Abstract: A split type connecting rod is capable of preventing problems of peeling and falling at the time of fracturing and splitting, securing alignment accuracy after the fracturing, reducing a processing time necessary for processing the groove and improving the processing accuracy. This split type connecting rod 100 includes a valley 106 formed on the inner circumferential surface of a crank-pin hole 101d of a large end portion 101e. Fracture starting point grooves 105 are also formed at the base of the valley 106.

Abstract: A split type connecting rod has a simple structure that is capable of suppressing rotation of a metal bearing, and avoiding problems such as burning. The split type connecting rod holds a crank-pin through a metal bearing which has locking lugs. A bearing locking groove locks at least one of the locking lugs when the metal bearing rotates forward in the circumferential direction of a crank-pin hole. A bearing locking groove locks at least one of the locking lugs when the metal bearing rotates backward. The bearing locking grooves are deviated from each other in the circumferential direction.

Abstract: A split type connecting rod has a simple structure that is capable of suppressing rotation of a metal bearing, and avoiding problems such as burning. The split type connecting rod 200 holds a crank-pin through a metal bearing 213 which has locking lugs 213c, 213d. A bearing locking groove 201h locks at least one of the locking lugs 213d when the metal bearing 213 rotates forward in the circumferential direction of a crank-pin hole 101d. A bearing locking groove 201i locks at least one of the locking lugs 213c when the metal bearing 213 rotates backward. The bearing locking grooves 201h, 201i are deviated from each other in the circumferential direction.

Abstract: A split connecting rod includes a fracture start groove that extends in an axial direction X and is located at the approximate center of each of opposing positions on an inner surface of a crank pin opening. A bearing securing groove is provided on either or both of the opposing positions on the inner surface of the crank pin opening. Notches are provided, respectively, at both ends of each of the opposing positions in the axial direction X on the inner surface of the crank pin opening. The fracture start groove has a stress concentration factor that is greater than those of the notches and the bearing securing groove. Preferably, steel for use as the material of a connecting rod has a carbon content of about 0.05% to about 0.45% by weight, more preferably about 0.10% to about 0.35% by weight.

Abstract: A connecting rod is formed using a method that includes providing a connecting rod blank. The connecting rod blank has a rod section disposed between a big end and a small end. The big end has a first hole generally sized to receive a crankpin of a crankshaft and at least one second hole generally sized to receive a bolt, wherein the axes of the first and second holes are generally normal to each other. The big end of the connecting rod has a dividing plane that extends through both the first and second holes. The connecting rod blank is processed by hardening at least the big end to a sufficient depth such that a first region of the big end lying between the first and second holes at the dividing plane is hardened, while leaving a substantial second region of the big end at the dividing plane generally unhardened. The connecting rod blank is further processed by splitting the big end along the dividing plane to produce a rod part fracture surface and a cap part fracture surface.

Abstract: A split connecting rod includes a fracture start groove that extends in an axial direction X and is located at the approximate center of each of opposing positions on an inner surface of a crank pin opening. A bearing securing groove is provided on either or both of the opposing positions on the inner surface of the crank pin opening. Notches are provided, respectively, at both ends of each of the opposing positions in the axial direction X on the inner surface of the crank pin opening. The fracture start groove has a stress concentration factor that is greater than those of the notches and the bearing securing groove. Preferably, steel for use as the material of a connecting rod has a carbon content of about 0.05% to about 0.45% by weight, more preferably about 0.10% to about 0.35% by weight.

Abstract: A split type connecting rod is capable of preventing problems of peeling and falling at the time of fracturing and splitting, securing alignment accuracy after the fracturing, reducing a processing time necessary for processing the groove and improving the processing accuracy. This split type connecting rod 100 includes a valley 106 formed on the inner circumferential surface of a crank-pin hole 101d of a large end portion 101e. Fracture starting point grooves 105 are also formed at the base of the valley 106.

Abstract: A split type connecting rod has a simple structure that is capable of suppressing rotation of a metal bearing, and avoiding problems such as burning. The split type connecting rod 200 holds a crank-pin through a metal bearing 213 which has locking lugs 213c, 213d. A bearing locking groove 201h locks at least one of the locking lugs 213d when the metal bearing 213 rotates forward in the circumferential direction of a crank-pin hole 101d. A bearing locking groove 201i locks at least one of the locking lugs 213c when the metal bearing 213 rotates backward. The bearing locking grooves 201h, 201i are deviated from each other in the circumferential direction.

Abstract: A connecting rod is formed using a method that comprising providing a connecting rod blank having. The connecting rod blank has a rod section disposed between a big end and a small end. The big end has a first hole generally sized to receive a crankpin of a crankshaft and at least one second hole generally sized to receive a bolt, wherein the axes of the first and second holes are generally normal to each other. The big end of the connecting rod has a dividing plane that extends through both the first and second holes. The connecting rod blank is processed by hardening at least the big end to a sufficient depth such that a first region of the big end lying between the first and second holes at the dividing plane is hardened, while leaving a substantial second region of the big end at the dividing plane generally unhardened. The connecting rod blank is further processed by splitting the big end along the dividing plane to produce a rod part fracture surface and a cap part fracture surface.

Abstract: An improved drive unit and suspension arrangement therefor for a small snowmobile having an open tubular frame. The drive unit includes an internal combustion engine and a pulley type transmission. The pulley type transmission is supported within a transmission casing and is affixed to the frame for rigidifying the frame. The suspension permits more vertical compliance than for and aft compliance for vibration dampening without adversely effecting the rigidity.

Abstract: An improved drive unit and suspension arrangement therefor for a small snowmobile having an open tubular frame. The drive unit includes an internal combustion engine and a pulley type transmission. The pulley type transmission is supported within a transmission casing and is affixed to the frame for rigidifying the frame. The suspension permits more vertical compliance than fore and aft compliance for vibration dampening without adversely effecting the rigidity.

Abstract: A frame and body construction for a small snowmobile comprised of a generally open tubular frame to which a light weight generally inverted cup shape body is detachably connected. To prevent carburetor icing, an insulating box encircles the carburetor and cooperates with the body, when the body is in place.