ROADHEADER GEARBOX WITH OVERLOAD AND BEARING PROTECTION

摘要

A gearbox includes a shaft input spherical bearing and a shaft output spherical bearing enabling the ring gear to float within the housing and not engage the housing. The shaft output spherical bearing permits angular displacement of the output shaft with respect to the longitudinal axis of said output shaft. A spline connection enables the ring gear to pivot with respect to the cover. Loads transmitted to the housing of the gearbox are not transferred to the gear systems and the gear systems self-align within the housing. According to another embodiment, there is provided an overload protection device in combination with a prime mover and gearbox transmission which supplies torque through the gearbox transmission to a load. According to a further embodiment, there is provided a bearing lubrication system for a gearbox utilized to drive earth boring machines. An input shaft with is driven by the prime mover and rotates therewith. An external spline on the input shaft mates with an input gear having an internal spline. Upon overload of the gearbox transmission, the input shaft fractures an annular groove in the input shaft. A bushing prevents travel of the portion of the input shaft which is driven by the prime mover and which continues to spin after the fracture. Lubricating oil is forced and pumped into and through the first passageway through the floating ring gear and into the annulus between the gearbox housing and the floating ring gear. Lubricating oil from the annulus is pumped into and through the second passageway and through the joint between the second and third passageway, and through the third passageway into the void in the cover. Thereafter the oil passes through the fourth passageway between the void in the cover and the circumferential recess in the cover and lubricating the bearing mounted adjacent the recess in the cover/housing.