JP2006022901A - Reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely capture metal powders mixed in lubricating oil. <P>SOLUTION: Sediments of metal powers M in the lubricating oil are captured on the surface of a magnetic plate 27 by placing the magnetic plate 27 rotating integrally with an output shaft 17 beneath a planetary-gear reduction mechanism 16. Since the captured metal powders M are attracted by the magnetism of the magnetic plate 27, even though the lubricating oil is agitated in a housing 12 in operating time of the reduction gear 11, the metal powers M are inhibited from falling out of the magnetic plate 27. Consequently, the metal powders M mixed in the lubricating oil are prevented from entering the inside of an upper bearing 19 and a lower bering 20 to smoothly rotate over a long period the output shaft 17 supported by the bearings 19, 20 placed up and down. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a speed reducer suitably used for, for example, a hydraulic excavator, a swing device for a hydraulic crane, and the like.

  In general, construction machines such as a hydraulic excavator and a hydraulic crane are generally configured by a self-propelled lower traveling body and an upper revolving body that is rotatably mounted on the lower traveling body. A turning device for turning the upper turning body is provided between the lower traveling body and the upper turning body, and the turning device decelerates the rotation of a rotation source such as a hydraulic motor and increases torque. A reduction gear is provided.

  This type of prior art reduction device is usually a cylindrical housing that extends upward and downward, a reduction mechanism that is provided in the housing and decelerates rotation of the rotation source, and is rotatable in the housing via a bearing. And an output shaft that outputs rotation decelerated by the speed reduction mechanism. The housing is filled with lubricating oil that lubricates gears constituting the speed reduction mechanism, bearings that support the output shaft, and the like, and this lubricating oil is sealed in the housing by an oil seal provided on the lower end side of the housing. It has been stopped.

  By the way, when the speed reducer described above is operated, for example, abrasion powder generated from the meshing portions of the gears constituting the speed reduction mechanism, etc., remaining without being removed by washing during processing of each member constituting the speed reducer Metal powder such as chips is mixed into the lubricating oil in the housing.

  These metal powders penetrate into the bearing that supports the output shaft to inhibit smooth rotation of the output shaft, or adhere to the oil seal that seals the lubricating oil, thereby causing wear of the oil seal. There is a problem of accelerating.

  On the other hand, conventionally, an output shaft that is rotatably supported in the housing via upper and lower bearings and outputs rotation reduced by a reduction mechanism and a male screw portion formed on the output shaft are screwed together. An annular member that surrounds the upper bearing from the outer peripheral side in a portion of the housing to which the upper bearing is mounted, including a nut member that pressurizes each bearing and a rotation-preventing member that rotates the nut member with respect to the output shaft. A speed reducer has been proposed in which a groove is provided and a skirt portion that covers the entire outer periphery of the upper bearing is provided on the anti-rotation member (see, for example, Patent Document 1).

JP-A-9-144854

  The speed reducer according to this prior art can suppress the metal powder mixed in the lubricating oil from entering the bearing by the skirt portion provided in the anti-rotation member, and the metal powder settled in the lubricating oil. It can guide along the skirt part of a rotation stop member in the annular groove provided in the housing. Then, by discharging the lubricating oil in the housing to the outside through the oil draining pipe that opens in the vicinity of the groove, the metal powder staying in the annular groove can be discharged to the outside together with the drained oil. ing.

  However, the above-described reduction gear according to the prior art is configured to discharge the metal powder staying in the annular groove of the housing to the outside of the housing together with the drain oil, so that the lubricating oil in the housing is discharged to the outside. Unless otherwise, the metal powder will remain in the housing along with the lubricating oil.

  For this reason, when the lubricating oil is agitated in the housing by the operation of the reduction gear, the metal powder staying in the annular groove again floats in the housing due to the flow of the lubricating oil, and this metal powder stays in the bearing. There is a problem that it penetrates to hinder the smooth rotation of the output shaft or adheres to the lip portion of the oil seal to accelerate its wear.

  In addition, since the oil reduction pipe is opened near the annular groove provided on the outer peripheral side of the upper bearing, the reduction gear according to the prior art described above does not store the lubricating oil stored between the upper bearing and the oil seal. When all the lubricating oil filled in the housing cannot be discharged through the oil drain pipe, complicated work for disassembling the speed reduction device is required.

  Further, since the outer peripheral side of the upper bearing is covered with the skirt portion of the anti-rotation member, when the lubricating oil is newly filled in the assembled reduction gear housing, the upper bearing is obstructed by the skirt portion of the anti-rotation member. It becomes difficult to supply lubricating oil into the space between the oil seal and the oil seal, and it takes time to fill the housing with an appropriate amount of lubricating oil. As described above, the speed reducer according to the prior art has a problem that workability when the lubricating oil filled in the housing is replaced is poor, and maintenance performance is deteriorated.

  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 provide a speed reducer that can reliably capture metal powder mixed in lubricating oil.

  In order to solve the above-described problems, the present invention includes a cylindrical housing extending upward and downward, a reduction mechanism that is provided in the housing and decelerates rotation of a rotation source, and a lower side above and below the reduction mechanism. And an output shaft that is rotatably provided in the housing and outputs the rotation decelerated by the reduction mechanism.

  According to the first aspect of the present invention, a magnetic plate is provided below the speed reduction mechanism so as to be fixed to one of the output shaft and the housing. The purpose is to capture the metal powder in the filled lubricating oil.

  The invention of claim 2 is that the plate is formed by an annular plate surrounding the output shaft from the outside in the radial direction, and the plate is provided with an oil hole through which the lubricating oil in the housing flows.

  According to a third aspect of the present invention, a bearing for rotatably supporting the output shaft is provided between the housing and the output shaft, and the outer periphery of the output shaft is positioned above the bearing to pressurize the bearing in the axial direction. The nut member is screwed and the plate is fixed to the output shaft by being attached to the nut member.

  According to a fourth aspect of the present invention, a male spline to which the carrier constituting the speed reduction mechanism is spline-coupled is provided on the outer peripheral side of the output shaft, and the plate is attached to the nut member while being fitted to the outer peripheral side of the male spline. There is.

  According to a fifth aspect of the present invention, a bearing that rotatably supports the output shaft is provided between the housing and the output shaft, and the outer periphery of the output shaft is positioned above the bearing to pressurize the bearing in the axial direction. The nut member is screwed and the plate is fixed to the output shaft by being sandwiched between the inner ring of the bearing and the nut member.

