GB519086A - Improvements in or relating to hydraulic driving plants - Google Patents

Abstract

519,086. Hydraulic machines. JACKSON, L. MELLERSH-. (Aktiebolaget Imo-Industri.). Sept. 23, 1938, No. 27783. [Classes 69 (ii) and 135] Hydraulic plant for driving two or more rotary machines comprises a rotary liquid motor of the positive displacement type (constant volume per revolution) coupled to each machine, said motor being connected in series and supplied by a common liquid pump delivering a constant or substantially constant quantity of liquid per unit of time. for instance also of the positive displacement type; a manually operable starting valve is connected in parallel with each motor, and an automatically operating valve is also connected in parallel with each motor, the latter valve being adapted to open at a given liquid pressure. A single valve may combine both functions. Pump 10 driven by motor 11 is connected by a pressure line 15 with the motor 20 of a centrifugal machine 21 and also with a space 16 in a starting valve 17. The exhaust from the motor 20 passes by pipe 22 to a braking valve 23 and thence by a pipe 24 to the upper chamber 25 of valve 17 and also by pipe 26 to the starting valve 17a of a second machine. Each valve is formed as a differential piston member 33, the lower space 16 being coupled to the upper space 25 when valve lifts under excess pressure in the pipe line 15. The upper space 25 communicates through passages 42 with the inner part of the valve which has a spring 37 and this upper space 25 is coupled to the pipe line 26. The valve is adapted to be permanently held up by the screwed spindle 38. The starting valves 17, 17a are coupled in parallel with their respective motors 20, 20a, whereas the braking valves 23, 23a are coupled in series therewith. When the machines are at rest, the braking valves 23, 23a are closed, the hand wheels 39 being screwed down and the springs acting as the closing means. For starting up, the spindles 38 of the starting valves are screwed upward to open these valves and when the motor 11 is started up liquid flows from the pump 10 through the pressure conduit 15 and starting valve 17 back through the return pipe 27. Upon the braking valve 23 being opened by hand the motor 20 is started, and as it accelerates, pressure is developed so that the valve 17 experiences a differential pressure which acts against the tension of this spring. When the second motor 20a is started up the flow is continued from.the first motor through 20a before passing back to the return passage 27. Specification 231,865, [Class 110 (ii)], is referred to.