JP2009150475A - Reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduction gear for restricting intrusion of grease into a housing by improving workability when exchanging a seal member for sealing between the housing and a shield plate. <P>SOLUTION: A notch groove 26 having an upper wall surface 26A facing a shield plate 25 and a peripheral wall surface 26B extending in the axial direction on the inner diameter side of the upper wall surface 26A toward the shield plate 25 is provided in a corner part between a peripheral side and a lower surface side of a cylinder part 13B structuring a lower housing 13, and a seal member 27 formed into an annular shape by using an urethane rubber is provided between the notch groove 26 and the shield plate 25. With this structure, since the seal member 27 is installed in the peripheral wall part 26B of the notch groove 26 from the peripheral side thereof, abrasion condition of the seal member 27 is easily confirmed from outside. Further, when exchanging the seal member 27, it is unnecessary to remove the seal member 27 by disassembling a reduction gear 11, and workability when exchanging the seal member 27 is thereby improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

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 on the lower running body is provided between the lower traveling body and the upper turning body, and the turning device decelerates rotation of a rotation source composed of a hydraulic motor or the like. A reduction gear for increasing the torque is provided.

  This type of prior art reduction device usually has a housing provided with a rotation source at the upper end, a reduction mechanism provided in the housing for reducing the rotation of the rotation source, and the housing extending upward and downward. An output shaft that outputs rotation reduced by the speed reduction mechanism, a pinion that is provided on the lower end side of the output shaft and meshes with a gear, and is spaced apart upward and downward between the housing and the output shaft. An upper seal and a lower bearing which are provided and rotatably support the output shaft, and an oil seal which is provided between the upper and lower bearings and is provided between the housing and the output shaft and seals lubricating oil in the housing. And a disc-shaped shielding plate provided between the lower bearing and the pinion.

  Here, the inner side of the shielding plate is sandwiched between the lower bearing and the pinion, and the outer side extends to the lower end of the housing. When the grease that lubricates the meshing portion between the pinion and the gear provided on the output shaft is ejected toward the housing by the pump action when the pinion and the gear mesh, this grease enters the housing. It is the structure which can prevent that with a shielding board.

  In addition, a seal member is provided between the shielding plate and the housing. The seal member seals the lubricating oil for lubricating the lower bearing in the housing, and is ejected from the meshing portion of the pinion and the gear. This prevents the grease and foreign matter mixed in the grease from entering the housing (see, for example, Patent Documents 1 and 2).

Japanese Utility Model Publication No. 63-44573 German Patent Application Publication No. 19603007

  However, in the reduction gear device according to Patent Document 1 described above, the seal member is fixed to the outer peripheral side of the shielding plate sandwiched between the inner ring of the lower bearing and the pinion of the output shaft. For this reason, when the seal member worn by sliding contact with the shielding plate is replaced, it is necessary to disassemble the entire reduction gear in order to remove the shielding plate disposed between the lower bearing and the pinion. There exists a problem that workability | operativity at the time of replacing | exchanging a member will fall.

  On the other hand, in the reduction gear device according to Patent Document 2, an annular groove is formed on the lower surface of the housing, and a seal member is provided between the annular groove and the shielding plate. For this reason, even if the seal member is worn due to sliding contact with the shielding plate, there is a problem that the wear state of the seal cannot be confirmed from the outside. In addition, when replacing the seal member, it is necessary to disassemble the entire speed reducer to remove the shielding plate disposed between the lower bearing and the pinion, thus reducing workability when replacing the seal member. There is a problem of end up.

  The present invention has been made in view of the above-described problems of the prior art, and improves workability when replacing a seal member that seals between a housing and a shielding plate, and allows grease or the like to enter the housing for a long time. An object of the present invention is to provide a speed reducer that can be suppressed over a wide range.

  In order to solve the above-described problems, the present invention provides a housing provided with a rotation source on the upper end side, a speed reduction mechanism provided in the housing for decelerating the rotation of the rotation source, and upward and downward directions in the housing. An output shaft that extends to be output and outputs rotation decelerated by the speed reduction mechanism, a pinion that is provided on the lower end side of the output shaft and meshes with a gear, and an upward and downward direction between the housing and the output shaft An upper bearing and a lower bearing that are provided apart from each other and rotatably support the output shaft, and are located between the upper and lower bearings and provided between the housing and the output shaft. An oil seal that seals the lubricating oil that lubricates the speed reduction mechanism, an inner peripheral side is sandwiched between the lower bearing and the pinion, and an outer peripheral side extends to a lower end portion of the housing, and the pinion and the teeth Applied to the speed reduction device comprising a disc-shaped shield plate the engaging portion is grease lubricated to block from entering into the housing with the.

  The invention according to claim 1 is characterized in that the lower end of the housing is notched over the entire periphery in a state of opening at the corners of the outer peripheral side and the lower surface side of the housing, A notch groove having an upper wall surface facing downward and an annular peripheral wall surface extending in the axial direction on the inner diameter side of the upper wall surface is provided, and an annular seal member is provided between the notch groove and the shielding plate. The seal member includes a main body portion that is attached to the peripheral wall surface of the notch groove from the outer periphery side thereof with a binding force, and a protruding shape that protrudes from the main body portion and contacts the upper wall surface of the notch groove and slidably contacts the shielding plate. This is because it is constituted by a lip portion.

  According to a second aspect of the present invention, the projecting lip portion of the seal member is configured by a triangular lip portion having a triangular cross section protruding from the upper surface side and the lower surface side of the main body portion.

  The invention of claim 3 is that two or more of the protruding lip portions of the seal member are provided on the upper surface side and the lower surface side of the main body portion.

  According to a fourth aspect of the present invention, the projecting lip portion of the seal member is concentrically arranged with an equal diameter on the upper surface side and the lower surface side of the main body portion.