  According to a sixth aspect of the present invention, a bearing for rotatably supporting the output shaft is provided between the lower portion of the housing and the output shaft, and the lower portion of the housing is located below the bearing and is disposed in the housing. An oil seal that seals the lubricating oil is provided inside, and a sleeve is provided on the outer peripheral side of the output shaft that is located on the lower side of the bearing and in contact with the oil seal. The plate is sandwiched between the inner ring and the sleeve of the bearing. Thus, the configuration is fixed to the output shaft.

  According to the seventh aspect of the present invention, an annular mounting seat is provided on the inner side surface of the housing, which is positioned below the speed reduction mechanism and surrounds the output shaft from the outer peripheral side, and the plate is attached to the mounting seat so The configuration is fixed.

  According to the invention of claim 8, a bearing for rotatably supporting the output shaft is provided between the lower portion of the housing and the output shaft, and the lower portion of the housing is positioned below the bearing and sealed. A holding member is provided, and the seal holding member is provided with an oil seal that seals lubricating oil in the housing, and the plate is configured to be fixed to the housing by being sandwiched between the seal holding member and the oil seal. It is in.

  According to the invention of claim 1, since the magnetic plate is provided below the speed reduction mechanism, metal powder such as wear powder generated from the meshing portion of each gear constituting the speed reduction mechanism, Even if mixed in the lubricating oil in the housing, the metal powder can be adsorbed and captured by the plate. In this case, since the metal powder is adsorbed on the plate, it is possible to reliably prevent the metal powder from floating in the housing even if the lubricating oil is stirred during the operation of the speed reducer. Therefore, the metal powder mixed in the lubricating oil can enter the bearing and hinder the smooth rotation of the output shaft, or it can adhere to the oil seal that seals the lubricating oil in the housing and accelerate its wear. Can be prevented, and the reliability of the reduction gear can be increased.

  In addition, by capturing the metal powder mixed in the lubricating oil with the plate, the lubricating oil can be kept clean for a long period of time, so the lubricating oil is discharged outside the housing to remove the metal powder. The frequency of performing can be reduced, and the maintainability can be improved.

  According to the second aspect of the present invention, the oil hole through which the lubricating oil in the housing flows is provided in the plate. For example, when lubricating oil is supplied into the housing from above the plate, the lubricating oil is applied to the plate. It flows into the lower part of the plate through the provided oil hole. Thereby, the supply operation of the lubricating oil into the housing can be performed quickly without being obstructed by the plate, and the maintainability can be improved.

  According to the invention of claim 3, since the plate is attached to the nut member positioned on the upper side of the bearing and screwed to the outer peripheral side of the output shaft, the metal powder that settles in the lubricating oil is removed from the bearing. It can be captured by the plate at a higher position than the above, and the metal powder can be reliably prevented from entering the bearing. In this case, since the plate is attached using a nut member which is an existing part, it is not necessary to add a new part to attach the plate, and an increase in the number of parts can be suppressed.

  According to invention of Claim 4, since it was set as the structure attached to a nut member in the state which fitted the plate to the outer peripheral side of the male spline provided in the output shaft, rotation prevention (loosening of a nut member using a plate) )It can be performed. In other words, by replacing the existing anti-rotation member attached to the nut member with the plate attached to the nut member, the plate captures the metal powder and prevents the nut member from rotating without causing an increase in the number of parts. Can also be used. Therefore, the metal powder mixed in the lubricating oil can be captured by the plate and the lubricating oil can be cleaned simply by replacing the anti-rotation member used in the existing speed reducer with a magnetic plate.

  According to the fifth aspect of the present invention, since the plate is fixed to the output shaft by being sandwiched between the inner ring of the bearing and the nut member, the mounting operation of the plate can be simplified. . In addition, since it is possible to eliminate the need for parts such as a dedicated bolt for attaching the plate, an increase in the number of parts can be suppressed.

  According to the invention of claim 6, the bearing and the oil seal are provided on the lower side of the housing, the sleeve on which the oil seal slides is provided on the outer peripheral side of the output shaft, and the plate is disposed between the inner ring and the sleeve of the bearing. Since it is configured to be sandwiched, the plate can be fixed to the output shaft using existing components such as a bearing, an oil seal, and a sleeve. As a result, the plate mounting operation can be simplified, and an increase in the number of components can be suppressed by eliminating the need for components such as dedicated bolts for mounting the plate.

  According to the seventh aspect of the present invention, since the plate is fixed to the housing by being attached to a mounting seat provided on the inner surface of the housing, the plate is captured by the plate when rotating together with the output shaft. It is possible to prevent the metal powder from being detached from the plate. In addition, since no gap is formed between the housing and the plate to allow the metal powder to pass therethrough, the lubricant is agitated by the operation of the speed reducer, so that the metal powder is lubricated along the inner surface of the housing. Even if it settles inside, this metal powder can be reliably captured by the plate.

  According to the invention of claim 8, since the seal holding member and the oil seal are provided on the lower side of the housing and the plate is sandwiched between the seal holding member and the oil seal, the seal holding member, the oil seal The plate can be fixed to the housing using existing parts such as. As a result, the plate mounting operation can be simplified, and an increase in the number of components can be suppressed by eliminating the need for components such as dedicated bolts for mounting the plate.

  Hereinafter, embodiments of a reduction gear according to the present invention will be described in detail with reference to FIGS.

  First, FIG. 1 to FIG. 5 show a first embodiment of the present invention, and this embodiment will be described by taking as an example a case where it is applied to a turning device mounted on a hydraulic excavator.

  In the figure, reference numeral 1 denotes a hydraulic excavator. The hydraulic excavator 1 includes a self-propelled crawler-type lower traveling body 2 and an upper revolving body mounted on the lower traveling body 2 through a swirling wheel 3 so as to be capable of swiveling. 4 and a work device 5 that is provided on the front side of the upper swing body 4 so as to be able to be lifted and lowered and that performs excavation work such as earth and sand.

  Here, as shown in FIG. 2, the turning wheel 3 is fixed to an inner ring 3 </ b> A fixed on a round body 2 </ b> A constituting the lower traveling body 2 and a lower surface side of a turning frame 4 </ b> A constituting the upper turning body 4. The outer ring 3B and a plurality of steel balls 3C (only one is shown) disposed between the inner ring 3A and the outer ring 3B. An inner tooth 3D is formed on the inner peripheral side of the inner ring 3A over the entire circumference, and grease that lubricates a meshing portion between the inner tooth 3D and a pinion 18 described later is provided on the inner peripheral side of the inner tooth 3D. The accommodated grease bath 6 is provided.

