Background Art At present, piston pumps are usually used as pumps for liquid substances, e. g. liquids and gases. Standard piston pump consists of a cylindrical piston in the sliding position which is deposited. in a cylinder chamber, a crankcase with a crank, a piston rod and sealing components. The inconvenience of piston pumps rests in their space demand because a piston and a cylinder are necessary, and in relatively short life cycle due to the piston and/or cylinder wear.

Disclosure of Invention The above mentioned inconveniences are removed by the technical solution proposed. The key point is that a pump for liquids has been developed, where the current piston-based equipment has been replaced by a newly designed crank system. The proposed pump for liquids consists of a supporting body in the form of a crankcase, fitted with a leak-proof lid, inside the crankcase there is a crank space of cylindrical shape for a crank, which is deposited in this crank space and its piston rod shank is attached to a crank disk. A crank disk has been selected with a perpendicular central pin and on the opposite side there is a connecting element perpendicularly and eccentrically situated against the piston rod. The essence of the new solution rests in the fact that there are two crank spaces and two crank disks, each on one end of the piston rod and located in one crank space. Then, the first crank space is of the same dimensions as the second crank space and both crank spaces are situated next to each other in the crankcase, which means in the same height and in parallel to each other. Between them there is at least one input and one output channel for medium pumped and also a

groove with a sliding sealing element, separating the first crank space from the second one. The shank of the crank piston rod passes through the sealing element and this shank is deposited in a sliding position against the sealing element.

The shape and diameter of crank disks are selected in a convenient way, especially they tightly fit to the crank spaces. In the crankcase they are in a position, where their central pin passes through the centre of the bottom of crank spaces, especially through central openings making in the crankcase for this purpose.

The piston rod shank attachment to the crank disk is conveniently done in such a way, that the piston rod shank is equipped with a piston rod eye on both ends, whilst both crank disks are equipped with an eccentrically positioned perpendicular piston rod pin on the side opposite to their central pin. Each of these piston rod pins is located in one piston rod eye. It is also possible to use a different form of attachment, for instance a reversed one, where the piston rod pin is created and, on the contrary, a crank disc eye in the crank disk, however the first alternative is much more convenient form the point of production and functionality.

In optimum case, the piston rod shank is flat and its height and the piston rod eyes height, too, is equal to the height of the free space in a crank space, e. g. it equals to the depth of the crank space minus the crank disc height. The distance of piston rod eyes has to be equal to the distance of axes of the central openings.

This enables the tightness and optimum functionality of the equipment.

The input channel and the output channel, both of them, lead to both crank spaces. This mouth end as well as the space of the first crank space and also space of the second crank space, are all connected by the groove. There is a sliding sealing element placed in the groove, whereas this sealing element in all its positions separates the first crank-space from the second crank space and the piston rod shank passing through it separates the input channel from the output channel.

The channels are conveniently placed in pairs, at least in the area of their mouths which lead to the crank spaces. In case convenient pairs of input and output channels are created, then one member of the pair always leads to the first crank space and the second one into the second crank space.

The sealing element can be set up in various ways but it must always separate the first crank space from the second one and enable a sliding passage of the piston rod shank. The design with a rotating sealing roller is a convenient solution here. If the sealing element is fitted with the rotating sealing roller, the sealing roller has got a piston rod shank opening for the piston rod shank. The sealing roller is located in such way that its axis is in parallel position to the axes of central pins and to piston rod eyes, and the shank opening is a slot which is closely fit to the piston rod shank. This enables perfect separating and sealing function of the sealing element and also sliding and simultaneous rotating motion of the piston rod shank.

The equipment is put into operation by rotation of crank disks. For this purpose a suitable driving unit is attached to one of the crank dick central pins or, which is better, on both of them. Owing to the fact that during this equipment operation there are irregular mutual rotations of both crank pins, it is necessary to use separate drive for each crank disk.

