JP2016125506A - Planetary reduction gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve miniaturization and reduction in cost of a planetary reduction gear device by restricting movement of a planetary gear and the like in an axial direction so as to omit processing for slide abrasion.SOLUTION: In a motor case 16 for constituting a motor device 15, a flange part 16A in which a position opposing to the other opening 14A of a housing 12 is expanded, and a projection 16B which is located on an inner diameter side of the flange part 16A, which projects toward the housing 12 from the flange part 16A and which is fitted in th other opening 14A of the housing 12 are provided. Between the other opening 14A of the housing 12 and the projection 16B of the motor case 16, a thrust plate 29 is provided, which comes into contact with the planetary gear when a planetary gear 24 moves to the side of the motor device 15 so as to restrict the movement of the planetary gear 24.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a planetary gear reduction device that is suitably used in construction machines such as a hydraulic excavator and a hydraulic crane.

  Generally, a planetary gear speed reduction device is a cylindrical body that is open at both ends in the axial direction, a housing in which one opening is attached to a base body, and a hydraulic or electric type attached to the other opening of the housing in a motor case. A motor device that houses the motor, a reduction mechanism that is provided in the housing and decelerates the rotation of the motor device, and an output shaft that outputs the rotation of the motor device decelerated by the reduction mechanism. ing.

  In this case, the speed reduction mechanism meshes with the sun gear splined to the rotation shaft of the motor device, and the inner gear provided on the outer peripheral side of the sun gear and the inner peripheral side of the housing, And a carrier having a gear support shaft that rotatably supports the planetary gears (see, for example, Patent Document 1).

JP 2003-222205 A

  By the way, in the speed reduction mechanism, the gears may be tilted due to tilting due to the load of the shaft supporting the gears or poor processing accuracy of the gears. When each gear is tilted, the direction of the tangential load generated between the gears is changed, and a thrust load is generated as a component force of the tilted tangential load. The thrust load causes the gears to move in the axial direction, so that the gears are lifted up, and an appropriate meshing tooth width cannot be maintained between the gears. For this reason, there exists a problem that the surface pressure of a tooth surface goes up and the lifetime of a gearwheel falls.

  Therefore, in Patent Document 1 described above, in order to prevent the axial movement of the gear due to the thrust load, a plate is provided on the upper end surface of the carrier via a pin, and the plate abuts on the gear that moves due to the thrust load. It is structured to restrict movement. In this case, in the configuration according to Patent Document 1, a central portion near the rotating shaft is used on the lower end side of the motor case, and the thrust load of the entire speed reduction mechanism is received via the plate. For this reason, there is a risk that sliding wear exceeding the allowable value may occur in the central part of the motor case, so that the central part has a sliding area and sliding parts so that the sliding wear is within the allowable value. It is necessary to heat-treat. Thereby, there exists a problem that it becomes an obstacle of size reduction and cost reduction of the whole planetary gear speed reduction device.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to eliminate the processing for sliding wear by restricting the movement of the planetary gear or the like in the axial direction, thereby reducing the size and reducing the size. An object of the present invention is to provide a planetary gear reduction device that can be made cost-effective.

  The present invention forms a cylindrical body whose both ends in the axial direction are open, and a housing in which one opening is attached to the base, and a hydraulic or electric motor accommodated in the other opening of the housing and housed in the motor case. A motor device provided in the housing and decelerating the rotation of the motor device, and an output shaft for outputting the rotation of the motor device decelerated by the decelerating mechanism. A plurality of sun gears spline-coupled to the rotating shaft of the motor device, and an inner gear provided on the outer peripheral side of the sun gear and the inner peripheral side of the housing and revolving while rotating around the sun gear. The present invention is applied to a planetary gear reduction device constituted by a planetary gear and a carrier having a gear support shaft that rotatably supports each planetary gear.

  A feature of the configuration adopted by the present invention is that the motor case constituting the motor device has a flange portion that is widened at a position facing the other opening of the housing, and is positioned on the inner diameter side of the flange portion. A projecting portion that projects from the flange portion toward the housing and fits into the other opening of the housing, and the planet is between the other opening of the housing and the projecting portion of the motor case. There is provided a thrust plate that abuts when the gear moves toward the motor device and restricts the movement of the planetary gear.

  According to the present invention, by restricting the movement of the planetary gear or the like in the axial direction, the processing for sliding wear can be omitted, and the planetary gear reduction device can be reduced in size and cost.

