HK1196341B - Track-module apparatus and open drive wheel therefor - Google Patents

Description

Track module apparatus and open drive wheel therefor

Technical Field

The present invention relates generally to the field of vehicle track-module systems for replacing wheels, and more particularly to a single upper drive wheel having an upper portion engaged by an endless flexible rubber track that also extends around a lower portion of a plurality of ground-engaging idler wheels and bogie wheels to hold a driven track along the ground to move the vehicle.

Background

Agricultural vehicles such as tractors, combines and the like are commonly used in the agricultural field for performing various tasks, and construction vehicles and other large work vehicles are used for performing many different tasks on various ground surfaces. Typically, these vehicles have large wheels with tires on which the vehicle is supported on the ground. However, to improve traction, a vehicle-track-module system (or "track-module") is used in place of wheels with tires, such track-module system providing a much larger ground-contact area that spreads the weight of the vehicle and tends to prevent the vehicle from sinking into mud or other soft ground.

Each such track module has a large upper drive wheel connectable to the axle for rotation therewith, a plurality of idler and bogie wheels, and an endless flexible rubber (i.e. rubber or rubber-like) track having a main inner surface and spaced apart track lugs projecting inwardly therefrom, the track extending around the wheels and being driven by its engagement with the drive wheel. Of course, such drive wheels have circumferentially spaced drive members that engage the track lugs.

In recent decades, there have been many significant advances in vehicle track-module systems, some examples of which improvements can be seen in U.S. patent nos. re36,284 (Kelderman), 6,543,862 (Kahle et al), and 6,536,854 (Juncker et al), to ATI corporation of miltefong, indiana (the assignee of the invention disclosed and claimed herein). The drive wheel configurations of the '862 and' 854 patents are intended to reduce track wear by reducing shear forces on the track lugs. The lack of track interfering side structures and thus the ability to freely adjust the side-to-side position of the track on the drive wheel is part of these advances, and the improvement is particularly important given that early excessive wear has become a major concern for track module technology. However, despite significant advances in track module technology, there remains a need for improved apparatus, including a need for improved drive wheels, which overcome certain problems and deficiencies in the prior art.

A pressing need for track-module and track-module drive wheels is the need for much lighter equipment. In the past, operational requirements have made drive wheel constructions very heavy. It has been realized that lighter drive wheels will mean lower cost and higher operating efficiency. There is a continuing need for lighter track-module drive wheels, and naturally lighter track modules, without compromising operating requirements.

Another continuing need is the need to facilitate the installation of endless rubber tracks on track modules. Past constructions were generally cumbersome and removal and installation of the tracks was therefore an annoying process. In some cases, removal and installation may require removal of the idler to allow removal and/or installation. There is a continuing need to facilitate the removal and installation of rubber tracks.

Another drawback of prior art track modules and track-module drive wheels is that it is difficult or impossible to properly accommodate, via counterweights, a particular track module of different vehicles having different horsepower ratings. There is a continuing need for a track module or track module drive wheel that can be easily weight adjusted to suit a particular vehicle.

Another problem in the field of track modules, and indeed that recognized by certain past improvements, is allowing cleaning of mud and debris along the track and drive wheels from between the track and drive wheels. There is a need for a drive wheel having a high degree of openness to minimize the accumulation or ingestion of mud and debris. Avoiding or minimizing the accumulation of mud and debris will increase the operational efficiency and effective interaction of the track and drive wheels.

Another problem is that prior art track-module drive wheels having outer belts from which the drive members extend may actually exhibit varying pitch diameters during driving interaction with the track lugs. Furthermore, depending on the configuration of the contact surface between the rubber track and the drive wheel, this situation may be exacerbated by the accumulation of mud and debris. The different pitch diameters can cause excessive track wear due to stresses in the track material. There is a continuing need for a drive wheel configuration that eliminates or minimizes pitch diameter variation.

The foregoing needs and problems have been largely referred to as troublesome needs and problems. A solution to such a problem would be an important advance in the art that still retains the advantages of track module technology, even the advantages of automatic track wheel adjustability during operation without an intervening drive wheel side structure.

Disclosure of Invention

It is an object of the present invention to provide an improved track-module apparatus and track-module drive wheel that overcomes certain problems and deficiencies of the prior art, including those described above.

More specifically, it is an object of the present invention to provide improved track-module and track-module drive wheels that are lightweight and thus facilitate efficient operation.

It is another object of the present invention to provide an improved track-module apparatus and track-module drive wheel that avoids or minimizes the accumulation of mud and debris along the drive wheel and rubber track between the drive wheel and rubber track.

It is another object of the present invention to provide an improved track-module apparatus and drive wheel that significantly facilitates the removal and installation of rubber tracks from the track modules.

