| 摘要 |
A tractor driving system has an overload coupling in which a hydraulic system disconnects a driven output shaft upon overload. Also, the system includes a gauge which is visible to the driver station as well as adjusting features that enable the transmitted torque to be preselected and monitored. In one aspect, fluid in the ducts, chambers, etc., which normally form a constant volume space, holds a plunger in a recess between two coupling parts. Upon overload, the plunger end is forced out of the recess and hydraulic fluid is displaced through a relief valve until fluid returns the plunger, either by opening the circuit to a pump, or by spring biasing a piston in the system with a set screw. In the meanwhile, one part can rotate with respect to the other part. In another aspect, two sets of gears can be alternatively used to drive the output shaft at different speeds. The gear sets can be operated by a double acting plunger having two bevelled ends. One end engages a recess of one gear set and the other end, a recess in a second set, when the plunger is selectively moved to operate either set. Upon overload, the plunger is displaced to a neutral position in which no output drive takes place. A switching block in communication with a pump and reservoir can establish communication with fluid pressure and a spring biased valve used to establish the limit of torque being transmitted. The signalling device can house the set screw that controls the pressure within the system.
|
