RU2780601C1 - Body of a multi-stage pump and multi-stage pump for gas - Google Patents

Abstract

FIELD: pumps.

SUBSTANCE: group of inventions relates to the body of a multi-stage pump and to the multi-stage pump, wherein said pump can constitute, in particular, a vacuum pump. Body of a multistage pump comprises at least a first working chamber (20), a second working chamber (21), a connecting channel (26a) providing the communication of the output (27) of chamber (20) with the input of chamber (21), and an air-tight passage (40) for the circulation of the cooling liquid. Channel (26a) constitutes a side channel of the body of the multistage pump, provided with at least one heat-conducting wall (33) partially defining the channel (26a), with an outer surface (34). At least part of the channel (26a) passes between the surface (34) of the wall (33) and the passage (40).

EFFECT: group of inventions is aimed at raising the effectiveness of removal of heat released from the compression of gas in the body of the multistage pump during the operation thereof.

13 cl, 11 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to the housing of a multistage pump, as well as to a multistage pump, which in particular may be a vacuum pump. In the following description and the appended claims, the term "pump" includes gas supply pumps, vacuum pumps, as well as compressors, while the expression "pump housing" means a part that may belong to such a gas supply pump, such a vacuum pump, or such compressor.

BACKGROUND OF THE INVENTION

As is known, a multistage pump is a pump that includes a plurality of successive working chambers, the connecting channels of which are interconnected so that the gas compressed in one of the working chambers, which is not the last one, enters the next working chamber.

The compression of the gas produced in each working chamber is accompanied by the release of heat, for the removal of which various cooling devices have been proposed.

European patent EP 2626562 B1 describes a multistage pump in which, during movement between two successive working chambers, the gas passes along a plate equipped with cooling fins and designed to remove heat to the ambient atmospheric air by simple natural convection.

Another solution for dissipating heat generated during gas compression in a multistage pump is to use heat exchangers, each of which cools the gas as it travels between two consecutive working chambers. JP 2001-27190 proposes a cooling solution based on this solution.

It is also known to cool a multistage pump by circulating a coolant such as water. As described in US Pat. No. 8,573,956 B2, the cooling circuit runs between the last working chamber and the penultimate working chamber, and then under the other working chambers. As described in JP 2014-55580, a straight coolant pipe runs either in a gas connection passage between two working chambers or between two successive working chambers.

JP 2001-20884, like JP 2-95792 (JPH 0295792 A), also proposes coolant cooling. At the same time, cooling is carried out from the outside as the coolant passes around the working chambers and around the connecting channels connecting the working chambers to each other.

The cooling of multistage pumps described in the documents and patents mentioned above is characterized by an efficiency that cannot be considered fully satisfactory.

SUMMARY OF THE INVENTION

The technical objective of the invention is, at least, to increase the efficiency of heat removal, generated during compression of the gas in the casing of a multistage pump during its operation.

According to the invention, this technique is achieved by means of a pump casing, including at least a first working chamber, a second working chamber, a connecting channel providing communication between the outlet of the first working chamber and the inlet of the second working chamber, as well as a sealed passage for the circulation of the coolant. The connecting channel is a side channel of the multistage pump housing, which has at least one heat-conducting wall, partially limiting the connecting channel, and having an outer surface outside. At least part of the connecting channel extends between this outer surface of the heat-conducting wall and the sealed passage.

Each of the first and second working chambers provides for the placement in it of at least one means for moving the gas downstream. During compression in each of the first and second working chambers, the pumped gas is heated. Entering the connecting channel, the gas is cooled by means of a heat-conducting wall, which, in turn, is cooled by the environment. Thus, the first cooling of the multistage pump casing occurs due to natural convection and radiation to the environment. At the same time, the second cooling of the multistage pump housing occurs due to the transfer of heat to the coolant circulating in the sealed passage. Thus, in accordance with the invention, there is a double cooling of the casing of the multistage pump.

Since the invention makes it possible to improve cooling, the invention makes it possible to increase the pumping efficiency, which is an advantage. In particular, by increasing the pumping efficiency, the maximum pump performance can be increased. In other words, the advantage of the invention is the possibility of achieving an increase in the maximum performance of the pump.

The multistage pump housing as defined above may have one or more other advantageous features, alone or in combination, in particular as defined below.