It is another object of the present invention to provide an improved track-module apparatus and track-module drive wheel that readily allows a particular track module to accommodate the size/horsepower rating of the vehicle in which the module is used.

It is another object of the present invention to provide an improved track-module apparatus that reduces track wear associated with pitch diameter differences by minimizing the difference in pitch diameter.

It is another object of the present invention to provide track-module and track-module drive wheels that provide such advantages and solutions without compromising the operational requirements of such equipment.

The present invention relates to improvements in vehicle track-module apparatus, comprising: an upper drive wheel connectable to the axle to rotate together with the axle; a plurality of idler wheels and load-bearing wheels including first and second idler wheels and one or more load-bearing wheels therebetween; and an endless flexible rubber track having a major inner surface and spaced lugs projecting therefrom, the track extending around the wheels and being driven by its engagement with the drive wheel. Features of the present invention form an improved track module and track-module drive wheel that overcomes the above-referenced problems and disadvantages. In describing the improved drive wheel, the terms "axial" and "radial" as used in various forms refer to the drive wheel axis.

In one aspect of the present invention, a driving wheel includes: (1) a circular intermediate main plate having a central portion adapted to be connected to the axle, the intermediate main plate terminating circumferentially in an edge of a first diameter and having an inner side and an outer side forming an inner surface and an outer surface of the drive wheel (i.e., exposed sides thereof); (2) circumferentially spaced drive members extending axially across and projecting radially beyond the main plate edge to a second diameter, each drive member having an axially inboard end, an axially outboard end, and an intermediate portion therebetween fixed to the main plate edge at an intermediate location thereof, and each drive member further having an outer track engaging surface; and (3) a substantially flat rigid ring concentric with the intermediate main plate and secured to the inboard end portion of the drive member, the rigid ring having an inner diameter no less than about one-half of the first diameter and an outer diameter no greater than about the second diameter.

In certain preferred embodiments, the rigid ring has an inner diameter that is not less than the first diameter, i.e., the diameter of the circular intermediate plate. This keeps the weight low, keeps the side surfaces of the middle main plate exposed, and provides a manufacturing advantage that allows the rigid ring and the circular middle plate to be cut from the same metal plate. In certain preferred embodiments, the at least one annular wheel weight is attached around a central portion of the intermediate main plate at one side surface of the intermediate main plate, most preferably at the outer side of the intermediate main plate. The well exposed side surfaces of the intermediate main plate facilitate easy installation of such wheel weights.

In a preferred embodiment, the difference between the second diameter (i.e. the diameter defined by the outer extent of the drive member) and the first diameter (i.e. the diameter of the circular intermediate main plate to which the drive member is attached) is greater than the length of the inner lugs that protrude from the main inner surface of the track. This difference is important because it reduces belt wear due to the difference in pitch diameter that would occur when there is a driving load at the first and second diameters, i.e., when the belt surface is operating in contact with the wheel structure at both diameters.

In certain preferred embodiments, the rigid ring fixed at the inner end portion of the drive member is slightly offset from its own inner end. This allows the drive member outer surface to extend inwardly and provides the possibility of a drive member outer surface length and a smaller outer diameter for the rigid ring.

In certain embodiments of the present invention, the drive wheel further comprises lug support members, each lug support member being secured to an edge of the intermediate main plate between an adjacent pair of drive members, and each lug support member having a lug support surface positioned to engage a distal end of one track lug.

In another aspect of the invention, a drive wheel includes a circular intermediate main plate as described above and circumferentially spaced drive members, each having an axially inboard end portion, an axially outboard end portion, and an intermediate portion therebetween, the intermediate portion being fixed to a main plate edge at an intermediate location thereof; and an outer track engaging surface having an axial dimension at least about 50% greater than an axial dimension of the track lugs. More preferably, the axial dimension of the outer track-engaging surface is at least about 65% greater than the axial dimension of the track lugs, and most preferably, the axial dimension of the outer track-engaging surface is at least about twice the axial dimension of the track lugs. The width dimension of the outer track-engaging surface of the drive member allows for good handling of the relative lateral track-wheel movement during operation, and is thus an important factor in reducing track wear.

In another aspect of the invention, a track-module apparatus includes: an upper drive wheel connectable to the axle to rotate together with the axle; a plurality of idler wheels and load-bearing wheels; and an endless flexible rubber track having a major inner surface and spaced lugs projecting therefrom, the track extending around the wheels and being driven by its engagement with the drive wheel, the improvement being the drive wheel of such track-module apparatus. More specifically, the drive wheel includes: (1) a circular drive wheel plate having a central portion adapted to be connected to an axle, a side surface, and a circumferential edge of a first diameter; (2) circumferentially spaced drive members extending axially across the drive wheel plate; and (3) at least one wheel weight attached to a side surface of the drive wheel plate in a position radially beyond a central portion of the drive wheel plate.

