Clearance adjustment for twin-screw pumps

A pump assembly comprising:

• a housing comprising:
• a first housing wall portion that defines an inlet port, an outlet port, and a flow chamber formed therein, wherein the flow chamber is configured to receive a fluid through the inlet port;
• and
• a second housing wall portion that defines a gear chamber formed therein,
• wherein the flow chamber and the gear chamber are fluidically isolated;
• a drive shaft configured to receive a rotational force outside the pump assembly, the drive shaft comprising a first portion inside the gear chamber and a second portion inside the flow chamber, wherein at least part of the second portion of the drive shaft is conically shaped;
• a first threaded screw comprising a first plurality of thread flanks and coupled to the second portion of the drive shaft;
• a first clamping nut configured to secure rotatably an axial position of the first threaded screw to the drive shaft;
• a bushing configured to envelope the conically shaped part of the second portion of the drive shaft;
• a second clamping nut configured to provide pretension to the bushing, wherein a clearance adjustment is performed by removal of the first and second clamping nuts, loosening of the bushing, and adjustment of an angularity between the bushing and the drive shaft;
• and
• a driven shaft comprising a first portion inside the gear chamber and a second portion inside the flow chamber, wherein the first portion of the driven shaft is configured to receive a rotational force inside the gear chamber from the drive shaft, and the second portion of the driven shaft is coupled to a second threaded screw comprising a second plurality of thread flanks intermeshed with the first plurality of thread flanks of the second portion of the drive shaft.

A pump assembly comprising:

• a housing comprising:
• a first housing wall portion that defines an inlet port, an outlet port, and a flow chamber formed therein, wherein the flow chamber is configured to receive a fluid through the inlet port;
• and
• a second housing wall portion that defines a gear chamber formed therein,
• wherein the flow chamber and the gear chamber are fluidically isolated;
• a drive shaft configured to receive a rotational force outside the pump assembly, the drive shaft comprising a first portion inside the gear chamber and a second portion inside the flow chamber;
• a first threaded screw comprising a first plurality of thread flanks and coupled to the second portion of the drive shaft;
• a driven shaft comprising a first portion inside the gear chamber and a second portion inside the flow chamber, wherein
• the first portion of the driven shaft is configured to receive a rotational force inside the gear chamber from the drive shaft,
• the second portion of the driven shaft is coupled to a second threaded screw comprising a second plurality of thread flanks intermeshed with the first plurality of thread flanks of the second portion of the drive shaft, and
• at least part of the second portion of the driven shaft is conically shaped;
• a first clamping nut configured to secure rotatably an axial position of the second threaded screw to the driven shaft;
• a bushing configured to envelope the conically shaped part of the second portion of the driven shaft;
• a second clamping nut configured to provide pretension to the bushing, wherein a clearance adjustment is performed by removal of the first and second clamping nuts, loosening of the bushing, and adjustment of an angularity between the bushing and the driven shaft.

A method for manufacturing a twin-screw pump assembly, the method comprising:

• forming a flow chamber, an inlet port, and an outlet port within a first housing wall portion of a housing to convey a fluid received through the inlet port to the outlet port;
• forming a gear chamber within a second housing wall portion of the housing to house one or more timing gears, a first portion of a drive shaft, and a first portion of a driven shaft, wherein the flow chamber and the gear chamber are fluidically isolated;
• positioning a drive shaft configured to receive a rotational force outside the pump assembly such that the first portion of the drive shaft is inside the gear chamber and a second portion of the drive shaft is inside the flow chamber;
• positioning a driven shaft, wherein
• the first portion of the driven shaft is inside the gear chamber and a second portion of the driven shaft is inside the flow chamber,
• the driven shaft is configured to receive a rotational force from the drive shaft inside the gear chamber, and
• at least part of the second portion of one of the drive shaft and the driven shaft is conically shaped;
• positioning a bushing to envelope the conically shaped part of the second portion of one of the drive shaft and the driven shaft;
• providing pretension to the bushing through a first clamping nut;
• securing an axial position of a first threaded screw to the drive shaft or an axial position of a second threaded screw to the driven shaft rotatably with a second clamping nut, wherein a clearance adjustment is performed by removal of the first and second clamping nuts, loosening of the bushing, and adjustment of an angularity between the bushing and one of the drive shaft and the driven shaft.