AU2003100461A4 - "Batman" rotary pump - Google Patents

Description

"BATMAN" ROTARY PUMP This invention relates to positive displacement rotary-piston machines of internal-parallelaxis type with co-operating members of intermeshing-engagement type.

DISCUSSION OF THE PRIOR ART Centrifugal pumps produce a high flow at moderate pressure. When it gets to high pressure the efficiency drops exponentially because a high speed rotation causes additional friction of pumping fluids and it results in a the sharp loss of efficiency. The pump can provide a big volume and stable flow for low pressure for air and fluids of low viscosity. In case of pumping more dense substance or mixtures with irregular viscosity the pump develops pulsation and suffers a great lost in efficiency.

As for positive displacement pumps, the leading ones are of the reciprocating and rotary types.

Because of the reciprocal motion of the piston the existing piston type compressors suffer the loss of efficiency due to consequent stops and accelerations in reversing directions. Another undesirable feature of the compressors is pulsation of the outcome flow and intake flow.

Among the rotary pumps we can distinguish lobe (roots), vane (Wankle) and screw pumps.

Lobe pumps are popular and simple in design however they suffer from intake pulsation and cannot use more then two rotors.

Vane type pumps have a good adiabatic efficiency, but they have some major drawbacks. The 20 vanes in most vane type blowers contact the outer case and wear. There are versions of vane pumps that hold the vanes from contacting the outer housing but they cannot be turned at very high speeds due to them being out of balance. Besides, they are very complicated in design. They also suffer from pulsation and cannot pump as much air as other types of pumps of similar size, so they need to be quite large to be effective.

Rotary screw compressors have recently become the predominant type in use in small to moderate sized facilities. They have a very good adiabatic and volumetric efficiency. Another benefit is that they have little to no intake pulsing. A screw pump compresses very smoothly, unlike most roots type compressors. It combines many of the advantages of a vane and roots type compressors, without having the disadvantages of either.

However screw type compressors are more expensive to make and are not cost efficient in small and inexpensive applications.

SUMMARY OF THE INVENTION The novel rotor profiles ("Batman" type), combined with a different from existing pumps intake/discharge system, constitute the present invention. It enjoys the advantages associated with different systems of the past while adding even further advantages to the new system.

Like in a screw pump, the continuous operating cycle consists of air/fluid being drawn in at one end, carried around against the case as with lobe (Roots) type and then as the interlocking male/female rotor parts mesh, squeezed into the diminishing space between rotors and discharged through the other end. Like in both lobe and screw pumps the rotation of the rotors is strictly synchronized through timing gears. The rotors do not contact each other or the case.

The advantage over the lobe pump is that any odd number of rotors can be used to satisfy volume demands. The advantage over the screw pump is in a better volumetric parameter and in a less cost of manufacturing.

The invention can be used in any application providing high pressure and/or controlled volume of pumped fluid. Among suggested options there are the following: a deep submersible water pump, a chemical dosage pump, a residential water treatment unit pump and others. Surface multiple rotor water pumps could be the most efficient and energy saving option for delivering water to high elevation places. Thanks to the design option to use as many rotors as required for the volume, the pumps will still use slow rotation speed which eliminates the problem of friction losses in centrifugal pumps and provides much better efficiency and energy saving.

Unlike the centrifugal pumps, this design allows to control the volume through the speed of rotating without the loss of the pressure in case if flexible requirements to the volume of pumping fluids. The pump can be used as a measuring device as the amount of displaced fluid is directly proportional to the number of rotor's revolutions. The pump can be used in pressure-washing machines, paint spraying machines and other portable devices, which provide a high pressure liquid.

The use of the pump can be especially beneficial when there are fluids of higher viscosity to be pumped as the suggested rotor design provides a smooth flow under high pressure.

The pump can be used instead of Roots blower in automobile engine superchargers as it provides better volumetric characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS To assist with understanding the invention, reference will now be made to the accompanying drawings and pictures which show one example of the invention.

The design can be divided into 4 principal parts, showed on Figure 1 Drive gear and timing gear part 1 Compression chamber case 2 Rotors 3 Fluid intake 4 and discharge tube Compression chamber cover 6 The number of compression chambers/rotors and their alignment can be different, for example, three 3-lobe rotors with straight alignment Figure 2-3 or six 2-lobe and 3-lobe rotors with polar alignment Figure Below we describe the principles of the design, which can be utilized in any specific form of alignment and number of parts.

Drive and timing gear part (Fig. 6-8) Timing gear provides the synchronized rotation of rotors towards each other.

There are 2 basic designs (which are not subject of this invention) preferable: Figure 6 Synchronization is done through concentric helical gears Figure 7 Synchronization is through helical gears, one of which is driven by a drive shaft placed at 90 degree to the gear axes.

Figure 8 Synchronization is performed through worm gears which are driven simultaneously by a drive shaft Compression chamber (Fig. 9-10) It is a housing for the rotors and it is provided with an inner surface which is concentric with the axes of the rotors.

Rotors, (Fig 11) All rotors of the pump have identical profile, which has vanes (lobes) I and recesses 2.

They are positioned in the housing such a way that a vane of one rotor fits into a recess of the other (fig All rotors are counter rotating. The phase of rotation when a vane of one rotor is introducing into the recess of the other rotor is a compression phase (fig 12 18). The profile of the rotors ensures a seal for compression. The clearance between rotors is a key to efficient compression. The fluid is drawn in through the intake orifice of the rotor -3 (fig. when it gets aligned with intake orifice (fig.21) of inner tube of intake and discharge system. The fluid is displaced through the discharge orifice of the rotor 4 (fig. which gets aligned with the discharge orifice 2 (fig.21) of inner tube of Fluid intake and discharge system.

A rotor is attached to and driven by a timing gear.

Figures 12-18 show the phases of compression Figure 12 initial position 0 degree rotation Figure 13 15 degrees rotation Figure 14 30 degrees rotation Figure 15 -45 degree rotation Figure 16 60 degree rotation Figure 17 75 degree rotation Figure 18 90 degree rotation compression is completed.

Figures 19-20 depict the distribution of fluid pressure in the case.

1 (fig.20) normal pressure 2 (fig.20) low pressure suction phase 3 (fig.20) high pressure compression phase.

The shape of a vane is symmetrical which nearly eliminates the pulsation, as the increase in volume pressed out at one side of the central rotor is compensated by decrease in volume pressed out at the other side. It provides a stable flow with pressure fluctuation within Fluid intake and discharge part, (fig 21) It is a tube that consists of the intake (upper) 1, the seal (in the middle) and the discharge 2 parts. The Intake has orifices by the number of rotor recesses. The orifices get aligned with the orifices of rotor recesses at the phase of fluid suction.

The Discharge has orifices by the number of rotor recesses. The orifices get aligned with the orifices of rotor recesses at the phase of compression.

No valves are required in this design, which significantly simplifies the construction and along with other advantages makes it maintenance free.

Claims (3)

1. The novel rotor profile ("Batman" type)

2. The intake/discharge system comprising the openings in rotors of claim 1 and intake/discharge tube that is placed inside the rotors.

3. The rotors of claim 1 having a linear or polar alignment.