  The invention according to claim 5 is that the projecting lip portion of the seal member is constituted by a plurality of types of triangular lip portions having a triangular cross section projecting from the main body portion with different projecting lengths.

  The invention according to claim 6 is that the seal member is formed using urethane rubber.

  According to the first aspect of the present invention, when the main body portion of the seal member is attached to the peripheral wall surface of the notch groove provided in the lower end portion of the housing with a binding force, the projecting lip portion protruding from the main body portion becomes the notch groove. Abuts against the upper wall surface and slidably contacts the shielding plate. The projecting lip portion slidably in contact with the shielding plate is quickly worn by the rotation of the shielding plate together with the pinion, and is stabilized in a state of being in sliding contact with the shielding plate with an appropriate surface pressure. As described above, the positive sealing function of the sealing member can be maintained over a long period of time by actively wearing the sealing member so that the sliding contact surface between the sealing member and the shielding plate is quickly adapted.

  In addition, the notch groove is formed in a state of being opened over the entire circumference at the corner portion of the outer peripheral side and the lower surface side of the housing, and the seal member can be attached to the peripheral wall surface of the notch groove from the outer peripheral side. The wear state of the seal member can be easily confirmed from the outside. In addition, since it is not necessary to disassemble the speed reducer in order to replace the seal member, it is possible to improve workability when replacing the worn seal member.

  According to the invention of claim 2, by forming the projecting lip portion of the seal member by the triangular lip portion, the tip end of the triangular lip portion is surely brought into contact with the upper wall surface of the notch groove, and the shielding plate is securely attached. Can be brought into sliding contact. As a result, the surface pressure of the triangular lip portion that is in sliding contact with the shielding plate can be increased and the initial wear can be promoted, so that the triangular lip portion can be brought into sliding contact with the shielding plate with an appropriate surface pressure at an early stage. As a result, the housing and the shielding plate can be reliably sealed by the sealing member, and the lubricating oil for lubricating the lower bearing is sealed in the housing and ejected from the meshing portion of the pinion and the gear. Since it is possible to prevent the grease, foreign matter and the like from entering the housing, the reliability of the reduction gear can be improved.

  According to the invention of claim 3, two or more projecting lip portions provided on the upper surface side of the main body portion abut on the upper wall surface of the notch groove, respectively, and two or more projecting shapes provided on the lower surface side of the main body portion. When the lip portion is in sliding contact with the shielding plate, the posture of the sealing member can be stabilized in a state where the sealing member is assembled between the notch groove and the shielding plate, and stable sealing performance can be maintained. .

  According to the invention of claim 4, the protruding lip portion provided on the upper surface side of the main body portion and the protruding lip portion provided on the lower surface side can be disposed at equal positions. For this reason, when assembling the seal member between the notch groove and the shielding plate, it is not necessary to distinguish between the upper surface side and the lower surface side of the seal member, and the erroneous assembly of the seal member can be eliminated. Workability at the time of assembling the members can be improved.

  According to the invention of claim 5, by forming the projecting lip portion of the seal member with a plurality of types of triangular lip portions having different projecting lengths from the main body portion, for example, the triangular lip portion having the largest projecting length is provided. Even if it is greatly worn by sliding contact with the shielding plate, other triangular lip portions having a small protruding length can be slidably contacted with the shielding plate with an appropriate surface pressure. Thereby, the lifetime of a sealing member can be extended and it can seal reliably between a housing and a shielding board over a long term with one sealing member.

  According to the invention of claim 6, by forming the seal member using urethane rubber, it is possible to enhance the wear resistance while ensuring the elasticity of the seal member. Therefore, the sealing member can be mounted with an appropriate binding force (tightening allowance) on the peripheral wall surface of the notch groove, and the life of the sealing member is extended, and the sealing performance between the housing and the shielding plate is prolonged. It can be kept appropriate over the entire range.

  Hereinafter, the embodiment of the speed reducer according to the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the present invention is applied to a swing device of a hydraulic excavator.

  First, FIG. 1 to FIG. 6 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a round body provided on a lower traveling body (not shown) of the excavator, and 2 denotes a turning frame constituting an upper turning body (not shown) of the hydraulic excavator.

  A swivel wheel 3 is provided between the round cylinder 1 and the swivel frame 2 so as to turn the swivel frame 2 with respect to the round cylinder 1. The swivel ring 3 is fixed on the round drum 1. The inner ring 3A, the outer ring 3B fixed to the lower surface side of the turning frame 2, and a plurality of steel balls 3C (only one is shown) disposed between the inner ring 3A and the outer ring 3B.

  Further, an inner gear 3D as a gear meshed with a pinion 20 described later is formed on the inner peripheral side of the inner ring 3A, and the pinion 20 and the inner gear 3D are formed below the inner gear 3D. A grease bath 4 containing grease for lubricating the meshing portion is provided.

  Reference numeral 5 denotes a turning device provided between the inner ring 3 </ b> A of the turning wheel 3 fixed to the round body 1 and the turning frame 2, and the turning device 5 turns the turning frame 2 on the round body 1. . Here, the turning device 5 includes a hydraulic motor 6 as a rotation source, and a later-described reduction device 11 that reduces the rotation of the motor shaft 6A of the hydraulic motor 6 and transmits a large rotational force (torque) to the turning wheel 3. It is roughly constituted by.

  Reference numeral 11 denotes a speed reducer that reduces the rotation of the hydraulic motor 6. The speed reducer 11 includes a housing 12, planetary gear speed reduction mechanisms 17 and 18, which will be described later, an output shaft 19, a pinion 20, an upper bearing 21, a lower bearing 22, and a shield. It is comprised by the board 25, the sealing member 27, etc.

  Reference numeral 12 denotes a cylindrical housing that forms an outer shell of the speed reducer 11. The housing 12 includes a lower housing 13 fixed to the upper surface side of the revolving frame 2 and an upper side fixed to the upper end side of the lower housing 13. The housing 14 is generally configured.

