Positive displacement pump

Abstract

The positive displacement pump comprises a shell, two partition pieces, a main shaft, a pump set and a motor assembly, and the shell is provided with a liquid inlet and a liquid outlet; the two partition pieces are oppositely arranged, a mounting chamber is formed between the two partition pieces, the first partition piece and the shell form a liquid inlet cavity communicated with the liquid inlet, and the second partition piece and the shell form a liquid outlet cavity communicated with the liquid outlet; the main shaft is fixedly arranged between the two partition pieces, the pump set comprises an inner gear rotationally arranged on the periphery of the main shaft in a sleeving mode and an outer gear meshed with the inner gear, the inner gear and the outer gear are eccentrically arranged, the first partition piece is provided with a liquid inlet channel, and the second partition piece is provided with a liquid outlet channel. The liquid inlet, the liquid inlet cavity, the liquid inlet channel, the pump set, the liquid outlet channel, the liquid outlet cavity and the liquid outlet form a first fluid path; the motor assembly is arranged in the mounting chamber and comprises a rotor and a stator fixedly arranged in the mounting chamber, the rotor is arranged on the periphery of the outer gear and fixedly connected with the outer gear, and the structure of the pump is more compact.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pump equipment, and specifically relates to a positive displacement pump. BACKGROUND

[0002] The existing positive displacement pump, such as a gear pump, includes an internal gear pump, wherein a large internal gear is used as a driving wheel, and an external gear meshing with the internal gear is used as a driven wheel. This structure needs to be configured with a main shaft fixedly connected with the internal gear, and a motor driving the main shaft to rotate. The motor is external, thereby prolonging the size of the pump in the axial direction of the main shaft, increasing the volume of the entire positive displacement pump, and making the overall size not coordinated. CONTENT OF THE UTILITY MODEL

[0003] The present application provides a positive displacement pump with a more compact structure.

[0004] The present application provides a positive displacement pump, which comprises:

[0005] A housing is provided with a liquid inlet and a liquid outlet at two ends respectively;

[0006] Two partition members include a first partition member and a second partition member arranged oppositely and forming an installation chamber therebetween, the first partition member and the housing form a liquid inlet cavity in communication with the liquid inlet, and the second partition member and the housing form a liquid outlet cavity in communication with the liquid outlet;

[0007] A main shaft is fixedly arranged between the two partition members, and the installation chamber is arranged around the main shaft;

[0008] A pump set includes an internal gear rotatably sleeved on the outer periphery of the main shaft, and an external gear meshing with the internal gear, the internal gear and the external gear are arranged eccentrically, the first partition member is provided with a liquid inlet channel, and the second partition member is provided with a liquid outlet channel, the liquid inlet, the liquid inlet cavity, the liquid inlet channel, the pump set, the liquid outlet channel, the liquid outlet cavity and the liquid outlet form a first fluid path;

[0009] A motor assembly is arranged in the installation chamber, the motor assembly includes a rotor and a stator fixedly arranged in the installation chamber, the rotor is arranged on the outer periphery of the external gear and fixedly connected with the external gear.

[0010] The following also provides several optional modes, but not as an additional limitation to the above general scheme, just a further supplement or preferred, without technical or logical contradiction, each optional mode can be combined with the above general scheme, and can also be combined between multiple optional modes.

[0011] Optionally, the second partition member is provided with a cooling channel in communication with the installation chamber, and the liquid inlet, the liquid inlet cavity, the liquid inlet channel, the pump group, the liquid outlet channel, the liquid outlet cavity and the cooling channel form a second fluid path.

[0012] Optionally, the rotor and the outer gear are connected by a key.

[0013] Optionally, the partition member is provided with a sink, the liquid inlet channel is in communication with the liquid inlet cavity through the sink of the first partition member, and the liquid outlet channel is in communication with the liquid outlet cavity through the sink of the second partition member.

[0014] Optionally, the shell is a hollow cylindrical structure, the partition member includes a first connecting portion fixedly connected with the shell and a second connecting portion for fixing the main shaft, the second connecting portion is radially inwardly retracted relative to the first connecting portion, and the motor assembly is arranged around the second connecting portion.

