can be realized. As a result, the shape of the bearing can be reduced by an amount corresponding to the preload due to retightening, and the strength of the bearing can be reduced.

  The bearing fixing device according to the present invention is the bearing fixing device according to the present invention, wherein both ends of the elongated hole are formed in a semicircular portion, and the semicircular portions of the both ends of the elongated hole with respect to the axis of the rotating shaft are formed. The angle formed by the respective centers is set to an angle equal to the spline 1 pitch angle of the spline portion formed on the rotating shaft or the spline portion formed on the lock plate.

  According to the present invention configured as described above, when the tightening of the nut member is stopped upon reaching the specified drag torque, the maximum value of the rotational angle of the retightening that has been predicted empirically in the past, that is, the pitch of the spline 1 Since it forms in the long hole which accept | permits an angle | corner, a volt | bolt can be reliably screwed in the screw hole of a nut member. In addition, since the elongated hole is not longer than necessary, a sufficient strength of the lock plate can be ensured.

  In the bearing fixing device according to the present invention, in the above invention, the nut member includes an annular convex portion that abuts on a carrier included in the planetary speed reduction mechanism, and the convex plate accommodates the lock plate in the convex portion. Forming an angle between the both ends of the notch with respect to the axis of the rotary shaft, an angle between both ends of the portion located in the notch of the lock plate with respect to the axis of the rotary shaft, and the spline. It is characterized in that the angle is set larger than the sum of the angle equal to one pitch angle.

  In the present invention configured as described above, when the lock plate is fixed to the nut member with the bolt, even if the lock plate is rotated by one pitch of the spline with respect to the rotation shaft, the lock plate is notched in the protruding portion of the nut member. There is no interference with the forming end. Therefore, by appropriately rotating the lock plate by one pitch of the spline, the position of the long hole of the lock plate with respect to the screw hole of the nut member can be set to a desired position such that the screw hole comes to the center of the long hole, for example. .

  The bearing fixing device according to the present invention is provided in a swivel device having a swivel motor that swivels a swivel body in the above invention, and the rotating shaft transmits the rotational force of the swivel motor via the planetary reduction mechanism. And the bearing comprises a tapered roller bearing that supports the turning output shaft. The present invention configured as described above can be effectively used in a construction machine having a revolving structure.

  In the bearing fixing device according to the present invention, in the above invention, two of the elongated holes are provided along the circumferential direction of the same circle drawn around the axis of the rotating shaft, and the bolts are A total of two are provided corresponding to each of the long holes. In the present invention configured as described above, the lock plate can be firmly fixed to the nut member by the two bolts.

  According to the present invention, the bolt hole of the lock plate fixed to the nut member that presses the bearing against the housing is a circumferential direction of a circle drawn around the axis of the rotating shaft supported by the bearing by the spline connection of the lock plate. Since the bolt is inserted through this elongated hole, the specified drag torque is reached and the tightening of the nut member is stopped, and then the nut member is retightened. The nut member can be prevented from rotating without being required. By these, the shape of the bearing can be made smaller than the conventional one by the amount corresponding to the preload by retightening, and the strength of the bearing can be weakened. Accordingly, it is possible to reduce the size of the housing in which the bearing is held, and to reduce the manufacturing cost of the bearing fixing device as compared with the related art.

  Hereinafter, the best mode for carrying out a bearing fixing device according to the present invention will be described with reference to the drawings.

  The bearing fixing device according to the present embodiment is provided in the turning device 6 shown in FIG. 4 described above, for example. The swivel device 6 shown in FIG. 4 is provided in the hydraulic excavator shown in FIG. 3 as described above. That is, the basic configuration of the turning device 6 provided with the bearing fixing device according to the present embodiment is the same as the configuration excluding the lock plate 26 portion shown in FIG.

  Although the description is the same as described above, the turning device 6 provided with the bearing fixing device according to the present embodiment also includes the housing 15 in which the turning motor 7, the planetary speed reduction mechanism 11, and the turning output shaft 10 shown in FIG. I have. In the housing 15, bearings 19 and 20 that support the rotating shaft, that is, the turning output shaft 10 are accommodated. These bearings 19 and 20 are tapered roller bearings. On the bearing 19, a nut member 21 for applying a preload to the bearings 19 and 20 is provided. The threaded portion 21A of the nut member 21 and the threaded portion 10B of the turning output shaft 10 are screwed together. The nut member 21 is rotated with respect to the turning output shaft 10 and pressed against the bearing 19, thereby bearings 19,20. The bearings 19 and 20 are fixed to the housing 15 while pre-loading them.