  Here, on the lower side of the lower housing 13, a lower flange portion 13A that gradually increases in diameter downward, and a cylindrical portion 13B that protrudes downward from the radially inner side of the lower flange portion 13A are provided. A notch groove 26 described later is formed in the lower end portion 13C of the cylindrical portion 13B. Further, on the inner peripheral side of the lower housing 13, an upper bearing mounting portion 13D for mounting an upper bearing 21 described later and a lower bearing mounting portion 13E for mounting a lower bearing 22 described later are spaced upward and downward. Is provided. Further, the lower flange portion 13A of the lower housing 13 is fixed to the revolving frame 2 using a plurality of bolts 15, and the lower flange portion of the upper housing 14 using a plurality of bolts 16 on the upper end side of the lower housing 13. 14A is fixed.

  A hydraulic motor 6 as a rotation source is fixed to the upper end side of the upper housing 14. In addition, two internal gears 14B and 14C that are spaced upward and downward are formed on the inner peripheral side of the upper housing 14 over the entire circumference.

  Reference numeral 17 denotes a first stage planetary gear reduction mechanism as a reduction mechanism provided in the housing 12 below the hydraulic motor 6. The planetary gear reduction mechanism 17 decelerates the rotation of the hydraulic motor 6. is there. Here, the planetary gear speed reduction mechanism 17 meshes with the sun gear 17A splined to the motor shaft 6A of the hydraulic motor 6 and the sun gear 17A and the internal gear 14B of the upper housing 14, and surrounds the sun gear 17A. A plurality of planetary gears 17B (only one is shown) that revolves while rotating, and a carrier 17C that rotatably supports each planetary gear 17B.

  Reference numeral 18 denotes a second-stage planetary gear reduction mechanism as a reduction mechanism provided in the housing 12 below the planetary gear reduction mechanism 17. The planetary gear reduction mechanism 18 is a first-stage planetary gear reduction mechanism. The rotation of the hydraulic motor 6 decelerated by 17 is further decelerated. Here, the planetary gear reduction mechanism 18 meshes with the sun gear 18A spline-coupled to the carrier 17C of the first stage planetary gear reduction mechanism 17, the sun gear 18A, and the internal gear 14C of the upper housing 14, A plurality of planetary gears 18B (only one is shown) revolving while rotating around the gear 18A, and a carrier 18C that rotatably supports each planetary gear 18B. The carrier 18C of the planetary gear speed reduction mechanism 18 is splined to the upper end side of an output shaft 19 described later.

  An output shaft 19 is rotatably provided in the housing 12, and the output shaft 19 extends upward and downward (axial direction) in the housing 12 and can be rotated by an upper bearing 21 and a lower bearing 22 described later. It is supported by.

  Here, a male spline 19A is formed on the upper end side of the output shaft 19, and the male spline 19A is splined to the carrier 18C of the planetary gear reduction mechanism 18. As a result, the rotation of the hydraulic motor 6 is transmitted to the output shaft 19 while being decelerated in two stages by the planetary gear speed reduction mechanisms 17 and 18, and the output shaft 19 rotates at a low speed with a large torque (torque). It has become. A male screw portion 19B to which a nut member 23 described later is screwed is formed below the male spline 19A.

  Reference numeral 20 denotes a pinion integrally provided on the lower end side of the output shaft 19. The pinion 20 protrudes downward from the lower end portion of the cylindrical portion 13 </ b> B constituting the lower housing 13 and is provided on the inner ring 3 </ b> A of the swivel wheel 3. It meshes with the internal gear 3D. The pinion 20 transmits the rotation of the output shaft 19 to the inner ring 3 </ b> A of the turning wheel 3.

  Reference numeral 21 denotes an upper bearing provided between the housing 12 and the output shaft 19. The upper bearing 21 is provided on the outer ring 21 A fitted to the upper bearing mounting portion 13 D of the lower housing 13 and on the upper end side of the output shaft 19. The inner ring 21B is fitted and a plurality of rolling elements 21C provided between the outer ring 21A and the inner ring 21B.

  Reference numeral 22 denotes a lower bearing which is located below the upper bearing 21 and provided between the housing 12 and the output shaft 19. The lower bearing 22 is fitted to the lower bearing mounting portion 13 </ b> E of the lower housing 13. The combined outer ring 22A, an inner ring 22B fitted to the upper end side of the output shaft 19, and a plurality of rolling elements 22C provided between the outer ring 22A and the inner ring 22B.

  The upper bearing 21 and the lower bearing 22 support the output shaft 19 so as to be rotatable with respect to the housing 12 while being appropriately pressurized in the axial direction by a nut member 23 described later. Further, the upper bearing 21 is lubricated by lubricating oil sealed in the housing 12 by an oil seal 24 described later, and the lower bearing 22 is placed in the lower housing 13 by an oil seal 24 and a seal member 27 described later. It is configured to be lubricated by the sealed grease.

  Reference numeral 23 denotes a nut member positioned between the planetary gear speed reduction mechanism 18 and the upper bearing 21 and screwed to the male screw portion 19B of the output shaft 19. The nut member 23 has a disk shape as a whole, and the output shaft By being screwed onto the 19 male screw portions 19B, the lower surface thereof comes into contact with the inner ring 21B of the upper bearing 21. Further, by tightening the nut member 23, the upper bearing 21 and the lower bearing 22 can be pressurized in the axial direction.

  Reference numeral 24 denotes an annular oil seal that is located between the upper bearing 21 and the lower bearing 22 and provided between the housing 12 and the output shaft 19. The oil seal 24 has an outer peripheral side inside the lower housing 13. The inner peripheral side is slidably contacted with the outer peripheral surface of the output shaft 19 with appropriate elasticity. The oil seal 24 seals the lubricating oil for lubricating the planetary gear reduction mechanisms 17 and 18, the upper bearing 21, and the like in the housing 12.

