Crawler system and crawler link structure

1. A crawler system comprising a crawler ( 2 ) in which pairs of opposed right and left links ( 1 a ) ( 1 b ) are endlessly connected, each link having a first part on one end, a second part on the other end, and a solid third part connecting the first part and second part, wherein the first part at the one end of the pair of the right and left links ( 1 a ) ( 1 b ) is connected by a cylindrical connection part ( 3 ), the third parts thereof in the longitudinal direction are connected by an engaging part ( 4 ) which engages with a concave tooth ( 29 ) of concavo-convex teeth ( 28 ) of a crawler sprocket ( 27 ), the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) integrally molded as a unit, and the pairs of right and left links ( 1 a ) ( 1 b ) are endlessly connected by inserting connection pins ( 12 ) to the connection parts ( 3 ).

2. A crawler system comprising a crawler ( 2 ) in which pairs of opposed right and left links ( 1 a ) ( 1 b ) are endlessly connected, each link having a first part on one end, a second part on the other end, and a solid third part connecting the first part and second part, wherein the first part at the one end of the pair of the right and left links ( 1 a ) ( 1 b ) is connected by a cylindrical connection part ( 3 ), the third parts thereof in the longitudinal direction are connected by an engaging part ( 4 ) which engages with a concave tooth ( 29 ) of concavo-convex teeth ( 28 ) of a crawler sprocket ( 27 ), the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) integrally molded as a unit, and the pairs of right and left links ( 1 a ) ( 1 b ) are endlessly connected by inserting connection pins ( 12 ) to the connection parts ( 3 ), and the connection parts ( 3 ) are not in contact with the concavo-convex teeth ( 28 ) of the crawler sprocket ( 27 ).

3. A crawler system comprising a crawler ( 2 ) in which pairs of opposed right and left links ( 1 a ) ( 1 b ) are endlessly connected, wherein one end of the pair of the right and left links ( 1 a ) ( 1 b ) is connected by a cylindrical connection part ( 3 ), middle parts thereof in the longitudinal direction are connected by an engaging part ( 4 ) which engages with a concave tooth ( 29 ) of concavo-convex teeth ( 28 ) of a crawler sprocket ( 27 ), the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) integrally molded as a unit, and the pairs of right and left links ( 1 a ) ( 1 b ) are endlessly connected by inserting connection pins ( 12 ) to the connection parts ( 3 ), and an arrangement pitch between the adjacent connection parts ( 3 ) in the longitudinal direction is longer than an engagement pitch between the engaging parts ( 4 ) in a sprocket engaging part.

4. The crawler system according to claim 3 , wherein the engaging part ( 4 ) has a face ( 30 ) for receiving a shoe plate ( 21 ).

5. The crawler system according to claim 3 , wherein the engaging part ( 4 ) is provided so as not to correspond to dirt drainage holes ( 40 a ) ( 40 b ) of the shoe plate ( 21 ).

6. The crawler system according to claim 3 , wherein the connection part ( 3 ) is also integrally molded as a portion of said unit.

7. The crawler system according claim 4 , wherein the links ( 1 a ) ( 1 b ) and the shoe plate ( 21 ) can be assembled and dissembled.

8. A crawler link structure comprising a pair of opposed right and left links ( 1 a ) ( 1 b ), each link having a first part on one end, a second part on the other end, and a solid third part connecting the first part and second part, a connection part ( 3 ) connecting the first parts at the one end of the pair of right and left links ( 1 a ) ( 1 b ), and an engaging part ( 4 ) connecting the third parts of the pair of opposed right and left links in the longitudinal direction, wherein, the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) are integrally molded as a unit, and the engaging part ( 4 ) engages with a concave tooth ( 29 ) of concavo-convex teeth ( 28 ) of a crawler sprocket ( 27 ).

