Technical area

The invention belongs to the mechanical engineering category, more specifically to the hydraulic positive-displacement machines; pumps for liquids or elastic fluids. According to the International Patent Classification the group would be F 04 B.

Technical problem

Construction of a pump which would

• Operate as a continuous piston which on one side discharges a constant amount of liquid or compressible fluid and, on the other side, sucks in the same amount

• Enable operation as a pump, hydro engine and vacuum pump

• Have higher intake volume than own work-volume and consequently smallest possible dimensions for given intake volume

• Have a high or the highest possible efficiency

• Be of simple and technologically available construction

• Be able to work with the minimal rotational speed so that it can be hand-powered State of the art

It is not known when the first devices to elevate water from a lower to a higher level have been constructed. The scoop wheel as been known since B.C. and it is still used. The development of technology has brought pumps and hydraulic systems, so that the pumps are today, after the electric motors, the most frequently found types of machines.

Hydraulic systems use only hydrostatic pumps, which can be of many different constructions.

As this invention belongs to the group of vane pumps, we will discuss those in more detail. Vane pumps are among the simplest hydrostatic pumps. Such a pump consists of a rotational form stator, rotor and vanes, which are connected to the rotor. The rotor is placed eccentric to the stator. The vanes themselves rotate in the stator slots using a spring and centrifugal force. The capacity change diagram of a vane pump is not even, but saw-shaped. The parts taking the most abuse are the tips of the vanes, which are in contact with the stator, where the specific stresses are quite high, such as friction and intensive abrasive forces. The pressures obtained are dependant of rotational speed. Such pumps are not efficient in lower rotational speeds. Specific effect of one rotation is low, around 20% of total work volume. These pumps are typically used in low and medium pressure settings. The total efficiency is around 0.8. This invention improves all characteristics of a vane pump, in having an absolutely constant diagram of capacity change, specific capacity coefficient larger than 1 (much higher than in any kind of pump), pressure is independent of rotational speed, high pressure can be achieved, friction between vane tips and housing is insignificant and no wearing occurs, it can work with low rotational speeds; the same output volume requires pump dimensions several times lower than existing solutions.

Summary of the invention

Concentric vane pump consist of a housing with internal surface consisting of two concentric circles, each of 90° placed on the opposite sides, larger with the radius of R, smaller with the radius r and two auxiliary parts of the circle, connecting the concentric parts of the housing, rotor with two slots at 90°, used to place two identical vanes, with lengths equal to R+r. The housing also has openings for entry and exit of the fluid. The diameter of the rotor is 2*r, reduced by the necessary clearance to enable frictionless rotation. The vanes have themselves slots in the middle which enable them to move in the slots of the rotor. In the area of the larger radius R of the housing and rotor, the ring sector is formed with the area of P=(R ² -r*)*Tr/4. This area multiplied with the height H of the pump represents its work volume. The turning of the rotor makes each tip of the each vane pass this sector of the volume, so one turn of the rotor will use work volume 4 times, so that output volume will be V=(R ² - Γ ² )*ΤΤ*Η . If the pump dimensions are conveniently chosen, the specific volume of the output in one rotation can be higher than the total volume of the housing. As the tips of the vanes alternatively push the liquid of the work volume with constant section, they create the vacuum behind themselves and suction in the same amount of liquid, acting as a continuous piston.

Brief description of drawings

Figure 1 shows cross section of the pump, and

Figure 2 shows longitudinal section of the pump. Detailed description of the invention

The pictures show concentric rotational vane pump, consisting of a housing with intake opening 4 and outlet opening 5, rotor 2 with slots 8 and vanes 3. The housing is performed with two concentric ring parts, with the center at 0, on the opposite sides of the housing 1 and at 90°. The larger arc with the radius R and the smaller with the radius of r. The arches with radius of r1 and r2 are used to connect the concentric rings R and r, while maintaining the large enough space between the housing 1 and vanes 3.

Rotor with the center at 0 has two perpendicular slots 8 with vanes placed in them. The vanes slide in the slots 8, which is enabled by the openings of height h, which is slightly larger than the half of the vane height H, which is equal to the height of the working part of the housing 1. Between larger part of the housing 1 and rotor 2 and vanes 3 from position A to position B, the circular ring is formed, with the height of H, giving the work volume of the pump of V=(R ² -r ² )*n*H. The length of the vanes 3 is R+r, it is therefore obvious that they almost touch, with the necessary clearance, the housing 1 at all positions between A and B. When rotor 2 is rotated in the direction 7, one end of the vanes 3 in the position A1 opens the outlet opening 5, while the vane in position B1 pushes the fluid from the work volume V to the position A1 , at the same time sucking in fluid at intake opening 4. As one end of the vane comes to position A1 the end of the other comes to position B1 and without interruption continues to push the fluid in the direction 7 toward outlet opening 5, therefore sucking in the fluid in opening 4. Such a process is continuously repeated as the rotor is rotated so that all four ends of the vanes push out one volume V in each rotation, so the total output volume of the pump is V=(R ² -r ² )*TT*H. This volume obviously has a constant magnitude, so it is clear that the diagram of the capacity change of the concentric pump is absolutely constant. The ends of vanes 3 experience constant pressure as they move from position B to position A, so there is no change in pressure and therefore no force applies to the vanes in the direction of the housing 1. As there is no force, there can be no friction, so internal losses of energy are very small. The housing has also a channel 6 which makes pressure of the fluid at the both sides of the vanes 3 equal as they pass from position A to B1 and from A1 to B. If the dimensions of the pump are well chosen, it can be achieved that the specific capacity Vs of the pump is bigger than work volume of the pump, which would make its volume efficiency coefficient higher than 1 , which is 3 to 10 times more than all possible pump types. This in turn makes the dimensions of the concentric pump several times smaller for the same capacity. As the pressure of the concentric pump is independent of the number of rotations per minute, it can be used with all types of power: engine, wind or human power, which makes it particularly useful in many applications. The pump can achieve the highest pressures. The construction is simple and easily achieved and its small dimensions enable great capacities, even 1000 I per one revolution. It is obvious that such an invention can be used in all applications of volumetric pumps.