Endless track for traction of a vehicle
View Patent ↗In some aspects, an endless track for traction of an off-road vehicle (e.g., an agricultural vehicle, an industrial vehicle, a construction vehicle, or a military vehicle) includes an elastomeric belt-shaped body having an inner surface for facing wheels of the vehicle and a ground-engaging outer surface. The endless track also includes elastomeric lugs, such as drive/guide lugs projecting from the inner surface and/or traction lugs projecting from the ground-engaging outer surface. The elastomeric lug may have a material defining an arrangement of zones of different materials (e.g., different elastomeric materials) to exhibit a desired variation of a material property (e.g., a modulus of elasticity) across the arrangement of zones of different materials. A zone of the elastomeric lug may have a dedicated function, such as a wear indicator zone. An elastomeric drive lug can include an uneven drive surface for engaging a drive member of a drive wheel.
1. An endless track for traction of an off-road vehicle, the endless track being mountable around a plurality of wheels of the off-road vehicle, the plurality of wheels comprising a drive wheel for driving the endless track, the endless track comprising:
an elastomeric belt-shaped body comprising an inner surface for facing the wheels and a ground-engaging outer surface for engaging the ground; and
a plurality of elastomeric drive/guide lugs projecting from the inner surface, each elastomeric drive/guide lug of the plurality of elastomeric drive/guide lugs having a material composition defining an arrangement of zones of different materials, the arrangement of zones of different materials comprising a plurality of zones of different elastomeric materials, the plurality of zones of different elastomeric materials comprising at least three zones of different elastomeric materials, the elastomeric drive/guide lug exhibiting a desired variation of a material property across the arrangement of zones of different materials.
2. The endless track of claim 1 , wherein the desired variation of the material property includes an increase of the material property inwardly.
3. The endless track of claim 1 , wherein the material property is a modulus of elasticity.
4. The endless track of claim 3 , wherein the desired variation of the modulus of elasticity includes an increase of the modulus of elasticity inwardly.
5. The endless track of claim 3 , wherein the desired variation of the modulus of elasticity has a spatial rate of change of no more 5 MPa/mm.
6. The endless track of claim 3 , wherein the desired variation of the modulus of elasticity has a spatial rate of change of no more than 3 MPa/mm.
7. The endless track of claim 1 , wherein the desired variation of the material property reduces a potential for crack propagation in the elastomeric drive/guide lug.
8. The endless track of claim 1 , wherein the desired variation of the material property includes a discrete gradient of the material property.
9. The endless track of claim 1 , wherein the arrangement of zones of different materials comprises at least four zones of different materials.
10. The endless track of claim 1 , wherein the plurality of zones of different elastomeric materials comprises at least four zones of different elastomeric materials.
11. The endless track of claim 1 , wherein the arrangement of zones of different materials comprises a plurality of layers of different materials disposed on one another.
12. The endless track of claim 1 , wherein the arrangement of zones of different materials comprises a zone of non-elastomeric material.
13. The endless track of claim 12 , wherein the non-elastomeric material is a metallic material.
14. The endless track of claim 12 , wherein the non-elastomeric material is a polymeric material.
15. The endless track of claim 1 , wherein at least two zones of the arrangement of zones of different materials have different thicknesses.
16. The endless track of claim 1 , wherein a first zone of the arrangement of zones is more inward and thicker than a second zone of the arrangement of zones.
17. The endless track of claim 1 , wherein a first zone of the arrangement of zones is thicker and stiffer than a second zone of the arrangement of zones.
18. The endless track of claim 1 , wherein the material property is a first material property, the elastomeric drive/guide lug exhibiting a desired variation of a second material property across the arrangement of zones of different materials.
19. The endless track of claim 18 , wherein the first material property is a modulus of elasticity and the second material property is a coefficient of friction with at least one of the wheels contactable by the elastomeric drive/guide lug.
