This invention concerns a positive pressure pump or motor of the type built up from roller bodies designed to roll between two rings or discs in the same manner as those of a radial or axial ball bearing, i.e. for instance an inner ring or an outer ring, allowing for a pump effect by means of providing harmonic variation of the tangent¬ ial distance between the roller bodies during a revolut- ion around the main axis, i.e. the mutual axis of the rings or discs, the bodies approaching each other at the delivery side and moving away from each other at the suction side. In this connection, pumps and motors are to be understood in general terms, indeed, since these designations should also cover for instance compressors, and you may in this connection work with both liquid and gaseous mediums. So when the invention is described in the following sections primarily in relation to pumps, this is being done solely for convenience of language.

Pumps of the type mentioned are known from the German pub- lication releases Nos. 2224273 and 2240950. In the case of the pumps known from these, the roller bodies are forced out into the movement where the mutual distance varies, despite the fact that they do at the same time roll on an inner ring and an outer ring in the same manner as that of a roller bearing. Thus, the roller bodies are forced away from pure rolling for they are forced into sliding on the roller surfaces. This, of course, will involve a friction loss, and at the same time it will cause friction surface wear. Thus, these pumps cannot be run by providing a relative movement between the inner ring and the outer ring, either, since, as ment¬ ioned above, the necessary friction will vanish owing to wear. The known pumps referred to are driven in the manner that you hold the inner ring or the outer ring and transfer the rotation of the roller bodies through

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the means adjusting the distance between the bodies, i.e. you push the roller bodies round. This will, of course, entail a friction loss, too. ^■ »

The purpose of the present invention is that of remedy¬ ing these drawbacks, and the pump or the motor to the invention is characterized in that the means for harmon¬ ic variation of the tangential distance between the roller bodies consist in that the roller surfaces have been designed in a manner to ensure that the distance of the rolling points from the main axis will vary at the circumference, at least in respect of one of the roller surfaces. In the case of a construction of this nature, there will be pure rolling between the parts moved, and the entire friction existing at the rolling points will then be available for the pressure build-up, ^' and thus for the power transmission. Thus, it will be possible to build pumps or motors of the type referred to which will work with higher pressure and effect and be more durable, too, since there will not be the same frict¬ ion surface wear as in the case of those known. Besides, the design to the invention will be greatly simplified in comparison with the designs known since it does not in¬ clude a separate embedded device for producing the dist- ance variation between the roller bodies. This device has been replaced by a special design of the roller paths for the roller bodies.

Another essential advantage of the design to the invent- ion is the fact that its build-up is so simple. Thus, you will not have to provide bearings for it since the pumping parts will provide the necessary control of the rotating parts in relation to the fixed ones.

One embodiment of the invention, mainly built up as a radial bearing, i.e. with an outer ring and an inner ring, is characterized in that the roller surface on the inner ring is shaped as a rotary body, in that the inner ring

has been connected to a driving shaft or a driven shaft, and in that the outer ring design has been maintained in a house. Thus, an expediency of design- is a ^~ *ttained to which the part containing the modified roller surfaces and determining the positioning of the inlet and the out¬ let has been placed under the non-rotating part.

A further development of this embodiment is characterized in that the outer ring design is made up of two rings lying beside each other. This design is simple to produce

A further development of this embodiment is characterized in that it has means of pressing the two outer rings axially against each other, for instance a spring. Thus, you may compensate for roller surface wear.

Another embodiment is characterized in that between each pair of roller bodies following each other a loose filling- in body has been placed of a size sufficient for mainly filling in the space between the two roller bodies when these are in the position where the tangential distance between them is at its minimum since the outline of a roller body and a filling-in body viewed in the tangent¬ ial direction is more or less the same. Thus, you may avoid noxious space and at the same time have the dist¬ ance between the roller bodies distributed.

A third embodiment is characterized in that the roller bodies are balls embedded between an inner ring and an outer ring design. This allows for low cost production since you use ball bearing ball standard designs, made with fine tolerances and at a low price.

A fourth embodiment is characterized in that the roller bodies are barrel-shaped, in that the ring, design is made up of an inner ring and two outer rings with cone-shaped inner roller surfaces which at two symmetric points bear against each barrel-shaped roller body, in that an elastic deforming sealing ring has been inserted between the two

outer rings, and in providing means of tipping the axes for each of the two outer rings in relation to the main axis both one way and the other since the inner ring has been designed to rotate whereas the outer rings are being detained against rotation. By adjusting the outer rings at a constant number of revolutions, this design will allow for adjustment of the flow continuouly both one way and the other.

This invention is explained further with reference to the drawing where

Pig. 1 shows a radial section through an embodiment of a pump according to the invention along a section line

A-A in Pig. 2,

Pig. 2 a section between the pump to the line B-B in Pig. 1,

Pig. 3 an axial section through another embodiment not showing, however, certain parts, and

Fig. 4 an axial section through a third embodiment in the same manner as that of Fig. 3.

