In previously known, traditional pumps for fluids such as liquid or gas, as a rule a static pump pressure is generated which increases down through a liquid proportionally with the depth and which propels the fluid through, for example, a pipeline. When these pumps known in the prior art are employed, friction between the fluid and the various movable parts in the pump, between the various particles in the fluid and between fluid and pipeline will result in resistance leading, amongst other things, to reduced pressure. The pressure loss when using previously known pumps in connection with the transfer of a fluid through a pipeline makes it necessary to establish pumping stations when long distances are involved in order to raise the pressure in the pipeline. In some areas of application this is rather inexpedient, such as, for example, in the recovery of oil from subsea reservoirs located deep in the sea bed at great depths where the distance from a pump to the surface is so great that it is almost impossible to pump oil and gas without the occurrence of excessively high pressure loss in the pipeline between the pump in the reservoir and the surface.

In the present invention fluid is transported by means of a device such as a pump, which by means of an oscillator generates longitudinal waves in the fluid. An oscillator produces oscillations at a specific frequency preferably about a neutral position between a first and a second position. The oscillator consists of one or more inertial elements which accumulate kinetic energy and one or more energy-accumulating devices for potential energy. Due to the fluid's influence on the inertial element the oscillations will be damped

after a time, i. e. the amplitude of the last oscillation will be reduced by a decrement relative to the amplitude of the previous oscillation. An amount of work according to the amplitude decrement must therefore be supplied to the damped inertial element. This work is supplied from an external power source which may be a motor of various types, such as a petrol motor, electric motor, gas turbine or the like which supplies energy to an oscillator possibly via a transmission device.

Thus a pump according to the present invention consists substantially of one or more oscillators which produce controlled, single-stage mechanical oscillations preferably about a neutral position at a specific frequency.

The oscillator comprises one or more inertial elements and one or more energy-accumulating devices for potential energy, such as a spring, an elastic element, homopolar magnets, an enclosed compressible medium or the like.

The inertial element is a body with specific mass, working area and moment of inertia which accumulates the system's kinetic energy Ek.

Ek = 1, m v2 Spiral springs or other elastic devices (two magnets of the same polarity, a compressible medium in a closed form or the like) are accumulators of the system's potential energy Ep.

Ep = m x2 The translatory oscillating power source moves at a specific frequency which, for example, may be between 1 and 1 OOHz. This movement with its kinetic energy is transferred to the closest energy-accumulating device (spring) which is compressed, attaining a potential energy. The energy- accumulating device then expands, releasing its potential energy to form kinetic energy, creating a translatory movement which in turn is transferred to an inertial element. The inertial element compresses the energy- accumulating device on the opposite side and kinetic energy is transformed into potential energy in this accumulating device which in turn pushes the inertial element back, transferring its potential energy to kinetic energy. The inertial element which is an accumulator of kinetic energy, and the elastic devices which are accumulators of potential energy thereby form an oscillating system. The inertial element moves with a relatively small

amplitude and considering the frequency at which the element oscillates, the velocity (v) becomes low while the acceleration becomes high. At a frequency of 100 Hz and amplitude ~ 1 mm, e. g., the amplitude velocity is 0.628 m/s and the acceleration amplitude 40 g, where g is the acceleration of the force of gravity from 1500 to 5000 m/s. On normal consideration of the fluid mass m which is transferred per time unit, a reaction force is then obtained of F = ma where a is the acceleration. When the acceleration here is high the reaction force becomes correspondingly high. Moreover, at any time the sum of potential and kinetic energy is constant.

When the moment of inertia compresses the fluid, a volume of liquid is expelled from the pump, thereby creating a power impulse (a hard wave) which moves along the fluid at a velocity which is considerably higher than the velocity of the liquid flow.

The inertial element's movement can be represented by a sine shape and the fluid's damping gives an amplitude decrement between two subsequent oscillations. The work which requires to be supplied to the system is thereby represented by the damped device's amplitude decrement. This work is provided by the external power source which transfers power to the oscillator from the energy-accumulating device as a translatorily oscillating movement.

The object of the invention is to provide a wave system for transport of fluid, especially a pump of the type mentioned in the introduction, which is not encumbered by the disadvantages of standard pumps known in the prior art, particularly in connection with pumping of a fluid in a pipeline. In other cases, such as in long transfers of fluid in subsea pipelines or pipelines on shore, by using a pump according to the present invention, fluid may be transferred through the pipeline over a substantial distance without the necessity of installing pumps to raise the pressure in the fluid as a result of pressure loss in the pipeline. In recovery of oil from oil reservoirs located on the sea bed, a pump according to the present invention may be installed on a platform at the surface instead of down in the oil reservoir, which is the case with previously known pumps.