  Reference numeral 7 denotes a turning device for turning the upper turning body 4 on the lower traveling body 2. The turning device 7 decelerates the rotation of the hydraulic motor 8 as a rotation source and the motor shaft 8A of the hydraulic motor 8, and turns the turning wheel. 3 is composed mainly of a later-described speed reducer 11 that transmits a large rotational force (torque) to 3. In this case, for example, a motor case or the like of the hydraulic motor 8 is provided with an oil supply pipe 9 for supplying lubricating oil into the reduction gear 11.

  Reference numeral 11 denotes a reduction gear that reduces the rotation of the hydraulic motor 8 (motor shaft 8A). The reduction gear 11 includes a housing 12, planetary gear reduction mechanisms 15 and 16, an output shaft 17, and upper and lower bearings 19 and 20, which will be described later. , An oil seal 25, a magnetic plate 27, and the like.

  Reference numeral 12 denotes a cylindrical housing that forms an outer shell of the speed reducer 11. The housing 12 includes a stepped cylindrical lower housing 13 fixed with bolts to the upper surface side of the swing frame 4A, and the lower housing. A cylindrical upper housing 14 fixed to the upper end side of 13 using a bolt is configured as a cylindrical body extending upward and downward.

  Here, on the inner peripheral side of the lower housing 13, an upper bearing mounting portion 13A to which an upper bearing 19 described later is mounted and a lower bearing mounting portion 13B to which a lower bearing 20 described later is mounted are upward and downward. Are spaced apart from each other.

  On the other hand, a hydraulic motor 8 is attached to the upper end side of the upper housing 14, and a motor shaft 8 </ b> A of the hydraulic motor 8 extends into the upper housing 14. Further, on the inner peripheral side of the upper housing 14, upper inner teeth 14A that mesh with a planetary gear 15B described later and lower inner teeth 14B that engage with a planetary gear 16B described later are formed over the entire circumference. ing.

  Reference numeral 15 denotes a first stage planetary gear speed reduction mechanism provided in the housing 12 below the hydraulic motor 8. The planetary gear speed reduction mechanism 15 is a sun spline-coupled to the motor shaft 8 A of the hydraulic motor 8. A plurality of planetary gears 15B (only one shown) meshing with the gear 15A, the sun gear 15A and the upper internal teeth 14A of the upper housing 14 and revolving around the sun gear 15A, and the planetary gears The carrier 15C is configured to rotatably support 15B.

  Reference numeral 16 denotes a second-stage planetary gear reduction mechanism located in the housing 12 below the planetary gear reduction mechanism 15, and the planetary gear reduction mechanism 16 is splined to the carrier 15 </ b> C of the planetary gear reduction mechanism 15. A plurality of planetary gears 16B meshing with the sun gear 16A, the sun gear 16A and the lower inner teeth 14B of the upper housing 14 and revolving around the sun gear 16A, and the planetary gears 16B. The carrier 16C is rotatably supported.

  Reference numeral 17 denotes an output shaft provided in the housing 12 so as to extend upward and downward. The output shaft 17 is formed in a stepped columnar shape having a small-diameter shaft portion 17A and a large-diameter shaft portion 17B. It is rotatably supported by the lower housing 13 via a bearing 19 and a lower bearing 20. The output shaft 17 outputs the rotation of the hydraulic motor 8 decelerated by two stages by the planetary gear reduction mechanisms 15 and 16.

  Here, on the upper end side of the small-diameter shaft portion 17A, as shown in FIGS. 3 and 4, a male spline (shaft spline) 17C into which the carrier 16C of the planetary gear speed reduction mechanism 16 is fitted, and a lower side than the male spline 17C. A male screw portion 17D is formed which is positioned on the side and to which a nut member 21 described later is screwed.

  Reference numeral 18 denotes a pinion integrally provided on the lower end side of the large-diameter shaft portion 17B of the output shaft 17. The pinion 18 projects downward from the lower end side of the housing 12 (lower housing 13), and the internal teeth 3D of the swivel wheel 3 are provided. Is engaged. The pinion 18 transmits the rotation of the output shaft 17 to the turning wheel 3 (inner wheel 3A).

  Reference numeral 19 denotes an upper bearing mounted on the upper bearing mounting portion 13A of the lower housing 13, and the upper bearing 19 is composed of, for example, a tapered roller bearing, and an outer ring 19A fitted to the upper bearing mounting portion 13A and the output shaft 17 The inner ring 19B is fitted and fixed to the small-diameter shaft portion 17A, and a plurality of substantially conical rolling elements 19C provided between the outer ring 19A and the inner ring 19B.

  Reference numeral 20 denotes a lower bearing attached to the lower bearing mounting portion 13B of the lower housing 13, and the lower bearing 20 is a tapered roller bearing similar to the upper bearing 19, and is fitted to the lower bearing mounting portion 13B. The outer ring 20A, the inner ring 20B fitted and fixed to the large-diameter shaft portion 17B of the output shaft 17, and a plurality of substantially conical rolling elements 20C provided between the outer ring 20A and the inner ring 20B. It is configured.

  Here, the upper bearing 19 and the lower bearing 20 support the output shaft 17 so as to be rotatable with respect to the housing 12 in a state where the nut member 21 described later is appropriately pressurized in the axial direction. .

  Reference numeral 21 denotes a nut member positioned below the planetary gear speed reduction mechanism 16 and screwed to the male screw portion 17D of the output shaft 17, and the nut member 21 is a male screw portion 17D of the output shaft 17 as shown in FIG. The lower surface of the upper bearing 19 is brought into contact with the inner ring 19B, and the upper bearing 19 and the lower bearing 20 are appropriately pressurized in the axial direction.

  In addition, a magnetic plate 27 described later is attached to the upper surface side of the nut member 21, and the nut member 21 is configured to be rotated around the output shaft 17 by the magnetic plate 27.

  Reference numeral 22 denotes a seal holding member attached to the lower end side of the lower housing 13 constituting the housing 12, and the seal holding member 22 is an annular flange portion fixed to the lower end surface of the lower housing 13 using a bolt 23. 22A and a cylindrical portion 22B protruding downward from the flange portion 22A. The seal holding member 22 holds the oil seal 25 on the lower end side of the housing 12 by fitting an oil seal 25 described later on the inner peripheral side of the cylindrical portion 22B.