1 is a front view showing a hydraulic excavator provided with a planetary gear reduction device according to a first embodiment of the present invention. 1 is a cross-sectional view showing a planetary gear speed reduction device according to a first embodiment of the present invention. It is sectional drawing of the principal part expansion which expands and shows the upper side part of the planetary gear speed reducer of FIG. It is sectional drawing which looked at the deceleration mechanism from the arrow IV-IV direction in FIG. FIG. 5 is a cross-sectional view similar to FIG. 4, showing the speed reduction mechanism and the thrust plate in a separated state. It is a perspective view which shows a thrust plate alone. It is sectional drawing which looked at the thrust plate from the arrow VII-VII direction in FIG. It is a perspective view which shows the motor case by the 2nd Embodiment of this invention independently. It is sectional drawing which looked at the deceleration mechanism by the 2nd Embodiment of this invention from the same position as FIG. It is sectional drawing which looked at the thrust plate by the 3rd Embodiment of this invention from the same position as FIG.

  Hereinafter, as an embodiment of a planetary gear speed reduction device according to the present invention, a case where the present invention is applied to a power source for turning a hydraulic excavator will be described as an example and described in detail with reference to the accompanying drawings.

  1 to 7 show a first embodiment of the present invention. In FIG. 1, a hydraulic excavator 1 which is one of construction machines is used for excavation work of earth and sand. The hydraulic excavator 1 includes a self-propelled crawler-type lower traveling body 2 and an upper revolving body 3 that is rotatably mounted on the lower traveling body 2. A work device 4 is provided on the front side of the upper swing body 3 so as to be able to move up and down, and the work device 4 is used for excavation work and the like. Further, a turning wheel 5 described later is provided between the lower traveling body 2 and the upper turning body 3, and the upper turning body 3 is supported on the lower traveling body 2 via the turning wheel 5 so as to be turnable.

  The swivel wheel 5 is disposed between the lower traveling body 2 and the upper revolving body 3. As shown in FIG. 2, the turning wheel 5 includes an inner ring 5 </ b> A fixed on the support cylinder 2 </ b> A of the lower traveling body 2, and an outer wheel fixed to the lower surface side of the turning frame 3 </ b> A serving as a base of the upper turning body 3. 5B and many steel balls 5C (only one is shown) provided between the inner ring 5A and the outer ring 5B. An internal gear 5D is formed on the inner circumference side of the inner ring 5A over the entire circumference. And the structure which the upper revolving body 3 performs turning operation | movement on the lower traveling body 2 when the below-mentioned planetary gear speed reducer 11 operates and the outer ring 5B fixed to the turning frame 3A rotates around the inner ring 5A. It has become.

  Next, the planetary gear reduction device 11 according to the present embodiment will be described. The planetary gear speed reduction device 11 is used as a turning motor for turning the upper turning body 3 on the lower traveling body 2.

  The planetary gear speed reduction device 11 is provided between the lower traveling body 2 and the upper revolving body 3 and turns the upper revolving body 3 supported on the lower traveling body 2 via the swirling wheels 5. The planetary gear speed reduction device 11 includes a housing 12, a motor device 15, speed reduction mechanisms 22, 28, and an output shaft 30, which will be described later.

  The housing 12 is disposed on the swing frame 3 </ b> A of the upper swing body 3. The housing 12 is a cylindrical body having both ends in the axial direction opened by a lower housing 13 attached to the upper surface side of the revolving frame 3A and an upper housing 14 attached to the upper end side of the lower housing 13. Is formed.

  The lower end side of the lower housing 13 is one opening 13A that opens downward in the axial direction, and the opening 13A is provided with a large-diameter annular flange portion 13B. The flange portion 13B is attached to a turning frame 3A as a base using a bolt 13C.

  The upper end side of the upper housing 14 is the other opening 14A that opens upward in the axial direction. As shown in FIG. 3, the end surface 14A1 on the opening 14A side is in contact with a flange portion 16A that forms a motor case 16 described later. It abuts on the surface 16A1. Further, on the inner diameter side of the opening 14A, an enlarged diameter step portion 14B into which a protrusion 16B described later is fitted is provided by expanding the inner peripheral surface of the upper housing 14 from the tooth bottom of the inner gear 14C described later. It has been. The height dimension of the diameter-expanded step portion 14B (the dimension between the end surface 14A1 of the opening 14A and the bottom surface 14B1 of the diameter-expanded step portion 14B) is the height dimension of the protruding portion 16B of the motor case 16 described later and the thrust described later. The dimension is a size obtained by adding the thickness of the plate 29.