[0015] Optionally, along the axial direction of the main shaft, the second connecting portions of the two partition members clamp the pump group, and the end surface of the second connecting portion close to the pump group is provided with a first wear-resistant layer.

[0016] Optionally, the rotor and the second connecting portion are arranged in a spaced manner, and a wear-resistant ring is arranged between the rotor and the second connecting portion.

[0017] Optionally, the second connecting portion has an inwardly retracted section corresponding to the rotor, and the wear-resistant ring is arranged between the rotor and the inwardly retracted section.

[0018] Optionally, the outer circumferential surface of the inwardly retracted section is provided with a second wear-resistant layer.

[0019] Optionally, the pump group is arranged in multiple groups along the axial direction of the main shaft, and the outer gears of each group are fixedly connected with the same rotor.

[0020] The volumetric pump of the present application, after being powered on, the stator generates a magnetic field to drive the rotor to rotate, synchronously driving the outer gear to rotate, and the inner gear meshing with the outer gear rotates relative to the main shaft, eliminating the need for a separate motor arranged outside the shell, reducing the size of the main shaft in the axial direction, making the overall size of the pump body more uniform, and the stator and the rotor are arranged around the outer periphery of the pump group, making the structure more compact. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a sectional view of a volumetric pump according to an embodiment of the present application;

[0022] Figure 2 is a sectional view of a volumetric pump according to another embodiment of the present application.

[0023] The reference signs in the drawings are explained as follows:

[0024] 1000, volumetric pump;

[0025] 100, housing; 101, liquid inlet cavity; 102, liquid outlet cavity; 103, mounting chamber;

[0026] 110, liquid inlet; 120, liquid outlet; 130, barrel; 140, head;

[0027] 210, first partition; 211, liquid inlet passage;

[0028] 220, second partition; 221, liquid outlet passage; 222, cooling passage; 230, first connecting portion; 240, second connecting portion; 241, inner retracted section; 250, sink;

[0029] 300, main shaft;

[0030] 410, inner gear; 420, outer gear; 510, stator; 520, rotor; 610, wear-resistant ring; 620, spline. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0032] It should be noted that when a component is referred to as being “connected” with another component, it can be directly connected with the other component or there can be a middle component. When a component is referred to as being “disposed on” another component, it can be directly disposed on the other component or there can be a middle component.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this description, the terms “and / or” includes any and all combinations of one or more of the associated listed items.

[0034] In the present application, the terms “first”, “second”, etc. are used only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number or order of the indicated technical features. Therefore, the features defined with “first”, “second” can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of “plurality” is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0035] For the convenience of description, "end" in the text means the end point of the structure or a certain point or area in the direction or the specific structure connected to the point or area.

[0036] Referring to Figure 1 The application provides a positive displacement pump 1000, which comprises a housing 100, two partition members, a main shaft 300, a pump set and a motor assembly. The housing 100 is provided with a liquid inlet 110 and a liquid outlet 120 at two ends in a certain direction (for example, the axial direction of the main shaft 300). The two partition members comprise a first partition member 210 and a second partition member 220 arranged in the housing 100. The two partition members are arranged in the axial direction of the main shaft 300 and are spaced apart. The space between the two partition members and the housing 100 forms a mounting chamber 103. The first partition member 210 and the housing 100 on the other side of the mounting chamber 103 form a liquid inlet cavity 101 connected to the liquid inlet 110. The second partition member 220 and the housing 100 on the other side of the mounting chamber 103 form a liquid outlet cavity 102 connected to the liquid outlet 120.

