| 摘要 |
1465121 Hydrostatic transmissions; linkwork CLARK EQUIPMENT CO 24 Sept 1974 [24 Sept 1973] 41452/74 Headings F2W and F2K In a hydrostatic transmission arrangement for a vehicle in which separate transmissions, each comprising a variable-displacement pump and a variable-displacement motor, drive wheels on the opposite sides of the vehicle, the displacements of the motors 38 (Fig. 4) are adjustable together to either maximum displacement (for low-speed drive) or to a reduced displacement position (for higher-speed drive) by a linkage in which a lever 42 interconnects the motor control members 40, this lever being movable between positions corresponding to lower-speed and higher-speed drive by a manual control member, with wedging means yeildably holding the motor control members in the selected position against the action of the motor pistons on motor swash plates. In the arrangement shown in Fig. 4 the lever 42 is pivoted to one control member 40 and engages the other through a pin and slot connection 45. A bellcrank 47 also engages lever 42 as shown through another pin and slot connection, 44, 49 and the other end of bell-crank 47 is pivoted to a rod 50 which is in turn pivoted to the end of a manually movable lever (52) (Fig. 3, not shown). The arrangement of the pin and slot connection 45 and bell-crank 47 is such that in either position of control members 40 (in the full-line or broken line position of the linkage as shown) the levers 40 are wedged in position against the bias of the pistons on the swash plates. An over-centre spring arrangement (such as that shown at 56a in Fig. 5) acts on the manually movable lever (52) so that this lever is biased to one of its two extreme positions. In the embodiment shown in Fig. 5, which is, unlike that of Fig. 4, for axially aligned motors 38a, a rod 60 connected by ball joints to a bell-crank 47a and to control lever 42a replaces the pin and slot connection shown in Fig. 4 between bell-crank 47 and lever 42. The transmission arrangement is described in an end-loader in which steering is effected by differential variation of the variable pumps supplying the motors, these having separate manual control members. |