  A cylindrical sleeve 24 is located between the pinion 18 and the lower bearing 20 and is fitted and fixed to the large-diameter shaft portion 17B of the output shaft 17. The sleeve 24 rotates integrally with the output shaft 17. To do. Here, the upper surface of the sleeve 24 is in contact with the lower surface of the inner ring 20 </ b> B constituting the lower bearing 20, and the lower surface of the sleeve 24 is in contact with the upper surface of the pinion 18. The outer peripheral surface of the sleeve 24 faces the inner peripheral surface of the cylindrical portion 22B that constitutes the seal holding member 22, and is a seal surface 24A in which an inner peripheral side of an oil seal 25 described later is in sliding contact.

  An annular oil seal 25 is held on the lower end side of the housing 12 by the seal holding member 22, and the outer peripheral side of the oil seal 25 is fitted and fixed to the cylindrical portion 22 </ b> B of the seal holding member 22. The inner peripheral side is in sliding contact with moderate elasticity with the seal surface 24A of the sleeve 24 attached to the output shaft 17 side. The oil seal 25 seals the lubricating oil filled in the housing 12, and the planetary gear reduction mechanisms 15, 16, the upper bearing 19, the lower bearing 20, and the like are lubricated by the lubricating oil. It has become.

  An oil drain pipe 26 is provided on the lower end side of the lower housing 13 constituting the housing 12. The oil drain pipe 26 is located between the upper bearing 19 and the lower bearing 20 and is located in the lower housing 13. Is open. The oil drain pipe 26 discharges the lubricating oil filled in the housing 12 to the outside of the housing 12.

  Reference numeral 27 denotes a magnetic plate which is positioned below the planetary gear speed reduction mechanism 16 and is attached to the nut member 21. As shown in FIGS. 3 to 5, the magnetic plate 27 is made of a magnetic material such as iron-based metal. It is formed as an annular plate having a larger diameter than the nut member 21 and slightly smaller than the inner surface of the lower housing 13. And the magnetic plate 27 used as the permanent magnet is comprised by giving the magnetization process using a magnetizer to the plate formed with this magnetic material.

  The magnetic plate 27 is attached to the nut member 21 using bolts 28, thereby partitioning the inside of the housing 12 upward and downward between the planetary gear reduction mechanism 16 and the upper bearing 19, and integrally with the output shaft 17. The metal powder mixed in the lubricating oil in the housing 12 is adsorbed and captured while rotating.

  Here, as shown in FIG. 5, a female spline (hole spline) 27A that fits into the male spline 17C of the output shaft 17 is formed at the center of the magnetic plate 27, and the female spline 27A is sandwiched from the radial direction. Bolt insertion holes 27B through which the bolts 28 are inserted are formed at two locations. In addition, a plurality of (for example, eight) oil holes 27C are formed on the outer peripheral side of the magnetic plate 27 so as to surround the female spline 27A and are arranged at equal intervals in the circumferential direction.

  As shown in FIGS. 3 and 4, the magnetic plate 27, with the female spline 27 </ b> A fitted to the male spline 17 </ b> C of the output shaft 17, the bolt 28 inserted through each bolt insertion hole 27 </ b> B into the nut member 21. By being screwed, it is configured to be fixed to the output shaft 17 via the nut member 21.

  As a result, the magnetic plate 27 serves to stop the nut member 21 from rotating with respect to the output shaft 17 and rotates integrally with the output shaft 17 while maintaining a minute gap with the inner surface of the housing 12. It plays the role of adsorbing and capturing the metal powder mixed in the lubricating oil. Each oil hole 27 </ b> C of the magnetic plate 27 guides the lubricating oil to the lower side of the magnetic plate 27 when the lubricating oil is supplied into the housing 12 from the oil supply pipe 9 after the speed reducer 11 is assembled, for example. Thus, the refueling operation is performed quickly.

  The reduction gear 11 according to the present embodiment has the above-described configuration. When the motor shaft 8A of the hydraulic motor 8 rotates, the rotation of the motor shaft 8A is reduced by two stages by the planetary gear reduction mechanisms 15 and 16 and output. The pinion 18 is transmitted to the shaft 17 and rotates with a large rotational force (torque).

  Then, the pinion 18 revolves along the inner ring 3A while meshing with the inner teeth 3D provided on the inner ring 3A of the turning wheel 3, and the revolution force of the pinion 18 is transmitted to the turning frame 4A via the housing 12, The turning frame 4A turns on the round body 2A.

  Here, during the operation of the speed reducer 11 described above, wear dust generated from the meshing portions of the sun gears 15A and 16A and the planetary gears 15B and 16B constituting the planetary gear speed reduction mechanisms 15 and 16, etc., the planetary gear speed reduction mechanism 15 , 16 and the metal powder M such as chips remaining without being removed by washing at the time of processing each member is mixed into the lubricating oil in the housing 12 (see FIG. 3).

  Then, the metal powder M mixed in the lubricating oil is agitated in the housing 12 together with the lubricating oil by the operation of the speed reducing device 11 and settles down to the lower side of the planetary gear speed reducing mechanism 16 by its own weight.

  Here, the speed reduction device 11 according to the present embodiment is provided with a magnetic plate 27 that is positioned below the planetary gear speed reduction mechanism 16 and rotates integrally with the output shaft 17. For this reason, the metal powder M that has settled down to the planetary gear speed reduction mechanism 16 can be attracted and captured on the surface of the magnetic plate 27 by the magnetism of the magnetic plate 27.

  In this case, since the captured metal powder M is adsorbed by the magnetism of the magnetic plate 27, the metal powder M is removed from the magnetic plate 27 even if the lubricating oil is stirred in the housing 12 during the operation of the speed reducer 11. It is possible to suppress the withdrawal. Accordingly, the metal powder M mixed in the lubricating oil can be prevented from entering the upper bearing 19 and the lower bearing 20, and the output shaft 17 supported by the upper and lower bearings 19, 20 can be kept for a long time. And can be rotated smoothly. Further, the metal powder M mixed in the lubricating oil can be prevented from adhering to the sliding contact portion between the outer peripheral surface of the sleeve 24 and the oil seal 25, and the life of the oil seal 25 can be extended.