[0037] The main shaft 300 is fixedly arranged between the two partition members, for example, arranged in the middle. The mounting chamber 103 is arranged around the main shaft 300. The pump set comprises an internal gear 410 rotatably arranged on the outer periphery of the main shaft 300 and an external gear 420 engaged with the internal gear 410. The internal gear 410 and the external gear 420 are arranged eccentrically and meet the design requirements of a cycloid gear pump or other designs of a trochoidal gear pump. The first partition member 210 is provided with a liquid inlet passage 211, and the second partition member 220 is provided with a liquid outlet passage 221. The liquid inlet 110, the liquid inlet cavity 101, the liquid inlet passage 211, the pump set, the liquid outlet passage 221, the liquid outlet cavity 102 and the liquid outlet 120 form a first fluid path. It should be noted that Figure 1 The liquid inlet passage 211 and the liquid outlet passage 221 are not in the same circumferential direction, that is, the two passages are circumferentially staggered.

[0038] The motor assembly is arranged in the mounting chamber 103 and comprises a stator 510 and a rotor 520. The stator 510 is fixedly arranged in the mounting chamber 103, specifically arranged circumferentially around the main shaft. The rotor is arranged on the outer periphery of the external gear 420 and fixedly arranged with the external gear 420. The stator 510 generates a magnetic field after being energized, drives the rotor 520 to rotate, synchronously drives the external gear 420 to rotate, and drives the internal gear 410 engaged with the external gear 420 to rotate around the main shaft 300, so as to realize the flow of fluid through the first fluid path. Compared with the prior art, the motor is arranged separately outside the housing, the size in the axial direction of the main shaft is reduced, the overall size of the pump body is more uniform, and the stator and the rotor are arranged circumferentially around the pump set, so that the structure is more compact.

[0039] For the convenience of description, the circumferential direction, the axial direction and the radial direction in the text are based on the axial direction of the main shaft unless otherwise specified.

[0040] In an embodiment, the fluid is refrigerant, the corresponding displacement pump is a refrigerant pump, the second partition member 220 is provided with a cooling channel 222 in communication with the installation chamber 103, the liquid inlet 110, the liquid inlet cavity 101, the liquid inlet channel 211, the pump group, the liquid outlet channel 221, the liquid outlet cavity 102 and the cooling channel 222 form a second fluid path, and the refrigerant can cool the components in the installation chamber 103 through the second fluid path. The flow path of the refrigerant is realized by the arrows in Figure 2 .

[0041] The shell 100 is a hollow cylindrical structure, including a cylindrical body 130 and two end covers 140 connected in two parts, one of which is provided with a liquid inlet 110, and the other is provided with a liquid outlet 120. The partition member includes a first connecting part 230 connected with the shell 100 (fixed with the cylindrical body 130 in the figure), and a second connecting part 240 for fixing the main shaft 300, the first connecting part 230 is disc-shaped, and the second connecting part 240 is columnar and radially inwardly recessed relative to the first connecting part 230, the second connecting parts 240 of the two partition members clamping the pump group, and the motor assembly is arranged around the outer periphery of the second connecting part 240.

[0042] The rotor 520 and the outer gear 420 are fixedly connected by, for example, splines 620. The rotor 520 and the second connecting part 240 are arranged in radial direction with a spacing to avoid direct contact and increase wear. In a preferred embodiment, a wear-resistant ring 610 is arranged between the rotor 520 and the second connecting part 240, which is made of, for example, silicon carbide. Alternatively, a second wear-resistant layer is arranged on the outer surface of the second connecting part 240 in contact with the wear-resistant ring 610, which is formed by, for example, a micro-arc oxidation process on the outer surface of the second connecting part 240. A first wear-resistant layer is arranged on the end surface of the second connecting part 240 close to the pump group, and the wear-resistant coefficients of the first wear-resistant layer and the second wear-resistant layer are the same or different.

[0043] The second connecting part 240 has a recessed section 241 corresponding to the rotor 520, and the wear-resistant ring 610 is arranged between the rotor 520 and the recessed section 241 to reduce the radial dimension.

[0044] In an embodiment, the pump group is arranged in multiple groups along the axial direction of the main shaft, the outer gears 420 of each group are fixedly connected with the same rotor 520, and the inner gears 410 of each group are rotatably arranged on the same main shaft 300. As shown in Figure 2 , the pump group is four groups, and can also be two groups or three groups.

