Fuel pump check valve

A high-pressure automotive fuel pump comprising:

• an electric motor including a drive shaft:
• a fuel pumping element attached to the drive shaft;
• an inlet passage by which low-pressure fuel from a source thereof is drawn into the pump;
• a cap fitting onto one end of the fuel pump and including a pump outlet passage through which high-pressure fuel is pumped to an engine of the vehicle;
• and,
• a check valve assembly installed in the outlet passage, the assembly comprising a retainer seated at an outlet end of the outlet passage, a check valve which, when the pump is off, blocks an inlet into the outlet passage to prevent fuel flow through the outlet passage and into the pump resulting in a decrease in fuel pressure, but, when the pump is operating is forced away from the inlet to open the valve and allow fuel to freely flow through the outlet passage, the fuel flowing both around and through the check valve as it flows through the outlet passage with the flow of fuel around and through the check valve, when the valve is open, providing for quiet operation of the fuel system so when the pump is operating no discernible noise or chattering is produced by the check valve, and a spring one end of which seats against the retainer and the other end of which seats against the check valve, the spring being a fully collapsible spring by which, when the check valve is opened, the check valve collapses the spring sufficiently that one end of the check valve abuts against the retainer so that the outlet passage is fully opened.

A high-pressure automotive fuel pump comprising:

• an electric motor including a drive shaft;
• a fuel pumping element attached to the drive shaft;
• a fuel inlet passage by which low-pressure fuel from a source thereof is drawn into the pump, and a fuel outlet passage through which high-pressure fuel is pumped to an engine of the vehicle;
• a retainer seated at an outlet end of the outlet passage;
• a check valve which, when the pump is off, blocks an inlet into the outlet passage to prevent fuel flow through the outlet passage and into the pump resulting in a decrease in fuel pressure in a fuel system in which the pump is installed, but, when the pump is operating is forced away from the inlet to open the valve and allow fuel to freely flow through the outlet passage, the check valve including a hollow base and a sealing element spaced from the base so to provide a fuel flow path around the sealing element and through the base when the check valve is open, and means for spacing the base and sealing element from each other to provide a fuel flow path around the sealing element and into the base;
• and,
• a spring one end of which seats against the retainer and the other end of which seats against the check valve, the flow of fuel around and through the check valve when the valve is open providing for quiet operation of the fuel system so when the pump is operating no discernible noise or chattering is produced by the check valve, the spring being a fully collapsible spring by which, when the check valve is opened, the check valve collapses the spring sufficiently that one end of the check valve abuts against the retainer so that the outlet passage is fully opened.

In a fuel system having a fuel flow path through which fuel flows from a source thereof to a location where the fuel is combusted, a check valve assembly including a check valve having a closed position so, when fuel is not flowing through the path the check valve blocks the path to prevent fuel flow back through the path to the source, thereby preventing a decrease in fuel pressure in the fuel system, but, when fuel is flowing through the path is forced to an open position which allows fuel to freely flow through the path, the check valve assembly further including a hollow base and a sealing element spaced from the base so to provide a fuel flow path around the sealing element and through the base when the check valve is open, means for spacing the base and sealing element from each other to provide a fuel flow path around the sealing element and into the base, and a retainer and a spring one end of which seats against the retainer and the other end of which seats against the check valve, the spring being a fully collapsible spring by which, when the check valve is opened, the check valve collapses the spring sufficiently that one end of the check valve abuts against the retainer so that the outlet passage is fully opened, the flow of fuel around and through the check valve when the valve is open providing for quiet operation of the fuel system with no discernible noise or chattering being produced by the check valve.