EE01644U1 - Rotary piston pump - Google Patents

Abstract

The invention relates to a rotary piston pump 1 comprising in a spherical inner chamber 3 of a pump housing 2 with suction and pressure sides, a pair of rotary pistons 4, 5 in the form of universal-joint forks 6, 7 and a cross 8, between said forks 6, 7. The forks 6, 7 of the rotary pistons 4, 5 mesh with the cross 8 between them and form four pump chambers of variable volume when the rotary pistons 4, 5 and the cross 8 between are rotated. Each rotary piston 4, 5 is attached centrally to a hollow support shaft 13, 13’, 14, 14’ through a conical joint 10 and is fixed in place with a bolt joint 16 extending through the hollow support shaft, where said support shaft is equipped with bearings 11, 12 and gasketed.

Description

 TECHNICAL FIELD

The invention relates to a positive displacement pump, more particularly to a spherical rotary piston pump.

STATE OF THE ART

Estonian utility model EE00122U1 (published 15.10.1997) discloses a rotary piston pump, which comprises a pair of two-armed rotary pistons and a cross between their arms in a spherical inner chamber of a pump housing with suction and pressure sides. The arms of the rotary pistons mesh with the cross between them and form four pump chambers of variable volume when the pair of rotary pistons and the cross between them rotate.

In the case of rotary piston pumps, one of the important technical problems is the bearings and seals of the pair of rotary pistons, whose service life is usually exhausted before other pump parts.

This usually means replacing the entire pump. In reality, however, other parts of the pump are able to continue working. In addition, the pump's rotary pistons are usually made of stainless steel, which is difficult to machine, especially considering its spherical outer surface. The rotary pistons are located in a spherical piston chamber in the pump housing, the precise and suitable manufacturing of which, so that the rotary piston can rotate freely in it, but with sufficient density to pump a flowing medium, is also difficult, time-consuming and relatively expensive.

Thus, there is a need for a design in which the bearings and seals of the pump's rotary pistons can be easily repaired and/or replaced if necessary. This would allow the full working life of the other parts of the pump to be utilized and significantly reduce the costs associated with pumping, for example, fuels, oils, water, and wastewater.

The present invention is directed to solving the problems described above.

ESSENCE OF THE INVENTION

The present invention provides a rotary piston pump comprising a pair of two-armed rotary pistons and a cross between the arms in a spherical inner chamber of a pump housing with suction and pressure sides. The arms of the rotary pistons mesh with the cross between them.

and form four variable volume pump chambers when the pair of rotary pistons and the cross between them rotate. The axes of rotation of the rotary pistons intersect and are both located in the dividing plane of the pump housing.

Each rotary piston is attached via a conical joint to a hollow sealed and bearing-supported support shaft with a central bolted joint extending through the cavity of said support shaft, wherein at least one of said support shafts is configured to be driven by an electric motor.

In a preferred embodiment of the invention, each of said support shafts is located in a separate support housing together with bearings.

At least one support housing is connected to the pump housing via a flange connection.

In a first embodiment of the invention, at least one of said support housings has an integrated electric motor stator surrounding an electric motor rotor fixedly positioned on said support shaft.

In another embodiment of the invention, at least one of said hollow support shafts extends from the other end of the support housing and is connected to an electric motor.

In a third embodiment of the invention, an electric motor stator is integrated into both of said support housings, surrounding an electric motor rotor that is stationary on said support shaft.

This solution allows you to replace bearings and seals without disassembling the pump housing containing the rotary piston and crosspiece.

This solution is also modular, as depending on the density (viscosity) of the pumped medium, both rotary pistons can be equipped with an electric motor as needed, using the same pump housing, which uses one electric motor to drive the pump via only one rotary piston.

The use of two electric motors also reduces the friction between the cross between the rotary pistons and the rotary piston branches compared to using only one electric motor. It also reduces the load on the bearings. This in turn reduces wear on the mentioned parts and extends the entire working life of the pump.

