WO1988001693A1

WO1988001693A1 - Magnet ball pump

Info

Publication number: WO1988001693A1
Application number: PCT/US1986/001840
Authority: WO
Inventors: Niels O. Young
Original assignee: Young Niels O
Priority date: 1986-09-05
Filing date: 1986-09-05
Publication date: 1988-03-10

Abstract

A fluid pump including a double-entry impeller (47) whose outer boundary is defined by a dissected spherical surface. The spherical surface includes an equatorial region (59) which may be a groove or a cylindrical surface. The impeller is polarized magnetically and forms a dipole whose axis is normal to the plane of the equatorial region. The rotating magnetic field of a polyphase stator winding spins the impeller, and aligns the impeller spin axis along the stator axis.

Description

MAGNET BALL PUMP

BACKGROUND OF THE INVENTION The present invention generally involves the field of technology pertaining to fluid pumps. More specifically, the invention relates to an improved fluid pump wherein the impeller of the pump is also the rotor of an electric motor so that electromagnetically induced rotation of the impeller upon energization of the motor causes fluid to be pumped between inlet and outlet sides of the pump.

SUMMARY OF THE INVENTION The invention comprises a highly compact fluid pump which utilizes an impeller of substantially spherical configuration and formed of magnetic material. The impeller is a polarized magnetic solid bounded by an interrupted spherical surface. It is free to spin about any axis within a chamber whose wall is an interrupted spherical surface of slightly larger diameter. Surrounding the impeller is a polyphase stator consisting of soft magnetic material and windings. The center of symmetry of the stator assembly is approximately coincident with the center of symmetry of the impeller. The axis of symmetry of the stator is approximately coincident with the spin axis of the impeller. The magnetic axis of the impeller aligns itself at right angles to the axis of symmetry of the stator by the action of magnetic forces whether or not the stator is electrically energized. When the polyphase stator is energized electrically, its rotating magnetic field captures the impeller and causes it to spin in synchrony. The impeller is provided with an equatorial region therearound, preferably configured in the form of a groove, whereby rotation of the impeller creates a radial outflow between the inlet and outlet of the socket assembly and thereby pumps fluid centrifugally.

The socket assembly is defined by an inlet socket and an outlet socket, each of which is provided with a corresponding recess which collectively define a chamber for supporting the impeller when the sockets are placed in aligned engagement with each other. The input socket functions to receive fluid from the inlet side of the pump and is configured to divide the inlet fluid into two streams of approximately equal mass flow. One stream goes directly to one eye of the impeller, and the other stream is directed to another eye of the impeller by means of a plurality of passageways formed in the sockets. The fluid received by the impeller from the two flow paths is pumped out of the socket assembly through a plurality of passageways formed therein and directed to a confluence at the outlet side of the pump.

This pump, which is designated an "orbic" pump, has a number of advantages over existing pumps. The impeller, which is the orb, normally performs as a double-entry impeller and, therefore, operates at a desirable high specific speed. The orb normally spins without contact, being supported hydrodynamieally, and is therefore saved from wear except during starting and stopping of the pump. Wear is further minimized because the orb is free to turn, at random, about its magnetic axis - so as to distribute wear uniformly and in random directions, over the entire spherical surface of the orb.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a left hand view from the input side of a pump according to a preferred embodiment of the invention;

Figure 2 is an enlarged, fragmentary vertical sectional view, partly in elevation, taken on the staggered section line 2-2 of Figure 1; Figure 3 is a side elevational view of the input socket; Figure 4 is an end elevational view as viewed from the left of Figure

3j

Figure 5 is an end elevational view as viewed from the right of Figure

3;

Figure 6 is a side elevational view of the output socket;

Figure 7 is an end elevational view as viewed from the left of Figure 6; Figure 8 is an end elevational view as viewed from the right of Figure 6;

Figure 9 is an enlarged, isometric view of the input and output sockets in their position of aligned engagement to form the socket asssembly, with the spherical-shaped impeller being depicted in dotted lines and disposed within the chamber defined by corresponding recesses provided with the sockets;

Figure 10A is an enlarged, isometric view of a preferred embodiment of an impeller utilized in the pump of the invention; Figure 10B is an enlarged, isometric view of another embodiment of an impeller which may be utilized in the pump of the invention; and

