Patent GB-361537-A (GB)
Title: Improvements in and relating to speed control mechanism for prime movers
IPC: G05D13/00
Filed: 1930-10-20
Abstract: 361,537. Speed governors for steam turbines. BRITISH THOMSON-HOUSTON CO., Ltd.; Crown House, Aldwych, London-(Assignees of Standerwick, R. G. ; 17, Brookhouse Drive, Marblehead, Massachusetts, U.S.A.) Oct. 20, 1930, No. 31423. Convention date, Oct. 19, 1929. [Classes 57 and 110 (iii).] In a speed-governing arrangement for prime movers, a correcting mechanism is employed so that should the speed depart from that of a standard speed mechanism the governing mechanism is adjusted so that the prime mover neither gains nor loses in the total number of revolutions which go to make up a constant speed over a long period. The Figure shows a turbine 1 driving an alternator 85. The centrifugal governor 37 is connected to the pilot valve 36 controlling fluid to the piston 32 the rod of which is connected by linkage to the pilot valve 17 controlling fluid to the piston 13 operating the inlet valve 4 of the turbine 1, and provided with the usual follow-up mechanism. The follow-up sleeve 28 of the pilot valve 36 is connected to the floating lever 26, to which is also pivoted the power piston 45 the pilot valve 48 of which is connected to a link 50, pivoted to link 51 and connected by an adjustable connection 52 to a rod 53 firmly secured to and forming part of the lever 26. When the link 52 is directly beneath the pivot of the sleeve 28 upon the rod 26, the governing is virtually isochronous, by positioning the connection to the left or right of the sleeve 28, a negative or positive correction is obtained. The connecting passage 48a is designed as a throttle passage so that the correction due to the power piston 45 lags behind the operation of the other servomotors. A commutator 72 provided with five segments 77 .. 81 is driven through suitable gearing by a synchronous motor 82 connected to the bus-bars 83 supplied by the generator 85. A contact 95 is arranged upon the armature 94 of a solenoid 93 energized at periods by a light-sensitive cell 91 subjected to a beam of light from a source of light 90 passing through the aperture 89 in the pendulum 88 of a master control clock. The segments 77 .. 81 are connected to slip rings and arranged in circuits including the lamps 109, 120, 121, relays 96, 99, 101 and solenoids 66, 67 the cores of which are connected to a T-shaped lever 63 connected by a lever 62 to a bell crank 61 connected to the lever 51. During normal running, at each impulse, the contact 95 contacts with the segment 77 and completes a circuit to a green lamp 109. Should the comparison member's get slightly out of phase, the contact 95 contacts with either segment 78, .79 and breaks the circuit to the lamp 109. Upon further departure from synchronous movement, contact 95 contacts with either segment 80, 81 completing the circuit to one of two red lamps 120, 121 and either solenoid 66, 67, the energized solenoid moving the pilot valve 48 to reset the sleeve 28 to temporarily increase or decrease the governing speed to correct the error. Specifications 262,133 and 271,896, [both in Class 57, Governors &c.], are referred to.