Patent GB-263949-A (GB)
Title: Improvements in or relating to hydraulic power transmitting apparatus
IPC: F16D67/00
Filed: 1925-10-08
Abstract: 263,949. Vickers, Ltd., and Sinclair, H. Oct. 8, 1925. Hydraulic transmission of power in winding engines, haulages, rolling mills, or other mechanism in which reversals are required, and it is required to accelerate a shaft from rest to full speed under load. Forward and reverse hydraulic transformers or couplings of the F÷ttinger or other turbine type are employed, the inlet valve being operated by means giving a wide initial opening so that a rapid partial filling is effected, the inlet being thereafter restricted by a torque-controlled or other device. Means are also provided whereby both couplings may be filled simultaneously for braking, and for preventing too sudden reversal - of the hand control lever. In the form shown in Fig. 2, the inlet valve 17 is moved to fill one of the couplings by means of a spindle 18 operated from the control lever 26, eccentrics 33 simultaneously operating forks 31, Fig. 4, to move spindles 29 endwise so that the outlet valves 10<a> 10<b> are moved to close the outlet from that coupling and open that from the other coupling. A torque-controlled device 19 subsequently reduces extent of the opening of the valve 17. When braking is required, weights 39 are released by the lever 26 or by an automatically operated trip 40, and through connections open an auxiliary valve 43 for filling both couplings and rotate the spindles 29, so that the outlet valves 10<a>, 10 b are closed. Where the drive is from an electric motor, the torque-controlled device comprises primary and secondary members 52, 53, Fig. 5, connected by springs 54. the member 52 being excited by transformers in the main circuit of the motor except when the lever 26 is in its neutral position. When the lever 26 is moved from its neutral position, the members 52, 53 move together and the spindle 18 is rocked directly or through a servomotor 45. When the torque reaches a value sufficient to overcome the springs 54, the member 53 moves in the direction requisite to reduce the opening of the inlet valve. Unduly rapid reversal of the l8lVer 26 is prevented by stops 62 on a member 61 connected by a link to a floating lever 64, the ends of which are connected to the members 52, 53. Where the prime mover is not an electric motor, or where the electric motor is fitted with a flywheel, a mechanical torque-controlled device is employed. This may consist of a coupling comprising discs with projections 69, 70, Fig. 6, engaged by a sinuous spring 71, one of the discs carrying a casing with external teeth 73. A ring 77 having internal teeth meshing with the teeth 73 and with helical teeth 74 on a third disc 75 is moved axially in proportion to the torque transmitted and through multiplying levers 78 and a slidable collar 79 acts on the inlet valve, either mechanically or through a fluid-pressure. device.. In the latter case, the lever 26 is connected to the valve spindle 18 through a floating lever 84, also connected to the valve 88 and piston 85 of a regulating cylinder 87. When the torque transmitted attains a predetermined value, a valve 93 is actuated from the collar 79, to place a pressure inlet 90 into communication with a port 91 leading to the valve 88, and by means of a recess 95 with an outlet 92, the pressure of the fluid passing to the valve 88 being determined by the extent of movement of the valve 93. In a modification, the collar 79 acts on the valve 96, Fig. 7, of the regulating cylinder through a floating lever 97 connected by means including a bell-crank lever 98 to the regulating piston. In a further form, the torque-controlled device may consist of a long tube 100, Fig. 8, rigidly fixed to the driving shaft at one end and carrying the disc 75 at the other, and the flexible coupling may be dispensed with. An arrangement for operating the inlet valve without the use of a torque-controlled device comprises a slidable cylinder 101, Fig. 9, connected to the lever 26 and having a piston 103 connected to the floating lever 58 of the servomotor 45, centering springs 104 being provided. Operation of the lever 26 fully opens the inlet valve, and the liquid in one end of the. cylinder is put under pressure. The pressure acts on a plunger 106 or 107, Fig. 10, and when it attains a predetermined value moves a piston valve 105, which is normally locked by a spring- pressed ball 112. The two ends of the cylinder are put into communication, and a centering spring moves the piston 103, so that the inlet valve opening is reduced. In another form, the cylinder 101 is fixed, and the lever 26 and piston 103 are connected to opposite ends of a floating lever which is also connected to the centering springs and servomotor.