  As shown in FIGS. 1 and 2, the lock plate 41 provided in the bearing fixing device according to the present embodiment has a spline portion 41 </ b> A that is coupled to the spline portion 10 </ b> C of the turning output shaft 10. Further, the bolt hole of the lock plate 41 into which the bolt 27 for fixing the lock plate 41 to the nut member 21 is inserted extends along the circumferential direction of a circle drawn around the axis of the turning output shaft 10 that is a rotating shaft. For example, it consists of two long holes 41B. As shown in FIG. 1, two bolts 27 for fixing the lock plate 41 to the nut member 21 are also provided, one for each of the two long holes 41B. The bearing fixing device according to the present embodiment includes the nut member 21, the lock plate 41, and the bolt 27 described above.

  Both ends of each of the long holes 41 of the lock plate 41 are formed in semicircular portions, and angles formed by the centers of the semicircular portions at both ends of one long hole 41 with respect to the axis of the turning output shaft 10. These two long holes 41 are formed on the lock plate 41 so that the angle X corresponds to the spline 1 pitch angle of the spline portion 10C formed on the turning output shaft 10 or the spline portion 41A formed on the lock plate 41. Are spaced apart.

  For example, as shown in FIG. 1, when a reference line passing through the center of the tooth tip of one spline of the spline portion 10C of the turning output shaft 10 is considered, the reference line is drawn on the upper side of FIG. The angle W formed by the center of the semicircular portion located on the other long hole 41B side of the other long hole 41B drawn on the lower side of FIG. The angle W formed by the center of the semicircular portion located on the side of the one long hole 41B drawn on the upper side of FIG. 1 of the other long hole 41B drawn on the lower side of FIG. / 2) Two long holes 41B are provided in the lock plate 41 so as to be X.

As shown in FIG. 1, the nut member 21 is provided with a convex portion 21B that contacts the lower end of the carrier 18 of the planetary speed reduction mechanism 11, and a notch portion 21B1 into which the lock plate 41 is inserted into the convex portion 21B. Is formed. The angle Z formed by both ends of the notch 21B1 with respect to the axis of the turning output shaft 10 is the angle Y formed by both ends of the portion located in the notch 21B1 of the lock plate 41 with respect to the axis of the turning output shaft 10 and the spline. The angle is set larger than the sum of the angle X equal to one pitch angle. That is, Z ≧ Y + X
It is set to the relationship.

  The configuration of the other turning device 6 and the configuration of the hydraulic excavator provided with the turning device 6 are the same as those shown in FIGS.

  In the turning device 6 shown in FIG. 4, the turning output shaft 10 supported by the bearings 19 and 20 through the planetary reduction mechanism 11 is rotated by driving the turning motor 7. By the rotation of the turning output shaft 10, the turning body 4 turns with respect to the traveling body 2 through meshing between the gear portion 10 </ b> A of the turning output shaft 10 and the inner ring 3 </ b> A of the turning wheel 3. The hydraulic excavator shown in FIG. 3 performs various operations such as excavation of earth and sand and release of excavated earth and sand by turning the revolving body 4 or turning the front working machine 5 in the vertical direction.

  Further, when the bearings 19 and 20 that support the turning output shaft 10 are fixed to the housing 15, as described above, the nuts 21 are screwed into the turning output shaft 10 so that the bearings 19 and 20 are preloaded. . The bearings 19 and 20 are fixed to the housing 15 while being pressed by the preload.

  The bearing fixing device according to the present embodiment configured as described above rotates the housing 15 relative to the turning output shaft 10 when managing the preload of the bearings 19 and 20 for fixing the bearings 19 and 20 to the housing 15. Then, the nut member 21 is screwed into the turning output shaft 10 to apply a preload to the bearings 19 and 20, and when the drag torque at this time reaches a specified value, the tightening by the nut member 21 is stopped. Thereafter, without tightening the nut member 21, the bolt 27 is inserted from the portion of the long hole 41 </ b> B of the lock plate 41 positioned on the screw hole 21 </ b> C of the nut member 21, and the bolt 27 is inserted into the screw hole of the nut member 21. The lock plate 41 is fixed to the nut member 21 with the bolts 27 by being screwed to the 21C. As a result, the rotation of the nut member 21 with respect to the turning output shaft 10 can be realized.

  That is, the bolt 27 is inserted from the long hole 41B of the lock plate 41 into the screw hole 21C of the nut member 21 without tightening the nut member 21 when the specified drag torque is reached, thereby preventing the nut member 21 from rotating. Can be realized. Therefore, the shape of the bearings 19 and 20 can be reduced by an amount corresponding to the preload by retightening, and the strength of the bearings 19 and 20 can be reduced. As a result, the housing 15 in which the bearings 19 and 20 are held can be reduced in size, and the manufacturing cost of the bearing fixing device according to the present embodiment can be reduced.

  Further, according to the present embodiment, when the specified drag torque is reached and the tightening of the nut member 21 is stopped, the maximum value of the rotational angle of the retightening that has been predicted empirically in the past, that is, the spline 1 pitch angle. Therefore, the bolt 27 can be securely screwed into the screw hole 21 </ b> C of the nut member 21. Moreover, since the size of the long hole 41B is not larger than necessary, sufficient strength of the lock plate 41 can be ensured. As a result, a stable and highly reliable detent structure for the nut member 21 can be realized.

