High-pressure fuel pump for an internal combustion engine with direct injection

In an internal combustion engine with at least one combustion chamber and direct injection of fuel into the at least one combustion chamber, a high-pressure fuel pump comprising:

• a low-pressure connection for low-pressure fuel, said low-pressure connection being configured to supply low-pressure fuel to the high-pressure fuel pump;
• a low-pressure fuel supply chamber;
• a pump element;
• a high-pressure connection for discharging fuel from the high-pressure fuel pump;
• a medium-pressure fuel supply chamber;
• a medium-pressure fuel connection for supplying medium-pressure fuel to the high-pressure fuel pump, said medium-pressure fuel connection opening into said medium-pressure fuel supply chamber;
• a fuel switching valve disposed downstream of said low-pressure fuel supply chamber, said fuel switching valve selectively connecting one of said low-pressure fuel supply chamber and said medium-pressure fuel supply chamber in a fluid-conducting manner to said pump element;
• said low-pressure connection, said low-pressure fuel supply chamber, said fuel switching valve, said pump element, and said high-pressure connection being provided in succession in a fuel flow direction;
• a pump housing with a cover;
• said low-pressure fuel supply chamber, said medium-pressure fuel supply chamber, said pump element, and said fuel switching valve being disposed in said pump housing;
• and
• said low-pressure fuel supply chamber, said medium-pressure fuel supply chamber, said pump element, said fuel switching valve, said low-pressure connection, said high-pressure connection, and said medium-pressure fuel connection together forming a unified device.