Abstract: The invention provides a shaft for a roller wheel which is excellent in strength and can achieve a weight saving. The invention provides a shaft for a roller wheel which rotatably supports a roller (3) outward fitted between both end portions (5a, 5b) in a state in which both end portions (5a, 5b) are fixed, and receives a load in a diametrical direction via the roller (3). Recess portions (6, 6) are provided on a side to which the load is not applied, on an outer peripheral surface corresponding to the roller (3). The load applying direction is a vertical direction. A cross sectional shape of the shaft in the recess portions (6, 6) is formed in a shape which is constituted by an upper circular arc portion (10) on an upper side, a lower circular arc portion (11) on a lower side, and a vertical connection portion (12) passing through a shaft axis (0) and connecting the upper circular arc portion (10) to the lower circular arc portion (11).

Abstract: A crawler track tension adjusting device is provided in which a driving unit of a closed structure is used as a control operation mechanism and automatic tension adjustment is carried out in response to a control signal to create optimum tension on a crawler belt. To this end, the crawler track tension adjusting device comprises: (a) a tension adjusting cylinder which is operated in a direction to increase tension and in a direction to reduce tension under the same condition; (b) a hydraulic pump driven by a motor; (c) a hydraulic circuit including an electromagnetic direction selector valve disposed in an oil pipeline for connecting the hydraulic pump to the tension adjusting cylinder; and (d) a hydraulic sensor for detecting the operating condition of the tension adjusting cylinder disposed in the hydraulic circuit. The hydraulic sensor is connected to an additionally installed controller to operate the hydraulic pump and the direction selector valve thereby controlling the tension adjusting cylinder.

Abstract: Right and left track adjusters each comprise a tension adjusting cylinder operable in forward and backward directions in the same condition; a motor-driven hydraulic pump; and a direction selector valve disposed in a hydraulic circuit for connecting the motor-driven hydraulic pump to the tension adjusting cylinder. The hydraulic circuit includes operating condition detecting means for detecting the operating condition of the tension adjusting cylinder. A controller located in the work vehicle judges a signal released from the operating condition detecting means. If the pressure condition is determined to be higher than a preset value, the tension adjusting cylinder is moved backward to avoid abnormal tension in the crawler belt. If it has a steady-state value, the movement of the tension adjusting cylinder is controlled according to a judgment based on a set value corresponding to the traveling direction of the vehicle, thereby properly adjusting the tension of the crawler belt.

Abstract: An equalizer bar itself serving as a suspension device of a track-type vehicle has spring effects imparted through torsional deformation relative to vertical oscillatory movements of track frames. Arm portions are fixed in directions opposite to each other in two ends of an equalizer bar main body. Free end portions of the arm portions are individually supported in the track frames to be rotatable in directions opposite to each other. The track frames are therefore regulated in the magnitudes of oscillatory movements according to the spring effects of the equalizer bar main body, whereby travel-time oscillations, oscillatory movements, and/or the like of the vehicle body are sufficiently restrained.

Abstract: A travel driving apparatus for a track-type earthmoving machine is provided which can reduce abrasion wear of a sprocket and a bushing and which enables easy replacement of worn members. A contact member is detachably mounted to an opposing surface of a track shoe to a sprocket, and a tooth top portion of the sprocket is brought into contact with the contact member, thereby securing a gap between a bushing of a track chain and a tooth bottom portion of the sprocket. The tooth top portion of the sprocket and a surface portion of the contact member have surface portions which are brought into contact with each other at a time when the sprocket rotates.

Abstract: To provide a roller for a crawler type traveling vehicle. The manufacture of this roller is streamlined by simplifying a structure for holding a seal mechanism between a bearing part and the outside and a thrust bearing and facilitating working while eliminating the need for welding. Roller pieces shaped to be axially separable are combined with a support shaft and formed integrally at a parting section (including a stepped engagement part and an external engagement part) by press fitting. The support shaft is provided with a projection for restraining the left and right roller pieces from moving in an axial direction.

Abstract: The invention provides a crawler type traveling apparatus which can be stably used for a long time period, and furthermore provides a crawler belt sprocket and a segment thereof which is best suited for the crawler type traveling apparatus.

Abstract: To provide a bearing device, which can be easily processed, and whereby, its durability is capable of being improved and a load (tractional force) can be remarkably increased till the burn-in occurs and a pin for the bearing device. The bearing device is provided with a bush and a pin to be inserted in this bush. When an external force is acting in a certain direction, the bush and the pin are relatively rocked, and a slidable range H is formed, in which an outer peripheral face of the pin and an inner peripheral face of the bush partially and slidably contact with each other. An oil reservoir is provided at the side of the pin in order to prevent a no-lubrication portion, to which no lubrication oil is supplied, from being formed in the slidable range H.

Abstract: A seal assembly has simple assembly structures, and provides secure sealing effects. A crawler-track connection structure allows the seal assembly to be easily mounted, and securely prevents overflow of a lubricant and the like to the outside. A pair of meal rings (1) and (1) individually having lip portions (23) and (23) are disposed such that each of the lip portions (23) and (23) protrudes in a direction opposing an axial direction, and a load seal ring (2) is compressed and inserted between the pair of seal rings (1) and (1). The load seal ring (2) exerts reaction forces on the pair of lip portions (23) and (23) outwardly in the axial direction.