Figure 11 is an isometric view of a key for securing the input and output sockets in aligned engagement with each other.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A pump 1, according to a preferred embodiment of the invention, is shown in Fig. 1 from the fluid input side thereof, and includes a motor housing 3, an end cap 5 and a coupling assembly 7 for connecting a fluid supply line (not shown) to a fluid input line 9. The details of pump 1 shall now be described with particular reference to Fig. 2. Pump 1 includes a housing section 11 which is centrally disposed through motor housing 3 and extends outwardly from either side thereof to define an input section 13 and an output section 15. Sections 13 and 15 therefore form, respectively, the input and output sides of pump 1. Input section 13 is internally threaded for receiving a threaded stem 17 of cap 5, which is sealed thereto by an appropriate fluid sealing means 19, such as a gasket, O-ring, or the like. Stem 19 is also internally threaded to receive a threaded end 21 of input line 9. A socket retainer 23 is also threadedly engaged within input section 13. Cap 5 and input section 13 are preferably of a corresponding hexagonal transverse cross-sectional configuration.

Housing section 11 is provided with a reduced diameter stepped portion 25 against which a polyphase stator assembly 27 may be disposed within motor housing 3. Stator assembly 27 is also disposed against and around a central section 28 of housing section 11, and is energized through at least three electrical connections, of which only 29 and 31 are shown, from an appropriate source of electricity.

Output section 15 is externally threaded and provided with a nut 33 for securing housing section 11 to motor housing 3. Output section 15 is also internally threaded and connected to a threaded end 35 of a fluid output line 37, which is in turn connected to a delivery line (not shown) by means of a coupling assembly 39.

The interior of central section 28 is provided with a circumferential stepped portion 41. As is therefore apparent from Fig. 2, portions of the internal surfaces of socket retainer 23, central section 28 and stepped portion 41 collectively define a substantially cylindrical chamber 43 within which is disposed a socket assembly 45 having a corresponding exterior configuration, which socket assembly 45 internally supports a spherical-shaped impeller 47 for free rotation therein. Socket assembly 45 is defined by an input socket 49 and a corresponding output socket 51, both of which are maintained in aligned engagement with each other, preferably through the use of an alignment key 53, the latter to be later described in detail. Input socket 49 is provided with a substantially hemispherical recess 55 that includes a circumferential flow groove 55a and a circular input groove 55b. Likewise, output socket 51 is also provided with a corresponding substantially hemispherical recess 57 that includes a circum erential flow groove 57a and a circular output groove 57b. Recesses 55 and 57 collectively define a substantially spherical chamber within which impeller 47 is supported for free rotation. As is also apparent, circumferential flow grooves 55a and 57a collectively define a single annular spacing around impeller 47 for permitting fluid flow therethrough. Fluid flow is also permitted around and through spacings defined by circular input groove 55b and circular output groove 57b.

Impeller 47 is made of polarized magnetic material, preferably samarium-cobalt, Neodymium-iron, platinum-cobalt, or the like, and is supported within socket assembly 45. Impeller 47 is a permanent magnet, and it seeks to align its magnetic axis to lie in a plane normal to the axis of the stator assembly 27. Its magnetic axis is therefore always approximately within this plane whether or not the stator is energized. Magnetic forces - 5 -

resulting upon energization of stator assembly 27 causes impeller 47 to rotat about a mechanical axis normal to its axis of magnetic polarization. The mechanical axis is coincident with the spin axis of impeller 47. The mechanical axis is approximately coincident (excepting mechanical tolerances

5 and other minor perturbations) with the axis of symmetry of housing section 11, and also with the axis of symmetry of either or both input and output sockets

49 and 51. As seen in Fig. 2, impeller 47 is essentially orb-shaped, i.e., bounded by a spherical surface that is interrupted by a circumferential groove

59 defined by a recessed equatorial region around impeller 47. Groove 59 is

10 disposed in a plane that is normal to the magnetic polarization axis of impeller

47 so that, when stator winding 27 is energized through electrical connections including 29 and 31, impeller 47 is caused to rotate about an axis normal to its magnetic polarization axis, this axis being a mechanical axis approximately coincident with the axis of sym etry of sockets 49 and 51, as shown in Fig. 2.

15 Groove 59 has several simultaneous functions. It accepts fluid entering the impeller from both sides and therefore defines a pair of opposed impeller eyes.

Fluid entering each such eye is divided into two radially outflowing streams, there being four such streams existing concurrently within the boundary of groove 59. Fluid within each of said outflowing streams is slung outward

20 centrifugally by the spin of the impeller and in the fashion of a centrifugal pump impeller. In a region of groove 59 at the greatest radius from the spin axis, the four streams come together in pairs as shown at A in Fig. 10A.

