Source: http://www.freepatentsonline.com/y2005/0253339.html
Timestamp: 2019-09-19 21:37:10
Document Index: 72106044

Matched Legal Cases: ['art 25', 'art 25', 'art 25', 'art 25', 'arts 25', 'art 25', 'art 25', 'arts 25', 'art 25', 'art 25']

Rotating apparatus for construction machine - Hitachi Construction Machinery Co., Ltd.
United States Patent Application 20050253339
A swinging pinion on the side of an upper swing structure is meshed with a ring gear which is provided on and around the inner periphery of an inner ring on the side of a vehicular base carrier. A grease bath is provided on the inner side of the inner ring and under a swing frame. A center joint is located in an opening which is provided in the swing frame at the center of swinging motions of the upper swing structure. The grease bath is formed by bath-forming walls around an central top plateau wall which is connected the center joint on the inner peripheral side. An annular seal member of resilient material is interposed between the top plateau wall of the grease bath and the lower side of the swing frame. The annular seal member is formed in a height which is larger than the width of spacing between the top plateau wall and the swing frame. At one side, the seal member is detachably fixed either on the side of the swing frame or on the side of the top plateau wall section. At the other side, the seal member is provided with an annular sliding portion which is held in sliding contact with the other one of the swing frame and the top plateau wall in an inclined posture in a radially inward direction.
Hoshi, Akio (Ibaraki, JP)
Tamura, Kazuhisa (Ibaraki, JP)
Tanaka, Nozomu (Ibaraki, JP)
Tabata, Shuuji (Ibaraki, JP)
Kawasaki, Koji (Ibaraki, JP)
Yanagisawa, Yukio (Ibaraki, JP)
10/506972
B66C23/84; E02F9/12; (IPC1-7): F16J15/32
Download PDF 20050253339 PDF help
20090322033 Shaft isolation seal December, 2009 Maier et al.
20090152822 Metal fixture for dust cover June, 2009 Niwa
20090230627 Water systems September, 2009 King Jr. et al.
20060006607 Seal with plastic inner cup January, 2006 Denton et al.
OLDS, MAIER & RICHARDSON, PLLC (PO BOX 20245, ALEXANDRIA, VA, 22320-1245, US)
1. A grease bath seal for a swing mechanism of a construction machine comprising: an inner ring on the side of a vehicular base carrier relatively rotatably coupled with an outer ring on a swing frame on the side of an upper swing structure of the construction machine, a ring gear provided on the inner periphery of said inner ring and meshed with a swinging pinion on the side of said upper swing structure, a center joint located within an opening provided in said swing frame at a rotational center thereof, and a grease bath located beneath said swing frame and around said center joint and defining an annular grease bath portion around a top plateau wall connected to said center joint, thereby to lubricate meshed portions of said ring gear and said swing pinion, wherein said grease bath seal comprises: an annular seal member having a height larger than a width of a spacing between said swing frame of said upper swing structure and said top plateau wall of said grease bath in a free state and interposed in a compressed state between said top plateau wall and said swing frame at a position radially outward of said center joint; and said seal member being detachably fixed either on the side of said swing frame or on the side of said top plateau wall of said grease bath, and having an annular sliding portion extended out in a radially inward direction from the other side for pressed sliding contact with said top plateau wall or said swing frame.
2. A grease bath seal as defined in claim 1, wherein said seal member is located at a position in the proximity of said center joint.
3. A grease bath seal as defined in claim 1, wherein said seal member is formed by an annular main block having an anchoring end portion of a length on the outer peripheral side and a lipped end portion on the inner peripheral side thereof, said lipped end portion having an annular lip portion erected at and along inner periphery thereof, and said grease bath seal further comprises a seal holder in the form of a ring of a staggered shape in section having a raised seal holder portion at a height from upper surface of said top plateau wall of said grease bath, and a base portion formed around outer periphery of said seal holder portion and fixed on said top plateau wall at a position in the proximity of said center joint.
4. A grease bath seal as defined in claim 3, wherein said lip portion is projected upward from said lipped end portion of said main block and adapted to be bent downward through upon abutment against lower side of said swing frame through elastic deformation for sliding contact with the latter over a width in radial direction.
5. A grease bath seal as defined in claim 3, wherein said seal member is provided with a lubricant reservoir on said main block radially on the outer side of said lip portion to store the same lubricant as the one in said grease bath.
6. A grease bath seal as defined in claim 5, wherein said lubricant reservoir is in the form of an annular groove formed on the top side of said lipped end portion radially on the outer side of said lip portion to store the same lubricant oil as the one in said grease bath.
7. A grease bath seal as defined in claim 5, wherein said lubricant reservoir is formed by an annular projection provided at and along outer periphery of said lipped end portion of said seal member.
8. A grease bath seal as defined in claim 7, wherein said annular projection is arranged to have a sufficient projection length for sliding contact with lower side of said swing frame.
9. A grease bath seal as defined in claim 8, wherein said annular projection is adapted to bent upon abutment against lower side of said swing frame through elastic deformation in an opposite direction relative to direction of elastic deformation of said lip portion.
