VARIABLE DISPLACEMENT VANE PUMP WITH INTEGRATED FAIL SAFE FUNCTION

• Main Author: VALKENBERG, RALPH
• Format: Patent
• Language: English; French
• Published: 20.02.2018
• Subjects: BLASTING; CRANKCASE VENTILATING; ENGINE PLANTS IN GENERAL; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; LUBRICATING; LUBRICATING INTERNAL COMBUSTION ENGINES; LUBRICATING OF MACHINES OR ENGINES IN GENERAL; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; POSITIVE DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENTMACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENTPUMPS; STEAM ENGINES; THERMAL INSULATION IN GENERAL; WEAPONS

A variable displacement vane pump has a pressure controlled valve moveable between first and at least second valve positions based on an output pressure of the pressurized lubricant delivered through the outlet. The pressure controlled valve provides an integrated fail safe function to the pump when an electrical valve fails. The pressure controlled valve is inactive in the first position for an output pressure below a threshold level, allowing an electrical valve (current, solenoid, pulse width modulation (PWM) valve) to selectively control pressure in the control chamber under normal operation of the pump. In fail safe regulation mode, the electrical valve function is disabled and the pressure controlled valve is active in its second position, controlling pressure in the control chamber. Channels and vents in the pump can be opened and closed based on selective movement of the valve when the outlet pressure is at or above a threshold level.