| 摘要 |
<p>Two motors (12,14) are arranged on opposing sides of a common shaft (16), drive plates (30,32) of the pump/motors (12,14) being rigidly coupled to each other, for example by being in hard contact with opposing sides of the shaft (16). By providing hard contact between the pump/motor drive plates (30,32) and a common shaft (16), the drive plates and shaft act as a substantially solid element under compression, thereby substantially canceling axial loads generated by the pump/motors (12,14) directly through the shaft (16). Residual axial loads are handled via bearings (34,36) positioned on the shaft (16) adjacent the drive plates (30,32) in such a manner that the drive plates are in light contact only with the bearings (34,36). As a result, friction experienced by the bearings is substantially reduced as compared to conventional systems, thereby improving the efficiency of the system. To further reduce loads on the bearings (34,36), the pump/motors (12,14) are arranged to ensure that they generate radial forces in a direction that is opposite to that of a separation force generated by a torque transferring device carried on the shaft (16) and transmitted to the bearings (34,36). A common housing (17) surrounding the two pump/motors (12,14), bearings (34,36) and torque transferring device is divided into three regions, to segregate the bearings (34,36) and torque transferring assembly from the pump/motors (12,14). In this manner, the regions containing the pump/motors (12,14) are substantially filled with oil to, for example, fully lubricate the pump/motors (12,14), while the central region containing the gears and torque transferring device contains a significantly smaller volume of oil to simply splash lubricate the contents of the region, thereby reducing drag on the bearings (34,36). Control means are provided for selectively moving the two pump/motors (12,14) substantially simultaneously to a selected displacement angle, using mechanical systems alone and in combination with hydraulic systems.</p> |