A pump according to the present invention is further specified in the introductory part of the following independent claim with characterising features as indicated in the characterising part of the independent claim 1,

and different embodiments of a pump according to the present invention are indicated in the following dependent claims.

The invention will now be described in more detail with reference to the figures which schematically illustrate the invention's mode of operation and different embodiments of pumps according to the invention.

Figure 1 is a sectional schematic view from the side of the invention in a simple embodiment; figure 2 is a diagrammatic representation of the movement of the oscillating system; figure 3 is a sectional view from the side of a further embodiment of a pump according to the present invention; figure 4a is a front view of a further embodiment of a pump according to the present invention; figure 4b is a sectional view from the side of the embodiment illustrated in figure 4a; figure 5a is a sectional view from the side of a further embodiment of a pump according to the present invention; figure 5b illustrates section A-A from the embodiment illustrated in figure 5a; figure 6 is a sectional view from the side of a further embodiment of a pump according to the present invention; figure 7 is a front view of the embodiment illustrated in figure 6; figure 8 is a sectional view from the side of a further embodiment of a pump according to the present invention; figure 9 illustrates section A-A from the embodiment illustrated in figure 8; figure 10 is a sectional view from the side of a further embodiment of a pump according to the present invention; figures 1 la and 1 lb are a sectional view from the side of an embodiment of a valve system for use in connection with a pump;

figure 12 is a sectional view from the side of a further embodiment of a valve system for use in connection with a pump.

In figure 1 there is illustrated an oscillator with valve bodies 7 installed in a pipeline 6. The inertial element 1 is provided with valve bodies 7 which permit the inertial element 1 to pump surrounding fluid by means of movement in one direction only, while movement in the opposite direction takes place with less resistance and completely or almost without pump effect. The inertial element 1 abuts against the springs 2 and 3 which constitute the energy-accumulating devices for potential energy. An external oscillating force is further applied to the spring 2 from the element 5 with an amplitude A. The inertial element 1 and the springs 2 and 3 constitute an oscillator (an oscillating system) with, amongst other features, a natural frequency E. The element 5 applies a compression to the spring 2 which gives it a potential energy. This potential energy is released to form kinetic energy in the inertial element 1 as the latter is moved towards the spring 3, thereby compressing it. The inertial element's kinetic energy is thereby transformed into potential energy in the spring 3 which, when it is compressed, pushes the inertial element 1 back towards the spring 2. This creates an oscillating system which is damped by the fluid transferred by the inertial element 1.

In figure 2 the oscillating linear translatory movement of the inertial element 1 is described in a sine shape where the damping constitutes an amplitude decrement D between two subsequent oscillations. The work required to create oscillations with the same amplitude is supplied from the power source 5 illustrated in figure 1. The springs 2 and 3 may be replaced by other energy-accumulating devices such as, e. g., closed devices with a compressible medium, magnets with the same polarity, elastic materials such as rubber etc. which have little loss due to internal frictional resistance. The power source 5 may be any kind of rotating or linear machinery which either directly or via a transmission device provides a translatorily oscillating movement with amplitude A at a specific frequency. The frequency can be optional.

Figure 3 illustrates a further embodiment of a pump according to the present invention where the inertial elements 1 and 2 form a part of an oscillator. A valve system 9 may be installed at the pump's inlet portion, as illustrated in

fig. 3, at the outlet portion or in both places. The inertial element 1 is in the form of a cylinder with preferably rigid, immovable annular ribs 1', 1", 1"', and so on. Between the ribs 1', 1", 1"'respectively there are arranged rows of preferably rigid immovable ribs 2', 2", 2"'attached to an internal hub 2. The space between internal and external ribs is sealingly closed by annular seals 3. Oscillations of the inertial element about the central point alters the space between external and internal ribs. It leads to oscillating movement of liquid via openings 4 and formation of hard longitudinal waves. Thus, at an oscillating frequency of 100 Hz and amplitude up to 1 mm, for example, the inertial element has a velocity 6 m/s and acceleration ~ 40g.

On each side of the inertial elements 1 and 2 there are mounted energy- accumulating elements for potential energy, which in this case are _ represented in the form of springs 5 and 6. Oscillating energy is supplied via an external power source from the element 7 with amplitude A. The element 7 applies a compression to the spring 5 in the direction of the inertial element 1 which is moved towards the spring 6, thereby compressing it. The spring 6 is compressed against the backing plate 8, whereupon it expands with the result that the inertial element 1 moves in the opposite direction towards the spring 5. The valve system 9 is located at the pump inlet portion and is arranged in such a manner that the liquid flow moves only in one direction.