Preferably, at least part of the sealed passage is located between the connecting channel and at least one of the first and second working chambers. When this is the case, the coolant circulating in the sealed passage simultaneously cools the connecting channel and at least one of the first and second working chambers. Which translates into more efficient cooling.

Preferably, at least part of the sealed passage is located between the first working chamber and the second working chamber. When this is the case, the coolant circulating in the sealed passage effectively cools the first and second working chambers.

Preferably, the housing of the multistage pump includes at least one heat-conducting baffle separating the connecting channel and the sealed passage from each other. Such a heat-conducting baffle effectively removes heat from the connecting channel to the coolant circulating in the sealed passage.

Preferably, the housing of the multistage pump includes at least one heat-conducting baffle separating the sealed passage and the first working chamber from each other. Such a thermally conductive baffle effectively removes heat from the first working chamber to the coolant circulating in the sealed passage.

Preferably, the sealed passage partially surrounds the first working chamber and/or the second working chamber. When this is the case, cooling of at least one of the first and second chambers is more efficient.

Preferably, the sealed passage includes at least one coolant inlet and at least one coolant outlet.

Preferably, the housing of the multistage pump includes at least one axial passage for the rotating shaft, wherein the axial passage segment connects the first and second working chambers.

Preferably, the multistage pump housing has a first side and a second side opposite the first side relative to the axial channel, while the connecting channel runs at the level of the first side of the multistage pump housing, while the multistage pump housing limits another connecting channel that provides communication between the output of the first working chamber and the inlet of the second working chamber, and this other connecting channel runs at the level of the second side of the casing of the multistage pump.

Preferably, the multistage pump housing has a third side and a fourth side opposite to the third side relative to the axial channel, while the outlet of the first working chamber is at the level of the third side of the multistage pump housing, the inlet of the second working chamber is at the level of the fourth side of the multistage pump housing.

Preferably, the inlet of the first working chamber is at the level of the fourth side of the multistage pump casing, while the outlet of the second working chamber is at the level of the third side of the multistage pump casing.

Preferably, the connecting channel is the first connecting channel, while the housing of the multistage pump includes a third working chamber and a second connecting channel, which is a channel that provides communication between the outlet of the second working chamber and the inlet of the third working chamber, while the heat-conducting wall is the first heat-conducting wall, wherein the housing of the multistage pump includes at least a second heat-conducting wall, while the second heat-conducting wall partially limits the second connecting channel, and has an outer surface outside, while at least part of the second connecting channel passes between the outer surface of the second heat-conducting wall and the sealed passage. When this is the case, the gas is cooled simultaneously both during passage through the first connection channel and during passage through the second connection channel.

Preferably, the multistage pump housing includes two ends, through each of which passes an axial channel, while the outer surface of the heat-conducting wall forms part of the side surface passing between the two ends of the multistage pump housing.

Preferably, the heat transfer wall has two main opposing surfaces and a constant or variable thickness between these two main opposing surfaces, one of which is the outer surface of the heat transfer wall.

Since this is a side channel, the connecting channel provides communication between the outlet of the first working chamber and the inlet of the second working chamber, without passing between the first and second working chambers.

Preferably, over most of its length, the connecting channel has a cross section that is elongated in a direction substantially parallel to the axial channel.

The subject of the invention is also a multistage pump including the multistage pump housing described above. The outer surface of the heat-conducting wall is outside the pump.

The multistage pump as defined above may have one or more other advantageous features, alone or in combination, in particular as defined below.

Preferably, the multistage pump includes at least a first rotor for moving gas downstream in the first working chamber, at least a second rotor for moving gas downstream in the second working chamber, and a rotating shaft on which the first and second rotors are mounted. .

Preferably, the multistage pump is a vane pump, a gear pump, a gear pump, preferably it includes at least another first rotor in the first working chamber, another second rotor in the second working chamber and another rotating shaft on which the other first and second rotors, while the first rotor and the other first rotor are suitable for moving gas downstream in the first working chamber, being driven in opposite directions, while the second rotor and the other second rotor are suitable for moving gas downstream in the second working chamber, being driven in opposite directions.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features will become more apparent upon reading the following description of specific embodiments of the invention, which are non-limiting examples and presented in the accompanying drawings, in which:

- fig. 1 is a side view of a multistage pump according to one embodiment of the invention,

