US-12617481-B2 - Support roller for vehicle tracks

US12617481B2US 12617481 B2US12617481 B2US 12617481B2US-12617481-B2

Abstract

A support roller for vehicle tracks, includes a tubular body rotatable on a supporting shaft integral with a chassis; the tubular body has an external surface for accommodating a portion of an internal face of a respective chain. The supporting shaft comprises at least three consecutive cylindrical segments having constant external diameters and increasing progressively from one segment to the next. The tubular body comprises an internal cavity provided with a first portion whose dimensions are complementary to the segment of said shaft that has the largest diameter and an intermediate portion, which in the assembly configuration faces and is proximate to a segment of the shaft having an intermediate diameter; the intermediate portion has a different diameter than the first portion. An annular interspace that accommodates rolling elements is formed between the segment having an intermediate diameter of the supporting shaft and the intermediate portion of the tubular body.

Inventors

Eustachio CALIA
Adriano Bellini
Askar Echamanov

Assignees

ITALTRACTOR ITM S.P.A.

Dates

Publication Date: 20260505
Application Date: 20190506

Claims (11)

1 . A support roller for vehicle tracks, of the type comprising at least one tubular body which can rotate on a supporting shaft which is integral with a chassis of a vehicle, said at least one tubular body being provided with at least one external surface for the temporary accommodation of a portion of an internal face of a respective chain, characterized in that said supporting shaft is symmetrical with respect to a central plane that is transverse and perpendicular to a rotation axis and comprises two symmetrical external contoured regions each comprising at least three consecutive cylindrical segments, having external diameters which are constant and increase progressively from one segment to the next, said two symmetrical external contoured regions being mutually connected by a cylindrical central portion having an external diameter smaller than a segment of said external contoured regions that has the largest diameter; said at least one tubular body comprises a cylindrical internal cavity provided with at least one first portion whose shape and dimensions are usable in combination to those of a segment of one of said two external contoured regions of the supporting shaft that has the largest diameter, wherein said at least one first portion faces said segment of one of said two external contoured regions of the supporting shaft that has the largest diameter, and at least one intermediate portion, which faces and is proximate to, in the assembly configuration, a segment of said one of said two external contoured regions of the supporting shaft having an intermediate diameter, said intermediate portion having a different diameter than said first portion; an annular interspace for the accommodation of a plurality of rolling elements being formed between said segment having an intermediate diameter of said supporting shaft and said at least one intermediate portion of said tubular body.
2 . The roller according to claim 1 , characterized in that said at least one tubular body comprises two bodies, arranged symmetrically on a respective supporting shaft, each comprising said cylindrical internal cavity provided with said at least one first portion and with said at least one intermediate portion.
3 . The roller according to claim 1 , characterized in that said supporting shaft comprises: two terminal ends, which constitute a first segment and are intended for mating with the chassis of a vehicle and have a first diameter, at least one second cylindrical segment, which is connected with the region furthest from its end front of one of said terminal ends, at least one second segment having a second diameter that is larger than the first diameter, at least one third cylindrical segment, which is connected with said second segment, at least one third segment having a third diameter that is larger than the second diameter, at least one fourth cylindrical segment, which is connected with said third segment, at least one fourth segment having a fourth diameter that is larger than the third diameter, at least one fifth cylindrical segment, which is connected with said fourth segment, at least one fifth segment having a fifth diameter that is larger than the fourth diameter.
4 . The roller according to claim 3 , characterized in that the internal cavity of each of said two tubular bodies comprises: said first portion whose shape and dimensions are usable in combination to those of said fifth segment of said shaft; a second portion, whose shape and dimensions are usable in combination to those of said fourth segment of said shaft; said intermediate portion, which in the assembly configuration faces and is proximate to said third segment of said shaft.
5 . The roller according to claim 3 , characterized in that it comprises at least one closure flange, which can be coupled rigidly to said second segment of said shaft, for the locking of said rolling elements in said interspace formed between said tubular body and said supporting shaft, with consequent prevention of the axial translational motions of said tubular body.
6 . The roller according to claim 1 , characterized in that said shaft comprises: two terminal ends, which constitute a first segment and are designed to mate with the chassis of a vehicle, optionally with the interposition of a sleeve keyed thereon, which have a first diameter; at least one second cylindrical segment, which is blended with the region furthest from its end front of one of said terminal ends, at least one second segment having a second diameter that is larger than the first diameter; at least one third cylindrical segment, which is blended with said second segment, at least one third segment having a third diameter that is larger than the second diameter; at least one fourth cylindrical segment, which is blended with said third segment, at least one fourth segment having a fourth diameter that is larger than the third diameter.
7 . The roller according to claim 6 , characterized in that the internal cavity of each said tubular body comprises: said first portion having a shape and dimensions that are complementary to those of said fourth segment of said shaft that constitutes said intermediate portion, which in the assembly configuration faces and is proximate to said third segment of said shaft.
8 . The roller according to claim 6 , characterized in that it comprises at least one closure flange, which can be coupled rigidly to said first segment of said shaft for the axial locking of said tubular body.
9 . The roller according to claim 1 , characterized in that said shaft comprises: two terminal ends, which constitute a first segment and are intended for mating with the chassis of a vehicle and have a first diameter; at least one second cylindrical segment, which is blended with the region furthest from its end front of one of said terminal ends, at least one second segment having a second diameter that is larger than the first diameter; at least one third cylindrical segment, which is blended with said second segment, at least one third segment having a third diameter that is larger than the second diameter; at least one fourth cylindrical segment, which is blended with said third segment, at least one fourth portion having a fourth diameter that is larger than the third diameter; at least one fifth cylindrical segment, which is blended with said fourth segment, at least one fifth segment having a fifth diameter that is equal to the third diameter.
10 . The roller according to claim 9 , characterized in that the internal cavity of each said tubular body comprises: said first portion whose shape and dimensions are complementary to those of said fifth segment of said shaft; said intermediate portion, which in the assembly configuration faces and is proximate to said fourth segment of said shaft; a last portion, whose shape and dimensions are complementary to those of said third segment of said shaft; said third segment and said last portion comprising respective notches which, in the mutual alignment configuration, form an opening for the insertion of said rolling elements in the interspace formed between said fourth segment of said shaft and said intermediate portion of said at least one tubular body.
11 . The roller according to claim 9 , characterized in that it comprises at least one flange, which can be coupled rigidly to said second segment of said shaft, for the closure of said opening for accessing said interspace formed between said fourth segment of said shaft and said intermediate portion of said at least one tubular body.