In a preferred embodiment, the wheel weight is preferably annular and surrounds a central portion of the drive wheel plate, and is most preferably on the outside of the intermediate main plate. Certain preferred embodiments include a second wheel weight secured concentrically and adjacent to the first wheel weight.

It should be noted that the term "rubber track" as used herein refers to a track made of natural rubber, synthetic rubber or any rubber-like material.

Drawings

FIG. 1 is a perspective view of a preferred track-module apparatus according to the present invention.

Fig. 2 is a front elevational view of the apparatus of fig. 1.

Fig. 3 is a rear elevational view of the apparatus of fig. 1.

Fig. 4 is an enlarged perspective view of an improved drive wheel of such track-module apparatus.

Fig. 5 is an enlarged perspective view of the driving wheel viewed from the rear side of fig. 4.

FIG. 6 is another slightly enlarged perspective view of the track-module apparatus, but with a portion of the rubber track removed to better illustrate the drive wheels and their relationship to the rubber track.

FIG. 7 is a schematic diagram illustrating the relative axial dimensions of the track lugs and the outer track engaging surface of the drive member.

Fig. 8 is a perspective view similar to fig. 4 but showing two annular wheel weights secured to the drive wheel.

FIG. 9 is a perspective view of a drive wheel including a lug support member between adjacent pairs of drive members according to an embodiment of the present invention.

Detailed Description

Fig. 1-3 and 6 illustrate a track module 10 according to a preferred embodiment of the present invention, and fig. 4, 5, 7 and 8 illustrate an improved drive wheel 12 of the track module 10.

The drive wheel 12 can be connected to the axle of a tractor or other work vehicle such that the drive wheel 12 rotates with the axle, and the track module 10 includes, in addition to the drive wheel 12, first and second idler wheels 14A and 14B and a pair of bogie wheels 15A and 15B, all of which are rotatably mounted to the module structure. An endless flexible rubber track 16 extends around the wheels and is driven by engagement with the drive wheel 12. Rubber track 16 includes a major inner surface 18 and a plurality of spaced lugs 20 projecting from major inner surface 18.

As best shown in fig. 4 and 5, the drive wheel 12 includes a circular center main plate 22 having a center portion 24 adapted to be connected to the axle by an attachment eye ring as shown. The intermediate main plate 22 is the only large plate of the drive wheel 12. The plate 22 terminates circumferentially at an edge 26, the circle formed by the edge 26 having a first diameter. The intermediate main plate 22 has inner and outer sides 28A and 28B, respectively, and the inner and outer sides 28A and 28B form inner and outer surfaces of the drive wheel 12, i.e., exposed sides of the drive wheel 12, in consideration of the structure of the drive wheel 12.

The drive wheel 12 has drive members 30 circumferentially spaced along the main plate edge 22. The drive member 30 extends axially across the rim 22 and projects radially beyond the main plate rim 26 to a second diameter greater than the first diameter. (it should be understood that the term "diameter" means in this specification that the circle that contacts the portion of the drive member furthest from the axis of main plate 22 defines a circle having a diameter.) as shown, each drive member 30 includes a distal axially parallel cylindrical portion 30A and a drive member mount 30B positioned for track engagement.

Each drive member 30, in particular the cylindrical portion 30A, has an axially inner end portion 32A terminating at an axially inner end 33A, an axially outer end portion 32B terminating at an axially outer end 33B, and an intermediate portion 34 between the axially inner and outer end portions, which intermediate portion is fixed to the main plate edge 22 at an intermediate position thereof by a drive member mount 30B. Each drive member 30 also has an outer track-engaging surface 36 positioned for engagement with rubber track 16; more specifically, inner surface 18 of rubber track 16 and the surface of track lugs 20 will engage portions of track engaging surface 36 during driving operations.

Track module 10 also includes a flat rigid ring 40 concentric with intermediate main plate 22 and secured to drive member 30 at inboard end portion 32A. The rigid ring 40 has a circular inner edge 40A that is slightly larger in diameter than the first diameter (i.e., the diameter of the circular middle main plate 22). The rigid ring 40 is preferably cut from the same piece of sheet metal stock used to form the intermediate main plate 22. In such a manufacturing step, the cut line is such that the diameter of the inner edge 40A is slightly larger than the diameter of the main plate 22. The rigid ring 40 also has a circular outer edge 40B that has a diameter no greater than the second diameter (i.e., the diameter defined by the outermost portion of the drive member 30). This serves to eliminate any side surfaces that may interfere with lateral movement of track lugs 20 on track engaging surface 36 of drive member 30.

The difference between the second diameter (i.e., the diameter defined by the outer extent of drive member 30) and the first diameter (i.e., the diameter of circular middle main plate 22 to which drive member 30 is attached) is greater than the length of the inner lugs that protrude from main inner surface 18 of track 30, i.e., the radial distance between inner surface 18 and distal ends 20A of track lugs 20.