  Reference numeral 25 denotes a shielding plate provided between the pinion 20 and the lower bearing 22, and the shielding plate 25 is formed in a disk shape having a larger outer diameter than the outer ring 22 </ b> A of the lower bearing 22. The inner peripheral side of the shielding plate 25 is sandwiched between the upper surface of the pinion 20 and the inner ring 22B of the lower bearing 22 while being inserted through the output shaft 19, and the outer peripheral side of the shielding plate 25 is the lower housing. 13 extends to the lower end portion 13C of the cylindrical portion 13B, and faces the lower end portion 13C with a slight gap in the upper and lower directions.

  Thus, the shielding plate 25 rotates integrally with the pinion 20 in a state where the lower bearing mounting portion 13E and the lower bearing 22 of the lower housing 13 are covered from the lower side over the entire circumference, and When grease that lubricates the meshing portion between the internal gear 3D and the pinion 20 is ejected upward from the meshing portion, the grease enters the housing 12 through the gap between the outer ring 22A and the inner ring 22B of the lower bearing 22. It blocks out intrusion.

  Reference numeral 26 denotes a notch groove provided in the lower end portion 13C of the cylindrical portion 13B constituting the lower housing 13, and the notch groove 26 is provided with a seal member 27 described later. Here, as shown in FIG. 2 and the like, the notch groove 26 is formed such that a corner portion between the outer peripheral side and the lower surface side of the cylindrical portion 13B constituting the lower housing 13 is recessed radially inward over the entire circumference. Is formed in an annular shape over the entire circumference in a state opened to the outer peripheral side and the lower surface side of the cylindrical portion 13B. The notch groove 26 includes an upper wall surface 26A facing the upper surface 25A of the shielding plate 25 in the upper and lower directions, and an annular peripheral wall surface 26B extending in the axial direction with the inner diameter side of the upper wall surface 26A facing the shielding plate 25. It is comprised by.

  Reference numeral 27 denotes an annular seal member mounted between the notch groove 26 and the shielding plate 25. The seal member 27 seals grease for lubricating the lower bearing 22 in the lower housing 13, and The grease ejected from the meshing portion between the internal gear 3D of the swivel wheel 3 and the pinion 20 and foreign matters mixed in the grease are prevented from entering the lower housing 13.

  Here, as shown in FIGS. 2 to 5, the seal member 27 includes an annular main body portion 27A attached to the peripheral wall surface 26B of the cutout groove 26 from the outer peripheral side, and the cutout groove 26 from the upper surface side of the main body portion 27A. Upper triangular lip portions 27B and 27C as projecting lip portions projecting toward the upper wall surface 26A, and lower sides as projecting lip portions projecting from the lower surface side of the main body portion 27A toward the upper surface 25A of the shielding plate 25 It is constituted by triangular lip portions 27D and 27E. The seal member 27 is formed using a rubber material having appropriate elasticity, high hardness, and excellent wear resistance, such as urethane rubber.

  In this case, as shown in FIGS. 2 and 3, assuming that the outer diameter of the peripheral wall surface 26B of the notch groove 26 is D and the inner diameter of the main body 27A of the seal member 27 is d, these outer diameter D and inner diameter. The dimension d is set to the relationship of the following formula 1.

  Here, the sealing member 27 formed using urethane rubber, for example, as indicated by a two-dot chain line in FIG. 2, has a tensile force in the radial direction in a state where a part thereof is hooked on the peripheral wall surface 26 </ b> B of the notch groove 26. To increase the diameter (elastic deformation). Thereby, the seal member 27 is reduced in diameter by releasing the tensile force after passing through the shielding plate 25 from the lower side of the pinion 20 in the expanded state, and as shown by a solid line in FIG. It is configured to be mounted on the peripheral wall surface 26B of 26 from the outer peripheral side with an appropriate binding force.

  In this case, the notch groove 26 is formed in an open state on the outer peripheral side and the lower surface side of the cylindrical portion 13 </ b> B constituting the lower housing 13, and the seal member 27 is attached to the peripheral wall surface 26 </ b> B of the notch groove 26 from the outer peripheral side. Has been. Therefore, the seal member 27 attached to the notch groove 26 can be visually observed from the outside, and it can be easily confirmed whether or not the seal member 27 is properly assembled.

  Next, the upper triangular lip portions 27B and 27C each have an isosceles triangular cross-sectional shape and are formed to project from the upper surface side of the main body portion 27A, and one upper triangular lip portion 27B is the other upper triangular lip portion. The diameter is larger than that of the portion 27C. And the front-end | tip part of upper triangular lip part 27B, 27C contact | abuts with the moderate elasticity to the upper wall surface 26A of the notch groove 26. FIG.

  On the other hand, each of the lower triangular lip portions 27D and 27E has an isosceles triangular cross-sectional shape and is formed to project from the lower surface side of the main body portion 27A, and one lower triangular lip portion 27D is the lower side of the other. It has a larger diameter than the triangular lip portion 27E. And the front-end | tip part of lower triangular lip part 27D, 27E is slidably contacted with the upper surface 25A of the shielding board 25 with moderate elasticity.

  The upper triangular lip portion 27B and the lower triangular lip portion 27D are arranged concentrically with the same diameter, and the upper triangular lip portion 27C and the lower triangular lip portion 27E are arranged concentrically with the same diameter. Has been. Accordingly, the upper triangular lip portion 27B and the lower triangular lip portion 27D, and the upper triangular lip portion 27C and the lower triangular lip portion 27E can be arranged at the same position on the upper surface side and the lower surface side of the main body portion 27A, respectively. it can. For this reason, when assembling the seal member 27 between the notch groove 26 and the shielding plate 25, it is not necessary to distinguish the upper surface side and the lower surface side of the seal member 27, and erroneous assembly of the seal member 27 is eliminated. It has a configuration that can.