LIST OF ILLUSTRATIONS

The invention is described below with reference to the accompanying schematic drawings, in which:

Figure 1 shows an axonometric view of a first embodiment of the invention, in which one support shaft and its support housing are integrated with an electric motor;

Figure 2 shows the rotary piston pump according to Figure 1 with one half of the pump housing removed;

Figure 3 shows a longitudinal section of the rotary piston pump according to Figures 1 and 2;

Figure 4 shows an enlarged partial view of the longitudinal section of Figure 3 with support housings connected to the pump housing;

Figure 5 shows an axonometric view of a second embodiment of the invention, in which both support shafts and their support housings are integrated with an electric motor;

Figure 6 shows the rotary piston pump according to Figure 5 with one half of the pump housing removed;

Figure 7 shows a longitudinal section of the rotary piston pump according to Figures 5 and 6;

Figure 8 shows an enlarged partial view of the longitudinal section of Figure 7 with support housings connected to the pump housing;

Figure 9 shows an axonometric view of a third embodiment of the invention, in which one support shaft and its support housing are adapted to connect the support shaft to an electric motor;

Figure 10 shows the rotary piston pump according to Figure 9 with one half of the pump housing removed;

Figure 11 shows a longitudinal section of the rotary piston pump according to Figures 9 and 10.

EXAMPLES OF IMPLEMENTATION

For the sake of clarity, the same details and elements in different drawings are designated by the same reference numbers.

In the first, second and third embodiments of the rotary piston pump 1 according to the invention shown in Figures 1, 5 and 9, which are shown in Figures 2, 6 and 10 respectively with one half of the pump housing 2 removed, the structure in the spherical inner chamber 3 of the pump housing 2 is the same.

In all embodiments, the rotary piston pump 1 includes two-armed rotary pistons 4 and 5 in the spherical inner chamber 3 of the pump housing 2 with suction and pressure sides, and a cross 8 between the corresponding arms 6 and 7 of the rotary pistons 4 and 5, with a spherical part 9 in the middle of the arms of the cross 8.

The axes of rotation of the rotary pistons 4 and 5 are both located in the dividing plane of the pump housing 2, but the axes of rotation intersect at an angle. The arms 6 and 7 of the rotary pistons 4 and 5 mesh with the cross 8 between them and rest against the spherical part 9 in the middle of the arms of the cross 8.

Each rotary piston 4, 5 is supported on bearings 11 and 12 via a conical joint 10 and a central bolted joint 16 extending through a cavity 15 of the respective support shaft 13, 14 to a corresponding hollow support shaft 13, 14. The support shafts 13 and 14 are sealed at least at the end facing the rotary pistons 4 and 5 with a seal 17.

In the first embodiment of the invention in Figures 1 to 4, the support shaft 13 and its support housing 18 are integrated with an electric motor, i.e. the stator 19 of the electric motor is integrated into the support housing 18, which surrounds the rotor 20 of the electric motor on said support shaft 13. In this embodiment, the support shaft 13 is a drive shaft, with the rotary piston 4 at the end of which both the second rotary piston 5 and the cross 8 between the rotary pistons 4 and 5 are made to rotate. In principle, this design can be viewed as an electric motor with a hollow shaft, the shaft end of which has a conical joint 10 for connecting the rotary piston 4 or 5.

In the embodiment shown in Figures 1 to 11, the support housing 18 integrated with the electric motor is connected to the pump housing 2 by a flange connection 21.

In the first embodiment of the invention, the support shaft 14 of the second rotary piston 5 is located in the support housing 22 on bearings 11 and 12, where the support shaft 14 is sealed at the end facing the rotary piston 5 with a seal 17. The other end of the support housing is closed and, in the embodiment shown in Figures 1 to 3, closed with an end cover 23.

As can be seen from Figures 3 and 4, the parts of the support shafts 13 and 14 and the support housings 18 and 22 that extend into the pump housing 2 are of exactly the same shape and construction.

