GB831504A - Improvements in or relating to blower systems for supplying air to internal combustion engines - Google Patents

Abstract

831,504. Charge pumps. WIDDROP & CO. Ltd., H., PUNT, R. S., CAMPBELL & ISHERWOOD Ltd., and RAWLINSON, R. Sept. 10, 1957 [Nov. 6, 1956], No. 33798/56. Class 7(2) [Also in Group XXXVII] An electric motor 11 driving a scavenge air blower of a marine diesel engine 10 is supplied by a Ward-Leonard generator 12 having a field winding 14 supplied by an exciter 15 driven by a motor 16 and having a field winding 19 connected to an exciter 20 driven by the engine 10 so as to render the power supply to the motor 11 responsive to engine speed and therefore approximately consistent with the air requirements of the engine 10. The exciter 15 has a further field winding 18 connected to the constant-voltage supply of the motor 16, a trimmer 21 being so adjusted that with the engine 10 stationary the motor 11 is running at a speed just below that required to provide the air for minimum engine speed, a relief vent in the scavenge air trunking being possibly operative. A further trimmer 22 is so adjusted that at minimum engine speed the relief vent will probably not be operative. A change-over switch 23 is operated by the engine reversing lever to ensure that the system operates identically in whatever direction the engine rotates. A changeover switch 24 connects the winding 14 with the constant-voltage supply 17 for emergency manual operation of the Ward- Leonard control whilst isolating the exciter system to allow repairs thereto. The exciter field systems may have discharge resistances. The generator 12 is connected to the motor 10 through contactor means incorporating overload and no-field protection in conjunction with a field rheostat for the generator so that the motor can be started up direct on to the generator, an interlock being provided between the contactor means and the rheostat to ensure that the motor cannot be started with any appreciable field on the generator winding. Reference is made to use of the invention with more than one blower or blower motor, or for supercharging purposes or in a system responsive to engine load, load and speed, or altitude. According to the Provisional Specification, a blower system may be driven from a constant speed motor or motors or other engine through a variable-speed gear operated by electrical, mechanical or fluid-pressure means.