  Here, as shown in FIGS. 4 and 5, the axial dimension between the upper wall surface 26A of the notch groove 26 and the upper surface 25A of the shielding plate 25 is A1, and the upper triangular lip portions 27B and 27C of the seal member 27 are Assuming that the axial dimension between the lower triangular lip portions 27D and 27E is A2, the axial dimension A1 and the axial dimension A2 are set in the relationship of the following formula 2.

  Therefore, as shown in FIG. 5, when the seal member 27 is mounted between the cutout groove 26 and the shielding plate 25, the upper triangular lip portions 27B and 27C are elastically deformed in the axial direction while The lower triangular lip portions 27D and 27E are in sliding contact with the upper surface 25A of the shielding plate 25 with a pressing force while being elastically deformed in the axial direction.

  As a result, when the shielding plate 25 rotates together with the pinion 20, the lower triangular lip portions 27D and 27E of the seal member 27 are quickly worn due to sliding contact with the upper surface 25A of the shielding plate 25 with a large surface pressure. As shown in FIG. 6, the surface is stabilized in a state where it is in sliding contact with the upper surface 25A of the shielding plate 25 with an appropriate surface pressure. In this way, the lower triangular lip portions 27D and 27E of the seal member 27 are positively worn, and the sliding contact surface between the seal member 27 and the shielding plate 25 can be used at an early stage. The function can be maintained over a long period of time.

  The upper triangular lip portions 27B and 27C provided on the upper surface side of the main body portion 27A and the lower triangular lip portions 27D and 27E provided on the lower surface side are each formed with a cross-sectional shape of an isosceles triangle. Thereby, each lip | rip part 27B, 27C, 27D, 27E is a case where the grease which lubricates the lower side bearing 22 is sealed in the lower side housing 13, and the meshing part of the internal gear 3D of the turning wheel 3 and the pinion 20 The structure has substantially the same rigidity in the case of preventing the grease sprayed from from entering the lower housing 13.

  Further, the two upper triangular lip portions 27B and 27C provided on the upper surface side of the main body portion 27A abut on the upper wall surface 26A of the notch groove 26, respectively, and the two lower triangular lip portions provided on the lower surface side of the main body portion 27A. The lip portions 27D and 27E are in sliding contact with the upper surface 25A of the shielding plate 25, respectively, so that the posture of the sealing member 27 is stabilized in a state where the sealing member 27 is assembled between the notch groove 26 and the shielding plate 25. Thus, a stable sealing property can be maintained.

  The reduction gear 11 according to the present embodiment has the above-described configuration. When the motor shaft 6A of the hydraulic motor 6 rotates, the rotation of the motor shaft 6A is reduced by two stages by the planetary gear reduction mechanisms 17 and 18. The pinion 20 is transmitted to the output shaft 19 and rotates with a large rotational force (torque).

  The pinion 20 revolves along the inner ring 3A while meshing with an internal gear 3D provided on the inner ring 3A of the turning wheel 3, and the revolving force of the pinion 20 is transmitted to the turning frame 2 via the housing 12. The revolving frame 2 performs a revolving operation on the round cylinder 1.

  At this time, as shown in FIG. 5, the upper triangular lip portions 27B and 27C of the seal member 27 abut against the upper wall surface 26A of the notch groove 26 with a pressing force in a state of being elastically deformed in the axial direction. 27D and 27E are in sliding contact with the upper surface 25A of the shielding plate 25 with a pressing force in a state of being elastically deformed in the axial direction.

  Therefore, when the shielding plate 25 rotates together with the pinion 20, the lower triangular lip portions 27D and 27E of the seal member 27 are worn quickly by slidingly contacting the upper surface 25A of the shielding plate 25 with a large surface pressure. Therefore, due to the elasticity of the upper triangular lip portions 27B and 27C in contact with the upper wall surface 26A of the notch groove 26, the main body portion 27A is moved downward (to the shielding plate 25 side) by the amount of wear of the lower triangular lip portions 27D and 27E. As shown in FIG. 6, the lower triangular lip portions 27 </ b> D and 27 </ b> E are stabilized while being in sliding contact with the upper surface 25 </ b> A of the shielding plate 25 with an appropriate surface pressure.

  As a result, the lower triangular lip portions 27D and 27E of the seal member 27 are positively worn, and the sliding contact surface between the seal member 27 and the shielding plate 25 can be quickly adapted. The function can be maintained for a long time. As a result, the seal member 27 seals the grease that lubricates the lower bearing 22 in the lower housing 13, and the grease that is ejected from the meshing portion between the internal gear 3 </ b> D of the swivel ring 3 and the pinion 20, It is possible to prevent the mixed foreign matter or the like from entering the lower housing 13 and improve the reliability of the reduction gear 11.

  In this case, the notch groove 26 is formed in an open state on the outer peripheral side and the lower surface side of the cylindrical portion 13 </ b> B constituting the lower housing 13, and the seal member 27 is attached to the peripheral wall surface 26 </ b> B of the notch groove 26 from the outer peripheral side. Therefore, for example, when the bolt 15 shown in FIG. 1 is removed and the turning device 5 is removed from the turning frame 2, the wear state of the seal member 27 is changed without disassembling the speed reduction device 11 and removing the shielding plate 25. This can be confirmed from the outside, and it is possible to accurately determine whether or not to replace the seal member 27.

  Next, when the worn seal member 27 is replaced, a tool such as a screwdriver is inserted between, for example, the notch groove 26 and the shielding plate 25 without disassembling the reduction gear 11, and the tool is sealed. It is hooked on the member 27 and pulled out of the notch groove 26. The worn seal member 27 can be easily removed from the cutout groove 26 by cutting a part of the seal member 27.

