Regulated pump

A pump comprising:

• a rotor assembly;
• a casing for housing the rotor assembly and having a pressure region and a suction region therein;
• a cover for mating with the casing;
• a control piston positioned within the casing and being movable in an axial direction in relation to the casing, the control piston sealing the pressure region from the suction region and defining a supply chamber;
• and
• a spring having a non-linear spring rate and biasing the control piston in the axial direction, wherein the casing has a pressure-regulation channel formed therein and extending between the pressure region and a waist of the control piston.

A pump comprising:

• a rotor assembly;
• a casing for housing the rotor assembly and having a pressure region and a suction region therein;
• a cover for mating with the casing;
• a sliding block positioned within the casing and movable in a radial direction in relation to the casing, the sliding block sealing the pressure region from the suction region;
• a piston fixedly coupled to the sliding block and movable in the radial direction;
• and
• a spring contacting the piston and biasing the piston in the radial direction, wherein the casing has a pressure-regulation channel formed therein and extending between the pressure region and a waist of the piston.

A pump comprising a rotor assembly, a casing for housing the rotor assembly and having a pressure region and a suction region therein, and a piston positioned within a bore of the casing and movable in an axial direction within the bore between a first and a second position, wherein:

• the pressure region is in fluid communication with the suction region when the piston is in the second position;
• the piston substantially seals the pressure region from the suction region when the piston is in the first position;
• the casing has a pressure-regulation channel formed therein and adjoining the pressure region and the bore so that the pressure region and the bore are in fluid communication;
• and
• a pressurized supply medium within the pressure region exerts a force on the piston by way of the pressure-regulation channel and the force causes the piston to move from the first position toward the second position when a pressure of the supply medium is greater than a predetermined value.

A pump comprising a rotor assembly, a casing for housing the rotor assembly and having a pressure region and a suction region therein, a sliding block positioned within the casing, and a hydraulic piston fixedly coupled to the sliding block and positioned within a bore of the casing, the sliding block and the hydraulic piston being movable between a first and a second position within the casing, wherein:

• the pressure region is in fluid communication with the suction region when the sliding block and the hydraulic piston are the second position;
• the sliding block substantially seals the pressure region from the suction region when the sliding block and the hydraulic piston are in the first position;
• the casing has a pressure-regulation channel formed therein and adjoining the pressure region and the bore so that the pressure region and the bore are in fluid communication;
• and
• a pressurized supply medium within the pressure region exerts a force on the hydraulic piston by way of the pressure-regulation channel and the force causes the hydraulic piston and the sliding block to move from the first position toward the second position when a pressure of the supply medium is greater than a predetermined value.