The design shown in Pigs. 1 and 2 is that of a pump mainly built up as a radial ball bearing. The individual elem¬ ents bear the same reference numbers in the two figures. In a house 1 an outer ring design has been fastened, con¬ sisting of two rings 2 and 3, these rings- being held by a cover 4. Inside rings 2 and 3 balls 5 and 6 have been placed at .regular intervals. Inside the balls bear against an inner ring 7 mounted on a driving shaft 8 protruding through the house 1 by a packing 9 . In the house 1 or in the cover 4, an inlet passage not shown and an outlet passage not shown have been made. Finally, filling-in

bodies 10 of a special shape have been inserted between balls 5 and 6 following each other. The surfaces of the filling-in bodies 10 facing the balls are ttius spherical surfaces of the same radius as those of balls 5 and 6. Further, the filling-in bodies 10 viewed in the tangential direction are shaped as .circles of the same radius as that of the balls. Part 11 in Fig. 2 is thus a filling-in body. The outer rings 2 and 3 together form a roller surface of a special shape. Solely production-technical considerat- ions are behind the fact that the outer ring design consists of two rings 2 and 3. The shape of the surface at the top and at the bottom in Fig. 2 thus represents extremes. At the bottom of Fig. 2, the roller surface has been shaped so that the contact point is at the reference figure 12, a fact actually illustrating something known since a ball at this point will then move at an angular velocity of half that of the inner ring when retaining the outer-ring. This is a question of the angular velocity of a ball in its planetary motion. On the other hand, at the top of Fig. 2 the roller surface has been shaped so that the ball will roll at two symmetric contact points 13 and 14 lying at a lesser radius that that of the contact point 12. At this point the balls will thus have an angular velocity less than half the angular velocity of the inner ring. Between these two extremes of the shape of outer rings 2 and 3, at the top and at the bottom of Fig. 2, respectively, the shape of the outer ring grooves gradually merges from one form to the other. The grooves are thus shaped as two closed curves meeting or touching each other at point 12 at the bottom of Fig. 2. Thus, it would seem clear that a given ball on its way round along the outer rings will be in planetary motion, showing a growing velocity at one half of the circumference and a declining velocity at the other half of the circumference. Thus, at one half of the circumference the distance between the balls will thus decrease whereas the distance will increase at the other half. One side will be the delivery side and the other the suction side, as for instance intimated in Fig. 1.

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The filling-in pieces 10 serve to reduce the noxious space and to maintain the distance between the balls. As would

<* appear, theoretically there will be no noxious space when using filling-in pieces of the shape described.

Fig. 3 shows another embodiment to which parts correspond¬ ing to the parts of Fig. 2 bear the same-reference numbers. In addition to that, this design differs from the former in that the house 1 has been fastened against another house- 20 which may be a motor house by means of stay bolts 21. In this Fig. 3, connection borings 22 and 23 have also been shown, constituting the pump inlet and discharge. The two outer rings 2 and 3 have been spring-loaded against each other in axial direction by means of a disc spring 24, thus compensating for the wear which balls and rings are exposed to. An elastic sealing ring 25 has been inserted between rings. Thus, there will be nothing to prevent you from pressing the two outer rings against each other in a different way, for instance by means of the hydraulic pressure produced by the pump. Thus, the friction avail¬ able will rise gradually with the need for it.

Fig. 4 shows a design equal to the former ones where the corresponding parts bear the same reference numbers. The roller bodies 30 are barrel-shaped, i.e. the surfaces are double curved. The roller surfaces on the outer rings 2 and 3 are conical, and no means of capsizing the outer rings 2 and 3 in relation to each other have been shown; these means may be those of conventional screws. Thus, adjustment of the volume flow to a given number of revol¬ utions is made possible. In the case of this design, the roller bodies could on the hand have been shaped as reversed truncated cones, the bases against each other, whereas the roller surfaces on outer rings 2 and 3 could have been double curved. Elastic seal rings 31, 32, and 33 have been inserted between rings 2 and 3 and the rings in the house.

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Since outer rings 2 and 3 have been designed to capsize around axes at right angles to the paper level and through the longitudinal axis, it will not be expedient to press

<<- rings 2 and 3 against each other by means of disc springs. Consequently a pair of springs has been placed lying dia¬ metrically opposite each other at a level at right angles to the paper and containing the longitudinal axis out of which one has been shown in Fig. 4 and bears reference number 34. The ends of spring 34 may be attached to pro- truding pins 35 and 36.

This invention has obviously not been limited to the embodiments shown,, these having primarily been based on radial bearing designs. One might as well imagine e bodi- ments based on axial bearing designs.

The designs shown illustrate pumps but the invention might obviously just as well be applied to designs work¬ ing as motors.