10. A grease bath seal as defined in claim 1, wherein said top plateau wall is divided into two separable plateau sections, said two separable plateau sections including an outer plateau wall section formed integrally with other bath-forming walls of said grease bath, and an inner plateau wall section connected to said center joint on the inner peripheral side thereof.
11. A grease bath seal as defined in claim 10, wherein inner and outer peripheral ends of said outer and inner plateau wall sections are joined with each other at a position, and said seal member is located across joined ends of said outer and inner plateau wall sections.
12. A grease bath seal as defined in claim 1, wherein said plateau wall is connected to said center joint in such a way as to leave one or a plural number of gaps or opening around said center joint.
In view of the foregoing situations, it is an object of the present invention to provide a grease bath seal for a swing mechanism of a construction machine, which can prevent intrusion of pollutants or other foreign material into a grease bath over an extended period of time in a reliable manner.
Hereafter, the present invention is described more particularly by way of its preferred embodiments with reference to the accompanying drawings. Referring first to FIG. 1, there is shown a hydraulic power shovel or excavator as an example of construction machine having a working mechanism including an excavation means on an upper swing structure which is rotatably mounted on a vehicular base carrier.
A center joint 25 is placed in an opening 24 which is provided at the center of rotation of the swing frame 10. The center joint 25 serves to make connections of pipes which supply pressure oil to and from the drive motor of the vehicular base carrier 1. Lower part 25B of the center joint 25 is fixed on the vehicular base carrier 1 and relatively rotatably coupled with an upper part 25A. Boot rubber 26 is fitted around the upper part 25A of the center joint in such a way as to shield the opening 24. This boot rubber 26 may be omitted in a case where the opening 24 is completely sealed by means of a seal member 31 which will be described hereinlater. The lower part 25b of the center joint 25 is connected to the inner end of a top plateau wall 27 of the grease bath, which is extended horizontally inward from upper end of the sloped or inclined wall 23.
Namely, in the enlarged view of FIG. 3, indicated at 30 is a seal holder and at 31 a seal member 31. The seal holder 30 is in the form of a staggered metal ring which is formed by bending an annular metal strip at a radially halfway position into a staggered shape having a base portion 30a, which is securely fixed on the upper side of the top plateau wall 27, a riser wall portion 30b which rises in a radially outward direction by a predetermined distance from the base portion 30a, and an annular holder wall portion 39c which extends radially inward from the riser wall portion 30b substantially in parallel relation with the top plateau wall 27. The seal holder 30 is arranged to accommodate the seal member 31 between the annular gripping wall portion 30c and the riser wall portion 30b. Namely, the seal member 31 is removably and fixedly gripped in position by the annular gripping wall portion 30c and the riser wall portion 30b of the seal holder member 30. On the other hand, the seal member 31 is formed of resilient material like rubber, and provided with a main seal block 32 in the form of an annular block having substantially a rectangular shape in section. More specifically, the main seal block 32 of the seal member 31 is composed of an anchoring end portion 33 and a lipped end portion which is formed integrally with the anchoring end portion 33 radially on the inner side of the latter. The lipped end portion 34 is thicker than the anchoring end portion 33 and thus stepped up from the latter. A lip 35 is extended radially outward from at the inner periphery of the lipped end portion 34.
The seal member 31 which is retained in position by the seal holder 30 functions to prevent dirt, soil or other contaminants from entering the grease bath 21 through the opening 24 which is formed in the swing frame 10 for mounting the center joint 25. Outer peripheral edges of the fixed base end portion 30a of the seal holder 30 are located radially inward of the upper end of the inclined wall 23 which is connected to the top plateau wall 27. The diameter at the fore distal end of the lip portion 35 of the seal member 31 is larger than the diameter of the opening 24. Namely, the seal member 31 is interposed between the central plateau wall portion 27 and the swing frame 10 at a position which is as close as possible to the opening 24.
The annular gripping wall portion 30c of the seal holder member 30 is provided at a lower level than the top surface of the anchoring end portion 33 of the seal member 31. Therefore, along with the anchoring end portion 33, the main ring block 32 is retained substantially in a compressed state and intimately pressed against the top plateau wall 27 of the grease bath. Preferably, in a free state, the main ring block 32 of the seal member 31 is arranged to have an outside diameter slightly larger than an inside diameter at the outer end of the riser wall portion 30b of the seal holder 30. As a consequence, the seal member 31 is biased in radially outward directions, and, once fitted in the seal holder 30, it is retained in position in a stabilized state. In other words, the anchoring end portion 33 of the seal member 30 is held in tight and intimate contact with the upper side of the top plateau wall 27 and the seal holder 30 to form a tight seal therebetween.
The lip portion 35 is erected at or in the close proximity of the inner periphery of the lipped end portion 34 which has a predetermined width in the radial direction between the lip portion 35 and the anchoring end portion 33. An annular groove 34a is formed on the upper side of the lipped end portion 34 to serve as a reservoir of a lubricant. In this instance, grease is pooled in the lubricant reservoir groove 34a thereby to lubricate sliding surfaces on the lower side of the swing frame 10 and on the lip portion 35.