  In addition, an internal gear 14 </ b> C is formed on the inner peripheral side of the upper housing 14 so as to be located on the lower side of the enlarged diameter step portion 14 </ b> B and extending upward and downward. An end surface 14C1 on the upper side (motor device 15 side) of the internal gear 14C is flush with the bottom surface 14B1 of the enlarged diameter step portion 14B, and a thrust plate 29 described later is placed on the same surface of the bottom surface 14B1 and the end surface 14C1. Has been. Here, a motor case 16 to be described later is attached to the upper end side of the upper housing 14 using bolts 16E, and the lower end side of the upper housing 14 is attached to the upper end side of the lower housing 13 using bolts 14D. .

  The motor device 15 is attached to the opening 14 </ b> A on the upper end side of the upper housing 14. For example, the motor device 15 houses a hydraulic motor (not shown) in a motor case 16. That is, the motor device 15 includes a motor case 16, a hydraulic motor, and a rotating shaft 20. The motor device 15 rotationally drives the output shaft 30 via speed reduction mechanisms 22 and 28 described later.

  The motor case 16 forms an outer shell of the motor device 15 and houses a motor therein. The motor case 16 is provided with a flange portion 16A, a protruding portion 16B, a bottom portion 16C, and a boss 16D, which will be described later.

  The flange portion 16 </ b> A of the motor case 16 is formed by expanding the diameter of the lower position facing the opening 14 </ b> A of the upper housing 14. The contact surface 16A1 that forms the lower surface of the flange portion 16A contacts the end surface 14A1 of the opening 14A, and is fastened to the opening 14A of the upper housing 14 using a bolt 16E in this state.

  The projecting portion 16B is located on the inner diameter side of the flange portion 16A, and is formed as a cylindrical tubular body projecting downward from the flange portion 16A (contact surface 16A1) toward the upper housing 14. When the motor case 16 is mounted on the upper housing 14, the projecting portion 16 </ b> B is fitted to the enlarged diameter step portion 14 </ b> B provided in the opening 14 </ b> A of the upper housing 14, thereby connecting the upper housing 14 and the motor case 16. Positions on the same axis.

  The bottom portion 16C of the motor case 16 is formed with a diameter reduced from the flange portion 16A, thereby closing the lower side of the motor case 16. The boss 16D is formed as a cylindrical body provided on the inner diameter side of the bottom portion 16C, and protrudes downward toward the sun gear 23 described later. The boss 16D accommodates the bearing 17, the seal member 18 and the like on the inner peripheral side thereof. Here, in the boss 16D, the lower end surface 16D1 that can contact the sun gear 23 is formed as a flat surface that faces the upper surface 23B of the sun gear 23 with a gap. The lower end surface 16D1 of the boss 16D is configured to abut (slide) the upper surface 23B of the sun gear 23 when the sun gear 23 moves (displaces) upward due to the thrust load.

  The bearing 17 rotatably supports a rotating shaft 20 described later in the boss 16D, and is attached to the rotating shaft 20 in a press-fit state. The seal member 18 is located below the bearing 17 and is inserted into the boss 16D. Further, a collar 19 that is in fluid-tight sliding contact with the seal member 18 is attached to the rotary shaft 20 inside the seal member 18 in a press-fitted state.

  The rotating shaft 20 is connected to the motor in the motor case 16, and the lower side protrudes downward from the boss 16D. The protruding end of the rotary shaft 20 is a male spline 20A and is connected to a sun gear 23 of a first-stage reduction mechanism 22 described later. The rotating shaft 20 is rotatably supported in the motor case 16 by a bearing 17 or the like.

  Next, the configuration of the speed reducer 21 provided to decelerate the rotation of the motor device 15 in, for example, two stages will be described.

  The reduction gear 21 is disposed in the upper housing 14 and includes a first-stage reduction mechanism 22 positioned at the upper stage and a second-stage reduction mechanism 28 positioned at the lower stage as the next stage. The speed reducer 21 decelerates the rotation of the motor device 15 and outputs it to the output shaft 30.