  Then, as shown in FIG. 2, a part of the new seal member 27 is hooked on the peripheral wall surface 26B of the notch groove 26, and the opposite side is pulled in the radial direction. As a result, the seal member 27 expands in diameter (elastically deformed) as shown by the two-dot chain line, and after passing the outer peripheral side of the shielding plate 25 from the lower side of the pinion 20 while expanding the diameter of the seal member 27, The diameter of the seal member 27 is reduced to a natural state by releasing the tensile force. As a result, as shown by a solid line in FIG. 2, the new seal member 27 can be easily attached to the peripheral wall surface 26 </ b> B of the notch groove 26 from the outer peripheral side with an appropriate binding force.

  In this case, the notch groove 26 is formed in an open state on the outer peripheral side and the lower surface side of the cylindrical portion 13 </ b> B constituting the lower housing 13, and the seal member 27 is attached to the peripheral wall surface 26 </ b> B of the notch groove 26 from the outer peripheral side. can do. Therefore, the seal member 27 mounted in the notch groove 26 can be visually observed from the outside, and it can be easily confirmed whether or not the seal member 27 is properly assembled. Can be prevented.

  Thus, according to the present embodiment, the upper wall surface 26 </ b> A that opens to the outer peripheral side and the lower surface side of the cylindrical portion 13 </ b> B and faces the shielding plate 25 at the lower end portion 13 </ b> C of the cylindrical portion 13 </ b> B constituting the lower housing 13. A notch groove 26 having a peripheral wall surface 26B extending in the axial direction from the upper wall surface 26A toward the shielding plate 25 is provided, and an annular shape is formed between the notch groove 26 and the shielding plate 25 using urethane rubber. The seal member 27 is provided.

  For this reason, since the seal member 27 can be attached to the peripheral wall surface 26B of the notch groove 26 from the outer peripheral side, the wear state of the seal member 27 can be easily confirmed from the outside, and the seal member 27 is replaced. It is possible to accurately determine whether or not. Further, when the seal member 27 is replaced, it is not necessary to disassemble the speed reduction device 11 and attach / detach the seal member 27, so that workability when the seal member 27 is replaced can be improved.

  Further, two upper triangular lip portions 27B and 27C provided on the upper surface side of the main body portion 27A of the seal member 27 are in contact with the upper wall surface 26A of the notch groove 26, respectively, and are provided on the lower surface side of the main body portion 27A. The lower triangular lip portions 27D and 27E are in sliding contact with the upper surface 25A of the shielding plate 25, respectively, so that the sealing member 27 is mounted in the state where the sealing member 27 is assembled between the notch groove 26 and the shielding plate 25. Can be stabilized, and good sealing performance can be maintained over a long period of time.

  Further, the upper triangular lip portion 27B and the lower triangular lip portion 27D of the seal member 27 are arranged concentrically with the same diameter, and the upper triangular lip portion 27C and the lower triangular lip portion 27E have the same diameter. Since they are arranged concentrically, the upper triangular lip portions 27B and 27C and the lower triangular lip portions 27D and 27E can be arranged at the same position on the upper surface side and the lower surface side of the main body portion 27A. For this reason, when assembling the seal member 27 between the notch groove 26 and the shielding plate 25, it is not necessary to distinguish the upper surface side and the lower surface side of the seal member 27, and erroneous assembly of the seal member 27 is eliminated. Therefore, the workability at the time of replacement of the seal member 27 can be further enhanced.

  Next, FIGS. 7 to 11 show a second embodiment of the present invention. The feature of the present embodiment is that the upper surface side and the lower surface side of the seal member protrude from the main body portion with different projecting lengths. The configuration is such that a plurality of types of triangular lip portions are provided. 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 an annular seal member mounted between the notch groove 26 and the shielding plate 25, and the seal member 31 seals grease for lubricating the lower bearing 22 in the lower housing 13. At the same time, grease or the like ejected from the meshing portion between the internal gear 3D of the swivel wheel 3 and the pinion 20 shown in FIG. 1 is prevented from entering the lower housing 13. The sealing member 31 is used in this embodiment in place of the sealing member 27 according to the first embodiment described above.

  Here, the seal member 31 includes an annular main body portion 31A attached to the peripheral wall surface 26B of the notch groove 26, an upper triangular lip portion 32 described later provided on the upper surface side of the main body portion 31A, and a lower surface of the main body portion 31A. It is comprised by the below-mentioned lower triangular lip part 33 provided in the side, and is formed, for example using urethane rubber.

  In this case, the inner diameter dimension of the main body portion 31A is set smaller than the outer diameter dimension D of the peripheral wall surface 26B of the notch groove 26, similarly to the main body portion 27A of the seal member 27 according to the first embodiment. As a result, the seal member 31 can be attached to the peripheral wall surface 26B of the notch groove 26 from the outer peripheral side with an appropriate binding force.

  Reference numeral 32 denotes an upper triangular lip portion as a protruding lip portion provided on the upper surface side of the main body portion 31A, and the upper triangular lip portion 32 has an isosceles triangular cross-sectional shape as shown in FIG. Two upper large triangular lip portions 32A and 32B projecting in an annular shape on the upper surface side, and located between these two upper large triangular lip portions 32A and 32B, are smaller than the upper large triangular lip portions 32A and 32B. The upper middle triangular lip portion 32C and the upper small triangular lip portion 32D that project in an annular shape on the upper surface side of the main body portion 31A with an isosceles triangular cross-sectional shape constitute an aggregate of a plurality of types of lip portions.

  In this case, the protruding length of the upper middle triangular lip portion 32C from the main body portion 31A is set smaller than the protruding length of the upper large triangular lip portions 32A and 32B. Further, the protruding length of the upper small triangular lip portion 32D from the main body portion 31A is set to be smaller than the protruding length of the upper middle triangular lip portion 32C.

