GB496510A - Improvements in or relating to engine speed control mechanism - Google Patents

Abstract

496,510. Screw propellers. UNITED AIRCRAFT CORPORATION. July 30, 1937, No. 21173. Convention date, July 30, 1936. [Class 114] [Also in Groups XXVI, XXXV, and XXXVII] The speed of an engine is varied and controlled by adjusting the pitch of a screw propeller driven by the engine in response to a centrifugal governor, the loading of which is varied. The governor adjusts the pitch of the propeller through hydraulic mechanism and the loading spring of the governor is adjusted by an abutment moved by the wheel 32. An electric motor 42 drives through worm gearing a shaft 50 gearing with the wheel 32. Closure of a switch 104 to make contact with 110 causes current to pass through the field winding 114 and rotate the spindle 50 until the nut 60 engages the stop 64 and closes the switch 74 whereupon current flows through the field winding 113 and stalls the motor and illuminates lamp 118. When contact 108 is made, current flows through the field winding 112 and rotates the shaft 50 until the nut 60 engages the stop 66 and moves the cam 86 to engage the clutch 90 which rotates and operates switch 98 to open contacts 109 and close contacts 116 and current passes through the field winding 114 and reverses the motor when the clutch is released and the contacts 109 are made again. The motor hunts at this limit of its movement. Fig. 6 shows a multi-engined aircraft fitted with means for maintaining the engines in synchronism. The master engine 120 drives an alternator which supplies synchronous motors 122a, b, c. Each engine 120a, b, c drives alternators each supplying a synchronous motor 136a, b, c, and arranged as shown so that each motor, e.g. 122a and 136a drives elements of a differential gear and differences in speed cause movement of the third element of the differential gear to operate a switch to adjust the loading spring of the governor, in the manner described above, to adjust the propeller of the engine 120a.