The conical joints 10 and bolted joints 16 on the support shafts 13 and 14 are identical and are suitable for receiving and securing both rotary pistons 4 and 5.

The second embodiment of the invention shown in Figures 5 to 8 differs from the first embodiment shown in Figures 1 to 4 only in that both support shafts 13 and 13' and their support housings 18 and 18' are integrated with the electric motor and are of exactly the same construction, therefore in the figures, to distinguish them, the second support shaft is marked with the reference number 13' and the second support housing with the reference number 18'. Since all the details contained in them are exactly the same, the same reference numbers have been used for them.

This embodiment is suitable for pumping more viscous and therefore more difficult to pump liquids. Since both rotary pistons 4 and 5 are driven separately via the support shafts 13 and 13', the friction between the respective arms 6 and 7 of the rotary pistons 4 and 5 and the cross 8 is reduced, and thus the wear of these parts is reduced.

The third embodiment of the invention shown in Figures 9 to 11 differs from the first embodiment shown in Figures 1 to 4 in that the electric motor is not integrated into the support housing 18', but the end of the support shaft 14' in this support housing 18' extends from the end cover 24 of the support housing 18' for connection to the electric motor. Otherwise, the construction of the support shafts 14 and 14' and the support housing 18 and 18' is the same.

The second support shaft 14 and the support housing 18 are of the same construction as described in connection with the first embodiment in FIGS. 1 to 4 .

The present invention is not limited to the embodiments shown in the drawings and in the above exemplary embodiment, but may also have other embodiments within the scope of the claims.

LIST OF REFERENCE NUMBERS

1 - rotary piston pump

2 - pump housing

3 - spherical inner chamber

4 - rotary piston

5 - rotary piston

6 - rotary piston branch

7 - rotary piston branch

8 - cross

9 - spherical part in the middle of the cross branches

10- conical joint

11- camp

12- camp

13, 13’- support shaft

14 - propshaft

14’- support shaft

15 - cavity

16 - bolted joint

17 - gasket

18, 18’- support body

19 - electric motor stator

20- electric motor rotor

21- flange connection

22- support housing

23 - end cap

24- end cap

Claims (6)

1. A rotary piston pump (1) comprising a pair of two-armed rotary pistons (4, 5) in a spherical inner chamber (3) of a pump housing (2) with suction and pressure sides and a cross (8) between their arms, where the arms (6, 7) of the rotary pistons (4, 5) mesh with the cross (8) between them, and with which four variable-volume pump chambers are formed upon rotation of the pair of rotary pistons (4, 5) and the cross (8) between them, where the axes of rotation of the rotary pistons (4, 5) intersect and are both located in the dividing plane of the pump housing (2), characterized in that each rotary piston (4, 5) is attached via a conical joint (10) to a hollow sealed support shaft (13, 13', 14, 14') supported on bearings (11, 12) through the support shaft (13, 13'), 14, 14') with a central bolted joint (16) extending into a cavity (15), wherein at least one of the support shafts (13, 13', 14') is configured to be driven by an electric motor. 2. Rotary piston pump (1) according to claim 1, characterized in that each support shaft (13, 13', 14, 14') with bearings (11, 12) is in a support housing (18, 18', 22). 3. Rotary piston pump (1) according to claim 1 or 2, characterized in that at least one support housing () is connected to the pump housing (2) via a flange connection (21). 4. Rotary piston pump (1) according to claim 1, 2 or 3, characterized in that at least one of the support housings (18, 18') has an integrated electric motor stator (19) around an electric motor rotor (20) fixedly located on the support shaft (13, 13'). 5. A rotary piston pump (1) according to claim 1, 2 or 3, characterised in that at least one of the hollow support shafts (14') extends from the other end of the support housing (22) for connection to an electric motor. 6. Rotary piston pump (1) according to claim 1, 2 or 3, characterized in that an electric motor stator (19) is integrated into both of the support housings (18, 18'), which is arranged around an electric motor rotor (20) fixedly located on the support shaft (13, 13').