The equipment proposed enables pumping or compression of liquid substances, liquids and gases, without the necessity to use the piston system. The advantages of the equipment proposed rest namely in space saving and long life cycle. The equipment enables a miniature design because the crank spaces are used for pumping and this eliminates the need for additional space for sliding motion of the piston. This equipment can be used in many technical branches, for example as a hydro-generator, a hydro-engine, an air-pump, a compressor, a pneumatic engine or an element of a combustion engine.

Brief Description of Drawings The invention is explained by drawings form Fig. 1 to Fig. 6, where shows : Fig. 1 the spatial arrangement of the pump for liquids, in spatial view on individual equipment parts transversally from the front side.

Fig. 2 a view of the pump cross-section lead perpendicularly through the centres of crank spaces.

Fig. 3 the top view on crank spaces of the same pump without lid, figures 4 to 6 show the equipment functionality with display of the following working positions of the same pump.

Example of Invention Exemplary embodiment of the invention and best mode for carying out the invention is the pump for liquids according to the figures from Fig. 1 to Fig. 6. I As a supporting body of this equipment there is the crankcase 1 with two crank spaces 2= 2"situated next to each other, of cylindrical shape and same size. Both of them are situated in the crankcase 1 next to each other and one crank disk 3 is placed in each of them. The mouth of a pair of input channels 4 and the mouth of a pair of output channels 5 for medium which is pumped, and also a groove 6 are placed between the first crank space 2'and second crank space 2". A sealing element 7 is movably located in the groove 6. The sealing element 7 separates the first crank space 2 from the second crank space 2". The piston rod shank 8 of the crank passes through the sealing element 7. Crank disks 3 are of such a shape and diameter that their perimeters tightly fit to the crank spaces 2'. 2". One central pin 9 located in central openings 10 of the crankcase 1 in the middle of the crank spaces 2. 2"leads downwards from each crank disk 3. The piston rod shank 8 is equipped with a piston rod eye 11 on both ends. Both the crank disks 3 are on the opposite side to the central pin 9 provided by the excentrically situated piston rod pin 12. Each piston rod pin 12 is located in one piston rod eye 11. The piston rod shank 8 is flat, its height and the piston rod eye 11 height is the same and is equal to the depth of a free space in the crank spaces 2, 2", which remained after placement of crank disks 3. The distance of piston rod eyes 11 is equal to the distance of central openings 10. The sealing element 7 is fitted with the rotating sealing roller 13 with a piston rod shank opening 14 for the piston rod shank 8 The axis of the sealing roller 13 is parallel to the axes of central pins 9 and piston rod pins 12 and the shank opening 14 is of a shape of a slot adjoined to the piston rod shank 8. The driving unit can be connected to one or both central pins 9 of crank disks 3. A removable lid 15, which tightly closes crank spaces 2', 2", is located on the crankcase 1 and also on the top of movable parts, that is the shank 8 of a piston rod and piston rod eyes 11, but it is not too tight, to avoid any obstacle for moving.

The equipment operates, as follows. After being put into operation, the central pins 9 start to rotate which makes the crank disks 3 rotate, as well, in the direction

against each other. The motion is transferred through the piston rod pins 12 onto piston rod eyes 11. This causes movement of piston rod shank 8. The piston rod shank 8 is sliding in the shank opening 14 and it is simultaneously turning according to the current mutual position of piston rod eyes 11. The rotation of sealing roller 13 enables to change piston rod position without any interference with the sealing element 7 functionality. The size of free space in crank spaces 2, 2"is changed in front of and behind the piston rod shank 8. Piston rod eyes 11 rotate around the sides of the cylinder casing of the crank spaces 2'. 2". In the area of the enlarging of space in the crank space 2 2", the pumped medium is sucked from input channels 4, in the area of the space reduction the medium is either compressed or pushed to the output channels 5. The flow or pushing out of the medium occurs only case the discharge channel 5 is opened. Due to the simultaneous and also mutually independent change of inside spaces of both crank spaces 2 l 2", it is possible to pump or compress different medium in each of them.