Hydrodynamic torque transmitting unit, particularly for a hydrodynamic

Abstract

The disclosure contains a hydrodynamic torque transmitting unit particularly for a hydrodynamic brake. A working chamber that is filled with working fluid contains a stator and a rotor. An inlet valve controls inlet of fluid to the working chamber. A piston connected with the inlet valve selectively closes the valve. The piston initially opens the inlet valve fully for a surge of working fluid into the working chamber. In a stage I condition, valving and pressure chambers associated with the piston returns the inlet valve to an intermediate position reducing the inflow of working fluid into the working chamber after the initial surge. In a stage II condition, the pressure chambers remain continuously pressurized for holding the inlet valve in the condition of maximum supply of working fluid to the working chamber. Various piston arrays are described in different embodiments. In the various embodiments, different piston arrangements, utilizing two pressure chambers operating selectively together or in opposition to each other, determine the various positions of the piston which moves the inlet valve. Appropriate valving and switches direct the pressure supply to the different pressure chambers at different times for moving the piston as needed to move the inlet valve. The switching is done either through a time delay arrangement and/or through a sensor directly connected with the working chamber for sensing the pressure therein.