The details of input socket 49 and output socket 51 making up socket assembly 45 shall now be described in detail with reference to Figs. 3-8. As 25 first seen in Figs. 3-5, input socket 49 is substantially cylindrical in configuration and provided with a plurality of circumferentially spaced channels 61 that are separated from each other by a plurality of raised land sections 63. Socket 49 is also provided with an inlet opening 65 and, as seen in Fig. 4, channels 61 radiate outwardly from the peripheral edge of opening 65. 30 Each land section 63 is provided with a substantially semi cylindrical and radially directed outlet passageway 67.

The details of outlet socket 51 shall now be described with reference to Figs. 6-8. Output socket 51 is also substantially cylindrical in configuration and provided with a plurality of circumferentially spaced channels 69 separated from each other by a plurality of raised land sections 71. Each channel 69 further includes a substantially semicylindrical outlet passageway 72 for alignment with a corresponding outlet passageway 67 to collectively define a cylindrical outlet passageway. Each land section 71 is provided with a channel 73 for alignment with a corresponding channel 61 of input socket 49. Each channel 73 further terminates in a radially directed input passageway 75 for feeding fluid into the interior of socket 51. As more clearly seen in Fig. 8, channels 69 converge radially and terminate at a closed end portion 76 of socket 51. With reference to Fig. 9, socket assembly 45 is shown with input socket 49 and output socket 51 in aligned engagement with each other and impeller 47 disposed therein. Fluid directed from the input side of socket assembly 45 is immediately separated into two flow paths, one path being directed linearly into the interior of assembly 45 through opening 65, and the other path being defined by a plurality of subdivided streams flowing radially outwardly along channels 61 and thereafter longitudinally along channels 61 and corresponding aligned channels 73 into input passageways 75. The two flow paths of input fluid are substantially equal and are directed against groove 59 of impeller 47 from opposite sides thereof. The input fluid is thereafter radially directed outwardly through the cylindrical passageways collectively defined by corresponding semicylindrical output passageways 67 and 72, and thereafter along channels 69 to the output side of socket assembly 45. A purpose of socket assembly 45 is to control the feeding and distribution of input^" fluid flow to rotating impeller 47. The separation of the input flow into two flow paths by input socket 49 and output socket 51 serves to supply each side of the impeller 47 with approximately equal mass flow of fluid; that is, each eye of the double-entry impeller 47 experiences axial or thrust forces which are approximately equal. By means of equalizing these axial forces in this manner, the net thrust load upon the impeller is minimized and so is the drag imposed thereon. Such drag would otherwise tend to retard the spin of the impeller and so reduce the conversion efficiency of the pump. Accordingly, optimum pumping efficiency is realized through the cooperation of rotating impeller 47 and its associated socket assembly 45 in the manner described herein. The geometry of the fluid flow paths with respect to impeller 47 shall now be described with reference to Fig. I0A. The main input flow is designated in the direction indicated at 77, which flow is shown to be linearly directed for impact against groove 59 from opening 65 in one flow path, and against groove 59 from the opposite side thereof in the direction indicated at 79 from a second flow path fed from radial streams through passageways 75. By virtue of the rotation imparted to impeller 47, input flow from the two described paths is pumped radially outwardly along four paths: 77 to A, 77 to A', 79 to A, and 79 to A'. In other words, input flow 77 divides into two equal flows directed toward A and toward A*. At the same time, input flow 79 divides into two equal flows directed toward A and A'. Then output stream A receives flow equally from input 77 and input 79; and mutatis mutandis, output stream A' receives flow equally from input 77 and input 79. The output steams A and A' are collected within the grooves 55A and 57A within the corresponding sockets. The output streams decelerate and mix togehter into one flow, some of their velocity being converted into pressure head. This output flow then escapes from the sockets by means of passageways 67, 72, and 69.

With reference to Fig. 10B, there is shown a second embodiment of an impeller which may be used in the practice of the invention. An impeller 81 is depicted as formed from magnetic material having a substantially spherical outer surface 83 which is interrupted by an equatorial region in the form of a cylindrical surface 85, with the magnetic polarization axis of impeller 81 being coaxial with the longitudinal axis of cylindrical surface 85. As seen in Fig. 11, key 53 used for securing input socket 49 and output socket 51 in aligned engagement with each other is substantially of a flat L- shaped configuration, including a longitudinal leg 87 and a shorter transverse leg 89. In use, sockets 49 and 51 are aligned together as shown in Fig. 9 and longitudinal leg 87 of key 53 is then disposed within and overlaps a pair of corresponding channels 61 and 73. Accordingly, transverse leg 89 is disposed in the corresponding portion of channel 61 adjacent the peripheral edge of opening 65 of socket 49. It is nevertheless understood that any other suitable means well known in the art may be implemented to align sockets 49 and 51 for the practice of the invention as described herein. For example, cooperating means may be provided on both sockets 49 and 51 to effect an automatic keying together thereof into aligned engagement. The electrical energization of stator winding 27 through connections, of which 29 and 31 are two of three utilized, may be realized through an appropriate control circuit system.

