The invention is based on a pump or a motor for liquid or gaseous media as generically defined by the preamble to the main claim. In a known machine of this type (German published patent application DE-OS 42 41 320), the working part is driven via the shaft, and in the manner like a machine with spur toothing, the working parts between the work faces are reduced or increased in size for pumping the medium. Conversely, such a machine can also act as a motor, in that medium is pumped under pressure into the work chambers and by increasing the size of the work chambers generates a drive of the shaft. In both cases, two working parts in the machine housing are moved to rotate, which makes correspondingly high demands of the rotary bearing and the axial bearing and has a major power limitation with reference to the working pressure.
In another known machine of this type (U.S. Pat. No. 3,236,186), the two parts meshing with their teeth with one another on their face ends are disposed in a housing with a spherical interior, and in the center, a spherical embodiment on the parts makes the tumbling motion of the parts relative to one another that occurs upon rotation possible. Once again, there is a correspondingly major demand made of the rotary bearing of the parts as well as their axial bearing, so that above all narrow limits are set with regard to the magnitude of the working pressure. Moreover, the effort and expense for production of such convex or concave flank faces on the teeth of the spur toothing is extraordinarily high.
In these known pumps or motors, for engineering reasons conduits forming the inlet and outlet to and from the work chambers branch off radially to the working parts, so that once again there is a radial load on the working parts that corresponds to the power pressure. Aside from this, the flow of the medium via the radial peripheries of the edges controlling the orifices of the conduits causes corresponding wear to the working parts, which with a corresponding increase in the power loss over the service life of the machine likewise increases. Because of this wear, increasing on the spherical surface of the teeth, a leak from one work chamber to the next occurs in this outer spherical region of the teeth, and the otherwise advantageous slight overlap of the radial face end of the teeth with the diametrically opposed spherical wall has an especially adverse effect.
The object of the invention is to develop a pump or a motor for liquid or gaseous media, namely a machine in this respect, with which even substantially higher media working pressures can be managed without adverse effects and which can be produced without major manufacturing expense.
The machine according to the invention having the definitive characteristics of the main claim and of coordinate claims 10, 13 and 15 has the advantage that with a simple construction and correspondingly low costs, a machine for high working pressures is created, in which advantageously the pressures that in the known machines have a disadvantageous effect because of radial loading are now predominantly diverted into the more easily controlled axial direction. By the stationary disposition of the other work face, diametrically opposite the working part and defining the work chambers, bearing forces for a second working part are also dispensed with, so that only the working part toward the shaft on the slanted sliding plane has a bearing face, and predominantly only the shaft must have an axial bearing and only to a limited extent also a loaded radial bearing, or especially in accordance with claim 15 no loaded radial bearing. The tumbling of the working part corresponds to the rotation of the shaft. Because of this tumbling, the work chambers on rotation of the shaft decrease and increase in size in succession, as a result of which the corresponding power of the machine is created. In the known machines, in particular rotary piston machines such as the Wankel engine or an eccentric worm pump, thought is given mostly to a sectional plane, which leads to difficulties in imagining the design according to the invention. It is decisive for the invention that the stationary work face and the work face of the tumbling working part have a good form lock, including with the spherical surfaces, and there is surface constancy with tightness that remains throughout the work, or in other words is independent of the axial position of the working part.
In an advantageous feature of the invention, the center axis of the stationary work face is identical to the axis of rotation of the shaft. As a result, an optimal tumbling drive is attainable.
In an additional feature of the invention, the partly spherical inner wall that receives the tumbling working part changes over into a cylindrical opening in the housing the diameter of which is equivalent to the diameter of the working part. Particularly if the center axis of the stationary work face is coaxial with the shaft, on the one hand there is favorable support of the working part on the static work face, but also a large partly spherical overlapping face, separating the work chambers, between the working part and the housing.
In an additional advantageous feature of the invention, between the working part and the diametrically opposed, non-corotating work face, a common partly spherically embodied bearing surface is centrally present, which likewise serves the purpose of radially defining the pump work chambers. By this means as well, a major overlap dividing the work chambers exists between the spherical bearing surfaces, with corresponding advantages for the efficiency of the machine.
In an additional advantageous feature of the invention, the teeth of the diametrically opposed spur toothing are embodied as a cycloid toothing, with a power part and a blocking part with a cycloidal development of the sliding surface. Intrinsically, such a feature is known (German patent disclosure DE 42 41 320), but in an embodiment in which the work faces diametrically opposite one another each corotate. The advantages of the cycloidal development are preserved, however, if only one work face rotates, as in the invention. The advantages of the cycloidal development per se can be learned from the prior art.
In an additional feature of the invention, claimed on its own in claim 10, inlets/outlets from the pump work chambers branch off as static conduits axially symmetrically from the stationary work face and in a manner uncontrolled by the working part. As a result, a sharp control edge between the tumbling working part and a spherical wall, with corresponding worsening quality and intrinsically unavoidable wear of the control edges, is avoided. However, for some function systems an additional valve control is desired, and therefore in an additional feature of the invention in this respect, controllable valves may be disposed in the static conduits.