  Moreover, since the metal powder M mixed in the lubricating oil is captured by the magnetic plate 27, the lubricating oil can be kept clean for a long period of time. The frequency of discharging to the outside of 12 can be reduced, and the maintainability of the reduction gear 11 can be improved.

  Here, when the metal powder M mixed in the lubricating oil is adsorbed on the surface of the magnetic plate 27, and the metal powder M is deposited on the surface of the magnetic plate 27, the bolts 28 are removed and the magnetic plate 27 is removed. Is removed from the nut member 21. And, for example, after wiping and removing the metal powder M adhering to the magnetic plate 27, by attaching the cleaned magnetic plate 27 to the nut member 21, or by attaching a new magnetic plate 27 to the nut member 21, The metal powder M can be captured by the magnetic plate 27. Therefore, the lubricating oil in the housing 12 can be kept clean for a long period of time, and the reliability of the reduction gear 11 can be improved.

  In addition, since the magnetic plate 27 is provided with a plurality of oil holes 27C, for example, when the lubricating oil is supplied into the housing 12 through the oil supply pipe 9 or the like when the speed reducer 11 is assembled, It is possible to smoothly flow down to the lower side of the magnetic plate 27 through each oil hole 27 </ b> C provided in the magnetic plate 27. Thereby, the supply operation of the lubricating oil into the housing 12 can be quickly performed without being obstructed by the magnetic plate 27, and the maintainability can be improved.

  In addition, the speed reducer 11 according to the present embodiment forms the female spline 27A on the magnetic plate 27, and the magnetic plate 27 is fitted to the male spline 17C of the output shaft 17 in the state where the female spline 27A is fitted. It is set as the structure fixed using the volt | bolt 28. Thereby, the magnetic plate 27 has an action of capturing the metal powder M in the lubricating oil and an action of stopping (loosening) the nut member 21 that pressurizes the upper and lower bearings 19 and 20 with respect to the output shaft 17. Can also be used.

  Therefore, for example, instead of the existing locking member attached to the nut member 21, the magnetic plate 27 according to the present embodiment is attached to the nut member 21, so that the magnetic plate 27 can be lubricated without increasing the number of parts. The metal powder M mixed in the oil can be captured.

  Next, FIGS. 6 and 7 show a second embodiment of the present invention. The feature of this embodiment is that a magnetic plate is sandwiched between a nut member attached to an output shaft and an inner ring of a bearing. It is in the configuration. In the present 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.

  In the figure, reference numeral 31 denotes a reduction gear according to the present embodiment. The reduction gear 31 is substantially the same as the reduction gear 11 according to the first embodiment described above, and includes a housing 12, planetary gear reduction mechanisms 15 and 16, an output shaft. 17, upper and lower bearings 19, 20, a nut member 21, an oil seal 25, a magnetic plate 34 described later, and the like. However, the speed reduction device 31 according to the present embodiment is different from that according to the first embodiment in that the magnetic plate 34 is sandwiched between the inner ring 19B of the upper bearing 19 and the nut member 21. .

  Reference numeral 32 denotes a rotation stop plate fixed to the upper surface side of the nut member 21 with a bolt 33. The rotation stop plate 32 is formed, for example, as a disc having an outer diameter dimension substantially equal to that of the nut member 21, and its central portion. A female spline 32 </ b> A that fits with the male spline 17 </ b> C of the output shaft 17 is formed. The rotation stop plate 32 is fixed to the nut member 21 using the bolt 33 in a state where the female spline 32A is fitted to the male spline 17C of the output shaft 17, and the nut member 21 is stopped from rotating relative to the output shaft 17. (Loosening).

  Reference numeral 34 denotes a magnetic plate disposed between the nut member 21 and the upper bearing 19. The magnetic plate 34 is substantially the same as the magnetic plate 27 according to the first embodiment by using a magnetic material than the nut member 21. Further, a plate having a large diameter and slightly smaller than the inner surface of the lower housing 13 is formed, and the plate is configured as a permanent magnet by performing a magnetizing process using a magnetizer.

  Here, a shaft insertion hole 34A that is inserted into the small-diameter shaft portion 17A of the output shaft 17 is formed in the center of the magnetic plate 34, and the lubricating oil in the housing 12 flows on the outer peripheral side of the magnetic plate 34. A plurality of oil holes 34B are formed.

  The magnetic plate 34 includes the inner ring 19B of the upper bearing 19 fitted to the small diameter shaft portion 17A of the output shaft 17 and the output shaft 17 in a state where the shaft insertion hole 34A is inserted into the small diameter shaft portion 17A of the output shaft 17. It is fixed to the output shaft 17 by being sandwiched from above and below with the nut member 21 screwed into the male screw portion 17D. Thereby, the magnetic plate 34 rotates integrally with the output shaft 17 while maintaining a minute gap between the inner surface of the lower housing 13 and adsorbs and captures the metal powder M mixed in the lubricating oil. It has become.

  The reduction gear 31 according to the present embodiment has the above-described configuration, and the basic operation of capturing the metal powder M mixed in the lubricating oil by the magnetic plate 34 is according to the first embodiment described above. There is no particular difference from the reduction gear 11.

  However, according to the present embodiment, the magnetic plate 34 is screwed into the inner ring 19B of the upper bearing 19 fitted to the small-diameter shaft portion 17A of the output shaft 17 and the nut member 17D of the output shaft 17 that is screwed. 21 is configured to be sandwiched from above and below. For this reason, when the nut member 21 is screwed onto the male thread portion 17D of the output shaft 17 and the upper and lower bearings 19 and 20 are pressurized, the magnetic plate is interposed between the inner ring 19B of the upper bearing 19 and the nut member 21. The magnetic plate 34 can be easily fixed to the output shaft 17 simply by sandwiching 34, and the mounting work of the magnetic plate 34 can be simplified. In addition, parts such as dedicated bolts for attaching the magnetic plate 34 can be made unnecessary, so that an increase in the number of parts can be suppressed.

  Next, FIGS. 8 and 9 show a third embodiment of the present invention, which is characterized in that a magnetic plate is sandwiched between an inner ring of a bearing attached to an output shaft and a sleeve. It is in that. In the present 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.