- fig. 2 is a sectional view taken along II-II in FIG. 1 of the multistage pump shown in FIG. one,

- fig. 3 is a perspective view of the housing of a multistage pump according to one embodiment of the invention and which is part of the multistage pump shown in FIG. 1 and 2

- fig. 4 is a longitudinal sectional view in the vertical plane IV of FIG. 3 housing of the multistage pump shown in FIG. 3,

- fig. 5 is a longitudinal sectional view along the horizontal line V-V in FIG. 4 housing of the multistage pump shown in FIG. 3 and 4

- fig. 6 is a cross-sectional view along VI-VI in FIG. 4 housing of the multistage pump shown in FIG. 3 and 4

- fig. 7 is a cross-sectional view along VII-VII of FIG. 4 housing of the multistage pump shown in FIG. 3 and 4

- fig. 8 is a cross-sectional view along VIII-VIII in FIG. 4 housing of the multistage pump shown in FIG. 3 and 4

- fig. 9 is a cross-sectional view along IX-IX in FIG. 4 housing of the multistage pump shown in FIG. 3 and 4

- fig. 10 is a cross-sectional view along X-X in FIG. 4 housing of the multistage pump shown in FIG. 3 and 4

- fig. 11 is a cross-sectional view taken along XI-XI in FIG. 4 housing of the multistage pump shown in FIG. 3 and 4

DESCRIPTION OF THE PREFERRED EMBODIMENT

A multistage pump 1 according to one embodiment of the invention is shown separately in FIG. 1. It includes a housing 2 of a multistage pump, at each end of which there is a gearbox 3 connected to one of two electric motors 4 and 5 synchronized with each other.

As can be seen in FIG. 2, the multistage pump 1 is a vane pump. However, the invention is not limited to vane pumps. For example, the invention may relate to a gear or gear pump.

The multistage pump 1 includes two rotating shafts 8, which are driven in rotational motion in opposite directions, one by an electric motor 4, the other by an electric motor 5. Each rotating shaft 8 has three rotors, each of which is part of a pair of complementary rotors 9. Each rotor 9 carries a lot of blades, of which there are four in this example. However, the number of blades on the rotors 9 may be different from four.

The housing 2 of the multistage pump is shown separately in FIG. 3. It is formed by two crankcases 11 and 12, each provided with a discontinuous connecting flange 13. In FIG. 1, only screws 14 can be seen, located at the level of the connecting flange 13, fastening the crankcases 11 and 12 to each other by tightening.

The housing 2 of the multistage pump has an inlet 16 for the coolant, as well as two outlets for the same coolant.

As can be seen in FIG. 4, the housing 2 of the multistage pump defines a plurality of successive working chambers arranged in a straight line in a direction parallel to the rotating shafts 8, which are the first working chamber 20, the second working chamber 21 following the first working chamber 20, and the third working chamber 22 , following the second working chamber 21.

In the example shown, there are three working chambers 20-22, however, the number of working chambers may differ from 3.

As can be seen in FIG. 2, one of the pairs of complementary rotors 9 is located in the first working chamber 20. Similarly, a pair of complementary rotors is provided in each of the working chambers 21 and 22. For clarity, two rotating shafts 8 and rotors 9 of the multistage pump 1 in FIG. 4-11 are not shown.

As can be seen in FIG. 4, the intake port 23 of the multistage pump 1 passes through the inlet of the first working chamber 20, while the outlet of the third working chamber 22 passes through the delivery port 24 of the multistage pump 1.

The crankcase 11 partially limits the first working chamber 20, which one of the gearboxes 3 closes at the level of the end face 2a of the housing 2 of the multistage pump. The crankcase 11 and the crankcase 12 together delimit the second working chamber 21. The crankcase 12 partially delimits the third working chamber 22, which one of the gearboxes 3 closes at the level of the end face 2b of the casing 2 of the multistage pump.

The seals pressed into the grooves provide a seal between the crankcases 11 and 12. FIG. 5 they are marked with the position number 25.

As can be seen in FIG. 4 and 5 taken together, two symmetrical connecting channels 26a and 26b connect the outlet 27 of the first working chamber 20 with the inlet 28 of the second working chamber 21. The channels 26a and 26b are the first connecting channels. A pair of second symmetrical connecting channels 29a and 29b connects the outlet 30 of the second working chamber 21 with the inlet 31 of the third working chamber 22. FIG. 4, arrow C shows the gas trajectory from the intake hole 23 to the injection hole 24.

