Abstract: A gear pump is disclosed. The gear pump has a pump body with an inlet, a discharge and an interior side to the body. The gear pump also has a cavity plate having a gear cavity formed therein facing and abutting the interior side of the pump body. A drive gear and a driven gear are located within the gear cavity and engage one another. Each gear is rotatably supported on a shaft between the pump body and the cavity plate. A drive magnet assembly is connected to the drive gear shaft. A magnet cup has an interior chamber and a sealing surface which abuts against the interior side of the pump body providing the only required seal of the gear pump. The magnet cup is received over and encapsulates the magnet assembly, the cavity plate and the gears within the interior chamber and compresses the gear cavity against the interior surface of the body without requiring additional sealant to seal the gear cavity and magnet cup interior chamber.

Abstract: A reciprocating piston pump provides pulsation free delivery of liquid. It is suitable for use in compact environments or for the delivery of small amounts of liquid, as in chromatographic analysis devices. The pump includes two pistons with pumping chambers that are alternately connected to inflow and outflow lines through a control valve. The control valve moves between a first position in which inflow is directed to the first piston chamber and outflow to the second piston chamber, and a second position in which outflow is directed to the first piston chamber and inflow is directed to the second piston chamber. Each outflow pulse from the piston is sustained longer than each inflow pulse, and the outflow pulses are staggered and partially superimposed to provide substantially pulsation free delivery of liquid from the pump. A rotating cam moves the pistons of the pumps and the control valve between their operating positions described above.

Abstract: A pump housing is provided with a conduit extending through the housing between a pump inlet and pump outlet. A pump device is disposed within the housing and in communication with the conduit to pump fluid therethrough. A fluid flow meter also is disposed within the housing and in communication with the conduit to monitor fluid flow rate through the conduit. The fluid flow meter generates signals related to the fluid flow rate which are fed back to a control device operable to control the flow rate through the pump device. The flow meter may include a pair of meshed modified elliptical gears. The modified elliptical gears are based on a true elliptical shape, with bulged portions added between the major and minor axes of the elliptical shape. The modified elliptical gears have involute teeth that are relatively thick adjacent the minor axis and relatively thin adjacent the major axis.

Abstract: Pump heads comprising at least two gear-pump chambers are disclosed. Each chamber comprises a housing which defines a corresponding pump cavity. Each cavity contains a driving gear and at least one driven gear and has a separate inlet and outlet. The pump cavities are hydraulically interconnected by a fluid conduit allowing passage whenever the pump chambers are pumping a fluid so as to generate a higher pressure in one cavity relative to the other cavity, of the fluid from the higher-pressure cavity to the lower-pressure cavity sufficient to maintain hydraulic prime of both cavities.

Abstract: A clamp for occluding a flexible tube comprising a permanent magnet rotary actuator coupled to a rotatable cam. A spring-biasing mechanism is provided to counteract the rotation of the rotary actuator and to return the rotatable cam to a pre-determined position when power is withheld from the rotary actuator.

Abstract: Refrigerant is recovered using a single pump unit, regardless of the refrigerant's phase. This is achieved by sensing the phase of the refrigerant and changing the pump's operation accordingly. The refrigerant phase can be sensed by a temperature-responsive element, such as a thermistor, or by other phase-sensing technology. In a preferred embodiment, the pump unit is a vane pump whose rotational speed is changed in response to the refrigerant's phase. If liquid refrigerant is sensed,, the pump operates at a lower speed. If gas refrigerant is sensed, the pump operates at a higher speed. The two speeds are chosen so that the pump will draw an EPA-specified vacuum on the refrigerant present. In other vane-pump embodiments, the pump's operation is changed by changing rotational speed.

Abstract: Refrigerant is recovered using a single pump unit, regardless of the refrigerant's phase. This is achieved by sensing the phase of the refrigerant and changing the pump's operation accordingly. The refrigerant phase can be sensed by a temperature-responsive element, such as a thermistor, or by other phase-sensing technology. In a preferred embodiment, the pump unit is a vane pump whose rotational speed is changed in response to the refrigerant's phase. If liquid refrigerant is sensed, the pump operates at a lower speed. If gas refrigerant is sensed, the pump operates at a higher speed. The two speeds are chosen so that the pump will draw an EPA-specified vacuum on the refrigerant present. In other vane-pump embodiments, the pump's operation is changed by changing the pump's mechanical configuration, rather than its rotational speed.

Abstract: A pump assembly includes a pump head that is coupled to a permanent magnet rotor. The rotor is enclosed in a cavity defined by a fluid-tight cup that has an open first end and a closed second end. This cavity is in fluid connection with the pump head through its open first end. Outside the cup enclosure are disposed a plurality of electrical stator windings. A housing encloses all of the foregoing elements, and may also enclose a circuit board that includes circuitry for driving the stator windings. The pump assembly thereby provided is compact, efficient, and reliable.