As best shown schematically in fig. 7, the axial dimension of drive member 30, and in particular the axial dimension of outer track-engaging surface 36 of cylindrical portion 30A, is greater than twice the axial dimension of track lug 20. As mentioned above, the "width" of the drive member 30 serves to allow good handling of the relative lateral track-wheel movement during operation, and is thus an important factor in reducing track wear.

Fig. 8 shows an embodiment of the drive wheel 12 comprising two annular wheel weights 44 concentrically attached to the outer side 28B of the middle main plate 22. The size and number of wheel weights (if used) may be selected to meet the specific operating requirements of the vehicle to which track module 10 is attached.

Figure 9 shows an alternative embodiment of the drive wheel of the present invention. The drive wheel 50 in fig. 9 is substantially similar to the drive wheel 12, except that the drive wheel 50 includes lug support members 52, one lug support member being positioned between each pair of drive members 30. Lug support member 52 includes a lug support surface 52A positioned to contact lug distal surface 20A of track lug 20 during operation of the alternative embodiment. This feature provides some sharing of the drive load transmitted from the drive wheel 50 to the endless rubber track.

While the principles of the invention have been described and illustrated in connection with specific embodiments, it is to be understood that such embodiments are provided by way of example only and are not limiting.

Claims (15)

1. In a vehicle track-module apparatus comprising an upper drive wheel connectable to an axle for rotation therewith, a plurality of idler and bogie wheels, and an endless flexible rubber track having a major inner surface and spaced lugs projecting therefrom, the track extending around the wheels and being driven by engagement thereof with the drive wheel, the improvement wherein the drive wheel comprises:

a circular intermediate main plate having a central portion adapted to be connected to the axle, the intermediate main plate terminating circumferentially in an edge of a first diameter and having an inner side and an outer side forming an inner surface and an outer surface of the drive wheel;

circumferentially spaced drive members extending axially across and projecting radially beyond the main plate edge to a second diameter, each drive member having an axially inboard end portion, an axially outboard end portion and an intermediate portion between the axially inboard and outboard end portions, the intermediate portion having an intermediate position, and each drive member further having an outer track engaging surface, each drive member being secured to the main plate edge with the main plate and the intermediate position generally aligned; and

a substantially flat rigid ring concentric with the intermediate main plate and fixed at an inner end portion of the drive member, the rigid ring having an inner diameter not less than half the first diameter and an outer diameter not greater than the second diameter.

2. The vehicle track-module apparatus of claim 1 wherein the rigid ring has an inner diameter no less than the first diameter.

3. The vehicle track-module apparatus of claim 1 wherein the rigid ring secured at the inboard end portion of the drive member is offset from the inboard end.

4. The vehicle track-module apparatus of claim 1 further comprising at least one annular wheel weight attached to an outer side of the intermediate main plate about a central portion thereof.

5. The vehicle track-module apparatus of claim 4 wherein the at least one annular wheel weight includes a first wheel weight and a second wheel weight secured concentrically and adjacent to the first wheel weight.

6. The vehicle track-module apparatus of claim 1 wherein the difference between the second diameter and the first diameter is greater than the length of the lug protruding from the major inner surface of the track.

7. The vehicle track-module apparatus of claim 1 further comprising lug-support members, each lug-support member secured to the intermediate main plate edge between an adjacent pair of drive members and having a lug-support surface positioned to engage a distal end of one track lug.

8. The vehicle track-module apparatus of claim 1 wherein the axial dimension of the outer track-engaging surface of each drive member is at least 50% greater than the axial dimension of the track lugs.

9. The vehicle track-module apparatus of claim 8 wherein the axial dimension of the outer track-engaging surface is at least 65% greater than the axial dimension of the track lugs.

10. The vehicle track-module apparatus of claim 9 wherein the axial dimension of the outer track-engaging surface is at least twice the axial dimension of the track lugs.

11. The vehicle track-module apparatus of claim 10 further comprising lug-support members, each lug-support member being secured to the intermediate main plate edge between an adjacent pair of drive members and having a lug-support surface positioned to engage a distal end of one track lug.

12. The vehicle track-module apparatus of claim 1 wherein each drive member secured with the rigid ring includes a cylindrical portion positioned for track engagement, the cylindrical portion being secured to the main plate edge by a respective drive member mount.

13. The vehicle track-module apparatus of claim 12 wherein the drive member mount of each drive member is secured to its respective cylindrical portion along substantially an entire length of the drive member.

14. The vehicle track-module apparatus of claim 12 wherein the rigid ring has an inner diameter no less than the first diameter.

15. The vehicle track-module apparatus of claim 14 wherein the drive member mount of each drive member is secured to its respective cylindrical portion along substantially the entire length of the drive member.