  Reference numeral 33 denotes a lower triangular lip portion as a protruding lip portion provided on the lower surface side of the main body portion 31A. The lower triangular lip portion 33 has an isosceles triangular cross-sectional shape and is annularly formed on the lower surface side of the main body portion 31A. Two lower large lip portions 33A and 33B projecting from the lower large triangular lip portions 33A and 33B and smaller isosceles sides than the lower large triangular lip portions 33A and 33B The lower middle triangular lip portion 33C and the lower small triangular lip portion 33D that project in a ring shape on the lower surface side of the main body portion 31A with a triangular cross-sectional shape constitute an aggregate of a plurality of types of lip portions. .

  In this case, the protruding length of the lower middle triangular lip portion 33C from the main body portion 31A is set to be smaller than the protruding length of the lower large triangular lip portions 33A and 33B. The protruding length of the lower small triangular lip portion 33D from the main body portion 31A is set to be smaller than the protruding length of the lower middle triangular lip portion 33C.

  The upper large triangular lip portion 32A and the lower large triangular lip portion 33A are arranged concentrically with the same diameter, and the upper large triangular lip portion 32B and the lower large triangular lip portion 33B have the same diameter. They are arranged concentrically. The upper middle triangular lip portion 32C and the lower middle triangular lip portion 33C are arranged concentrically with the same diameter, and the upper small triangular lip portion 32D and the lower small triangular lip portion 33D have the same diameter. They are arranged concentrically. Thereby, the upper triangle lip part 32 and the lower triangle lip part 33 can be arrange | positioned in the same position by the upper surface side and lower surface side of 31 A of main-body parts. For this reason, when assembling the seal member 31 between the notch groove 26 and the shielding plate 25, it is not necessary to distinguish the upper surface side and the lower surface side of the seal member 31, and erroneous assembly of the seal member 31 is eliminated. It has a configuration that can.

  Here, as shown in FIGS. 8 and 9, the axial dimension between the upper wall surface 26A of the notch groove 26 and the upper surface 25A of the shielding plate 25 is B1, and the upper large triangular lip portions 32A, 32B of the seal member 31 are used. Assuming that the axial dimension between the lower large triangular lip portions 33A and 33B is B2, the axial dimension B1 and the axial dimension B2 are set in the relationship of the following formula 3.

  Further, assuming that the axial dimension between the upper middle triangular lip portion 32C and the lower middle triangular lip portion 33C of the seal member 31 is B3, the axial dimension B3 and the above-described axial dimension B1 are expressed by the following equation (4). The relationship is set.

  Further, when the axial dimension between the upper small triangular lip portion 32D and the lower small triangular lip portion 33D of the seal member 31 is B4, the axial dimension B4 and the axial dimension B3 are expressed by the following equation (5). The relationship is set.

  Therefore, as shown in FIG. 9, in the state where the seal member 31 is mounted between the notch groove 26 and the shielding plate 25, the upper large triangular lip portions 32A and 32B are elastically deformed in the axial direction while the notch groove 26 The lower large triangular lip portions 33A and 33B are in sliding contact with the upper surface 25A of the shielding plate 25 while being elastically deformed in the axial direction.

  As shown in FIG. 10, when the lower large triangular lip portions 33A, 33B are greatly worn by sliding contact with the shielding plate 25, the upper large triangular lip portion 32A that is in contact with the upper wall surface 26A of the notch groove 26 is used. , 32B is displaced downward (toward the shielding plate 25), and the lower middle triangular lip portion 33C is in sliding contact with the upper surface 25A of the shielding plate 25 with an appropriate pressing force.

  Furthermore, as shown in FIG. 11, when the lower large triangular lip portions 33A, 33B and the lower middle triangular lip portion 33C are worn greatly by sliding contact with the shielding plate 25, the upper large triangular lip portions 32A, 32B. Due to this elasticity, the main body 31A is further displaced downward, and the lower small triangular lip 33D is in sliding contact with the upper surface 25A of the shielding plate 25 with an appropriate pressing force.

  The speed reducer according to the present embodiment includes the seal member 31 as described above. Also in the present embodiment, the seal member 31 is attached to the peripheral wall surface 26B of the notch groove 26 from the outer peripheral side thereof. The wear state can be easily confirmed from the outside, and the workability when the seal member 31 is replaced can be improved.

  Moreover, according to the present embodiment, the upper triangular lip portion 32 provided on the upper surface side of the seal member 31 is divided into the upper large triangular lip portions 32A and 32B having different projecting lengths from the main body portion 31A, and the upper middle triangular lip. The lower triangular lip portion 33A, which is constituted by the portion 32C and the upper small triangular lip portion 32D and is provided on the lower surface side of the seal member 31, has a different protruding length from the main body portion 31A. 33B, the lower middle triangular lip portion 33C, and the lower small triangular lip portion 33D.

  As a result, when the lower large triangular lip portions 33A and 33B are greatly worn due to sliding contact with the shielding plate 25 with the seal member 31 mounted between the notch groove 26 and the shielding plate 25, the lower middle triangle The lip portion 33C can be brought into sliding contact with the shielding plate 25 with an appropriate surface pressure. When the lower middle triangular lip portion 33C is greatly worn, the lower small triangular lip portion 33D is brought into contact with the shielding plate 25 with an appropriate surface pressure. Can be in sliding contact. As a result, the life of the sealing member 31 can be extended, and the sealing between the lower housing 13 and the shielding plate 25 can be ensured over a long period of time by the single sealing member 31.