  In the figure, reference numeral 41 denotes a reduction gear according to the present embodiment. The reduction gear 41 is substantially the same as the reduction gear 11 according to the first embodiment described above, and includes a housing 12, planetary gear reduction mechanisms 15 and 16, an output shaft. 17, upper and lower bearings 19 and 20, a sleeve 42 described later, a magnetic plate 44, and the like. However, the speed reduction device 41 according to the present embodiment is different from that according to the first embodiment in that the magnetic plate 44 is sandwiched between the inner ring 20B of the lower bearing 20 and the sleeve 42. .

  Reference numeral 42 denotes a cylindrical sleeve located between the pinion 18 and the lower bearing 20 and fitted and fixed to the large-diameter shaft portion 17B of the output shaft 17. The sleeve 42 rotates integrally with the output shaft 17. To do. The outer peripheral surface of the sleeve 42 faces the inner peripheral surface of the cylindrical portion 22B constituting the seal holding member 22 over the entire periphery, and becomes a seal surface 42A in which a lip portion 43C of an oil seal 43 described later is in sliding contact. Yes.

  43 is an annular oil seal held on the lower end side of the housing 12 by the seal holding member 22. The oil seal 43 includes a metal ring 43A serving as a mandrel formed in an annular shape with a substantially J-shaped cross section, The seal portion 43B is made of a rubber material fixed to the metal ring 43A by means of baking or the like, and the inner peripheral side of the seal portion 43B is a lip portion 43C.

  The oil seal 43 seals the lubricating oil in the housing 12 by press-fitting the metal ring 43A into the cylindrical portion 22B of the seal holding member 22 and sliding the lip portion 43C against the seal surface 42A of the sleeve 42. It will stop.

  44 is a magnetic plate disposed between the lower bearing 20 and the sleeve 42. The magnetic plate 44 uses a magnetic material to form a plate having a slightly smaller diameter than the inner surface of the seal holding member 22. The plate is configured as a permanent magnet by performing a magnetizing process using a magnetizer.

  Here, a shaft insertion hole 44A that is inserted through the large-diameter shaft portion 17B of the output shaft 17 is formed at the center of the magnetic plate 44. The magnetic plate 44 has a shaft insertion hole 44A that extends through the large diameter of the output shaft 17. The output shaft is clamped from the upper and lower directions between the inner ring 20B of the lower bearing 20 and the sleeve 42 inserted into the large-diameter shaft portion 17B of the output shaft 17 while being inserted into the shaft portion 17B. 17 to be fixed. Thereby, the magnetic plate 44 rotates integrally with the output shaft 17 while keeping a minute gap between the inner surface of the seal holding member 22 and adsorbs and captures the metal powder M mixed in the lubricating oil. It has become.

  In this case, the magnetic plate 44 is disposed between the lower bearing 20 and the oil seal 25, and the lubrication oil supply operation into the housing 12 is not hindered by the magnetic plate 44. Are not provided with oil holes for the purpose of lubricating oil distribution.

  The reduction gear 41 according to the present embodiment has the above-described configuration, and the basic operation of capturing the metal powder M mixed in the lubricating oil by the magnetic plate 44 is according to the first embodiment described above. There is no particular difference from the reduction gear 11.

  However, according to the present embodiment, the magnetic plate 44 is sandwiched from the upper and lower directions between the inner ring 20B of the lower bearing 20 and the sleeve 42, which are inserted into the large-diameter shaft portion 17B of the output shaft 17. Since the configuration is adopted, the magnetic plate 44 can be easily fixed to the output shaft 17, and the mounting work of the magnetic plate 44 can be simplified.

  Next, FIGS. 10 and 11 show a fourth embodiment of the present invention. The feature of this embodiment is that an annular mounting seat that surrounds the output shaft from the outer peripheral side is provided on the inner surface of the housing. The magnetic plate is attached to the mounting seat. In the present 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.

  In the figure, reference numeral 51 denotes a reduction gear according to the present embodiment. The reduction gear 51 is substantially the same as the reduction gear 11 according to the first embodiment described above, and will be described later with a housing 52, planetary gear reduction mechanisms 15, 16, The output shaft 17, upper and lower bearings 19 and 20, a magnetic plate 56 described later, and the like. However, the speed reduction device 51 according to the present embodiment is different from that according to the first embodiment in that a magnetic plate 56 is fixed to a plate mounting seat 55 described later provided in the housing 52.

  Reference numeral 52 denotes a cylindrical housing extending upward and downward. The housing 52 includes a lower housing 53 fixed to the upper surface side of the turning frame 4 </ b> A and a cylindrical housing fixed to the upper end side of the lower housing 53. The hydraulic motor 8 is attached to the upper end side of the upper housing 54.

  Here, on the inner peripheral side of the lower housing 53, an upper bearing attachment portion 53A to which the upper bearing 19 is attached and a lower bearing attachment portion 53B to which the lower bearing 20 is attached are spaced apart upward and downward. Is provided. On the other hand, on the inner peripheral side of the upper housing 54, there are upper internal teeth 54A that mesh with the planetary gear 15B of the planetary gear reduction mechanism 15 and lower internal teeth 54B that mesh with the planetary gear 16B of the planetary gear reduction mechanism 16. Each is formed over the entire circumference.

  55 is a plate mounting seat provided on the inner surface of the lower housing 53 and positioned below the planetary gear speed reduction mechanism 16, and the plate mounting seat 55 is raised upward from the upper bearing mounting portion 53A for output. It is formed as an annular step portion surrounding the shaft 17 from the outer peripheral side. The plate mounting seat 55 is screwed with a plurality of bolt holes (female screw holes) 55A at equal intervals in the circumferential direction.

  A magnetic plate 56 is attached to the plate mounting seat 55. The magnetic plate 56 is formed of a magnetic material to form a plate having an outer diameter substantially equal to the outer diameter of the plate mounting seat 55. A permanent magnet is formed by performing a magnetizing process using the.

  Here, a nut member insertion hole 56A through which the lower end side of the nut member 21 is inserted with a slight gap is provided at the center of the magnetic plate 56, and each bolt of the plate mounting seat 55 is provided on the outer peripheral side of the magnetic plate 56. A plurality of bolt insertion holes 56B corresponding to the holes 55A are formed. Further, a plurality of oil holes 56C through which the lubricating oil in the housing 52 flows is formed between the nut member insertion hole 56A and the bolt insertion hole 56B.