  The first-stage reduction mechanism 22 is disposed in the upper housing 14 at the lower side of the motor device 15. The first-stage reduction mechanism 22 decelerates the rotation of the motor device 15 (rotating shaft 20) and transmits it to the second-stage reduction mechanism 28. The speed reduction mechanism 22 includes a sun gear 23, a planetary gear 24, and a carrier 25, which will be described later.

  As shown in FIG. 3, the sun gear 23 is formed as a spur gear attached to the rotating shaft 20 of the motor device 15. The center position of the sun gear 23 is a female spline 23A, and the male spline 20A of the rotary shaft 20 is coupled to the female spline 23A. The upper surface 23B of the sun gear 23 faces the boss 16D of the motor case 16 with a gap. The sun gear 23 has a lower surface 23C disposed on a plate 25E of a carrier 25 described later, and peripheral teeth 23D efficiently mesh with teeth 24D of a planetary gear 24 described later at this height position.

  A plurality of, for example, three planetary gears 24 are arranged between the sun gear 23 and the internal gear 14C of the upper housing 14, and mesh with the sun gear 23 and the internal gear 14C. Each planetary gear 24 has a shaft hole 24A at the center position, and a gear support shaft 26 is rotatably inserted into the shaft hole 24A via a bearing 27 described later. Each planetary gear 24 has an upper surface 24B and a lower surface 24C, and the upper surface 24B faces in the thrust direction so as to be in contact with a later-described thrust plate 29. Each planetary gear 24 has peripheral teeth 24D meshed with the sun gear 23 and the internal gear 14C. Thereby, each planetary gear 24 revolves around the sun gear 23 while rotating around the sun gear 23 and the internal gear 14C.

  The carrier 25 is provided so as to surround the outer peripheral side of the sun gear 23, and supports each planetary gear 24 rotatably. As shown in FIGS. 3 and 4, the carrier 25 includes an annular upper plate 25A, a lower plate 25B, and a connecting portion 25C that connects the upper plate 25A and the lower plate 25B. A female spline 25D is provided on the inner diameter side of the lower plate 25B, and the female spline 25D is connected to a second-stage sun gear 28A described later. Further, on the inner diameter side of the lower plate 25B, a plate 25E is provided on the upper side of the female spline 25D, and the lower surface 23C of the sun gear 23 faces the plate 25E. The carrier 25 supports three planetary gears 24 via a gear support shaft 26 and a bearing 27 so as to be rotatable.

  The second-stage reduction mechanism 28 is disposed in the upper housing 14 below the first-stage reduction mechanism 22 and decelerates the rotation of the first-stage reduction mechanism 22 to output a shaft 30 described later. To communicate. The speed reduction mechanism 28 meshes with the sun gear 28A splined to the carrier 25 of the first speed reduction mechanism 22, and the sun gear 28A and the internal gear 14C of the upper housing 14, and rotates around the sun gear 28A. However, a plurality of planetary gears 28B (only one is shown) that revolves and a carrier 28C that rotatably supports each planetary gear 28B. The carrier 28 </ b> C of the speed reduction mechanism 28 is splined to a male spline 30 </ b> A provided on the upper end side of the output shaft 30.

  Next, the configuration, operational effects, and the like of the thrust plate 29, which are features of the present invention, will be described.

  The thrust plate 29 is provided between the opening 14 </ b> A of the upper housing 14 that is the other opening of the housing 12 and the protrusion 16 </ b> B of the motor case 16. Specifically, the thrust plate 29 is sandwiched between the bottom surface 14B1 of the enlarged diameter stepped portion 14B and the end surface 14C1 of the internal gear 14C and the tip end surface of the protruding portion 16B on the outer peripheral portion 29A side. Has been placed. Accordingly, the thrust plate 29 is pressed and fixed to the bottom surface 14B1 of the enlarged diameter step portion 14B and the end surface 14C1 of the internal gear 14C by the protruding portion 16B.

  As shown in FIGS. 5 to 7, the thrust plate 29 is formed as an annular plate, and its outer diameter is set to be slightly smaller than the inner diameter of the enlarged diameter step portion 14B. On the other hand, the inner diameter dimension of the thrust plate 29 is set to a dimension in which the inner peripheral portion 29B side reaches the upper surface 24B of the planetary gear 24 while avoiding interference with the carrier 25 in a state where the thrust plate 29 is mounted in the enlarged diameter step portion 14B. ing. Thereby, when each planetary gear 24 tries to move upward beyond the bottom surface 14B1 of the enlarged diameter step portion 14B and the end surface 14C1 of the internal gear 14C, the thrust plate 29 moves the lower surface 29C of the teeth of the planetary gear 24. It can be brought into contact with the upper surface 24B including 24D.