Abstract: A pump assembly includes a pump head that is coupled to a permanent magnet rotor. The rotor is enclosed in a cavity defined by a fluid-tight cup that has an open first end and a closed second end. This cavity is in fluid connection with the pump head through its open first end. Outside the cup enclosure are disposed a plurality of electrical stator windings. A housing encloses all of the foregoing elements, and may also enclose a circuit board that includes circuitry for driving the stator windings. The pump assembly thereby provided is compact, efficient, and reliable.

Abstract: A rotary pump has a block with inlet and outlet ducts and ports. A pump housing forming a pump cavity and accommodating working means of the pump, e.g., gears, is located on one side of the pump block, whereas drive means such as a magnetic coupling are placed on the other side of the block. In the case of a gear pump, the driving gear is connected to the drive magnet of the coupling through a drive shaft which passes through the axial bore in the block. The drive gear meshes with a driven gear which is mounted on a second shaft, also supported in bushings in the block. One set of ends of the shafts extends outside the pump housing and are inserted into bushings loosely fitted in recesses of a bearing support plate. This plate is attached to the block by removable screws extending through holes in the supporting plate and pump housing.

Abstract: The drive and driven gears of a pump are formed with grooves extending inward from the tips of the teeth to inside the root diameter. Thus each gear is divided into a first portion which serves solely as a drive or driven gear and a second portion which serves the two functions of a conventional pump gear, mainly to perform the pumping function and part of the drive function. Fitting within the grooves of both gears is a suction shoe which also overlies the inlet duct of the pump block and the mesh points of the first portions of the gears plus about two teeth to either side of the mesh point. The shoe separates the large portion of the pump chamber from the inlet duct.

Abstract: One of the annular magnets used in a magnetic drive for pumps and other devices is enclosed on the outside in a thin metal jacket. The jacket and the interior of the magnet and preferably one end thereof are filled with a plastic material which is apertured to receive the shaft on which the magnet is to be mounted. Means is provided in the plastic material for balance weights. The jacket and plastic are impervious to fluids being pumped so that the fluids are not contaminated and the magnet is not attacked by the fluids. A preferred method of making the combination is disclosed.

Abstract: A module pump comprises a manifold having intake and outlet connections; a plate to which gears and a "shoe" (which function to define pump chambers for a pair of gears) or, in a pump having three gears two "shoes;" a drive for the gears, which in a preferred embodiment is a magnetic drive; and a barrier between the drive and the plate. Each of the modules is subject to variations in design depending upon end use and hence wide versatility is achieved without great increases in manufacturing cost since only one of the modules need be altered. Use of three gears doubles the capacity of the pump; if three gears are not needed the mounting holes for the third gear may be plugged. A unique bypass is installed in the manifold to permit flow back to the intake when the pressure exceeds an adjustable amount.

Abstract: One of two permanent magnets used to drive pumps and the like is split--i.e., the annular permanent magnet is split into two annular members, one fixed to one of the rotating members, the other freely rotatable independent of the other. The structure provides for recoupling without having to stop the driving magnet when decoupling has occurred. It also provides free travel and/or dynamic damping to alleviate oscillation and sporadic decoupling.The member fixed for rotation is a permanent magnet; the other is preferably a permanent magnet but may also be of a material which is magnetically permeable, in which case damping only is accomplished.

Abstract: A pump has a block and a cup-like member having a rim engaging the block to define a pump cavity. Recessed into the block and opening or extending into the cavity are an inlet and an outlet duct and three parallel pins. The drive and driven gears are mounted on two of the pins, one face of each gear being tight against the block, and the two ducts are on opposite sides of the mesh point of the gears. A shoe is mounted on the third pin and overlies the inlet duct and the mesh point of the gears plus about two teeth to either side of the mesh point. A spring biases the shoe into contact with portions of the gears and the block to define a pump chamber. After a differential between the inlet and outlet duct pressures is established, this differential supplements the spring. One means of driving the drive gear comprises a motor driven annular magnet on the outside of the cup-like member and a smaller magnet within the cup-like member drivingly connected to the drive gear.

Abstract: A pump body has a cavity containing gears and parts communicating between the exterior and the cavity as well as two shafts on which the gears revolve. One face of the cavity is closed off by an apertured plate. The drive gear shaft extends through the aperture in the plate and supports the driven magnet. Drive means also extend through the aperture causing the hub of the driven magnet to turn the drive gear. All parts to the motor side of the plate may be standardized, while the pump body and its contents may be specially adapted to the particular ultimate installation of the pump.