  The magnetic plate 56 is screwed into the bolt hole 55A of the plate mounting seat 55 with the bolt 57 inserted into the bolt insertion hole 56B in a state where the nut member insertion hole 56A is inserted into the lower end side of the nut member 21. It is fixed to the lower housing 53. Thereby, the magnetic plate 56 adsorbs the metal powder M mixed in the lubricating oil while being fixed to the lower housing 53 while maintaining a minute gap between the magnetic plate 56 and the nut member 21 fixed to the output shaft 17. It is configured to capture.

  The reduction gear 51 according to the present embodiment has the above-described configuration, and the metal powder M mixed in the lubricating oil during the operation of the reduction gear 51 is stirred in the housing 52 together with the lubricating oil by its own weight. It sinks below the planetary gear reduction mechanism 16 and is attracted to and captured by the surface of the magnetic plate 56.

  Here, the speed reduction device 51 according to the present embodiment is configured to be fixed to the lower housing 53 by attaching the magnetic plate 56 to the plate mounting seat 55, so that the magnetic plate 56 is integrated with the output shaft 17. There is no rotation. Thereby, the metal powder M captured by the magnetic plate 56 is not separated from the magnetic plate 56, and a large amount of the metal powder M can be reliably captured by the magnetic plate 56.

  Further, by attaching the magnetic plate 56 to the plate mounting seat 55 provided on the inner side surface of the lower housing 53, no gap is formed between the inner side surface of the lower housing 53 and the magnetic plate 56. For this reason, even if the metal powder M settles in the lubricant oil along the inner surface of the housing 52 by stirring the lubricant in the housing 52 when the speed reducer 51 is operated, the metal powder M is removed from the magnetic plate. 56 can be reliably captured.

  Next, FIGS. 12 and 13 show a fifth embodiment of the present invention. The feature of this embodiment is that a magnetic plate is sandwiched between a seal holding member provided on the lower side of the housing and an oil seal. It is in the configuration. In the present 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.

  In the figure, reference numeral 61 denotes a reduction gear according to the present embodiment. The reduction gear 61 is substantially similar to the reduction gear 11 according to the first embodiment described above, and includes a housing 12, planetary gear reduction mechanisms 15 and 16, an output shaft. 17, upper and lower bearings 19 and 20, a seal holding member 62, an oil seal 64, and a magnetic plate 65, which will be described later. However, the speed reduction device 61 according to the present embodiment is different from that according to the first embodiment in that the magnetic plate 65 is sandwiched between the seal holding member 62 and the oil seal 64.

  62 is a stepped cylindrical seal holding member attached to the lower end side of the housing 12, and the seal holding member 62 includes an annular flange portion 62A fixed to the lower end surface of the lower housing 13 with a bolt 63; The annular flange portion 62B protrudes upward from the flange portion 62A and is fitted to the lower bearing mounting portion 13B of the lower housing 13, and the cylindrical portion 62C protrudes downward from the flange portion 62A. The seal holding member 62 holds the oil seal 64 on the lower end side of the housing 12 by fitting an oil seal 64 described later on the inner peripheral side of the cylindrical portion 62C.

  Reference numeral 64 denotes an annular oil seal held on the lower end side of the housing 12 by a seal holding member 62. The oil seal 64 includes a metal ring 64A serving as a mandrel formed in an annular shape with a substantially J-shaped cross section, The seal portion 64B is made of a rubber material fixed to the metal ring 64A by means of baking or the like, and the inner peripheral side of the seal portion 64B is a lip portion 64C.

  The oil seal 64 is held by the seal holding member 62 on the lower end side of the housing 12 by press-fitting the metal ring 64 </ b> C into the cylindrical portion 62 </ b> C of the seal holding member 62, and the lip portion 64 </ b> C is connected to the output shaft 17. The lubricating oil is sealed in the housing 12 by being brought into sliding contact with the seal surface 24A of the sleeve 24 fitted to the large-diameter shaft portion 17B.

  Reference numeral 65 denotes a magnetic plate disposed between the seal holding member 62 and the oil seal 64, and the magnetic plate 65 is made of a magnetic material and has a slightly smaller diameter than the inner surface of the cylindrical portion 62C of the seal holding member 62. By forming and applying a magnetizing process to the plate using a magnetizer, the plate is configured as a permanent magnet.

  Here, at the center of the magnetic plate 65, a sleeve insertion hole 65A is formed in the upper end side of the sleeve 24 with a slight gap. The magnetic plate 65 is disposed in the cylindrical portion 62C of the seal holding member 62 with the sleeve insertion hole 65A inserted into the upper end side of the sleeve 24, and the metal ring 64A of the oil seal 64 is press-fitted into the cylindrical portion 62C. As a result, the flange 62B of the seal holding member 62 and the metal ring 64A of the oil seal 64 are sandwiched from above and below and fixed to the lower housing 13. As a result, the magnetic plate 65 adsorbs the metal powder M mixed in the lubricating oil while being fixed to the lower housing 13 while maintaining a minute gap between the magnetic plate 65 and the sleeve 24 fixed to the output shaft 17. To capture.

  The reduction gear 61 according to the present embodiment has the above-described configuration, and the metal powder M mixed in the lubricating oil when the reduction gear 61 is operated is stirred in the housing 12 together with the lubricating oil by its own weight. It sinks below the planetary gear reduction mechanism 16 and is attracted to and captured by the surface of the magnetic plate 65.

  Here, the speed reducer 61 according to the present embodiment sandwiches the magnetic plate 65 between the flange portion 62B of the seal holding member 62 and the metal ring 64A of the oil seal 64, whereby the magnetic plate 65 is placed in the lower housing. 13 is fixed to the structure. Thereby, the metal powder M captured by the magnetic plate 65 is not detached from the magnetic plate 65, and a large amount of the metal powder M can be reliably captured by the magnetic plate 65.

  In the first embodiment described above, the case where the magnetic plate 27 is configured as a permanent magnet by performing a magnetizing process on an annular plate formed using a magnetic material is exemplified. However, the present invention is not limited to this, and for example, a plate 71 such as a modification shown in FIG. 14 may be used.

  That is, for example, a non-magnetic material such as aluminum, copper, or a resin material is used, and an annular fixing portion 71A that is fixed to the nut member 21 and means such as adhesion and fitting on the outer peripheral side of the fixing portion 71A are provided. You may use the plate 71 comprised by magnets 71B, such as a permanent magnet, a ferrite magnet, a plastic magnet, a rubber magnet, etc. which were fixed by using.