  The inner diameter side (inner peripheral part 29B side) of the thrust plate 29 is a part that comes into contact with the planetary gear 24. The inner peripheral part 29B side is bent so as to bend away from the planetary gear 24, thereby lowering the lower surface 29C. The side is a flank 29D. The bending angle for forming the flank 29D is set to 5 ° to 45 °, preferably about 30 °. The flank 29D prevents abnormal wear, galling, and the like due to contact between the edges of the end faces of the thrust plate 29 and each planetary gear 24.

  Here, the thrust plate 29 has an outer peripheral portion 29 </ b> A disposed in the enlarged diameter step portion 14 </ b> B of the upper housing 14. In this state, the protruding portion 16B of the motor case 16 is inserted into the enlarged diameter step portion 14B, and the flange portion 16A is bolted to the opening 14A of the upper housing 14. Thereby, the thrust plate 29 can be fixed by being sandwiched between the bottom surface 14B1 of the diameter-expanded step portion 14B, the end surface 14C1 of the internal gear 14C, and the tip surface of the protruding portion 16B. In this state, the thrust plate 29 abuts when each planetary gear 24 moves to the motor device 15 side due to the thrust load, and can restrict the movement of each planetary gear 24.

  As shown in FIG. 2, the output shaft 30 is arranged so that the axial center position in the housing 12 extends upward and downward, and is rotatable in the lower housing 13 via an upper bearing 31 and a lower bearing 32. It is supported. The output shaft 30 outputs the rotation of the motor device 15 decelerated by the speed reducer 21. Here, the upper side of the output shaft 30 is a male spline 30A, and the male spline 30A is splined to the carrier 28C of the second-stage reduction mechanism 28.

  On the other hand, a pinion 30B is integrally provided on the lower side of the output shaft 30, and the pinion 30B protrudes downward from the lower end of the lower housing 13 and meshes with an internal gear 5D provided on the inner ring 5A of the swivel wheel 5. doing.

  The planetary gear speed reduction device 11 according to the first embodiment has the above-described configuration. When hydraulic oil is supplied to the motor device 15 and the rotary shaft 20 rotates, the rotation of the rotary shaft 20 is reduced. The first-stage reduction mechanism 22 and the second-stage reduction mechanism 28 are decelerated in two stages and transmitted to the output shaft 30, and the pinion 30B rotates with a large rotational force (torque). Then, the pinion 30B revolves along the inner ring 5A while meshing with the internal gear 5D provided on the inner ring 5A of the turning wheel 5, and the revolution force of the pinion 30B is transmitted to the turning frame 3A. A turning operation is performed on the lower traveling body 2.

  In each of the speed reduction mechanisms 22 and 28, if the shafts supporting the gears 23, 24, 28A, and 28B are tilted by a load or the processing accuracy of the gears 23, 24, 28A, and 28B varies, the gears 23, 24, 28A, and 28B may cause inclination. As described above, when the gears 23, 24, 28A, and 28B are inclined, the direction of the tangential load generated between the gears 23, 24, 28A, and 28B is changed, and a thrust is generated as a component force of the inclined tangential load. A load is generated. Since this thrust load acts to move the gears 23, 24, 28A, 28B in the axial direction, an axial shift (lift) occurs between the meshing gears 23, 24, 28A, 28B. It becomes impossible to maintain a proper meshing tooth width. For this reason, between each gear 23, 24, 28A, 28B, the surface pressure of a tooth surface rises and there exists a tendency for a lifetime to fall.

  As a countermeasure in this case, the boss 16D forming the motor case 16 of the motor device 15 is brought into contact with the upper surface 23B of the sun gear 23 moving to the motor device 15 side (upper side), whereby the sun gear 23 is obtained. The upward movement of the carrier 25 or the like can be restricted. However, when only the boss 16D of the motor case 16 receives the thrust load of the speed reduction mechanisms 22 and 28, it is difficult to keep the wear of the boss 16D within an allowable value, and the boss 16D and the sun gear 23 are damaged or abnormally worn. May occur.