  Further, in the present embodiment, an angle Z formed between both ends of the notch 21B1 of the nut member 21 with respect to the axis of the turning output shaft 10 is a lock plate disposed in the notch 21B with respect to the axis of the turning output shaft 10. 41 is set larger than the sum of the angle Y formed by both ends of the portion 41 and the angle X corresponding to the spline 1 pitch angle, the lock plate 41 is locked to the turning output shaft 10 when the lock plate 41 is fixed to the nut member 21. Even if the plate 41 is rotated by one pitch of the spline, the lock plate 41 does not interfere with the formed end portion of the notch portion 21B1 of the convex portion 21B of the nut member 21. Therefore, by appropriately rotating the lock plate 41 by one pitch of the spline, the position of the long hole 41B of the lock plate 41 with respect to the screw hole 21C of the nut member 21 can be selected as a desired position.

  Further, the bearing fixing device according to the present embodiment is provided in a turning device 6 having a turning motor 7 for turning the turning body 4, and the rotating shaft is turned by which the rotational force of the turning motor 7 is transmitted via the planetary reduction mechanism 9. Since the output shaft 10 and the bearings 19 and 20 are tapered roller bearings for supporting the swing output shaft 10, the bearings 19 and 20 can be effectively used in a construction machine such as a hydraulic excavator having the swing body 4. Of course, the present invention can also be applied to various machines different from construction machines, that is, various machines that fix a bearing supporting a rotating shaft to a housing.

  Further, in the present embodiment, two long holes 41B provided in the lock plate 41 are provided along the circumferential direction of the same circle drawn around the axis of the turning output shaft 10, and the bolts 27 are provided in the two long holes 41B. Accordingly, the lock plate 41 can be firmly fixed to the nut member 21 and a highly reliable bearing fixing device can be obtained.

It is a top view which shows one Embodiment of the bearing fixing device which concerns on this invention. It is a top view which shows the lock plate with which the bearing fixing device of this embodiment is equipped. It is a side view which shows the hydraulic excavator mentioned as an example of the construction machine provided with the turning apparatus containing a bearing fixing device. It is the front view which carried out the cross section of a part which shows the turning device in which the conventional bearing fixing device is included. It is an AA cross-sectional enlarged view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Running body 3 Turning wheel 4 Turning body 6 Turning apparatus 7 Turning motor 9 Planetary speed reduction mechanism 10 Turning output shaft (rotating shaft)
10A Gear part 10B Screw part 10C Spline part 15 Housing 18 Carrier 19 Bearing 20 Bearing 21 Nut member 21A Screw part 21B Convex part 21B1 Notch part 21C Screw hole 27 Bolt 41 Lock plate 41A Spline part 41B Long hole (bolt hole)

Claims (5)

A bearing fixing device for fixing a bearing supporting a rotating shaft to a housing,
A nut member that has a screw hole and presses the bearing against the housing; a spline portion that engages with a spline portion formed on the rotating shaft; and a lock plate that has a bolt hole and is fixed to the nut member In the bearing fixing device including the bolt inserted into the bolt hole of the lock plate and screwed into the screw hole of the nut member, and fixing the lock plate to the nut member,
The bolt hole of the lock plate is a long hole extending along the circumferential direction of a circle drawn around the axis of the rotation shaft in a state where the lock plate is splined to the rotation shaft. A bearing fixing device characterized by that. The bearing fixing device according to claim 1,
Each of the both ends of the elongated hole is formed in a semicircular portion, and an angle formed by the center of each of the semicircular portions at both ends of the elongated hole with respect to the axis of the rotating shaft is formed in the rotating shaft. A bearing fixing device, wherein the spline portion or the spline portion formed on the lock plate is set to an angle equal to a spline 1 pitch angle. The bearing fixing device according to claim 2,
The nut member includes an annular convex portion that contacts a carrier included in the planetary speed reduction mechanism, and forms a notch for accommodating the lock plate in the convex portion,
The angle between both ends of the notch with respect to the axis of the rotating shaft is equal to the angle between the ends of the portion of the lock plate located in the notch with respect to the axis of the rotating shaft and the pitch angle of the spline. A bearing fixing device characterized in that the angle is set larger than the sum of the angles. The bearing fixing device according to claim 3,
Provided in a turning device having a turning motor for turning a turning body;
The rotating shaft comprises a turning output shaft through which the rotational force of the turning motor is transmitted through the planetary reduction mechanism, and the bearing comprises a tapered roller bearing that supports the turning output shaft. . In the bearing fixing device according to any one of claims 1 to 4,
Two of the long holes are provided along the circumferential direction of the same circle drawn around the axis of the rotating shaft, and two bolts are provided, one for each of the two long holes. A bearing fixing device provided.

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