9. A crawler link structure comprising a pair of opposed right and left links ( 1 a ) ( 1 b ), a connection part ( 3 ) connecting one end of the pair of right and left links ( 1 a ) ( 1 b ), and an engaging part ( 4 ) connecting middle parts of the pair of opposed right and left links in the longitudinal direction, wherein, the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) are integrally molded as a unit, and the engaging part ( 4 ) engages with a concave tooth ( 29 ) of concave-convex teeth ( 28 ) of a crawler sprocket ( 27 ), wherein the connection part ( 3 ) is also integrally molded as a portion of said unit.

10. The crawler link structure according to claim 9 , wherein a shaft center of the connection part ( 3 ) and a shaft center of the engaging part ( 4 ) are shifted in the diameter direction, in a sprocket engaging part such that the connection part ( 3 ) in not in contact with the crawler sprocket ( 27 ).

11. A crawler system comprising a crawler ( 2 ) in which pairs of opposed right and left links ( 1 a ) ( 1 b ) are endlessly connected, wherein one end of the pair of the right and left links ( 1 a ) ( 1 b ) is connected by a cylindrical connection part ( 3 ), middle parts thereof in the longitudinal direction are connected by an engaging part ( 4 ), having a face ( 30 ) for receiving a shoe plate ( 21 ), which engages with a concave tooth ( 29 ) of concave-convex teeth ( 28 ) of a crawler sprocket ( 27 ), the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) integrally molded as a unit, and the pairs of right and left links ( 1 a ) ( 1 b ) are endlessly connected by inserting connection pins ( 12 ) to the connection parts ( 3 ).

12. A crawler system comprising a crawler ( 2 ) in which pairs of opposed right and left links ( 1 a ) ( 1 b ) are endlessly connected, wherein one end of the pair of the right and left links ( 1 a ) ( 1 b ) is connected by a cylindrical connection part ( 3 ), middle parts thereof in the longitudinal direction are connected by an engaging part ( 4 ), having a face ( 30 ) for receiving a shoe plate ( 21 ), which engages with a concave tooth ( 29 ) of concave-convex teeth ( 28 ) of a crawler sprocket ( 27 ), the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) integrally molded as a unit, and the pairs of right and left links ( 1 a ) ( 1 b ) are endlessly connected by inserting connection pins ( 12 ) to the connection parts ( 3 ), and the connection parts ( 3 ) are not in contact with the concave-convex teeth ( 28 ) of the crawler sprocket ( 27 ).

13. A crawler system comprising a crawler ( 2 ) in which pairs of opposed right and left links ( 1 a ) ( 1 b ) are endlessly connected, wherein one end of the pair of the right and left links ( 1 a ) ( 1 b ) is connected by a cylindrical connection part ( 3 ), middle parts thereof in the longitudinal direction are connected by an engaging part ( 4 ), which engages with a concave tooth ( 29 ) of concave-convex teeth ( 28 ) of a crawler sprocket ( 27 ), the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) integrally molded as unit, and the pairs of right and left links ( 1 a ) ( 1 b ) are endlessly connected by inserting connection pins ( 12 ) to the connection parts ( 3 ); wherein the connection part ( 3 ) is also integrally molded as a portion of said unit.

14. A crawler system comprising a crawler ( 2 ) in which pairs of opposed right and left links ( 1 a ) ( 1 b ) are endlessly connected, wherein one end of the pair of the right and left links ( 1 a ) ( 1 b ) is connected by a cylindrical connection part ( 3 ), middle parts thereof in the longitudinal direction are connected by an engaging part ( 4 ) which engages with a concave tooth ( 29 ) of concave-convex teeth ( 28 ) of a crawler sprocket ( 27 ), the right and left links ( 1 a ) ( 1 b ) and engaging part ( 4 ) integrally molded as a unit, and the pairs of right and left links ( 1 a ) ( 1 b ) are endlessly connected by inserting connection pins ( 12 ) to the connection parts ( 3 ), and the connection parts ( 3 ) are not in contact with the concave-convex teeth ( 28 ) of the crawler sprocket ( 27 ).

15. The crawler link structure according to claim 8 , wherein a shaft center of the connection part ( 3 ) and a shaft center of the engaging part ( 4 ) are shifted in the diameter direction, in a sprocket engaging part such that the connection part ( 3 ) is not in contact with the crawler sprocket ( 27 ).