Abstract: A pressure receiving surface (8) having a diameter gradually decreasing in an axially inward direction is formed at an outer end portion of a pin (1), whereas a pressing portion (7) is formed at a circumferential edge of an opening of a pin insertion hole (5) of a link (2). A retaining ring (3) is formed with a friction surface (9) to be press-contacted to the pressure receiving surface (8) when a force is applied from the pressing portion (7) upon development of a relative movement in a disengaging direction. The retaining ring (3) and the pressure receiving surface (8) share a greater area of contact than in the prior art, providing sufficient friction. This makes possible to provide a fastening structure of the link and the pin of a crawler belt which can be assembled by simple operation at a low cost, without requiring a high machining accuracy, and thus can be manufactured at a low cost.

Abstract: A travel driving apparatus for a track-type earthmoving machine is provided which can reduce abrasion wear of a sprocket and a bushing and which enables easy replacement of worn members. A contact member is detachably mounted to an opposing surface of a track shoe to a sprocket, and a tooth top portion of the sprocket is brought into contact with the contact member, thereby securing a gap between a bushing of a track chain and a tooth bottom portion of the sprocket. The tooth top portion of the sprocket and a surface portion of the contact member have surface portions which are brought into contact with each other at a time when the sprocket rotates.

Abstract: A crawler track is provided which is improved in the service life of bushings engaging a driving wheel (sprocket) of a track type vehicle, thereby reducing the running cost and which can be used under high loading conditions and therefore has a wide range of applications covering all types of machines from small-sized to large-sized work machines. In the crawler track of the track type vehicle having a track chain composed of a plurality of track links each having a pair of links spaced apart from each other in a lateral direction and a pin for coupling the pair of links, the track links being connected in the form of a loop by their pins, each bushing engaging the driving wheel (sprocket) is rotatably mounted to its associated pin and a beam for coupling the pair of links is disposed at the center of the space between every adjacent pins.

Abstract: The present invention is an elastic flat tread which can prevent an elastic solid from cracking even if the vehicle runs on a protruding object during traveling. For this purpose, the elastic flat tread is provided with any core (1, 11, 115) of a core (1, 11) attached to a link (6) and a core (115) attached to a metal plate (9A) which is attached to a link (8), and end portions (1a, 1b; 11a, 11h; 115a, 115b) in a longitudinal direction of the aforesaid any core (1, 11, 115) are bent toward the side not in contact with the ground.

Abstract: The present invention is an elastic flat tread which can prevent an elastic solid from cracking even if the vehicle runs on a protruding object during traveling. For this purpose, the elastic flat tread is provided with any core (1, 11, 115) of a core (1, 11) attached to a link (6) and a core (115) attached to a metal plate (9A) which is attached to a link (8), and end portions (1a, 1b; 11a, 11h; 115a, 115b) in a longitudinal direction of the aforesaid any core (1, 11, 115) are bent toward the side not in contact with the around.

Abstract: In a crawler belt comprising pairs of opposite links connected endlessly via pins press-fitted into the links, fixing surfaces of pins or links are successively pressed and deformed from the fixing surfaces in an axial direction along the circumferences inside or outside of openings of pin-press-fitting holes by means of local pressing in the axial direction, whereby the end portions of the pins or part of the circumferences of the openings in the links are expanded or narrowed in diameter. The expanded or narrowed portions are fixedly engaged with the opposing engaging spaces. The surface hardness of the expanded or narrowed portions is set to be lower than that of the other portions. With such structure and method, the links and pins can be easily and firmly connected with sufficient holding force in the axial direction, securing accurate, quick and easy fixing of pins and assembling of pins and links.

Abstract: The present invention is an elastic flat tread which can prevent an elastic solid from cracking even if the vehicle runs on a protruding object during traveling. For this purpose, the elastic flat tread is provided with any core (1, 11, 115) of a core (1, 11) attached to a link (6) and a core (115) attached to a metal plate (9A) which is attached to a link (8), and end portions (1a, 1b; 11a, 11h; 115a, 115b) in a longitudinal direction of the aforesaid any core (1, 11, 115) are bent toward the side not in contact with the ground.

Abstract: A pressure receiving surface (8) having a diameter gradually decreasing in an axially inward direction is formed at an outer end portion of a pin (1), whereas a pressing portion (7) is formed at a circumferential edge of an opening of a pin insertion hole (5) of a link (2). A retaining ring (3) is formed with a friction surface (9) to be press-contacted to the pressure receiving surface (8) when a force is applied from the pressing portion (7) upon development of a relative movement in a disengaging direction. The retaining ring (3) and the pressure receiving surface (8) share a greater area of contact than in the prior art, providing sufficient friction. This makes possible to provide a fastening structure of the link and the pin of a crawler belt which can be assembled by simple operation at a low cost, without requiring a high machining accuracy, and thus can be manufactured at a low cost.

Abstract: A seal assembly has simple assembly structures, and provides secure sealing effects. A crawler-track connection structure allows the seal assembly to be easily mounted, and securely prevents overflow of a lubricant and the like to the outside. A pair of seal rings (1) and (1) individually having lip portions (23) and (23) are disposed such that each of the lip portions (23) and (23) protrudes in a direction opposing an axial direction, and a load seal ring (2) is compressed and inserted between the pair of seal rings (1) and (1). The load seal ring (2) exerts reaction forces on the pair of lip portions (23) and (23) outwardly in the axial direction.