In an additional feature of the invention that is advantageous in this respect, as the valves, plate valves, with a mounting part having one outer and one inner ring, and having spring plates disposed between the rings and secured resiliently on one ring thereof, serve as the valves. Such plate valves can be produced extremely favorably and function on the order of a check valve.
In an additional advantageous feature of the invention, claimed on its in claim 13, the shaft has an increased diameter toward the slanted sliding plane, and corotating conduits acting as an inlet or outlet extend in the step thus formed.
In a feature of the invention that is advantageous in this respect, openings corresponding to the corotating conduits are present in the work face of the working part, which are controlled by the orifices of the conduits in the slanted sliding plane.
In an alternative advantageous feature of the invention, likewise claimed on its own in claim 15, the shaft, for carrying the liquid or gaseous media onward from and to the work chambers, has a connecting conduit extending in the shaft, in order to avoid radial loads on the shaft from the media being pumped, both toward the housing and toward the rotary bearing. Especially when the invention is used as a canned motor, this feature plays a decisive role, since only by radially relieving the bearing forces of the shaft can the working pressure and thus the power range of the machine be increased accordingly.
In a feature of the invention that is advantageous in this respect, openings are present on the bottom of the work chambers, which openings lead to a collection chamber that is present between the slanted sliding plane and the back side of the working part, and the collection chamber is closed radially toward the outside and leads directly to the connecting conduit. As a result, a direct connection between the work chamber and the connecting conduit is attained, with complete relief of radial forces at the shaft.
In an additional feature of the invention in this respect, at the bearing point between the slanted plane of the working part and the shaft, in the region where the medium is carried toward the connecting conduit, there are tapered places in the material, in order that the unilateral accumulation of material from these tapered places in the material that results in the forming of the slanted plane without mass compensation will be compensated for. As a result, the occurrence of unilateral radial forces from unilateral accumulations of material in the region of the slanted plane on the shaft is averted.
Additional advantages and advantageous features of the invention can be learned from the ensuing description, the drawings, and the claims.
One exemplary embodiment with a variant is shown in the drawings and described in further detail below.
Shown are:
In
in the mounting housing 1, a non-corotating work chamber housing 10 is disposed centrally, coaxially with the shaft 4, and is sealed off from the mounting housing 1 via an O-ring 11. This work chamber housing 10 receives a work chamber 12, which is defined on its other side by a rotating working part 13. The shaft 4, on the side toward the working part 13, has a slanted sliding plane 14, so that rotation of the shaft 4 leads to tumbling of the working part 13. The face end, remote from the sliding plane 14, of the working part 13 is toothed in the manner of a cycloid toothing, which correspondingly meshes with a static toothing that is present on the work housing 10, in the opposed wall face of the work chamber 12. Upon rotation of the working part 13 inside this work chamber housing 10 disposed in stationary fashion, the work chambers 12 increase and decrease in size, leading to the desired pumping or motor action, respectively. The teeth, associated with one another, of the working part 13 and the work chamber housing 10 touch in linear fashion toward the respective pump chamber boundary.
To attain guidance in the tumbling motion, the working part 13 is guided in spherical boundaries of the work chamber housing 10 receiving it, namely in a partly spherical surface portion 15, which also radially forms the outer boundary of the work chambers 12, and a central, smaller partly spherical surface portion 16, which defines the work chambers 12 radially inward. Both partly spherical surface portions 15 and 16 have the same center point M. The working part 13, on its side toward the face 16, likewise has a corresponding partly spherical rounded face 17 as well as a partly spherical rounded face 18 corresponding to the partly spherical surface portion 15 having the larger diameter. Because of this spherical overlap, not only is there a very favorable distribution of the axial forces from the shaft 4 to the work chamber housing 10, but there is also an extremely favorable separation from one work chamber to another and from a work chamber to other machine conduits, especially during operation, or in other words during the tumbling of the working part 13.
The work chamber housing 10 is secured in the mounting housing 1 via a threaded ring 19, and a valve plate 20 is fastened between the threaded ring 19 and the work chamber housing 10. In the view B shown in
A connection with the work chambers 12 exists via control conduits 22 to an annular chamber 23, surrounding the shaft, for the working medium, and depending on the use, the annular chamber 23 acts as an inlet or outlet conduit. In the exemplary embodiment shown, this annular chamber 23 communicates via radial conduits 24 with an outer annular chamber 25, as can be seen particularly in
The first variant of the exemplary embodiment, shown in
In
In the second variant, shown in
As can be seen from
All the characteristics in the specification, the ensuing claims and shown in the drawings may be essential to the invention both individually and in arbitrary combination with one another.
Number | Date | Country | Kind |
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10 2007 012 574.9 | Mar 2007 | DE | national |
10 2008 009 694.6 | Feb 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE2008/000425 | 3/13/2008 | WO | 00 | 12/31/2009 |