The first connection channels 26a and 26b, like the second connection channels 29a and 29b, are side channels of the housing 2 of the multistage pump. Each of the first connection channels 26a and 26b is partially defined by a side wall, which is a heat-conducting wall 33 having an outer surface 34 outside the multistage pump 1. The heat-conducting walls 33 are the first heat-conducting walls. Each of the second connecting channels 29a and 29b is partially limited by one of the two side walls, which are the second heat-conducting walls 36, each of which has an outer surface 37 outside the multistage pump 1.

The casing 2 of the multistage pump defines a sealed passage 40 for the circulation of a cooling liquid, which may be, for example, water.

As can be seen in FIG. 6, the sealed passage 40 communicates with outlets 17 through which the coolant present in the sealed passage can be discharged.

As can be seen in FIG. 7, the sealed passage 40 partially surrounds the first working chamber 20.

As can be seen in FIG. 9, the sealed passage 40 partially surrounds the second working chamber 21.

As can be seen in FIG. 10, the sealed passage 40 includes a distribution chamber 40a into which an inlet 16 opens to allow coolant to be supplied to the sealed passage 40.

As can be seen in FIG. 11, the sealed passage 40 partially surrounds the third working chamber 22.

As can be seen in FIG. 5-7, a sealed passage 40 is located between the first working chamber 20 and each of the first connecting channels 26a and 26b. The thermally conductive wall 42 partially delimits the first connection channel 26a and the sealed passage 40, which it separates from each other. Another thermally conductive wall 42 partially delimits the second connection channel 26b and the sealed passage 40, which it separates from each other. The thermally conductive partition 43 partially delimits the first working chamber 20 and the sealed passage 40, which it separates from each other.

During the operation of the pump 1, the gas sucked in by the pump 1 is compressed in the first, second and third working chambers 20-22 and is heated at this time.

The heat of the gas passing through the first connecting channels 26a and 26b is removed simultaneously by heat-conducting walls 33 and heat-conducting partitions 42. The first cooling occurs due to the fact that heat is transferred to the surrounding air by radiation and natural convection at the level of the outer surfaces 34 of heat-conducting walls 33. Second cooling is carried out at the level of heat-conducting partitions 42 by means of a coolant circulating in a sealed passage 40. Thus, the gas passing through the first connecting channels 26a and 26b is simultaneously subjected to a double cumulative cooling, which occurs on the two wide sides of each first connecting channel 26a and 26b.

In addition to cooling the heat-conducting baffle 42, the coolant circulating in the sealed passage 40 cools the heat-conducting baffle 43 and, consequently, through the heat-conducting baffle 43, the first working chamber 20.

As can be seen in FIG. 5-9, the sealed passage 40 is located between the second working chamber 21 and each of the second connecting channels 29a and 29b. The thermally conductive barrier 45 partially delimits the second connection channel 29a and the sealed passage 40, which it separates from each other. Another thermally conductive wall 45 partially delimits the second connection channel 29b and the sealed passage 40, which it separates from each other. The thermally conductive partition 46 partially delimits the second working chamber 21 and the sealed passage 40, which it separates from each other.

The heat of the gas passing through the second connecting channels 29a and 29b is removed simultaneously by heat-conducting walls 36 and heat-conducting partitions 45. The first cooling occurs due to the fact that heat is transferred to the surrounding air by radiation and natural convection at the level of the outer surfaces 37 of heat-conducting walls 36. Second cooling is carried out at the level of heat-conducting partitions 45 by means of a coolant circulating in a sealed passage 40. Thus, the gas passing through the second connecting channels 29a and 29b is simultaneously subjected to a double cumulative cooling, which occurs on the two wide sides of each second connecting channel 29a and 29b.

In addition to cooling the heat-conducting partition 45, the coolant circulating in the sealed passage 40 cools the heat-conducting partition 46 and, consequently, through the heat-conducting partition 46, the second working chamber 21.

Part of the hermetic passage 40 is located in the dividing wall 50 between the first working chamber 20 and the second working chamber 21, between which it passes, which results in improved cooling of the first and second working chambers 20 and 21. Part of the hermetic passage 40 is located in the dividing wall 51 between the second the working chamber 21 and the third working chamber 22, between which it passes, resulting in improved cooling of the second and third working chambers 20 and 21.

