Liquid dispensing pump system

An internal gear pump comprising:

• a stepper motor coupled to a drive shaft that is coupled to a rotor,
• the rotor extending into a pump chamber defined by a casing having an open end covered by a head plate, the pump further comprising an idler and an idler pin disposed inside a pump chamber,
• a head coupled to the head plate, the head comprising a head surface that faces towards the rotor, the head surface consisting of an aperture for receiving the idler pin, a crescent disposed below the aperture and a remaining planar head surface area that surrounds the aperture and the crescent and that abuttingly engages the rotor and the idler,
• the idler pin extending outward from the aperture of the head surface, the idler comprising a central hole that mateably receives the idler pin so that the idler abuttingly engages a first circular ring area of the head surface area disposed above the crescent and around the central aperture,
• the rotor abuttingly engaging a second circular ring area of the head surface area that extends below the crescent and partially overlaps the first circular ring area, the first and second circular areas being eccentric with respect to each other,
• the pump further comprising a stepper motor frictionally coupled to a drive shaft that is frictionally coupled to the rotor, the stepper motor being linked to a controller,
• the stepper motor imparting a stepped rotational movement to the drive shaft wherein a single rotation of the drive shaft comprises a plurality of steps, the controller sending a signal to the stepper motor to rotate the drive shaft a predetermined number of steps, the signal causing the stepper motor to rotate the drive shaft the predetermined number of steps, the controller calculating the predetermined number of steps corresponding to the signal sent to the stepper motor based upon an algorithm derived experimentally that defines a relationship between dispense amount and a number of steps required for the dispense amount that is unique for each fluid to be pumped, wherein the relationship is a linear relationship generated from an experimentally generated trend line.

An internal gear pump comprising:

• a stepper motor coupled to a drive shaft that is coupled to a rotor,
• the rotor extending into a pump chamber defined by a casing having an open end covered by a head plate, the pump further comprising an idler and an idler pin disposed inside a pump chamber,
• a head coupled to the head plate, the head comprising a head surface that faces towards the rotor, the head surface consisting of an aperture for receiving the idler pin, a crescent disposed below the aperture and a remaining planar head surface area that surrounds the aperture and the crescent and that abuttingly engages the rotor and the idler,
• the idler pin extending outward from the aperture of the head surface, the idler comprising a central hole that mateably receives the idler pin so that the idler abuttingly engages a first circular ring area of the head surface area disposed above the crescent and around the central aperture,
• the rotor abuttingly engaging a second circular ring area of the head surface area that extends below the crescent and partially overlaps the first circular ring area, the first and second circular areas being eccentric with respect to each other,
• the pump further comprising a stepper motor frictionally coupled to a drive shaft that is frictionally coupled to the rotor, the stepper motor being linked to a controller,
• the stepper motor imparting a stepped rotational movement to the drive shaft wherein a single rotation of the drive shaft comprises a plurality of steps, the controller sending a signal to the stepper motor to rotate the drive shaft a predetermined number of steps, the signal causing the stepper motor to rotate the drive shaft the predetermined number of steps, the controller calculating the predetermined number of steps corresponding to the signal sent to the stepper motor based upon an algorithm derived experimentally that defines a relationship between dispense amount and a number of steps required for the dispense amount that is unique for each fluid to be pumped, wherein the controller is linked to a power supply which is linked to the stepper motor and the signal is sent to the power supply which transmits sufficient power to the stepper motor to rotate the drive shaft the predetermined number of steps that corresponds with the signal.

An internal gear pump comprising:

• a stepper motor coupled to a drive shaft that is coupled to a rotor,
• the rotor extending into a pump chamber defined by a casing having an open end covered by a head plate, the pump further comprising an idler and an idler pin disposed inside a pump chamber,
• a head coupled to the head plate, the head comprising a head surface that faces towards the rotor, the head surface consisting of an aperture for receiving the idler pin, a crescent disposed below the aperture and a remaining planar head surface area that surrounds the aperture and the crescent and that abuttingly engages the rotor and the idler,
• the idler pin extending outward from the aperture of the head surface, the idler comprising a central hole that mateably receives the idler pin so that the idler abuttingly engages a first circular ring area of the head surface area disposed above the crescent and around the central aperture,
• the rotor abuttingly engaging a second circular ring area of the head surface area that extends below the crescent and partially overlaps the first circular ring area, the first and second circular areas being eccentric with respect to each other,
• the pump further comprising a stepper motor frictionally coupled to a drive shaft that is frictionally coupled to the rotor, the stepper motor being linked to a controller,
• the stepper motor imparting a stepped rotational movement to the drive shaft wherein a single rotation of the drive shaft comprises a plurality of steps, the controller sending a signal to the stepper motor to rotate the drive shaft a predetermined number of steps, the signal causing the stepper motor to rotate the drive shaft the predetermined number of steps, the controller calculating the predetermined number of steps corresponding to the signal sent to the stepper motor based upon an algorithm derived experimentally that defines a relationship between dispense amount and a number of steps required for the dispense amount that is unique for each fluid to be pumped, wherein the controller is linked to a personal computer which transmits the inputted dispense amount to the controller.

A control system for an internal gear pump comprising a stepper motor coupled to a drive shaft that is coupled to a rotor, the stepper motor imparting a stepped rotational movement to the drive shaft wherein a single rotation of the drive shaft comprises a plurality of steps, the control system comprising:

• a controller linked to the stepper motor, the stepper motor imparting a stepped rotational movement to the drive shaft wherein a single 360° rotation of the drive shaft comprises a plurality of steps, the controller sending a signal to the stepper motor to rotate the drive shaft a predetermined number of steps, the signal causing the stepper motor to rotate the drive shaft the predetermined number of steps, the controller calculating the predetermined number of steps based upon an inputted dispense amount, the controller calculating the predetermined number of steps and generating the signal sent to the stepper motor based upon an algorithm derived experimentally that defines a relationship between dispense amount and a number of steps required for each dispense amount that is unique for each fluid to be pumped, wherein the controller is linked to a power supply which is linked to the stepper motor and the signal is sent to the power supply which transmits sufficient power to the stepper motor to rotate the drive shaft the predetermined number of steps that corresponds with the signal.

A method for controlling an internal gear pump comprising an internal gear pump comprising a stepper motor coupled to a drive shaft that is coupled to a rotor, the stepper motor imparting a stepped rotational movement to the drive shaft wherein a single rotation of the drive shaft comprises a plurality of steps, the method comprising:

• linking a controller linked to the stepper motor, the controller comprising a memory,
• deriving an algorithm experimentally that defines a relationship between dispense amount and the number of steps that is unique for each fluid to be pumped,
• storing the algorithm in the memory of the controller,
• communicating a dispense amount to the controller,
• calculating the number of steps in the controller for dispensing the dispense amount using the algorithm,
• sending a signal from the controller to the stepper motor to rotate the drive shaft the calculated number of steps, wherein the relationship is a linear relationship generated from an experimentally generated trend line.