Friction drive belt
A friction drive belt includes: an adhesion rubber layer having a core wire embedded therein so as to form a helical pattern having a pitch in a lateral direction of the belt; a compression rubber layer provided on a surface of the adhesion rubber layer located on an inner side of the belt, and serving as a portion that is to contact pulleys, and a backing rubber layer provided on a surface of the adhesion rubber layer located on an outer side of the belt, and serving as a back portion of the belt. A ratio of tensile stress at 10% elongation of a rubber composition forming the adhesion rubber layer to that of a rubber composition forming the backing rubber layer is 1.77 or more, as measured in a longitudinal direction of the belt at an ambient temperature of 25° C. according to JIS K 6251.
1. A friction drive belt, comprising:
an adhesion rubber layer having a core wire embedded therein so as to form a helical pattern having a pitch in a lateral direction of the belt;
a compression rubber layer provided on a surface of the adhesion rubber layer located on an inner side of the belt that serves as a portion of the belt for contact with pulleys; and
a backing rubber layer provided on a surface of the adhesion rubber layer located on an outer side of the belt that serves as a back portion of the belt,
wherein a ratio of tensile stress at 10% elongation of a rubber composition forming the adhesion rubber layer to that of a rubber composition forming the backing rubber layer is 1.77 or more, as measured in a longitudinal direction of the belt at an ambient temperature of 25° C.
2. The friction drive belt of claim 1 , wherein the backing rubber layer has a thickness of 0.3-0.5 mm.
3. The friction drive belt of claim 1 , wherein the backing rubber layer is free of short fibers.
4. The friction drive belt of claim 2 , wherein the backing rubber layer is free of short fibers.
5. The friction drive belt of claim 1 , wherein the adhesion rubber layer is formed by a rubber composition of an ethylene-α-olefin elastomer as a material rubber.
6. The friction drive belt of claim 1 , wherein the backing rubber layer is formed by a rubber composition of an ethylene-α-olefin elastomer as a material rubber.
7. The friction drive belt of claim 5 , wherein the backing rubber layer is formed by a rubber composition of an ethylene-α-olefin elastomer as a material rubber.
8. The friction drive belt of claim 1 , wherein the adhesion rubber layer, the compression rubber layer, and the backing rubber layer form a V-ribbed belt.
9. The friction drive belt of claim 2 , wherein the adhesion rubber layer, the compression rubber layer, and the backing rubber layer form a V-ribbed belt.
10. The friction drive belt of claim 3 , wherein the adhesion rubber layer, the compression rubber layer, and the backing rubber layer form a V-ribbed belt.
11. The friction drive belt of claim 4 , wherein the adhesion rubber layer, the compression rubber layer, and the backing rubber layer form a V-ribbed belt.
12. The friction drive belt of claim 5 , wherein the adhesion rubber layer, the compression rubber layer, and the backing rubber layer form a V-ribbed belt.
13. The friction drive belt of claim 6 , wherein the adhesion rubber layer, the compression rubber layer, and the backing rubber layer form a V-ribbed belt.
14. The friction drive belt of claim 7 , wherein the adhesion rubber layer, the compression rubber layer, and the backing rubber layer form a V-ribbed belt.