[0045] In another embodiment, the partition member is provided with a sink 250, the liquid inlet channel 211 is connected with the liquid inlet cavity 101 through the sink 250 of the first partition member 210, and the liquid outlet channel 221 is connected with the liquid outlet cavity 102 through the sink 250 of the second partition member 220. The first connecting part 230 and the corresponding head 140 are closer, and the fluid can flow smoothly through the sink 250. Preferably, the liquid inlet 110 corresponds to the sink 250 of the first partition member 210. The sink 250 is centrally provided, and the specific shape of the sink 250 is not strictly limited. The generatrix of the sink 250 can be a straight line extending in the axial direction of the main shaft, or an inclined line (corresponding to a conical sink 250), etc.

[0046] The volumetric pump of the present application eliminates the separate configuration of the motor outside the shell, reduces the size of the main shaft in the axial direction, makes the overall size of the pump body more uniform, and the stator and rotor are arranged around the outer periphery of the pump group, so that the structure is more compact.

[0047] The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope disclosed in the specification. When the technical features in different embodiments are embodied in the same figure, it can be considered that the figure also discloses the combination of each embodiment involved.

[0048] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent application scope. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. A positive displacement pump characterized by, The utility model relates to a kind of pump, including: Shell, liquid inlet and liquid outlet are respectively arranged at both ends; Two partition members, including the first partition member and the second partition member arranged in the shell, two partition members are oppositely arranged and installation chamber is formed between them, the first partition member and the shell form liquid inlet cavity communicated with the liquid inlet, the second partition member and the shell form liquid outlet cavity communicated with the liquid outlet; Main shaft, fixedly arranged between the two partition members, the installation chamber is arranged around the main shaft; Pump group, including the inner gear rotatingly sleeved on the outer periphery of main shaft, and the outer gear engaged with the inner gear, the inner gear and the outer gear are eccentrically arranged, the first partition member is provided with liquid inlet channel, the second partition member is provided with liquid outlet channel, the liquid inlet, liquid inlet cavity, liquid inlet channel, pump group, liquid outlet channel, liquid outlet cavity and liquid outlet form first fluid path; Motor assembly, arranged in the installation chamber, the motor assembly includes rotor and stator fixedly arranged in installation chamber, the rotor is arranged on the outer periphery of the outer gear and is fixedly connected with the outer gear.

2. A positive displacement pump according to claim 1, characterized in that The second partition member is provided with cooling channel communicated with the installation chamber, and the liquid inlet, liquid inlet cavity, liquid inlet channel, pump group, liquid outlet channel, liquid outlet cavity and cooling channel form second fluid path.

3. The positive displacement pump of claim 1, wherein, The rotor and the outer gear are keyed.

4. The positive displacement pump of claim 1, wherein, The partition member is provided with a sink, the liquid inlet channel is communicated with the liquid inlet cavity through the sink of the first partition member, and the liquid outlet channel is communicated with the liquid outlet cavity through the sink of the second partition member.

5. The positive displacement pump of claim 1, wherein, The shell is a hollow cylindrical structure, the partition member includes a first connecting portion fixedly connected with the shell, and a second connecting portion for fixing the main shaft, the second connecting portion is radially inwardly retracted relative to the first connecting portion, and the motor assembly is arranged around the second connecting portion.

6. A positive displacement pump according to claim 5, characterised in that, Along the axial direction of the main shaft, the second connecting portion of the two partition members clamps the pump group, and the end surface of the second connecting portion close to the pump group is provided with a first wear-resistant layer.

7. A positive displacement pump according to claim 5, wherein The rotor and the second connecting portion are spaced apart, and a wear-resistant ring is arranged therebetween.

8. A positive displacement pump according to claim 7, characterised in that The second connecting portion has a retracted section corresponding to the rotor, and the wear-resistant ring is arranged between the rotor and the retracted section.

9. A positive displacement pump according to claim 8, characterised in that, The outer periphery of the retracted section is provided with a second wear-resistant layer.

10. The positive displacement pump of claim 1, wherein, The pump group is arranged in multiple groups along the axial direction of the main shaft, and the outer gear of each group is fixedly connected with the same rotor.

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