JP2020051587A - Seal structure of turning bearing - Google Patents

Abstract

To provide a seal structure of a turning bearing capable of restricting the seal degradation.SOLUTION: A seal structure of a turning bearing, comprises: a base substance; a revolving superstructure 4 that is located above the base substance and relatively rotational with respect to the base substance; a ring gear 21 provided in any one of the base substance and the revolving superstructure 4; a pinion 23 provided in the other of the base substance and the revolving superstructure 4 and meshing with the ring gear 21; lubricant for lubricating at least the engagement part of the ring gear 21 and the pinion 23; a bearing 25 that is located between the base substance and the revolving superstructure 4 and on the outside of the ring gear 21 and the pinion 23 in the radial direction; and a seal 27 for preventing debris from entry to the inside of the bearing 25, in which a ridge strip part 31 is provided between the ring gear 21, the pinion 23 and the seal 27, and projecting annularly upward from the base substance.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a seal structure for a slewing bearing of a construction machine, for example.

  2. Description of the Related Art Conventionally, there has been known a seal structure of a swing bearing provided between a traveling body as a base body and a revolving body rotatably provided on the traveling body (for example, see Patent Document 1).

JP-A-9-328777

  A swivel bearing provided between a base as a traveling body of a construction machine or the like and a swivel body that can swivel with respect to the base is provided with a seal for preventing foreign substances from entering the inside. Here, a ring gear and a pinion that meshes with the ring gear are provided between the base such as a construction machine and the revolving unit, and the revolving unit rotates with respect to the base by rotating the pinion by a driving source. A lubricant is filled between the ring gear and the pinion.

  However, the conventional one has a problem that the lubricant comes into contact with the seal and the deterioration of the seal is accelerated.

  In view of the above, an object of the present invention is to provide a seal structure of a slewing bearing that can suppress deterioration of a seal.

[1] To achieve the above object, the present invention provides:
A substrate;
A revolving structure that is positioned above the base and is rotatable relative to the base;
A ring gear having internal teeth provided on the upper surface of the base,
A pinion provided on the revolving structure, extending from the revolving structure toward the base below, and meshing with the internal teeth of the ring gear;
A lubricant that lubricates at least a meshing portion between the ring gear and the pinion;
Between the base and the revolving structure, a bearing disposed radially outside the ring gear and the pinion,
A seal for preventing foreign matter from entering the inside of the bearing,
A slewing bearing seal structure comprising:
The base is provided with a ridge that is located between the internal teeth of the ring gear and the seal and that projects annularly upward from the base.

  ADVANTAGE OF THE INVENTION According to this invention, even if the lubricant which lubricates a ring gear and a pinion flows between a base | substrate and a rotating body, and flows to a seal side, it can block a lubricant by a ridge part. Therefore, the protrusion can suppress or prevent the deterioration of the seal due to the lubricant.

  [2] In the present invention, it is preferable that the revolving structure is provided with an annular groove for receiving an upper end of the ridge. According to this configuration, the protrusion provided on the base body is received in the annular groove provided on the revolving structure, so that the lubricant can be more reliably prevented from entering the seal side.

  [3] Further, in the present invention, it is preferable that at least an upper end portion of the protruding ridge portion is formed such that a radial width increases radially inward as going upward. According to such a configuration, the direction of the flow is changed downward by the flowing lubricant hitting above the protrusion. This makes it possible to more appropriately prevent the lubricant from entering the seal side.

FIG. 1 is an explanatory view showing a construction machine according to an embodiment to which a slewing bearing seal structure of the invention is applied. FIG. 2 is a perspective view showing a partial cross section of the ring gear and the pinion according to the embodiment. Sectional drawing which shows the protrusion part of 1st Example. Explanatory drawing which shows the protrusion part and annular groove of 2nd Example. Explanatory drawing which shows the protrusion part of 3rd Example.

  A construction machine using a seal structure for a slewing bearing according to an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a construction machine 1 according to the present embodiment is a hydraulic shovel, and includes a traveling body 3 as a base having an endless track 2 and a revolving body 4 provided on the traveling body 3 so as to be pivotable. , Is provided.

  The revolving superstructure 4 includes an operator's cab 5 provided on the front left side and a machine room 6 provided adjacent to the rear of the operator's cab 5. The machine room 6 is provided with a power source such as an electric motor or an internal combustion engine (not shown) and an oil pump driven by the power source. The construction machine 1 drives the hydraulic motor using the hydraulic pressure output from the oil pump, and drives the endless track 2 of the traveling body 3 using the power output from the hydraulic motor. The power source may be a diesel engine, a gasoline engine, or may use both an internal combustion engine and an electric motor.

  A base end of a working machine 7 is connected to the front right side of the revolving unit 4 at a position beside the cab 5 and in front of the machine room 6.

  The work machine 7 includes a boom 8 whose base end is rotatably connected to the revolving unit 4, an arm 9 whose base end is rotatably connected to the distal end of the boom 8, and a rotatable end of the arm 9. And a bucket 10 whose base end is freely connected. The end of the rod 11a of the boom hydraulic cylinder extending from the revolving unit 4 is connected to the middle part of the boom 8, and the boom 8 is rotated by moving the rod 11a of the boom hydraulic cylinder forward and backward. The proximal end of the arm 9 is connected to the distal end of a rod 12a of an arm hydraulic cylinder 12 extending from the boom 8, and the arm 9 is rotated by moving the rod 12a of the arm hydraulic cylinder 12 forward and backward. The proximal end of the bucket 10 is connected via a link 14 to the distal end of a rod 13a of a bucket hydraulic cylinder 13 extending from the arm 9. By moving the rod 13a of the bucket hydraulic cylinder 13 forward and backward, the bucket 10 is moved. Rotate.