  Moreover, you may use the plate which affixed magnets, such as a permanent magnet, on the surface of the plate formed circularly using the magnetic material and the nonmagnetic material. The same applies to the magnetic plates 34, 44, 56, 65 used in the second, third, fourth, and fifth embodiments.

  In the first embodiment described above, the case where the magnetic plate 27 is formed as a flat plate is taken as an example. However, the present invention is not limited to this. For example, in order to efficiently capture the metal powder by increasing the surface area, it may be formed as a plate having a large number of pores, and dimple-like irregularities on the surface. You may form as a plate provided with the part. The same applies to the magnetic plates 34, 44, 56, 65 used in the second, third, fourth, and fifth embodiments.

  Moreover, in each embodiment mentioned above, the case where the two-stage planetary gear reduction mechanisms 15 and 16 are provided in the housing 12 is illustrated. However, the present invention is not limited to this. For example, a single-stage planetary gear reduction mechanism or a three-stage or higher planetary gear reduction mechanism may be provided.

  Furthermore, in each embodiment mentioned above, the case where it applied to the turning apparatus 7 of the hydraulic excavator 1 was described as an example. However, the present invention is not limited to this, and may be applied to, for example, a turning device for other construction machines such as a hydraulic crane, and various reduction devices used in addition to the turning device.

1 is a front view showing a hydraulic excavator to which a reduction gear according to a first embodiment of the present invention is applied. 1 is a longitudinal sectional view showing a reduction gear device according to a first embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view showing a main part of a housing, an output shaft, a nut member, a magnetic plate and the like in FIG. 2 in an enlarged manner. FIG. 4 is a cross-sectional view of a housing, an output shaft, a magnetic plate, and the like when viewed from the direction of arrows IV-IV in FIG. 3. It is a top view which shows a magnetic plate alone. It is a longitudinal cross-sectional view which shows the reduction gear device by the 2nd Embodiment of this invention. FIG. 7 is an enlarged cross-sectional view of a main part showing the main parts such as an output shaft, nut member, upper bearing, and magnetic plate in FIG. 6 in an enlarged manner. It is a longitudinal cross-sectional view which shows the reduction gear device by the 3rd Embodiment of this invention. FIG. 9 is an enlarged cross-sectional view of main parts showing the main parts such as an output shaft, a sleeve, a lower bearing, and a magnetic plate in FIG. 8 in an enlarged manner. It is a longitudinal cross-sectional view which shows the reduction gear device by the 4th Embodiment of this invention. It is a principal part expanded sectional view which expands and shows principal parts, such as a housing in FIG. 10, a plate mounting seat, and a magnetic plate. It is a longitudinal cross-sectional view which shows the reduction gear device by the 5th Embodiment of this invention. It is a principal part expanded sectional view which expands and shows principal parts, such as a housing in FIG. 12, a seal holding member, an oil seal, and a magnetic plate. It is a principal part expanded sectional view seen from the same position as FIG. 3 which shows the modification of a magnetic plate.

Explanation of symbols

11, 31, 41, 51, 61 Deceleration device 12, 52 Housing 13, 53 Lower housing 14, 54 Upper housing 15, 16 Planetary gear reduction mechanism 15A, 16A Sun gear 15B, 16B Planetary gear 15C, 16C Carrier 17 Output shaft 17C Male spline 19 Upper bearing 19A, 20A Outer ring 19B, 20B Inner ring 20 Lower bearing 21 Nut member 22, 62 Seal holding member 24, 42 Sleeve 25, 43, 64 Oil seal 27, 34, 44, 56, 65 Magnetic plate ( plate)
27A Male spline 27C, 34B, 56C Oil hole 28 Bolt 55 Plate mounting seat 71 Plate

Claims (8)

A cylindrical housing that extends upward and downward, a speed reduction mechanism that is provided in the housing and decelerates the rotation of a rotation source, and is positioned in the lower side above the speed reduction mechanism and rotates in the housing. A speed reducer comprising an output shaft that is provided and outputs a rotation decelerated by the speed reduction mechanism;
Below the speed reduction mechanism, a magnetic plate is fixed to one of the output shaft and the housing, and the metal powder in the lubricating oil filled in the housing is captured by the plate. A speed reducer characterized by being configured to perform.   The speed reducer according to claim 1, wherein the plate is formed by an annular plate surrounding the output shaft from the outside in the radial direction, and the plate is provided with an oil hole through which the lubricating oil in the housing flows. A bearing that rotatably supports the output shaft is provided between the housing and the output shaft,
A nut member that is positioned above the bearing and pressurizes the bearing in the axial direction is screwed to the outer peripheral side of the output shaft,
The speed reducer according to claim 1 or 2, wherein the plate is fixed to the output shaft by being attached to the nut member. Provided on the outer peripheral side of the output shaft is a male spline to which the carrier constituting the speed reduction mechanism is splined,
The speed reducer according to claim 3, wherein the plate is configured to be attached to the nut member in a state of being fitted to an outer peripheral side of the male spline. A bearing that rotatably supports the output shaft is provided between the housing and the output shaft,
A nut member that is positioned above the bearing and pressurizes the bearing in the axial direction is screwed to the outer peripheral side of the output shaft,
The speed reducer according to claim 1 or 2, wherein the plate is configured to be fixed to the output shaft by being sandwiched between an inner ring of the bearing and the nut member. A bearing that rotatably supports the output shaft is provided between the lower portion of the housing and the output shaft, and the lower portion of the housing is located below the bearing and is located in the housing. An oil seal is provided to seal the lubricating oil.
Provided on the outer peripheral side of the output shaft is a sleeve located on the lower side of the bearing and in contact with the oil seal,
The speed reducer according to claim 1 or 2, wherein the plate is configured to be fixed to the output shaft by being sandwiched between an inner ring of the bearing and the sleeve. Provided on the inner surface of the housing is an annular mounting seat that is located below the speed reduction mechanism and surrounds the output shaft from the outer peripheral side;
The speed reducer according to claim 1, wherein the plate is configured to be fixed to the housing by being attached to the attachment seat. A bearing that rotatably supports the output shaft is provided between the lower portion of the housing and the output shaft, and a seal holding member is provided on the lower portion of the housing and is located below the bearing. Providing the seal holding member with an oil seal that seals lubricating oil in the housing;
The speed reducer according to claim 1 or 2, wherein the plate is configured to be fixed to the housing by being sandwiched between the seal holding member and the oil seal.

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