Patent GB-457366-A (GB)
Title: Improvements in or relating to the regulation of internal combustion engine-electric power units for vehicles
IPC: G05D13/10
Filed: 1936-02-20
Abstract: 457,366. Transmitting mechanical power. SULZER FRERES SOC. ANON., Winterthur, Switzerland. Feb. 20, 1936, No. 5136. Convention date, July 8, 1935. Addition to 379,882, [Group XXVI]. [Class 38 (iv)] [See also Group XXIX] In a vehicle driven electrically from an internal-combustion engine controlled by a centrifugal governor having supplemental loading devices providing several operating speed ranges as in the parent Specification, the terminal voltage of the main generator is automatically controlled so as to maintain the engine output approximately constant over each working speed range. The several operating speeds are selected to avoid continuous running of the engine at speeds corresponding to torsional oscillation periods. In the system shown in Fig. 2, two supplemental governor loading springs provide, with the constantly acting loading spring, three working speed ranges, the springs being brought into action in succession by fluid pressure controlled by valves 25, 33 operated electrically. The governor controls the fuel supply through a regulating device 21 and also adjusts a resistance 53 in the circuit of the field 52 of the generator B which is directly driven by the engine and supplies current to traction motors C. The resistance 53 is also adjusted from the controller 46. The field 52 if supplied from an excitation machine directly driven by the engine and having automatic means including resistance 79 in field 80 for maintaining its output voltage constant. The manually operated regulator 46 adjusts the control drum 39 by means of a reversible motor 38 with two opposed field windings 44, 45. When the regulator 46 is in the zero position, the motor 38 is supplied with current through the field winding 45 whereby the drum 39 is turned to its zero position. To start the power unit with maximum output and tractive force, the regulator 46 is moved to position 4 whereby field winding 44 is energized and the motor 38 adjusts the drum 39 through positions 1, 2, 3 in succession unless it is stopped by the opening of contacts operated by a relay 48 responsive to the current in the generator-motor circuit 47 attaining a certain value. In position 1 of the drum 39, the cut-out 41 is energized so as to close the circuit through the generator field 52. Contacts 411 close a holding circuit when the drum is moved to positions 2 and 3. When the drum 39 moves to position 2, current flows through relay 26 whereby valve 25 is moved against a spring, to supply pressure fluid to bring into operation one of the supplemental governor springs so that the engine will then run over a higher speed range. In position 3, a valve 33 is similarly operated to bring into action another supplemental spring giving a still higher speed range. With the drum 39 in any of the positions 1, 2, 3, the governor adjusts valve 55 so that pressure fluid supplied through opening 60 may move piston 58 up or down and thus adjust resistance 53 in the circuit of generator field 52. The piston 58 is also controlled by valves 66, 70 which are biassed by springs to the flow-through positions in which they are shown, and are connected respectively to the fluid pressure supply 67, or to exhaust 71, by electric relays whereby piston 58 is moved downwards to increase resistance 53 in the circuit of field 52. Valve 66 is operated by winding 65 which is energized by closure of contacts by relay 49 when the current in the generator-motor circuit 47 rises to a somewhat higher value than that required to operate relay 48. Valve 66 is also operated by winding 73 when the regulator 46 is returned to position 2, 1 or 0. Valve 70 is similarly operated by relay 50 for a still higher value of current in the circuit 47 and by the regulator 46 in positions 1 or 0. In a modification, the regulator 46 is replaced by a simple two-way controller switch which controls the reversible motor 38. The drum operated by the motor 38 not only determines the operating speed range of the engine but also influences the engine torque by adjusting through electric relays a ported sleeve in which the valve 55 is adjusted by the governor. In a further modification, the ported sleeve is adjusted by a connection to the adjustable abutment of the governor springs. In a further modification, shown in Fig. 7, the governor is adjusted to operate through the different speed ranges, by an independent controller 95. The output is maintained substantially constant over each speed range by controlling the output voltage of the generator B in accordance with the current flow in the generator-motor circuit 47. The field 52 of the generator B is in this case supplied directly from the excitation generator N which is driven by a variable speed motor 96 supplied with current from the auxiliary generator M driven by the engine A. The terminal voltage of generator M is maintained constant by the voltage regulator 75. Motor 96 has in addition to its shunt and series field windings 97, 98, a winding 99 in the generatormotor circuit 47 so that the speed of the motor and hence the excitation of the main generator B varies in an inverse manner with respect to the current flow in the main circuit.