In FIG. 6-10, 53 designate the axial passages for one of the rotating shafts 8, each passing through the partition wall 50 and the partition wall 51.

The invention is not limited to the embodiment described above. In particular, the casing of a multistage pump according to the invention may include only one axial passage 53 for one rotating shaft 8, for example when it is part of a vane pump.

Claims (18)

1. The case of a multistage pump, containing at least: - the first working chamber (20), - the second working chamber (21), - a connecting channel (26a) providing communication of the output (27) of the first working chamber (20) with the input (28) of the second working chamber (21), and - sealed passage (40) for coolant circulation, characterized in that the connecting channel (26a) is a side channel of the multistage pump housing, which has at least one heat-conducting wall (33), partially limiting the connecting channel (26a) and having an outer surface (34) from the outside, while at least part of the connecting channel (26a) passes between this outer surface (34) of the heat-conducting wall (33) and the sealed passage (40). 2. Casing of the multistage pump according to claim 1, characterized in that at least part of the sealed passage (40) passes between the connecting channel (26a) and at least one of the first and second (20, 21) working chambers. 3. Housing multistage pump according to any one of paragraphs. 1 and 2, characterized in that at least part of the sealed passage (40) passes between the first working chamber (20) and the second working chamber (21). 4. Casing of a multistage pump according to one of the preceding claims, characterized in that it contains at least one heat-conducting partition (42) separating the connecting channel (26a) and the sealed passage (40) from each other. 5. Casing of a multistage pump according to one of the preceding claims, characterized in that it contains at least one heat-conducting partition (43) separating the sealed passage (40) and the first working chamber (20) from each other. 6. A multistage pump housing according to one of the preceding claims, characterized in that the sealed passage (40) partially surrounds the first working chamber (20) and/or the second working chamber (21). 7. Multistage pump housing according to one of the preceding claims, characterized in that the sealed passage (40) comprises at least one coolant inlet (16) and at least one coolant outlet (17). 8. Casing of a multistage pump according to one of the preceding claims, characterized in that the casing of the multistage pump contains at least one axial channel (53) for a rotating shaft (8), while the segment of the axial channel (53) connects the first and second working chambers ( 20, 21). 9. The multistage pump housing according to claim 8, characterized in that it has a first side and a second side opposite the first side relative to the axial channel (53), while the connecting channel (26a) passes at the level of the first side of the multistage pump housing, while the housing of the multistage pump limits another connecting channel (26b), which provides communication of the outlet (27) of the first working chamber (20) with the inlet (28) of the second working chamber (21), and this other connecting channel (26b) passes at the level of the second side of the multistage pump housing . 10. Multistage pump housing according to one of the preceding claims, characterized in that the connecting channel (26a) is the first connecting channel (26a), and the multistage pump housing comprises a third working chamber (22) and a second connecting channel (29a), which is a channel that provides communication between the outlet (30) of the second working chamber (21) and the inlet (31) of the third working chamber, while the heat-conducting wall (33) is the first heat-conducting wall (33), while the housing of the multistage pump contains at least the second heat-conducting wall (36), while the second heat-conducting wall (36) partially limits the second connecting channel (29a) and has an outer surface (37) on the outside, while at least part of the second connecting channel (29a) passes between the outer surface (37 ) of the second heat-conducting wall (36) and a sealed passage (40). 11. A multistage pump, characterized in that it comprises a multistage pump housing (2) according to any one of the preceding claims, wherein the outer surface (34) of the heat-conducting wall (33) is outside the pump. 12. Multistage pump according to claim 11, characterized in that it contains at least a first rotor (9) for moving gas downstream in the first working chamber (20), at least a second rotor for moving gas downstream in the second working chamber (21) and a rotating shaft (8) carrying the first and second rotors. 13. Multistage pump according to one of paragraphs. 11 and 12, characterized in that it is a vane pump or a gear pump or a gear pump, and in that it contains at least another first rotor (9) in the first working chamber (20), at least another second rotor in the second working chamber (21) and another rotating shaft (8) carrying the other first and second rotors, while the first rotor and the other first rotor (9) are configured to move the gas downstream in the first working chamber (20), being driven in opposite directions, wherein the second rotor and the other second rotor are configured to move the gas downstream in the second working chamber (21) while being driven in opposite directions.

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