The aforedeseribed orbic pump is especially well adapted and has been demonstrated to provide pressures between 20 and 150 psi at flows between 0.5 and 15.0 cm 3 sec -1. Its performance is enhanced upon using permanent magnetic materials having nptj a high energy product and a high remanence. It therefore provides an excellent vehicle for evaluating and exploiting the properties of newer magnetic materials, such as samarium- cobalt and neodymium-iron.

The pump of the present invention is extremely compact and particularly advantageous for use whenever a small pump structure is desired or required. For example, the invention may be used as a fuel pump or windshield washer pump in automotive and related applications. While the invention has been described and illustrated with reference to certain preferred embodiments thereof, it shall be appreciated that there are modifications, changes, additions, omissions and substitutions which may be resorted to by those skilled in the art and considered to be within the spirit and scope of the invention and the appended claims.

Claims

CLAIMS;

L A fluid pump comprising: a) a housing section including a fluid inlet and a fluid outlet; b) an inlet socket disposed within the housing section and provided with a first recess therein; c) an outlet socket provided with a second recess therein, the inlet and outlet sockets being disposed to form a socket assembly, wherein the first and second recesses collectively define a chamber; d) a substantially spherical impeller disposed within the chamber for rotation therein to pump fluid between the fluid inlet and the fluid outlet; and e) electromagnetic means for rotating the impeller.

2. The pump of Claim 1 wherein the impeller includes an equatorial region configured for centrifugal pumping of fluids.

3. The pump of Claim 2 wherein the impeller is of permanent magnetic material and the means for rotating the impeller includes an electrically energizable stator surrounding the socket assembly .

4. The pump of Claim 3 wherein the equatorial region is configured in the form of a circumferential groove and the plane of the groove is disposed normal to the magnetic polarization axis of the impeller.

5. The pump of Claim 3 wherein the equatorial region is configured in the form of a cylindrical surface and the longitudinal axis of the cylindrical surface is coaxial with the magnetic polarization axis of the impeller.

6. The pump of Claim 3 further including means for electrically energizing the stator.

7. The pump of Claim 1 wherein the inlet socket includes a plurality of spaced radially directed inlet passageways and means for dividing the inlet fluid flow into first and second flow paths, the first flow path being linearly directed through the inlet socket towards the impeller, and the second flow path being defined by a plurality of subdivided streams which are directed through the inlet passageways and toward the impeller from a direction opposite to the direction of the first flow path.

8. The pump of Claim 7 wherein the inlet and outlet sockets include a plurality of spaced radially directed outlet passageways and rotation of the impeller pumps fluid received from the two flow paths through the outlet passageways and fluid outlet of the housing section.

9. The pump of Claim 8 wherein the outlet passageways are each substantially cylindrical in configuration and are defined by aligned semicylindrical passageways formed in the inlet and outlet sockets.

10. The pump of Claim 8 wherein the inlet and outlet sockets are provided with a plurality of circumferentially spaced channels and raised land sections which are alignable for defining fluid flow paths.

1L The pump of Claim 1 wherein the sockets are in aligned engagement with each other.

12. The pump of Claim 11 further including means for securing the inlet and outlet sockets together in aligned engagement with each other to form the socket assembly.

13. The pump of Claim 1 wherein the inlet and outlet sockets are free to rotate.

14. The pump of Claim 1 wherein the impeller includes two opposed eyes through which fluid enters the impeller from both sides thereof and the sockets form channels for dividing the inlet flow and directing same into each eye of the impeller.

15. The pump of Claim 1 wherein the electromagnetic rotating means includes a polyphase stator assembly.

16. The pump of claim 15 wherein the polyphase stator assembly controls the direction of the impeller spin axis.

17. The pump of claim 15 wherein the polyphase stator assembly measures electrically the orientation of the spin axis.

18. The pump of Claim 15 wherein the polyphase stator assembly measures electrically the location of the spin axis.