structure are not separated by any appreciable margin. By providing the type of construction herein shown, it can be seen that coolants may be passed through the center of the shaft 4 and also if it is desired the pump may be suitably jacketed with coolant. This pump further operates on the basis of no rubbing contact between the components and no vanes are required on the rotor. Such vanes normally provide a cooling problem.
FIGURE 3 discloses a sectional view of another embodiment of the pump shown in FIGURE 2. The shaft 4 rotates in the direction w and the stator in this particular embodiment is provided with three converging surfaces 30, 31 and 32 which are spaced at 120° intervals about the shaft axis. This construction creates three converging areas 33, 34, and 35. Passing fluid through the lines 5, 5' and 5" into the wider portions of the converging areas will cause the creation of high pressure areas as shown by the curves 36, 37 and 38. This high pressure fluid may be discharged through the lines 6, 6' and 6" in a manner similar to that shown in FIGURE 2.
In horizontally supported shaft arrangements, the weight of the shaft causes the shaft to assume an attitude angle a relative to the direction of the gravity force on the shaft. The eccentric orientation of a shaft creates a force which acts in a direction through the center of the stator and rotor in a manner as to restore the shaft to a concentric position. Since the restoring force and the weight of the rotor act at an angle a to each other there is a resultant component of force created which tends to move the rotor axis in an oval path. In the case of a vertically disposed shaft this oval path will circumscribe the axis of the stator. In the case of a horizontal shaft this oval path will be spaced from the axis of the stator.
FIGURE 4 discloses a perspective exploded view of the stabilized bearing shown in FIGURE 1. The bearing 3 comprises three bearing portions 10, 11 and 12. The first bearing portion 10 has an eccentric surface 40, the second bearing portion 11 has an eccentric surface portion 41 and the third bearing portion has an eccentric surface 42.
In FIGURE 5 there is shown a partly diagrammatic sectional view taken normal to the axis of the shaft 4. The shaft 4 has a center axis O, the surface 40 has a center axis O', the surface 41 has a center axis O", and the surface 42 has an axis O'". It will be noted that the centers O', O" and O'" are located at 120° intervals on a circle concentric with the axis O. By this orientation of surfaces the bearing will have three converging areas with respect to the shaft 4. These converging areas will create hydrodynamic forces which have resultant forces which act to stabilize the shaft axis by counteracting any unbalanced forces acting on the shaft which are tending to make the shaft axis whirl in an oval path.
By referring to FIGURE 3 it can be seen that the construction disclosed has three converging areas equally spaced about the shaft. Each pressure distribution curve 36, 37 and 33 creates a resultant force which will tend to restrain any whirling motion of the axis O of the shaft 4.
By maintaining the shaft in its concentric position in the stator the shape of the converging areas will be maintained uniform thereby creating uniform pressure curves. This permits smooth operation of the pump and permits the discharge from each converging area to be passed to a common header. It will be appreciated that if these discharge pressures were unequal reverse flow could occur in at least one of the discharge openings 6, 6' or 6". A further difficulty would be encountered in that each discharge opening would provide fluid at a different pressure and this discharge pressure because of the whirling action of the rotor would have a fluctuating value. To avoid this, in the embodiment in FIGURE 1 the stabilizing bearing construction 3 is provided which is shown in FIGURES 4 and 5. In the embodiment of FIGURE 3 because of the particular orientation of the converging
areas, resultant forces are created which are inclined to stabilize the position of the shaft 4.
In a manner similar to that shown in FIGURE 3 wherein the pump construction is inherently stable it is appar
5 ent that the construction shown in FIGURES 4 and 5 is also basically stable and can be adapted to incorporate therein a pumping action. Referring to FIGURE 6 there is shown a sectional view through the second bearing portion 11 which has an eccentric surface 41. It can
10 be seen that by the use of an eccentric annular surface 41 that not only is a positive pressure distribution created as shown by the curve 47 but also a negative pressure distribution as shown by the curve 48. If it is desired to utilize the construction in FIGURE 4 as a
15 pump the fluid may be introduced as desired in the area covered by the pressure distribution curve 48. Since this area of the hydrodynamic device is subject to a negative pressure due to the diffusing action of the rotor, there will be a tendency of the fluid to pass between the shaft
2q and rotor by being drawn in by this negative pressure. As the fluid passes into the area enveloped by the curve 47 the pressure increases to a maximum at substantially the point of minimum clearance between the shaft 4 and the surface 41. In this area if it is desired the fluid
25 may be discharged through a line 46. It will be appreciated that similar pressure distribution exists with respect with the first bearing portion 10 and the third bearing portion 12. However, the pressure distribution curves in these latter two cases will be transposed 120° with
20 respect to the pressure distribution shown in FIGURE 6. This last disclosed construction also is one wherein the rotor 4 has its axis substantially stabilized by the resultant forces created by the three high pressure areas about the rotor. This latter construction also has the added
2_ advantage that the supply fluid is not required to overcome any of the hydrodynamic forces created by the pump which is the case of the embodiment shown in FIGURES 2 and 3.
It will also be appreciated that the stabilizing action does not only occur with three converging areas but may occur with any number greater than three. It is also possible to vary the angular disposition, the clearance and length of the converging areas created by the action of the stator and rotor. This may be necessary in certain instances where the weight of the shaft is a
4° considerable factor and has a large influence on the eccentricity of the shaft axis from the stator axis.
While there have been described preferred embodiments of the present invention, it will be appreciated that the invention is not limited thereto but that various
50 modificaions may be made without departing from the scope of the appended claims.
What I claim as new and desire to secure by Letters Patent of United States is:
1. In a pump, the combination of a rotor having an 55 outer cylindrical surface, a stator enveloping said rotor
and defining a continuous annular area therebetween, the inner periphery of said stator being defined by a plurality of contiguous arcuate surfaces converging toward the cylindrical surface of the rotor, the axis of
CO each arcuate surface being eccentric of the rotor axis, said converging surfaces being equally spaced about the axis of the stator and defining a step at each juncture between adjacent converging surfaces, means for supplying fluid between the stator and the rotor, rotation of
65 the rotor causing the generation of high pressures in the converging areas between the rotor and the stator, means for discharging the fluid from the high pressure areas generated between the stator and the rotor, said means for supplying the fluid between the stator and the rotor
70 being located in an area at a lower pressure than the area at which the fluid is discharged.
2. In a pump, the combination of a rotor having an outer cylindrical surface, a stator enveloping said rotor and defining a continuous annular area therebetween, the
75 inner periphery of said stator being defined by at least