Steuereinrichtung an Maschine mit rotierenden Arbeitsteilen.

摘要

717,183. Engine stop-gear; turbines. POWER JETS (RESEARCH & DEVELOPMENT), Ltd. Feb. 27, 1953 [March 14, 1952], No. 6663/52. Classes 110(3) and 122(4) [Also in Group XXIX] A protective control arrangement for a rotating machine comprises an overspeed trip mechanism and a device which is responsive to the oil pressure in the lubrication system supplying the machine bearings and is operable to shut down the machine in the event of the failure of the lubrication system which is pressurized by an independent auxiliary pump 29. A magnet 34 is mounted on a turbine shaft 33 of non-magnetic steel and rotates therewith between poles 35 to form an alternator whose output is led via leads 36 to a control circuit 38 incorporating a filter circuit whose output controls a solenoid 22. A butterfly valve 12 in the turbine inlet duct 10 is biased into the closed position by a spring 15 and has fixed to the outer end of its spindle 16 a plate 17 having two detents 18, 19 therein respectively co-operable with a pawl 20 on a spring- loaded lever 21 and the plunger 26 of a solenoid 27. The lever 21 may be operated to release the pawls 20 by operation of either the solenoid 22 or a solenoid 23 in series with the solenoid 27 and a pressure operated switch 24 in the circuit supplying current to the lubricating oil pump motor 30. When the turbine is at rest the valve 12 is closed, the detent 19 is engaged by the plunger 26, the pawl 20 is clear of detent 18 and all the solenoids are de-energized. To start the turbine, the lubricating oil pump motor switch 40 is closed and when sufficient oil pressure is developed to operate the switch 24, the solenoids 23 and 27 are energized thereby lowering the plunger 41 and freeing the plunger 26 from the detent 19. The valve 12 is then opened by a hand lever 14 and the pawl 20 engages the detent 18 to retain the valve in the open position. If the turbine overspeeds the solenoid 22 is energized and the plunger 42 thereof lifts the arm 21 to free the pawl 20 and the valve 12 is closed by the spring 15. If desired the circuit 38 may be arranged, under overspeed conditions, to also de-energize the solenoids 23 and 27 to prevent restarting. If the oil pressure fails the switch 24 opens and both solenoids 23, 27 are de-energized and the lever 21 is lifted by the plunger 41, the valve 12 is closed by the spring 15 and the plunger 26 engages the detent 19 to ensure that the valve cannot be reopened until the oil pressure is restored.