In figures 4a and b there is illustrated an inertial element 12 which is securely mounted on a torsion shaft 16 which produces an oscillating movement between two extreme points defined by 14 inside a pipe 15. The pipe is divided into two chambers by the partition 13. The torsion shaft 16 constitutes an accumulator of kinetic and/or potential energy and together with the inertial element 12 forms an oscillating system which can be represented in the same way as that illustrated in figure 2. In the inertial element 12 there are further mounted valve bodies which permit a pump effect only when the inertial element 12 moves in one direction. The valve system 18 may be installed at the pump's inlet portion, outlet portion or in both places.

Furthermore, in figures 5a and b there is illustrated a further embodiment of a pump where a pipe 20 acts as an oscillator where the pipe walls constitute a relatively rigid element and the pipe's mass is an inertial element. The shaft 21 produces axial oscillations and via elastic non-stretchable elements 22 the

pipe wall 20 is set in oscillating motion. The pump effect here is performed by the pipe wall 20.

A further embodiment of the present invention is illustrated in figures 6 and 7 where figure 6 illustrates a section of a pump device viewed from the side while figure 7 illustrates a cross section of the same pump device viewed from the left side of the pump device in figure 6. In figures 6 and 7 an inertial element 30 is mounted in a funnel-shaped part of a pipe 35 on a supporting device 31 which is located across the pipe's longitudinal direction.

The supporting device 31 is located at each end against springs 32,33 which constitute the energy-accumulating bodies for potential energy. Each of the ends of the supporting device 31 can be influenced by an oscillating force 34.

Thus, together with the inertial element 30 and the energy-accumulating bodies 32,33, the supporting element 31 will constitute an oscillating system which is influenced by the oscillating force 34. The oscillating system's motion will be as described in figure 2. The inertial element 30 is further surrounded by valve bodies 36,37 which permit fluid to flow only in the direction 40. This occurs alternately, so that when the inertial element 30 moves upwards in figure 6, the valve bodies on the"out"side of the valve body 36 open while the valves on the"in"side of the valve body 37 are closed. The inertial element 30 then moves downwards in figure 6 and the valves on the"in"side of the valve body 36 are closed while the"out"valves in the valve body 37 are opened. Pumping thereby takes place alternately on the top and bottom of the inertial element 30. The funnel-shaped part of the pipe 35 is provided at each end with flanges 38 and 39 for mounting in another pipe installation.

A further embodiment is illustrated in figures 8 and 9 in a partial section from the side and a cross section from the left side in figure 8 respectively.

Here there is illustrated an external housing 41 with an internal housing where membranes 41 are installed in the internal housing. Between the external and the internal housings is an opening 42 which is connected with an external power source 43. The opening 42 is filled with a fluid which is exposed to an oscillating varying pressure from the source 43. This causes the membranes 40 to move in an oscillating manner in and out towards the centre of the internal housing. This in turn provides a pump effect in the direction 45 for the fluid which is in the pipe 46. The membranes 40 together with the fluid in the opening 42 form an oscillating system with oscillating

movement as described in figure 2. The membranes 40 in this case are the pumping elements for the fluid in the pipe 46 and the membranes'flexibility may be the energy-accumulating body. Alternatively, the fluid in the opening 42 may be capable of compression or it may have an expansion chamber which offers it the possibility of being the accumulating body which together with the membranes 40 forms the oscillating system.

A further embodiment of the present invention is viewed in a section from the side in figure 10. An oscillator 1 is connected on a first side with a pump 2 via an elastic membrane 3 and on a second side with an external power source 4 via a spring 5 and dampers 6. The pump consists of an inertial element 7 and a pump housing 8 which further consists of an external housing 9 and an internal housing 10. In the walls of the internal housing 10 are mounted valve bodies 11. At the pump's outlet on the right-hand side there is a further valve system 12. Fluid is supplied from a pipe 13 to the pump housing 9.

Figure 11 a illustrates an embodiment of a valve system where the valve bodies 51 are eccentrically rotatably mounted on axes of rotation 52 with a long and a short end on each side of the shaft 52. When fluid flows in the direction 50 the valve bodies 51 close by rotating about the shafts 52 since the long end of the valve bodies 51 is exposed to the fluid flow 50. In figure l lb the fluid flows in the direction 53 and the short end of the valve bodies 51 is influenced by the fluid flow and the valves are opened by rotating about the shafts 52.

In figure 12 there is further illustrated another embodiment of a valve system which acts in a resonance regime.

In the above a number of embodiments are set forth illustrating the inventive concept. It should be noted, however, that these are only examples and the invention is defined and limited only by the following claims.