  Further, on the lower surface side of the seal member 31, there are provided three kinds of lip portions including lower large triangular lip portions 33A and 33B, lower middle triangular lip portion 33C, and lower small triangular lip portion 33D having different projecting lengths. It is configured. Thereby, for example, even when there is a variation in the processing accuracy of the seal member 31, any of the three types of lip portions having different projecting lengths can be slidably contacted with the shielding plate 25 with an appropriate surface pressure. The space between 31 and the shielding plate 25 can be reliably sealed.

  In the first embodiment described above, the upper triangular lip portion 27B and the lower triangular lip portion 27D, and the upper triangular lip portion 27C and the lower triangular lip portion 27E of the seal member 27 are respectively connected to the upper surface of the main body portion 27A. The case where it arrange | positions in the same position by the side and the lower surface side is illustrated. However, the present invention is not limited to this, and may be configured as, for example, a seal member 27 ′ of a modification shown in FIG. That is, the upper triangular lip portion 27B 'and the lower triangular lip portion 27D' and the upper triangular lip portion 27C 'and the lower triangular lip portion 27E' of the sealing member 27 'are respectively connected to the upper surface side and the lower surface side of the main body portion 27A'. It is good also as a structure arrange | positioned in different positions.

  Moreover, in embodiment mentioned above, the case where the two-stage planetary gear reduction mechanisms 17 and 18 are provided in the housing 12 is illustrated. However, the present invention is not limited to this. For example, a planetary gear reduction mechanism having one stage or three or more stages may be provided.

It is sectional drawing which shows the turning apparatus with which the reduction gear device by the 1st Embodiment of this invention was applied. It is sectional drawing which shows a lower housing, a pinion, a shielding board, a notch groove, a sealing member, etc. It is a partially broken perspective view which shows a sealing member alone. It is an expanded sectional view which shows the main-body part of a sealing member, an upper side triangular lip part, and a lower side triangular lip part. It is an expanded sectional view which shows the state which mounted | wore the sealing member between the notch groove and the shielding board. It is an expanded sectional view similar to FIG. 5 which shows the state which the lower triangular lip | wear part was abraded. It is sectional drawing similar to FIG. 2 which shows the sealing member by 2nd Embodiment with a lower housing, a pinion, a shielding board, a notch groove, etc. It is an expanded sectional view similar to FIG. 4 which shows the main-body part of the sealing member by 2nd Embodiment, an upper triangle lip part, and a lower triangle lip part. It is an expanded sectional view which shows the state which mounted | wore the sealing member by 2nd Embodiment between the notch groove and the shielding board. FIG. 10 is an enlarged sectional view similar to FIG. 9 showing a state in which the lower middle triangular lip portion is in sliding contact with the shielding plate. It is an expanded sectional view similar to FIG. 9 which shows the state which the lower small triangle lip part slidably contacted with the shielding board. It is an expanded sectional view similar to FIG. 4 which shows the modification of a sealing member.

Explanation of symbols

3 Turning wheel 3D Internal gear (gear)
6 Hydraulic motor (rotation source)
DESCRIPTION OF SYMBOLS 11 Reduction gear 12 Housing 13 Lower housing 13C Lower end part 17, 18 Planetary gear reduction mechanism (deceleration mechanism)
DESCRIPTION OF SYMBOLS 19 Output shaft 20 Pinion 21 Upper bearing 22 Lower bearing 24 Oil seal 25 Shield plate 26 Notch groove 26A Upper wall surface 26B Peripheral wall surface 27, 27 ', 31 Seal member 27A, 27A', 31A Body part 27B, 27C, 27B ', 27C ', 32 Upper triangle lip (projection lip)
27D, 27E, 27D ', 27E', 33 Lower triangular lip (protruding lip)

Claims (6)

A housing provided with a rotation source on the upper end side, a reduction mechanism provided in the housing for reducing the rotation of the rotation source, and extending in the upward and downward directions in the housing and decelerated by the reduction mechanism An output shaft that outputs rotation, a pinion that is provided on the lower end side of the output shaft and meshes with a gear, and is provided between the housing and the output shaft so as to be spaced upward and downward, and the output shaft can be rotated. An upper bearing and a lower bearing supported on the upper and lower bearings are provided between the upper and lower bearings, and are provided between the housing and the output shaft. The housing is sealed with lubricating oil for lubricating the speed reduction mechanism. An oil seal and grease that has an inner peripheral side sandwiched between the lower bearing and the pinion and an outer peripheral side extends to a lower end portion of the housing and lubricates a meshing portion of the pinion and the gear. The deceleration device comprising a disc-shaped shield plate to block from entering the Zing,
The lower end portion of the housing is cut out over the entire circumference in an open state at the corner portions on the outer peripheral side and the lower surface side of the housing, and the upper wall surface facing the shielding plate in the upward and downward directions, A notch groove having an annular peripheral wall surface extending in the axial direction on the inner diameter side of the wall surface is provided,
An annular seal member is provided between the notch groove and the shielding plate,
The seal member includes a main body portion that is attached to the peripheral wall surface of the notch groove from the outer peripheral side with a binding force, and a protruding lip that protrudes from the main body portion and contacts the upper wall surface of the notch groove and slidably contacts the shielding plate A reduction gear characterized by comprising a part.   The reduction gear according to claim 1, wherein the protruding lip portion of the seal member is configured by a triangular lip portion having a triangular cross section protruding from the upper surface side and the lower surface side of the main body portion.   The speed reducer according to claim 1 or 2, wherein two or more projecting lip portions of the seal member are provided on each of an upper surface side and a lower surface side of the main body portion.   The speed reducer according to claim 1, 2 or 3, wherein the protruding lip portion of the seal member is arranged concentrically with the same diameter on the upper surface side and the lower surface side of the main body portion.   5. The projecting lip portion of the seal member is constituted by a plurality of types of triangular lip portions having a triangular cross-section projecting from the main body portion with different projecting lengths. Reducer.   The speed reducer according to claim 1, 2, 3, 4 or 5, wherein the seal member is formed using urethane rubber.

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