  Referring to FIG. 2, traveling body 3 is provided with ring gear 21 having internal teeth 21 a on the inner peripheral surface. The revolving unit 4 is provided with a pinion 23 that meshes with the internal teeth 21 a of the ring gear 21. The pinion 23 is rotationally driven by a power source provided in the machine room 6 of the rotating body 4. An annular concave portion 22 is formed radially inside the ring gear 21. The annular recess 22 accommodates the pinion 23 in a state of being immersed in a lubricant (grease), and is filled with a lubricant (grease) for lubricating at least a meshing portion between the ring gear 21 and the pinion 23. The annular concave portion 22 has a rectangular cross section, and its outer peripheral surface is formed by the inner surface of the ring gear 21, and its bottom surface and inner peripheral surface are formed by the cover 41 attached to the traveling body 3.

  A bearing 25 is provided between the traveling unit 3 and the revolving unit 4. The bearing 25 includes an inner ring formed by the ring gear 21, an outer ring 25a disposed radially outward of the ring gear 21 as the inner ring, and a rolling element 25b. The outer race 25a is fixed to the revolving superstructure 4. A seal 27 is provided between the ring gear 21 as the inner ring and the outer ring 25a to prevent foreign matter from entering the rolling elements 25b.

[First embodiment]
FIG. 3 shows the projection 31 of the first embodiment. As shown in FIG. 3, the ridge 31 of the first embodiment is provided with an annular ridge 31 having a rectangular cross section so as to protrude upward from the upper surface of the ring gear 21 extending in the vertical direction along the central axis. ing. According to the construction machine 1 to which the seal structure of the slewing bearing according to the first embodiment is applied, the lubricant (grease) in the ring gear 21 is pushed upward by the meshing of the ring gear 21 and the pinion 23, so that the upper surface of the ring gear 21 is formed. The lubricant also rides on, but the lubricant that got on is blocked by the ridge 31 as shown by the arrow in FIG. This makes it difficult for the lubricant to reach the seal 27, thereby preventing or suppressing deterioration of the seal 27 due to the lubricant.

[Second embodiment]
FIG. 4 shows the protrusion 31 and the annular groove 33 of the second embodiment. In the construction machine 1 to which the seal structure of the slewing bearing according to the second embodiment is applied, the revolving unit 4 is provided with an annular groove 33 at a position facing the ridge 31. The upper end of the ridge 31 of the second embodiment is received in an annular groove 33 provided in the rotating body 4. Thus, a labyrinth structure can be formed by the ridges 31 and the annular groove 33, and the lubricant can be more reliably prevented from reaching the seal 27.

[Third embodiment]
FIG. 5 shows the ridge 31 of the third embodiment. At least the upper end of the ridge 31 of the third embodiment is formed so that the radial width increases radially inward as going upward. As a result, a wedge-shaped portion 31a that projects radially inward is formed on the inner peripheral side of the upper end of the protruding portion 31. According to the seal structure of the slewing bearing of the third embodiment, the lubricant flowing toward the seal 27 on the upper surface of the ring gear 21 hits the upper wedge 31a above the ridge 31 as indicated by an arrow in FIG. This changes the direction of flow downward. This makes it possible to more appropriately prevent the lubricant from entering the seal 27 side.

[Other Examples]
In the present embodiment, the protrusion 31 is provided on the ring gear 21 of the traveling body. However, the protrusion 31 of the present invention is provided on a portion of the base between the seal of the internal teeth. And it is not limited to a ring gear. For example, when the inner ring of the ring gear and the bearing is formed separately, it may be provided on the inner ring, or may be provided on another base portion.

DESCRIPTION OF SYMBOLS 1 Construction machine 2 Endless track 3 Running body (base)
4 Revolving superstructure 5 Operator cab 6 Machine room 7 Work implement 8 Boom 9 Arm 10 Bucket 11a Rod 12 Hydraulic cylinder for arm 12a Rod 13 Bucket hydraulic cylinder 13a Rod 14 Link 21 Ring gear (inner ring)
21a Internal teeth 22 Annular concave portion 23 Pinion 25 Bearing 25a Outer ring 25b Rolling element 27 Seal 31 Projection 31a Wedge-shaped portion 33 Annular groove 41 Cover

Claims (3)

A substrate;
A revolving structure that is positioned above the base and is rotatable relative to the base;
A ring gear having internal teeth provided on the upper surface of the base,
A pinion provided on the revolving structure, extending from the revolving structure toward the base below, and meshing with the internal teeth of the ring gear;
A lubricant that lubricates at least a meshing portion between the ring gear and the pinion;
Between the base and the revolving structure, a bearing disposed radially outside the ring gear and the pinion,
A seal for preventing foreign matter from entering the inside of the bearing,
A slewing bearing seal structure comprising:
A seal structure for a slewing bearing, wherein a ridge portion is provided between the internal teeth of the ring gear and the seal and protrudes upward from the base in a ring shape. The seal structure for a slewing bearing according to claim 1,
The revolving structure is provided with an annular groove for receiving an upper end of the ridge portion. The seal structure for a slewing bearing according to claim 1 or 2,
A seal structure for a slewing bearing, wherein at least an upper end portion of the ridge portion is formed so that a radial width increases radially inward as going upward.