Description

CROSS REFERENCES This application is a U.S. National Phase Application of International Application No. PCT/IT/2019/000032 filed on May 6, 2019, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present invention relates to a support roller for vehicle tracks. BACKGROUND Vehicles provided with tracks for transmitting the motion from the engine to the ground have widespread use. The use of tracked vehicles is preferred in environments in which traction is problematic. All the components of the vehicle that are necessary and support motion transmission between the reduction unit and the ground are known as undercarriage components and comprise: chain, driving wheel, track tensioning wheel, lower rollers, and upper rollers. During operation, the chain is assembled on the vehicle, forming a continuous structure that is closed onto itself, wound between two or more wheels arranged at a given operating center distance and guided by a variable number of rollers. The wheel that transmits motion from the engine to the chain is known as sprocket or tumbler. This component can be constituted monolithically or by a plurality of segments. There is also at least one idle wheel or track tensioning guiding wheel, for closing the winding of the chain. The chain, in its upper portion, can be supported by one or more rollers, termed upper rollers. The lower portion is instead supported by the lower rollers. The vertical loads produced by chain-vehicle interaction are transmitted to the chassis of said vehicle by means of the lower rollers. A roller, during its operation inside a tracked vehicle, is subjected to mechanical stresses caused by axial and radial loads generated by the interaction of the weight of the vehicle with the outside environment. Various solutions are currently used in order to absorb these loads and avoid misalignments which might compromise the correct motion of the chain. One of these solutions is to arrange bearings between the components of the roller. A solution with the use of bearings, despite providing good responses from the functional standpoint, on the other hand has high costs for the components, for assembly and for machining of the components that constitute the seat of the bearings. An alternative solution to the use of bearings is to interpose a sliding bushing between the shaft that supports the roller and the roller itself. In order to lower the friction coefficient, bear the loads and dissipate the heat, lubrication may be present in both solutions (bearings and sliding bushings). The most widespread lubrication system in design and construction practice is the oil bath type. Circulation of the lubricant therefore occurs by sloshing during the rolling motion of the roller with respect to the shaft. During this motion, the lubricant creates a supporting film between the shaft and the roller body, thus achieving the physical separation of the two components, reducing friction drastically and therefore allowing the correct operation of the roller. Seals are used to then avoid the leakage of the lubricant from the roller assembly by creating, between the roller and the corresponding supporting shaft, a containment chamber that is hermetic and closed toward the outside. The constructive choices for the seals are various. Mechanical seals with a front rotating seal, known as Duo-Cone, are generally used. The seals, in addition to achieving the task of avoiding the leakage of lubricant, are often able to withstand more or less substantial axial plays, vibrations, impacts, and to protect the inside of the roller from the presence of abrasive and corrosive materials and from environmental conditions with extreme temperatures. As regards the roller body, it is often provided by joining two parts, commonly known as roller halves. This joining is performed, in most cases, by welding, an operation which can cause a degradation of the performance of the welded materials due to the modification of the micrographic and mechanical characteristics of the materials themselves as well as a more or less extensive geometric deformation of the roller half proximate to the weld. SUMMARY The aim of the present invention is to solve the problems described above, proposing a support roller for vehicle tracks that does not require lubrication. Within the scope of this aim, an object of the invention is to propose a support roller for vehicle tracks constituted by low-cost components. Another object of the invention is to propose a support roller for vehicle tracks that is suitable to bear intense loads. A further object of the invention is to propose a support roller for vehicle tracks that is scarcely subject to wear. A further object of the present invention is to provide a support roller for vehicle tracks that has low costs, is relatively simple to provide in practice and is safe in application. This aim and these objects, as well as others which will become bette