Between the swing frame 10 and the top plateau wall 27, the seal member 31 is not necessarily required to produce sealing effects in those areas which are located radially inward of its own position. However, if a large amount of contaminants enters the opening 24 from the side of the upper swing structure 2, it may impose adverse effects on coupled portions of the upper and lower parts 25a and 25b of the center joint 25. This is the reason why the boot rubber 26 is fitted between the upper part 25a of the center joint 25 and the top side of the swing frame 10. Nevertheless, the provision of the boot rubber 26 is not a paramount requisite.
Further, if contaminants enter the opening 24 through the boot rubber 26 and deposit on and around the lower part 25b of the center joint 25, they may give rise to rust or deterioration of the seal member 31. For the purpose of precluding such troubles, the upper and lower parts 25a and 25b of the center joint 25 are coupled with each other in the manner as shown in FIG. 4. Namely, in order to pass the center joint 25, the top plateau wall 27 is provided with a through hole 27a which is larger than the outside diameter of the lower part 25b of the center joint 25, and a plural number of radial connecting projections 36 (four radial connecting projections 36 in the case of the particular embodiment shown) are provided at angular intervals around the lower part 25b of the center joint 25. The radial projections 36 are connected to the top plateau wall 27 by the use of bolts 38. Spacings 37 are provided between the top plateau wall 27 and the radial projections 36, so that contaminants getting around the center joint 25 can be quickly and smoothly discharged through the spacings 37 instead of lingering on or around the center joint 25.
When the upper swing structure 2 is turned, the lip portion 35 of the seal member 31 is caused to slide along the swing frame 10. The seal member 31, particularly the lip portion 35 of the seal member 31 is located closely to the center of rotation of the swing frame 10. Therefore, the radius of rotation of the lip portion 35, about the center of rotation of the swing frame 10, is very small, so that its abrasive wear can be suppressed to a minimum. In addition, abrasive wear is suppressed furthermore by supply of grease to sliding portions of the lip portion 35 and the swing frame 10 from the lubricant reservoir groove 34a which is provided on the main seal block 34.
However, in case it is desired to store a greater amount of grease in the annular storage groove 137, the upper end of the annular projection 136 may be flexibly bent in a radially outward direction away from the lip portion 135 as shown in FIG. 6. Further, in order to facilitate mounting of the seal member 131 itself, it is desirable to make arrangements as follows. Namely, to permit facilitated mounting of the seal member 131, the top plateau wall 127 is composed of two separably connected parts as shown in FIG. 5, i.e., an outer plateau wall section 127a which is provided integrally with the bottom and sloped walls of the grease bath in the foregoing first embodiment, and an inner plateau wall section 127b which is connected to the center joint 25. In this case, the seal holder 130 is provided on the part of the inner plateau section 127b.
The outer and inner plateau wall sections 127a and 127b are connected to each other by means of bolts 140 at a position radially on the outer side of the seal holder 130, with connecting end portions of the outer and inner plateau wall sections 127a and 127b overlapped one on the other over a predetermined length. In this instance, nuts 141 are fixedly provided on the top side of the outer plateau wall section 127a by welding or other fixation means. Besides, although not shown in the drawings, a seal member is interposed between overlapped end portions of the outer and inner plateau wall sections 127a and 127b.
With the arrangements just described, after removing the inner plateau wall section 127b along with the center joint 25, the seal member 131 is set in the seal holder 130 which is fixed on the inner plateau wall section 127b, and grease is filled in the lubricant reservoir groove 137. Then, an outer end portion of the inner plateau wall section 127b is abutted against the outer plateau wall section 127a from beneath and connected to the latter by tightening the bolts140 into the nuts 141. Whereupon, the lip portion 135 and the annular projection 136 of the seal member 131 are caused to flex in radially inward and outward directions, respectively, permitting to store a larger amount of grease therebetween. In this case, since the seal member 131 can be set in position on the inner plateau wall section 127b which is in a totally exposed state, it can be quite easily set in the seal holder 130 because the seal member 131 is subjected to compressive deformation in a less degree.
Further, shown in FIG. 8 is another modification in which a seal holder 230 is mounted on an outer plateau wall section 227a which is arranged to integrally include the respective bath-forming walls of the grease bath 21, and joined at its inner periphery end with an inner plateau wall section 227b which is connected to the center joint 25. In this case, for facilitating mounting of the seal member 231 and at the same time for sealing joined end portions with the seal member 231, the outer and inner plateau wall sections 227a and 227b are arranged to be joined at a position beneath the seal member 231. An annular extension 250 is fixedly welded or bolted to outer peripheral portions of the inner plateau wall section 227b and abutted against inner peripheral portions of the outer plateau wall section 227b from beneath thereby to support the loads of the outer plateau wall section 227a.
Being arranged in the manner as described above, the grease bath seal according to the present invention can prevent foreign matter such as water and mud from getting into a grease bath, preventing deterioration of a lubricant like grease and prolonging its service life in a very reliable manner.
Previous Patent: Blackjack side bet using community cards
Next Patent: Sealing apparatus having sequentially engageable seals