  However, in the present embodiment, the motor case 16 that constitutes the motor device 15 includes a flange portion 16A that is widened at a position facing the opening 14A of the upper housing 14 that forms the other opening of the housing 12, and the flange portion. A projecting portion 16B that is located on the inner diameter side of 16A and projects from the flange portion 16A toward the housing 12 and fits into the other opening 14A of the housing 12 is provided. Further, when each planetary gear 24 moves to the motor device 15 side (upper side) between the opening 14A of the upper housing 14 and the protrusion 16B of the motor case 16, the thrust direction of each planetary gear 24 is in contact. A thrust plate 29 for restricting the movement to is provided.

  As a result, the thrust plate 29 can restrict each planetary gear 24 from moving upward beyond the bottom surface 14B1 of the enlarged diameter step portion 14B and the end surface 14C1 of the internal gear 14C due to the thrust load. Therefore, the thrust loads of the speed reduction mechanisms 22 and 28 can be received separately by the boss 16D of the motor case 16 and the thrust plate 29. As a result, the boss 16D of the motor case 16 does not need to be devised to prevent sliding wear, for example, to increase the sliding area or to perform heat treatment on the sliding portion. Thus, the manufacturing cost can be reduced.

  Further, a flank 29D is formed on the inner peripheral portion 29B side of the thrust plate 29 by bending the thrust plate 29 to the opposite side to each planetary gear 24. Thereby, the thrust plate 29 can smoothly contact the upper surface 24B of each planetary gear 24, and damage and abnormal wear of the sliding portion can be prevented.

  Further, the opening 14A of the upper housing 14 is provided with an enlarged diameter step portion 14B into which the protruding portion 16B of the motor case 16 is fitted, and the bottom surface 14B1 of the enlarged diameter step portion 14B of the upper housing 14 is a motor device of the internal gear 14C. It is formed as the same surface as the end surface 14C1 on the 15th side, and the thrust plate 29 is pressed and fixed to the end surface 14C1 of the internal gear 14C. Accordingly, the thrust plate 29 can be fixed between the opening 14 </ b> A of the upper housing 14 and the protruding portion 16 </ b> B of the motor case 16 without using bolts, pins, or the like for fixing the thrust plate 29. As a result, the workability of assembling the thrust plate 29 to the planetary gear reduction device 11 can be improved, and the number of parts can be reduced to reduce the manufacturing cost.

  Next, FIG. 8 and FIG. 9 show a second embodiment of the present invention. The feature of the second embodiment resides in that the protrusion of the motor case is constituted by a plurality of protrusions divided in the circumferential direction. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  8 and 9, the motor case 41 according to the second embodiment is similar to the motor case 16 according to the first embodiment in the flange portion 41A, the protruding portion 41B, the bottom portion 41C, the boss 41D, and the bolt 41E. Etc. However, the motor case 41 according to the second embodiment is different from the motor case 16 according to the first embodiment in that the protrusion 41B is divided in the circumferential direction. That is, the protrusion 41B according to the second embodiment is configured by a plurality of, for example, five curved protrusions 41B1 arranged in the circumferential direction so as to form a circular shape. Thereby, the protrusion part 41B is formed in five virtues as a whole.

  Thus, also in the second embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. According to the second embodiment, the motor case 41 can be reduced in weight because the protrusion 41B of the motor case 41 is formed in the five virtues by the protrusions 41B1 divided in the circumferential direction.

  Next, FIG. 10 shows a third embodiment of the present invention. A feature of the third embodiment resides in that an arc-shaped chamfer is formed below the inner peripheral portion of the thrust plate. In the third embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 10, a thrust plate 51 according to the third embodiment is configured in substantially the same manner as the thrust plate 29 according to the first embodiment, and has an outer peripheral portion 51A, an inner peripheral portion 51B, a lower surface 51C, and a clearance surface 51D. doing. However, the thrust plate 51 according to the third embodiment forms the flank 51D by chamfering the lower corner (edge) in a circular arc shape without bending the inner peripheral portion 51B. This is different from the thrust plate 29 according to the first embodiment.

  Thus, also in the third embodiment configured as described above, it is possible to obtain substantially the same operational effects as those of the first embodiment described above. According to the third embodiment, the thrust plate 51 can be provided with the relief surface 51D as a chamfered portion by notching the corner portion facing the planetary gear 24 on the inner diameter side that contacts the planetary gear 24, and easily. Can be processed.

