| 摘要 |
1,168,271. Hydro-mechanical variable-ratio gear. SUNDSTRAND CORP. 19 Oct., 1966 [21 Feb., 1966], No. 46832/66. Heading F2D. A variable-ratio gear comprises an output sun 43, a planet carrier 45 clutchable to an input shaft 11 by a clutch 16 and connectible, by a clutch ] 7, to a ring gear 41 which is connected to a constant displacement hydrostatic unit 21 in hydraulic communication with a variable displacement hydrostatic pump unit 20 driven by the input shaft. The units may both be of the swash-plate type. For a low speed range the clutch 16 is disengaged and the clutch 17 engaged, so that the drive is all hydraulic and the output speed is increased as the displacement of pump unit 20 is increased from an initial zero position. In its maximum displacement position 25, the pump swash-plate 23 depresses a switch 55 to disengage the clutch 17 and engage the clutch 16. A split-torque drive ensues, the output speed increasing further as the displacement of pump 21 is reduced from its initial maximum position through neutral to its reverse maximum stroke position 26. The switch 55 is of the type adapted upon depression and release to assume one condition and retain it, and upon a successive depression and release to assume the other condition and retain it, so that on changing the pump swash-plate back to its first maximum stroke position the switch 55 when actuated disengages clutch 16 and engages clutch 17 to restore the low speed all hydraulic phase. All hydraulic reverse is obtained with the clutch 17 engaged and clutch 16 disengaged and the swash-plate 23 shifted to the reverse side of neutral. |
