GB848526A - Fluid operated prime mover - Google Patents

Abstract

848,526. Centrifugal governors. ROTOL Ltd. April 3, 1959 [April 11, 1958], No. 11650/58. Class 57. The centrifugally operated valve for controlling the flow of fluid through a prime mover (such as a turbine or swash-plate motor) having a motor-driven shaft 4 comprises two relatively movable members 6, 23 rotatable with the shaft and having ports 21, 22, 24 which co-operate with inlet and outlet galleries 11, 14 in the valve housing 2 and centrifugal control means arranged to produce relative rotation of the members 6, 23 so as to control the rate of fluid flow. As shown applied to a compressed air turbine, the valve member 23 is coupled to the shaft 4 by a torsion spring 25 connected at one end 30 to a threaded sleeve 31 screwed to the end of the shaft and at the other end 26 to the valve member. The latter member is provided with two abutments 56, 57, Fig. 3, which engage with bearings 50, 51 carried by flywieghts 40, 41 pivotally mounted in the rotor 5 of the turbine; the loading of the flyweights is effected by rotating the screwed sleeve 31 so as to increase the torsion of the spring 25 and clamping it in position by a screw 33, the threads of the sleeve and screw being of opposite hand in order to prevent loosening of the screw due to the bias of the spring. The valve member 6, which forms part of the rotor, is provided with two axially spaced rings of inlet and outlet ports 21, 22 which are interconnected, as shown in Fig. 1, by recesses 24 formed in the member 23. In operation, compressed air is fed into the inlet ports 21 via an annular gallery 14 formed in the turbine stator housing 2, circumferentially spaced ports 13 and an annular inlet manifold 11. The air then passes into the recesses 24, through the outlet ports 22 to act on blades 3 and thereby rotate the rotor 5. Above a predetermined speed of the latter, governed by the loading of the spring 25, the flyweights move outwardly against the resistance of the spring and, through the engagement of the bearings 50, 51 with the abutments 56, 57, rotate the valve member 23 relatively to the sleeve 6 so as to close the ports 21, 22 and thereby reduce the speed of the rotor; in order to increase the range of relative movement between the fully open and fully closed positions of the ports 21, 22, the latter are circumferentially staggered relative to the recesses 24. In a modification (Fig. 4, not shown) the recesses 24 and ports 21, 22 are replaced by an arrangement of ports which causes the flow of fluid between the valve member 6, 23 to be in an axial direction instead of a radial direction. Specification 730,560 is referred to.