  In the first embodiment described above, the enlarged diameter step portion 14B is provided in the opening 14A of the upper housing 14, and the thrust plate is formed on the bottom surface 14B1 of the enlarged diameter step portion 14B and the end surface 14C1 of the internal gear 14C. 29 was placed. However, the present invention is not limited to this, and the thrust plate may be placed only on the end face of the internal gear by omitting the diameter-expanded stepped portion. This configuration can be similarly applied to the second and third embodiments.

  In the first embodiment described above, a cylindrical boss 16 </ b> D protruding toward the sun gear 23 is provided on the lower end side of the motor case 16. However, the present invention is not limited to this, and the upper surface of the sun gear may be in contact with the lower end surface of the bottom of the motor case by omitting the boss of the motor case. This configuration can be similarly applied to the second and third embodiments.

  In the first embodiment described above, the case where a hydraulic motor is housed in the motor case 16 as a motor has been described as an example. However, the present invention is not limited to this. For example, an electric motor may be used as the motor. This configuration can be similarly applied to the second and third embodiments.

  In the first embodiment described above, the case where the speed reducer 21 is provided with the upper speed reduction mechanism 22 and the lower speed reduction mechanism 28 has been described as an example. However, the present invention is not limited to this, and the speed reduction mechanism may be provided in one or more stages. This configuration can be similarly applied to the second and third embodiments.

  Further, in each of the above-described embodiments, the planetary gear reduction device 11 of the excavator 1 has been described as an example. However, the present invention is not limited to this, and may be applied to, for example, a planetary gear reduction device used for traveling. Further, the present invention can be widely applied to planetary gear speed reducers provided in other construction machines such as hydraulic cranes.

3A Swivel frame (base)
DESCRIPTION OF SYMBOLS 11 Planetary gear reduction device 12 Housing 13 Lower housing 13A, 14A Opening 14 Upper housing 14B Expanded stepped portion 14B1 Bottom surface 14C Internal gear 14C1 End surface 15 Motor device 16, 41 Motor case 16A, 41A Flange portion 16B, 41B Protruding portion 20 Rotation Shaft 22 First stage reduction mechanism 23 Sun gear 24 Planetary gear 25 Carrier 26 Gear support shaft 28 Second stage reduction mechanism 29, 51 Thrust plate 30 Output shaft

Claims (4)

A housing in which both ends in the axial direction are open and one opening is attached to the base; and a motor device that is attached to the other opening of the housing and houses a hydraulic or electric motor inside a motor case; A reduction mechanism that is provided in the housing and decelerates rotation of the motor device, and an output shaft that outputs rotation of the motor device decelerated by the reduction mechanism,
The speed reduction mechanism meshes with a sun gear spline-coupled to the rotating shaft of the motor device, and an inner gear provided on the outer peripheral side of the sun gear and the inner peripheral side of the housing, and rotates around the sun gear. In the planetary gear reduction device constituted by a plurality of planetary gears that revolve while rotating and a carrier having a gear support shaft that rotatably supports each planetary gear,
The motor case constituting the motor device has a flange portion that is widened to face the other opening of the housing, and is located on the inner diameter side of the flange portion and projects from the flange portion toward the housing. A protrusion that fits into the other opening of the housing;
A thrust plate is provided between the other opening of the housing and the protruding portion of the motor case to contact the planetary gear when the planetary gear moves to the motor device side and restrict the movement of the planetary gear. A planetary gear reduction device characterized by that.   2. The planetary gear reduction device according to claim 1, wherein the thrust plate is configured to bend an inner diameter side in contact with the planetary gear to a side opposite to the planetary gear.   2. The planetary gear reduction device according to claim 1, wherein the thrust plate has a configuration in which a chamfered portion is provided by notching a corner portion facing the planetary gear on an inner diameter side in contact with the planetary gear. An inner diameter side of the other opening of the housing is provided with an enlarged diameter step portion into which the protruding portion of the motor case is fitted,
The bottom surface of the enlarged diameter step portion of the housing is formed as the same surface as the end surface of the internal gear on the motor device side,
4. The planetary gear reduction device according to claim 1, wherein the thrust plate is pressed and fixed to an end face of the internal gear by the protrusion of the motor case. 5.

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