GB724531A - Compressor and drive - Google Patents

Abstract

724,531.. Variable ratio gearing. GARRETT CORPORATION. May 29, 1952 [June 14, 1951], No. 13654/52. Class 80 (2) [Also in Group XXVI]. A compressor rotor 11 is driven at a relatively constant speed from an engine driven shaft 19 connected to a compressor driving shaft 18 by a two-ratio gear 22 in series with a continuously variable epicyclic gear 23. The gear 22, Fig. 3, comprises two gear wheels 24, 27 which mesh with gear wheels 25, 28 on an intermediate shaft 26 and which are respectively connectible with the shaft 19 by means of a one-way clutch 44 or a hydraulically actuated clutch 47 the one-way clutch overrunning when the clutch 47 is engaged. The shaft 26 drives the carrier 89 of planet wheels 88 which mesh with a ring gear 91 and a sun gear 103 on a shaft 99 splined to the compressor shaft 18. Rotation of the reaction ring 91 is retarded by an oil pump 108 connected thereto by a gear train 98, 105, 106. The output of the pump 108 is throttled by a valve 117 which is actuated against a spring 126 by a diaphragm 123 closing a pressure space 125. When a higher rotational speed of the compressor shaft 18 is required the fluid pressure admitted to the space 125 is increased by means such as described in Specification 715,290. Such pressure increase causes closing movement of the valve 117 resulting in producing greater resistance to rotation of the ring gear 91 with corresponding increase of speed of shaft 18. A drive is taken from the gear wheel 28 to a pump which supplies oil under pressure to actuate the clutch 47 and lubricate the gears: Oil is admitted to the operating space 58 of the clutch, via a hollow portion of the shaft 19, a port 61 and a passage 62, at low shaft speed. At a certain shaft speed centrifugal force moves a valve member 66 outwardly against spring action to close the port 61. Bleed holes 64 allow oil to escape from the space 58 and the clutch 47 disengages. The shaft 26 is then driven through the low ratio gear train 27, 28.