20. The endless track of claim 19 , wherein the desired variation of the modulus of elasticity includes an increase of the modulus of elasticity inwardly and the desired variation of the coefficient of friction includes a decrease of the coefficient of friction outwardly.
21. The endless track of claim 1 , wherein the material property is a crack propagation resistance.
22. The endless track of claim 21 , wherein the desired variation of the crack propagation resistance includes an increase of the crack propagation resistance outwardly.
23. The endless track of claim 1 , wherein the material property is a tensile strength.
24. The endless track of claim 1 , wherein a ratio of different values of the material property of adjacent zones of the arrangement of zones of different materials is at least 0.4.
25. The endless track of claim 1 , wherein a ratio of different values of the material property of adjacent zones of the arrangement of zones of different materials is at least 0.6.
26. The endless track of claim 1 , wherein a ratio of a minimum value of the material property in the elastomeric drive/guide lug and a maximum value of the material property in the elastomeric drive/guide lug is at least 0.2.
27. The endless track of claim 1 , wherein a ratio of a minimum value of the material property in the elastomeric drive/guide lug and a maximum value of the material property in the elastomeric drive/guide lug is at least 0.4.
28. An off-road vehicle comprising the endless track of claim 1 .
29. The off-road vehicle of claim 28 , wherein the off-road vehicle is an agricultural vehicle, a construction vehicle or a military vehicle.
30. The endless track of claim 1 , wherein a first one of the different elastomeric materials comprises rubber and a second one of the different elastomeric materials comprises an elastomer other than rubber.
31. The endless track of claim 30 , wherein the elastomer other than rubber is a polyurethane elastomer.
32. An endless track for traction of an off-road vehicle, the endless track being mountable around a plurality of wheels of the off-road vehicle, the plurality of wheels comprising a drive wheel for driving the endless track, the endless track comprising:
an elastomeric belt-shaped body comprising an inner surface for facing the wheels and a ground-engaging outer surface for engaging the ground; and
a plurality of elastomeric drive/guide lugs projecting from the inner surface, each elastomeric drive/guide lug of the plurality of elastomeric drive/guide lugs comprising a plurality of zones of different elastomeric materials, the plurality of zones of different elastomeric materials comprising at least three zones of different elastomeric materials, the elastomeric drive/guide lug exhibiting an increase of a modulus of elasticity inwardly over the plurality of zones of different elastomeric materials.
33. An endless track for traction of an off-road vehicle, the endless track being mountable around a plurality of wheels of the off-road vehicle, the plurality of wheels comprising a drive wheel for driving the endless track, the endless track comprising:
an elastomeric belt-shaped body comprising an inner surface for facing the wheels and a ground-engaging outer surface for engaging the ground; and
a plurality of elastomeric drive/guide lugs projecting from the inner surface, each elastomeric drive/guide lug of the plurality of elastomeric drive/guide lugs comprising a first elastomeric material, a second elastomeric material stiffer than the first elastomeric material, and a third elastomeric material stiffer than the second elastomeric material, the first elastomeric material being disposed between a periphery of the elastomeric drive/guide lug and the second elastomeric material, the second elastomeric material being disposed between the first elastomeric material and the third elastomeric material.
34. A method of making an endless track for traction of an off-road vehicle, the endless track being mountable around a plurality of wheels of the off-road vehicle, the plurality of wheels comprising a drive wheel for driving the endless track, the method comprising:
forming an elastomeric belt-shaped body of the endless track, the elastomeric belt-shaped body comprising an inner surface for facing the wheels and a ground-engaging outer surface for engaging the ground; and
forming a plurality of elastomeric lugs of the endless track which project from a given one of the inner surface and the ground-engaging outer surface, each elastomeric lug of the plurality of elastomeric lugs having a material composition defining an arrangement of zones of different materials, the arrangement of zones of different materials comprising a plurality of zones of different elastomeric materials, the plurality of zones of different elastomeric materials comprising at least three zones of different elastomeric materials, the elastomeric lug exhibiting a desired variation of a material property across the arrangement of zones of different materials.